Retired horses can make excellent pasturemates. Photo © EQUUS

Some horses are perfectly content living alone in a backyard paddock. Others, however, can become nervous wrecks without the security of a herd. Anxious horses may pace and fret, and even if they remain outwardly calm, the tension may increase their risk of gastric ulcers and other stress-related health disorders. If your horse would be happier with a companion, you have several options, including:

• Retirees. Rescue organizations have plenty of older and/or injured horses who cannot be ridden but would be ideal pasture companions. Make sure you’re prepared to take on the responsibility for any special veterinary or farriery care your retiree might need. If you don’t want to spread your feed budget that far, a smaller pony or Miniature Horse might be a more economical choice that

would still fulfill your horse’s need for a herdmate.

• Donkeys. These close cousins in the equine family are relatively easy keepers, and they usually get along well with horses. Most thrive on pasture and grass hay and need little more than basic care such as deworming, hoof trimming, dental care and vaccinations. Donkeys also come in all sizes, from Mammoths to Miniatures.

• Goats. Not all horses bond well with goats, and vice versa, but sometimes these two species form fast friendships. Care for a goat is generally similar to how you keep a horse--with access to fresh water, pasture and a run-in shelter, as well as fly control, vaccination and hoof trimming. But before you commit to getting a goat, make sure you research specifics of feed supplements he may need and the types of illnesses he is vulnerable to. Also, make sure you will have access to a veterinarian experienced with ruminants. If your horse’s regular veterinarian does not handle goats, she may be able to refer you to someone who does.

Whatever choice you make, consider bringing the new companion home on a trial basis and make the introduction slowly, to make sure everyone will get along. If all goes well, the company will help to keep your once-lonely horse happier and healthier for years to come.

This article first appeared in EQUUS issue #425.

In most horses, light exercise can help alleviate muscle soreness after vaccinations. Photo © Celia Strain/EQUUS

Q: What is the proper protocol for exercising your horse after he receives shots? Is it OK to work him or should he have the day off? When I had to have vaccinations because I was traveling out of the country, my arm was sore. Does this happen to horses, too?

A: Just as with people, horses may have a wide range of reactions after receiving vaccinations. The majority of equine vaccines are administered by intramuscular injections, or “shots into the muscle,” on the side of the neck.

For most horses, the

only reaction, if any, is a little local inflammation and soreness at the injection site, which lasts just a few days. Usually, light exercise the day of the vaccinations and the next will actually help make the sore muscles feel better. During these workouts you might notice a little stiffness, but most riders report that they cannot feel any difference. After the first day or two your horse can return to his normal exercise routine and level.

There are some exceptions to this rule: If your horse has significant swelling, a fever or severe stiffness after his vaccinations, talk to your veterinarian before resuming exercise.

Some equine vaccines are administered intranasally---via a fluid or mist shot up the nose. These don’t cause muscle soreness, but they can make a horse run a fever or feel a little depressed, so a day or two of rest might still be a good idea.

Your best bet is to ask your veterinarian whether there is any reason for concern at the time she administers the vaccinations. She will have selected vaccines for their effectiveness and safety and will want to hear about any reactions your horse has had in the past.

Of course, you’ll want to use common sense: Don’t start anything new at the same time as the vaccinations, don’t increase your horse’s workload, don’t exercise him if the weather is excessively hot or cold, and schedule a break in his schedule if he has run a fever or had other significant reactions in the past.

Melinda Freckleton, DVM
Haymarket Veterinary Service
Haymarket, Virginia

It's normal for a horse to lay down from time to time, but if he suddenly spends more time than usual down, it's cause for investigation.

Spice was spending nearly all her time lying down. The 16-year-old Paint mare didn’t appear to be weak or in pain---she could readily scramble to her feet when she wanted to. But she simply wouldn’t stay on her feet. For almost a month, she’d get up just two or three times a day to eat, drink, defecate and urinate, then she’d lie down again.

Several veterinarians came out to see Spice that April in 2008, but they found no obvious reasons for her peculiar behavior. She was current on her vaccinations, she wasn’t lame and her vital signs were normal.

Spice’s veterinarian was baffled and recommended a consultation with nearby Colorado State University. But the mare’s owner was afraid that the ride would be too difficult for her or that she would go down in the trailer. So Lutz Goehring, DVM, PhD, a faculty member with the veterinary teaching hospital, made a farm call.

Goehring found Spice lying calmly in sternal recumbency, propped up on her chest and looking as if she just decided to take a brief afternoon nap. “I was thinking I’d find a horse who looked ill or in distress, but she was happy, and it was obvious she had been really well cared for in the time she was down,” he says. “Her owner had bedded her on deep sand in a large roofed area. She looked like a mare who just happened to be lying down and resting.”

Spice also seemed normal as she got up, which she did with just a bit of encouragement. “She had no problem at all standing up. She was very coordinated and strong, with normal reflexes,” Goehring says. But, he adds, once the mare was on her feet, “we did notice something very unusual.”

As she stood Spice’s muscles became stiff and tense. “You could actually see the muscles contracting under the skin,” says Goehring. When she was asked to walk she moved in short, rigid steps. When she stood still, her hind and forelimbs were drawn closer together than normal, giving her the appearance she was standing on a large circus ball. These were all important, but somewhat contradictory, clues.

Process of elimination
Goehring worked through a number of potential diagnoses:
• Tying up (recurrent exertional rhabdomyolysis) causes severe, painful cramping of the large muscles, usually after exercise. When you see muscles contracting as Spice’s were, “you naturally think of tying up,” Goehring says, “but all of her muscles were affected, not just the hindquarters as you’d expect.” Also, horses who are tying up are usually in obvious pain, with profuse sweating and rapid breathing; Spice was not. “To be certain, we also tested her urine and blood and did not see any of the proteins you’d find associated with the muscle damage of tying up,” he adds.
• Hyperkalemic periodic paralysis (HYPP) is an inherited muscle disorder of Quarter Horses and related breeds that causes muscle tremors, weakness and recumbency. But Spice’s pedigree did not include any horses known to carry HYPP, nor did she display the characteristic weakness and collapse.
• Tetanus is a rigid paralytic disease caused when the anaerobic bacterium Clostridium tetani, which normally lives in soil and feces, enters a puncture wound. Tetanus can cause stiffness throughout the body, but Spice was current in her vaccinations against this disease, and she was not displaying any other classic signs of the condition, including the protrusion of the nictitating membrane across the eye.
• Botulism is a paralytic condition that occurs when a horse ingests food or water contaminated with toxins produced by the bacterium Clostridium botulinum. Horses with early stages of botulism often lie down for long periods as the associated paralysis develops. But botulism usually affects the muscles of the head and mouth first. Spice was eating and drinking normally.
• Laminitis, the inflammation of the sensitive soft tissues that connect the coffin bone to the interior of the hoof wall in the foot, can cause horses to stand with an unusual “base-narrow” stance like Spice was showing. But laminitis is extremely painful, yet the mare did not react at all to sole pressure from hoof testers, and radiographs of all four hooves showed no coffin bone rotation.
• Fractures to the pelvis or lower spine can leave a horse reluctant to walk, even if he doesn’t appear to be obviously lame. Goehring ruled out an injury like that in Spice with a rectal exam.
• Neurological diseases, such as equine protozoal myeloencephalitis (EPM) or West Nile encephalitis, can cause a variety of signs, including stiffness, recumbency, weakness and incoordination. To investigate this possibility Goehring performed a full neurological workup on Spice, checking the muscle tone in her tail and asking her to walk forward, backward and in small circles. “In neurological disease, you see some incoordination or asymmetry,” he says. “But we didn’t see any of that. She was moving stiffly but was not weak or clumsy.”

Having exhausted the possibilities for physical exams, Goehring gathered blood samples to follow up with laboratory tests, and he suggested transporting the mare to the University clinic so he could take spinal fluid samples and a muscle biopsy. But Spice’s owner was still concerned about the toll the trip might take on her mare and opted to pursue only tests that could be done on the farm---especially since Goehring didn’t yet have a particular diagnosis in mind.

Working on the assumption that some type of muscle pain was keeping the mare off her feet, Goehring prescribed a course of phenylbutazone and the muscle relaxant methocarbamol, and he asked Spice’s owner to provide him with frequent updates on the mare’s condition up until his next scheduled visit, in two weeks. By then, he hoped, the results of the blood tests would have shed more light on the cause of Spice’s trouble.

One last shot
Spice was getting worse when Goehring returned. Instead of lying on her chest, the mare was now spending most of her time stretched out flat on her side, and she was eating and drinking while down. She was also getting up less often, as little as only once a day to defecate and urinate before stretching out again on her opposite side.

The standard blood work had revealed nothing abnormal, and the tests were also negative for antibodies to the West Nile virus as well as Sarcocystis neurona, the organism responsible for EPM. Spice’s protein and enzyme levels were normal, indicating there was no muscle damage or malfunction, nor did her blood show any sign of inflammation or infection.

Goehring encouraged Spice to rise then spent a few minutes just watching her. He noticed the same pattern he’d seen on his first visit: “She’d walk around for a few minutes, and then you’d notice muscle contractions and a tightening of all her muscles. Then she would lie down in a very coordinated way. She didn’t seem upset or uncomfortable; it was almost as if she got tired, and lying down was her way to cope with the increased muscle contractions and what I assume was associated fatigue and soreness from it.”

The problem had to originate in either her muscles or her nerves---but given that the phenylbutazone and muscle relaxant had had no effect, a neurological explanation now seemed more likely. “If the problem wasn’t with the muscles, it had to be the nerves that control them,” says Goehring.

Yet Spice’s signs didn’t fit into any known neurological pathology. “A traumatic neurological event or a disease process generally affects neurons at one specific location in the nervous system, so you’ll see a horse lose control of his hindquarters or one side of his body. But every muscle on this mare seemed to be involved equally,” says Goehring. “Toxins can also affect a horse’s nervous system, but they tend to target a particular type of neuron and are progressive; eventually you’ll see seizures and other more serious problems.”

That left one area of possibility: an immune-related disease affecting only a specific portion of the central nervous system. “In immune-mediated diseases, the horse’s own body will attack a very specific target group of cells or structures,” says Goehring. “It was possible, we thought, that such a scenario could give us the strange presentation we were seeing. At the time, we had no idea what that specific process might be, but it was really our last shot.”

A one-in-a-million diagnosis
To test that hypothesis, Goehring recommended a course of injectable corticosteroids. “Steroids will suppress the body’s immune system, which can be a bad thing unless it’s the immune system itself that is harming the body,” he explains. If Spice’s condition was an immune-mediated neuropathy, the steroids would lead to improvement.

Goehring was headed to a conference, so a colleague oversaw the treatment, starting with a relatively high dose followed by smaller subsequent doses that tapered off over the course of a week. “At the conference, I discussed this case with several prominent equine neurologists and told them what I was going to try,” he says. “They were interested but maybe a little skeptical. So it was nice when I was able to share the text I got two days later that the treatment was working---the mare was up and moving more.”

Indeed, Spice showed a dramatic improvement: By the end of the week she was standing about 75 percent of the time. That success led Goehring to search the literature for a possible explanation.

He found one disease in human medicine that seemed to fit Spice’s case: Moersch-Woltmann syndrome, also called “stiff person syndrome” (SPS). People with SPS experience fluctuating muscle rigidity, particularly in their trunk and limbs. The first symptom is usually stiffness in the back that can come and go, often triggered by loud noises or stressful events.

Over weeks or months, the disease progresses until the painful spasms become increasingly frequent and involve the entire body, to the point of immobilizing the person for hours. Patients typically have a halting, stiff gait because the muscles never fully relax between spasms. They also report being exhausted by the episodes. SPS is extremely rare---the exact frequency is unknown but it may affect as few as one in a million people. The condition typically develops between the ages of 30 and 50, although babies may be born with it.

SPS was first named in 1956, and in the 1980s, researchers linked the disease with an autoimmune dysfunction after they discovered that the majority of affected individuals were producing high levels of antibodies to an enzyme called glutamic acid decarboxylase (GAD)---that is, their bodies were attacking and destroying this critical enzyme in large numbers. GAD is essential for the production of an amino acid called gamma-aminobutyric acid (GABA). GABA acts as an inhibitory neurotransmitter, meaning it slows down the activity of nerve cells.

“When a horse or person moves, certain muscles have to relax in order for others to contract,” explains Goehring. “For instance, when the biceps [on the front of the upper arm] contracts, the triceps [on the back of the upper arm] must relax [in order to raise the arm]. GABA helps make this happen by blocking nerve impulses.”

In people with SPS, the destruction of GAD, and the subsequent reduction in GABA, causes nerve cells to fire too often and too easily. And so, for example, the biceps and triceps muscles might struggle to contract simultaneously---a situation that produces the characteristic limb stiffness and muscle spasms.

Could horses experience an equine version of SPS? Goehring found one paper published in 2000 that described a Belgian Warmblood who had shown periodic stiffness similar to Spice’s and who had elevated antibodies to GAD, just as in SPS. The authors of the paper dubbed their observations “stiff horse syndrome.”

To see whether Spice might have stiff horse syndrome, Goehring had her blood tested for antibodies to GAD, along with a sample from a normal, healthy mare for comparison. Spice’s blood had a significantly higher amount of the antibodies. This result wasn’t a definitive diagnosis, but it did strongly suggest that the mare might have this rare condition.

Exploring unknown ground
Even though there was little precedent for treating Spice, her owner decided she wanted to try. The mare was kept on the corticosteroids for another month, during which time she gradually improved to her normal self. She was then weaned from the medication, after which she continued to remain on her feet as much as any normal horse. Continuing blood tests showed the mare’s GAD antibodies decreasing over the course of treatment.

“This made me more certain that she had some form of stiff horse syndrome,” says Goehring. “It seemed that we had interrupted the immune system enough for the assault on GAD to end, allowing GABA to be produced and regulate muscle activity.”

Goehring hypothesized that the muscle contractions Spice had been experiencing were simply exhausting the mare, which caused her to lie down more than normal. “What we were seeing wasn’t an inability to stand,” he says, “but an all-over soreness and tiredness that made her not want to.”

Months passed with no further developments, until the following spring, when the mare began lying down more than normal again. “I wasn’t surprised,” says Goehring, “because once the immune system returns to full function, it’s going to start attacking antibodies again. The question is just how quickly and to what extent.”

At that time, Goehring adds, “we looked into officially testing for GAD to quantify just how badly she might be affected, but new testing methods for human samples appeared to not work in horses.” Instead, he started Spice on another course of corticosteroids and, as before, the mare improved dramatically within a few days.

This pattern continued for four years: Every eight to 12 months Spice would begin to spend more time lying down, and a course of corticosteroids would get her back on her feet. To reduce the risk of adverse side effects, Goehring gave Spice the lowest amount necessary to see an improvement. But the mare never showed any other signs of illness or trouble until she died after an unrelated colic earlier this year.

Although stiff horse syndrome is undoubtedly quite rare, Goehring says he suspects it may occasionally go undiagnosed: “I’m certain there are horses out there with this right now, but no one knows. Personally, I see maybe one or two cases a year that come in as an orthopedic problem. The horses aren’t lame; they just have a generalized stiffness that gets worse with work. They have normal muscle enzyme activity, and when you put them through diagnostics like scintigraphy and radiographs you can’t find a problem, and they don’t have any other obvious illness. In these cases I add stiff horse syndrome to the list of considerations and suggest corticosteroid treatments.”

Unfortunately, he says, many owners are doubtful and reluctant to pursue that suggestion: “It’s as if they don’t believe me. But if they try it and the horse improves, we’re that much closer to an answer. And if we can do it before the horse goes down, even better.”

Goehring adds that Spice’s case shows that this condition, although chronic, can potentially be managed long-term with corticosteroids and attentive care: “This mare was watched closely by her owner, who learned what the signs of trouble were and then knew how to care for her. She’s really the reason this mare did so well.”

Need help finding your favorite H&R article from 2012? This complete list of 2012 articles should help.

Al Dunning’s How’s My Riding?
"Sitting Pretty,” Practice Pen, Jan., pg. 32
“Hard-Working Pair,” Practice Pen, Feb., pg. 32
“Trail-Course Prep,” Practice Pen, March, pg. 32
“Al Says, ‘Relax’” Practice Pen, May, pg. 46
“Small-Fry Horsemanship,” Practice Pen, June, pg. 28
“Rail Work,” Practice Pen, July, pg. 38
“Fence Work,” Practice Pen, Sept., pg. 40
“Reining Prep,” Practice Pen, Oct., pg. 40
“Schooling Session,” Practice Pen, Nov., pg. 34
"Sit Up in the Saddle," Practice Pen, Dec., pg. 34

Barns, Property Maintenance
“Melt Ice Safely,” Your Horse, Your Life, Jan., pg. 18
Stable Gear: “Stall Fronts,” Jan., pg. 64
“Savvy Storage,” Your Horse, Your Life, Feb., pg. 20
“Spring-Clean Your Barn,” Your Horse, Your Life, March, pg. 20
“Messy Job Made Easy,” Your Horse, Your Life, March, pg. 20
Special Advertising Section: “Barn & Ranch Makeover,” March, pg. 57
Stable Gear: “Barn Carts and Caddies,” April, pg. 78
“Nip It in the Mud,” May, pg. 80
“How to Handle a Hay Shortage,” June, pg. 56
“Three-Pronged Fly Control,” Your Horse, Your Life, June, pg. 30
“Small Size, Big Benefits,” Your Horse, Your Life, June, pg. 28
“Tack Theft—Now What?” July, pg. 68
Stable Gear: “Barn Fly Control,” July, pg. 78
“Winter-Prep Steps to Take Now,” Your Horse, Your Life, Sept., pg. 26
“Easier Hay Soaking,” Your Horse, Your Life, Oct., pg. 24
Stable Gear: “Winter Water Options,” Oct., pg. 70
“While You Wait,” Your Horse, Your Life, Nov., pg. 20

Behavior
“Sore Back; Foal Eats Manure,” Whole Horse Q&A, March, pg. 14
“Hematoma; Saddling Woes,” Whole Horse Q&A, April, pg. 14
“Rearing to Go—In A Bad Way,” Problem Solvers, June, pg. 88
“Club Foot; Sometimes Spooky,” Whole Horse Q&A, July, pg. 20
“Trailering Fears; Bowed Tendon,” Whole Horse Q&A, Aug., pg. 12
“Pasture Predator?” Your Horse, Your Life, Aug., pg. 19
“Clinician On Call,” Aug., pg. 43
“Keeping Kelly,” Aug., pg. 62
“Trailering Fears; Bowed Tendon,” Whole Horse Q&A, Aug., pg. 12
“Popped Splint; Trail Fears,” Whole Horse Q&A, Sept., pg. 14
“Barn Sour; Shoe Boil,” Whole Horse Q&A, Oct., pg. 15
“Eye Discharge; Pulling Back,” Whole Horse Q&A, Nov., pg. 12

Bob Avila’s Winning Insights
“Breeding Time Machine,” Practice Pen, Jan., pg. 30
“How Not to Lose,” Practice Pen, Feb., pg. 30
“Don’t Skip the Basics,” Practice Pen, March, pg. 30
“Tire Kickers,” Practice Pen, April, pg. 33
“Industry Update,” Practice Pen, May, pg. 38
“Horse Divorce,” Practice Pen, June, pg. 45
“What You Need to Succeed,” Practice Pen, July, pg. 36
“Know When to Quit,” Practice Pen, Aug., pg. 32
“Neck-Reining: Part 1: Introduce the Concept,” Practice Pen, Sept., pg. 34
“Neck-Reining: Part 2: Introduce the Curb Bit,” Practice Pen, Oct., pg. 32
“Neck-Reining: Part 3: The Romal Advantage,” Practice Pen, Nov., pg. 28
"Rules of Engagement," Practice Pen, Dec. pg. 26

Breed, Show Associations
“Did You Know? Surprising Facts About 10 Breeds,” Jan., pg. 50
“Once More, for the Memories,” Your Horse, Your Life, Feb., pg. 18
“New National AQHA Championship for YOU!” Your Horse, Your Life, Feb., pg. 18
“Important USEF Drug-Rule Changes,” Your Horse, Your Life, Feb., pg. 18
Gallop Poll: “If Wishes Were Reiners,” Your Horse, Your Life, Feb., pg. 18
Have You Tried: “Entry-Level Reining,” Practice Pen, Feb., pg. 38
“New Show Options for All Breeds,” Your Horse, Your Life, March, pg. 18
“Happy Birthday, APHA!” Your Horse, Your Life, April, pg. 18
“PtHA, AQHA Innovations,” Your Horse, Your Life, May, pg. 20
“Inudstry Update,” Practice Pen, May, pg. 38
Have You Tried: “Saddle-Log Programs,” Practice Pen, May, pg. 48
“Save Big at AQHA Novice Championships,” Your Horse, Your Life, pg. 24
“Painted ‘n Pretty,” Your Horse, Your Life, pg. 24
“Genetic Test for Appaloosas Now Available,” Your Horse, Your Life, June, pg. 26
“Arabians Slide to Paychecks,” Your Horse, Your Life, July, pg. 24
“AQHA Video Delux,” Your Horse, Your Life, Sept., pg. 20
“Find a Trainer, Help a Youth,” Your Horse, Your Life, Sept., pg. 20
“Philanthropy at Pinto World,” Your Horse, Your Life, Oct., pg. 22
“Numbers Up at Quarter Horse Shows,” Your Horse, Your Life, Nov., pg. 18
“ACTHA Rides Benefit Service Members,” Your Horse, Your Life, Nov., pg. 18
"Not Too Common: Grullas," Your Horse, Your Life, Dec., pg. 16

Retirement for most horses is a fairly informal process. No papers are filed or legal statuses changed; rather, an equine retiree simply does less of what he used to do or perhaps stops entirely. And, ideally, the end of a horse’s working career is determined less by his age than by his physical capacity and other less tangible factors.

“I hear people say all the time, ‘My horse is 18. It’s time to retire him,’” says David Trachtenberg, DVM, owner of Trachtenberg Veterinary Associates in Penfield, New York. “But the age in and of itself is meaningless; what matters is his health status. If he’s in good shape and is handling his workload with ease, there’s no reason to retire him. And, frankly, it can be detrimental, physically and mentally, for a horse to suddenly go from being active to not doing much at all.”

The best way to “retire” a horse is to gradually decrease his activity level, based on his changing physical abilities. But it’s not always easy to decide when to make those adjustments and to what extent. Of course, you never want to ask a horse to do work that his aging body can no longer handle, but---let’s face it---most of us have horses so we can enjoy riding them, and we’d like to do that as long as possible.

Balancing these objectives requires a clear-eyed assessment of your riding goals and your older horse’s ability to carry you to them. It also means judging whether an off day is a minor bump in the road or part of a larger decline in your horse’s health, and continually making adjustments in his management and lifestyle that can help him stay healthy and happy.

This process is full of uncertainty and is sometimes fraught with emotion. But it’s something that every older horse deserves.

When to say when
An acute injury usually leaves little room for doubt when it comes to planning a horse’s future workload. A horse with a torn tendon obviously can no longer do his job---at least until he heals---no matter his age. On the other hand, when an older horse’s decline is subtle, progressing without significant injury or loss of vigor, it can be difficult to see.

“If you see an animal every day it can be hard to recognize the gradual changes,” says Ruth Sobeck, DVM, of Palos Verdes, California. “That’s when your veterinarian can be extremely helpful. I may see an older horse only two or three times a year, so I’m going to notice that he’s stiffer or losing muscle mass. I’ll point that out to the owner and ask what the horse is doing work-wise and how he seems to be handling it. These discussions can be an eye opener for an owner who hasn’t seen, or hasn’t wanted to admit, that the horse is slowing down.”

Sometimes, however, signs that a horse can no longer handle his workload are apparent. “You’ll notice they tire a bit faster and take longer to recover,” says James Bleak, DVM, of Central Arizona Equine in Camp Verde, Arizona. “They may trip more or be sore the day after a big ride. These can all be signs of him slowing down.”

Too much work can also make an older horse behave differently. “Watch him carefully and see if he is still enjoying himself,” says Trachtenberg. “Are his ears forward? Is he moving out willingly? Does he seem happy about the work? Even if you don’t notice anything obviously physically wrong, a horse who starts to show behavior changes and acts like a ‘brat’ may
be telling you he needs his workload cut back.”

That said, any horse will have good and bad days, so you won’t want to read too much into a single episode. Instead, look for patterns. “It can be helpful to keep a calendar or diary to record just how your horse feels each day,” says Sobeck. “At the end of the month go back and take a look to see where you are.”

Solvable or inexorable?
Your veterinarian can help you distinguish age-related issues from problems that can be solved or at least made less severe. Simply ascribing your horse’s physical infirmitiesto “old age” can allow illness or injury to go undiagnosed. “Ninety percent of the time, arthritis is what I’m confronting in an older horse who is slowing down,” says Trachtenberg.“But chronic, low-grade laminitis can look very, very similar. Chances are it’s just arthritis, but if you make that assumption without a veterinarian’s input, you could overlook something significant.”

Sobeck says that in addition to arthritis, repeated soft-tissue stress can put a horse on a retirement track. “Many times an older horse injures the same ligament or tendon again and again. You rehabilitate them, but when you reach a certain level of work, they just come up lame again.”

Listening to your horse is paramount in making decisions for his future, but keep in mind that some horses won’t let you know when they hurt. “From my own personal experience I can tell you that some horses will lie, particularly Arabians,” says Sobeck. “They’ll tell you ‘I’m great, I’m fine, I can run on these tendons,’ when really they can’t. If the x-rays and ultrasounds are telling you one story, but the horse is giving you another, you have to overrule the horse for his own good.”

Nonmusculoskeletal conditions, such as heaves and Cushing’s disease, aren’t likely to drive a horse into retirement by themselves, unless severe, because medications can usually control them. “Untreated conditions can certainly lead to complications that can make it difficult for a horse to perform his job,” says Trachtenberg, “but most of these medical conditions can be managed so effectively that they aren’t a factor.”

Cutting back
Once you determine that your horse can no longer manage his current workload, you’ll be faced with even more decisions. The challenge will be to reduce his activity level enough to relieve the stress on his body but not so much that his relative inactivity precipitates new problems or exacerbates existing ones. There are no rules---or even rules of thumb---for determining how much a horse of a particular age and with particular conditions can do. That is done on a case-by-case and even day-by-day basis.

Consider the arthritic horse, says Trachtenberg: “You want to keep these guys moving and active---mild to moderate work is actually beneficial for the joints. But knowing how much to work a horse who is stiff is a judgment call. You’ve just got to take it day by day and make decisions based on what you see in the moment. If he is initially stiff and improves in the warm-up to his ‘base line’ but is not outright lame, go ahead and ride. If he’s feeling particularly good, maybe have a short canter. But if he’s acting more sore than usual, more lame than usual, it’s time to head back to the barn, maybe give him a bute, and see where you’re at tomorrow.”

Trachtenberg adds that riding an older horse sparingly won’t preserve his soundness. “I think the adage that ‘Horses only have so many miles in them’ applies more to the extreme sports, horses showing at the higher levels, or horses on demanding show schedules. You aren’t going to take five years off a mild or even moderately arthritic horse’s life just because you continued to trail ride him. Go ahead and enjoy him.”

An incremental approach to retirement, in which you follow the horse’s lead to slowly reduce his workload, is logical. “If your horse isn’t handling the rocky, mountainous trails well anymore, stick to the hills,” says Bleak. “And then when the hills are too much, ride the flat trails. Eventually, if he’s got the personality, he may just be led around with kids on his back, but that’s an important job, too.” The same years that took a physical toll on your horse may have made him a calm, experienced schoolmaster, perfect for younger or inexperienced riders.

Scaling back your horse’s work means a change in your own riding as well, which may raise another set of questions and challenges. “One particularly tough scenario I see a lot is when people buy a mature horse to learn on,” says Bleak. “These experienced horses teach them the ins and outs of an event, but then when the people are ready to advance to higher levels, the horses can no longer physically compete at that level. The owners love those horses but have to get a younger one if they want to continue in the sport.”

One way to handle this, says Bleak, is for riders to purchase a second horse when their older one begins to show early signs of aging. “The people school and train on the younger horse and save the older one for the main events, when it counts. By the time the older horse has to stop roping or running barrels, the younger one is ready to step up.”

But not everyone can afford this solution. “That’s a harsh reality,” says Trachtenberg. “You can’t always just go get another horse, so you’ve got to decide if you’re willing to adjust your riding habits and goals. Oftentimes I’m very surprised: I’ll have an owner who’s been doing high-level hunter/jumper competition for 10 years, and I’ll tentatively ask them if they are OK with just a trail horse. And they’ll say ‘yes.’ But sometimes the answer is ‘no.’ There’s nothing wrong with that; it just means we will have to have a frank discussion about whether or not it’s possible to keep this horse at that level of competition, for how long and at what expense.

“Horses have a unique dual role in our lives, beyond companion animals,” Trachtenberg continues. “In one role, they are a pet and we get a great amount out of the animal/human interaction. But in their other role, they have a utility in our lives. Most of us have horses because we want to ride them. When they get older and those roles don’t work together, owners are faced with a tough dilemma: Do I keep this animal I love and give up on my riding goals? Or do I pursue my passion without this particular horse? That is something I’m often counseling owners of older horses on.”

Retirement TLC
Even if your older horse is working less, or not at all, the task of caring for him won’t necessarily become easier. His needs will be different, but still important.

“The biggest mistake I see people make is just throwing a retired horse out in a field and assuming he’ll be fine,” says Bleak. “He still needs regular dental and hoof care, good nutrition, vaccinations and deworming. He can’t be expected to fend for himself.” Keep all regular farrier and veterinary appointments for your retired horse, and expect to even increase their frequency as he ages. What goes on at the appointments will change, but he still needs that level of professional attention.

Simply looking at an older horse daily will go a long way toward keeping him healthy. “You should visit him and groom him every day,” says Sobeck. “The grooming isn’t so much for looks, but it makes you take a closer look at his weight, skin and overall health. If you’re just casually throwing hay and water at him each day and not taking the time to run your hands over his body, you could miss something.”

Consistency is important, too. If your horse received an oral joint supplement while he was working, continue to give it in retirement, says Trachtenberg: “A few times I’ve gone to an emergency call for a horse unable to get up. After an investigation, I find out the horse was on a certain joint supplement for years, and the owner either stopped giving it or had just run out and figured it would be no big deal if the horse didn’t get it for a few days. But then the horse ends up not being able to get up. The only thing that changed was the supplement, so I have to figure that was making a difference.”

Sobeck discontinued joint injections when her horse retired but kept using an intramuscular PSGAG0 injection. “It’s a judgment call,” she says. “But I think it makes them feel better, and even if they aren’t competing, they deserve to be comfortable.”

As you tend to your horse’s physical needs, don’t overlook his mental health. Sometimes our notion of what lifestyle will make an older horse happy misses the mark. “I retired my show horse when he was 22 after a series of injuries,” says Sobeck. “It turned out he wasn’t particularly happy being out in a field all the time. He didn’t do poorly physically, but he lost his spark and seemed very disinterested in life.” Sobeck moved him back into the barn and he perked up almost immediately: “He was just a very social guy who liked the activity of the barn.”

Companionship is important to older horses, even if they don’t seem to appreciate it. “Older horses can seem really grumpy and almost antisocial,” says Bleak. “They’ll pin their ears and kick at youngsters, but they still need the company of another horse and will get upset if you take that away.” For instance, an older horse may not feel comfortable lying down unless a herdmate is nearby, and then he becomes sleep deprived. “Unless the grumpiness escalates to fighting and one of the horses is going to get hurt,” says Bleak, “try to give an older horse
a companion.”

Finally, don’t discount how much a horse might miss his old routine: “There is a 33-year-old mare at a large stable that I take care of,” says Trachtenberg. “We had progressively retired her from the lesson program due to neck arthritis. She had gone from jumping to walk-trot lessons and then no riding at all. About four weeks after full retirement, she managed to get out of her stall, walked straight to the riding ring and stood next to the instructor as the lesson was going on. That’s a horse who obviously missed the interaction that came with her job.” Even if an older horse can no longer be ridden, if you can find a way to include him in his previous activities---hand-walking him during a lesson, for instance, or shipping him to a show simply as a traveling companion for a younger horse---he’ll be happier.

Confining sick horses in a quarantine stall protects the health of his barnmates.

EHV Outbreak.
Horses Euthanatized.
Farms Quarantined.
Travel Restricted.
Shows Cancelled.

Headlines like these will catch any horse owner’s attention---usually, we all hope, with a sigh of relief that the outbreak is somewhere far away.

But that’s not always the case. Outbreaks of EHV-1, which may involve a potentially fatal strain of the equine herpesvirus that can produce neurological impairment, are not uncommon. The virus might crop up on one farm or a small cluster of farms somewhere in the country every year. Under the right circumstances, however, the outbreak can become widespread. When the disease appeared at the National Cutting Horse Association’s Western National Championships in Ogden, Utah, in the spring of 2011, each one of the 400 horses in attendance had some risk of exposure---and the threat wasn’t identified until all had returned to farms and ranches across 19 Western states.

For weeks that May, a number of shows and events were cancelled, and several barns and state veterinary hospitals were put under quarantine as new outbreaks cropped up in state after state from Washington to New Mexico. By the time the USDA-APHIS (United States Department of Agriculture’s Animal and Plant Health Inspection Service) declared the virus “contained” in late June, 33 cases of myeloencephalopathy caused by EHV infection had been confirmed in 10 states; 26 of those horses had attended the event in Ogden, Utah, and 13 died or were put down.

Yet officials say the 2011 EHV outbreak could have been far worse. Prompt action on the part of state and local animal health officials, veterinarians, event organizers and---most important---horse owners helped halt the spread of the virus.

If EHV or another contagious equine disease broke out near your property, would you know what to do? By establishing a plan now, and having a few basic materials and supplies on hand, you could not only protect the lives of your own horses, you could help prevent the next outbreak from growing into an epidemic.  A good biosecurity program need not be difficult or complex. In fact, your normal management practices are probably already covering most of the bases. Still, it’s a good idea to review your routines periodically just to make sure you’re not leaving any gaps, and to make plans for what you’d do in the event of a real emergency. Your veterinarian will help you tailor a program to your individual needs. Here’s where you can start.

Keep vaccinations up to date
Vaccination is an inexpensive but effective way to prevent your horse from contracting several serious diseases. The American Association of Equine Practitioners (AAEP) recommends that all horses receive vaccines against a “core” group of diseases: tetanus, eastern/western equine encephalomyelitis, West Nile virus and rabies. An additional eight vaccines are available for horses at risk of encountering diseases such as Potomac horse fever, strangles or EHV.

Which of these risk-based vaccinations a horse needs depends on several factors, including his geographic location, age and activities. Those who are frequently transported to horse shows, for example, require more protection than most “homebodies,” and the needs of a pregnant mare are different from those of a retired gelding.

Your veterinarian is your best resource for creating a vaccination protocol tailored to your horse. Especially if you’ve made any significant management or lifestyle changes in recent years, ask her to review your routine to make sure you’re still providing the appropriate protection for your horse.

Practice good daily hygiene
A number of diseases---including rhinopneumonitis, strangles and equine influenza---can be passed from horse to horse on human hands and with shared tack and equipment. Here are several tips for reducing the chances that you’ll inadvertently spread an illness around your barn:

• Wash your hands after handling each horse. Cleansing your hands is one of the simplest yet most effective ways to avoid spreading infections. Develop the habit of washing with soap regularly, and consider installing wall-mounted dispensers of hand sanitizer between stalls or in other strategic locations. If your barn receives visitors, post signs to discourage the practice of going from stall to stall to pet each horse in turn.

• Scrub water buckets and automatic waterers regularly. Keep one dedicated brush for each bucket. Also, never let the end of the hose touch the surface of the water as you fill the bucket.

• Keep equipment separate. Ideally, each horse will have his own dedicated grooming brushes, blankets and sheets, bits and other items. Colored duct tape is a good way to mark each item to help avoid mix-ups---assign each horse his own color and use it to “tag” all of his equipment. Also, avoid sharing items with strange horses at shows or other events.

• Disinfect equipment periodically. Practically everything that touches your horse picks up bacteria and other pathogens as well as dirt and grime. Machine washables, such as towels, blankets and saddle pads, can be disinfected in regular laundry cycles, but some higher end washers now feature sanitization cycles, which use steam or extra high heat to kill even more bacteria. Buckets, hoof picks and other impermeable objects can be disinfected with soapy water, bleach or other commercial cleaners (see “How To: Disinfect Buckets, Brushes and Other Tools,” opposite). Sponges are difficult to disinfect. Discard and replace them whenever they get dirty.

• Control rodents. Rats can carry several diseases that affect both horses and people. Keep grain bins sealed, and promptly clean up any feed spills to deter vermin. Barn owls, cats and other predators will help keep populations down.

• Manage manure responsibly. Some pathogens may be passed via contact with manure. Pick up wastes daily, and avoid tracking it around with your boots or wheelbarrow wheels. If you are caring for a sick horse, place a disinfectant footbath at your barn entrance. To make one, place AstroTurf or a textured welcome mat in a shallow basin and cover it with a 10 percent chlorine bleach solution. Then, step into it to scrub the organic material off the bottom of your boots as you enter and exit the barn, changing the footbath water as it becomes dirty.

Quarantine new or sick horses
A number of contagious diseases can be spread directly from horse to horse. “Modes of transmission include direct contact, inhalation, oral [ingestion], via open wounds or bites and venereal contact,” says Roberta M. Dwyer, DVM, professor at Maxwell H. Gluck Equine Research Center.

If you have a stable herd---a group of horses who live together and travel infrequently---chances are you’ll need to implement quarantine measures under only two circumstances: when you actually have a sick horse, and when you introduce a new horse.

Horses exposed to a number of common equine diseases may show no signs for a week or more, yet they are capable of passing the pathogens on to others. For example, a horse can easily be exposed to strangles or rhinopneumonitis at an auction, then carry the disease to the herd at his new home.

“New horses should be quarantined for at least two weeks prior to joining the herd,” says Dwyer. “Two weeks covers the incubation period for many equine infectious diseases, like influenza.” If the horse has a vague history or you’re unsure about his vaccination status, it’s wise to extend the isolation period to at least 21 days.

“New horses should have their temperatures taken twice daily for early detection of disease,” says Dwyer. Call your veterinarian at the first sign of fever. It’s also a good idea to monitor the temperatures of your resident horses during this time.

Another risk occurs when you have some horses who always stay at home but share space with others who do go to shows. The traveler could easily pick up an illness and spread it to the rest of the herd before you know he’s sick.

Have an action plan ready
To avoid wasting time in the event of a disease outbreak, establish an action plan. Keep on hand equipment and products that are necessary to clean and disinfect stalls, including plastic booties, gloves and protective coveralls. Consider how you would manage the practical aspects of isolating one or more members of your herd, and make sure you have ready access to your horse’s veterinary records, particularly his vaccination history.

Once you’ve developed a plan for dealing with sick horses, make sure everyone else who has access to your farm or works in your barn knows the procedures, too. Either meet with individuals informally or schedule a training session so that everyone knows how to recognize the first signs of illness and what to do if they spot something.

If an outbreak occurs in your area, get your information from reliable sources. Be wary of social media: When people panic, rumors run rife. Instead, rely on your veterinarian, your state veterinarian’s office or your state’s department of agriculture for updates. Sources like these will have websites with pages dedicated to news releases and alerts. Find the sites likely to cover your area, and bookmark them in a dedicated folder so you’ll be able to find them quickly in an emergency. Don’t forget to include the United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) at www.aphis.usda.gov.

Keep in mind that, even if a disease outbreak in your region does not affect your farm directly, equine transport may be restricted. You’ll find updates and bulletins on the state or federal websites.

Last year’s EHV-1 outbreak is behind us. It was contained in part due to the efforts of the National Cutting Horse Association’s quick response in spreading the word and voluntarily canceling events. But the countless individual owners, who heeded the warnings and kept their horses home, helped prevent a handful of cases from growing into a widespread epidemic.

Given the nature of this virus as well as other contagious diseases, similar outbreaks are certain to happen again. While you can’t guarantee your horse will never get sick, you can take steps to minimize his risks and the threat of the illness spreading. And that will benefit not just the residents of your own barn, but also the welfare of horses all around your state.

Senior horses—those in their midteens and older—can continue to live healthy, productive lives if given the special care they need. We asked Barb Crabbe, DVM, Horse&Rider magazine’s consulting veterinarian and author of The Comprehensive Guide to Equine Veterinary Medicine (Sterling Publishing Co., Inc.) for her advice. She stressed that older equines need all the same basic care other horses do, including regular vaccinations and deworming, plus routine hoof care. Beyond that, here’s what she recommends you do to keep your senior horse going strong.

Keep him moving.
As with humans, exercise benefits an aging horse in multiple ways, including keeping muscles strong and joints operative (which preserves his ability to rise from the ground after resting). Full-time turnout (with appropriate pasture mates that won’t haze or injure him) is ideal. With under-saddle exercise, keep expectations realistic. A 25-year-old horse is roughly comparable to a 75- to 100-year-old human. And while there are some 80-year-old humans running marathons, many others are already in wheelchairs. So stay aware of your own senior horse’s changing capabilities and energy levels as you continue to ride him.

Mind those teeth.
Tooth problems, common in older horses, can contribute to malnutrition, weight loss, and colic. Periodontal disease is also a hazard as horses age. Schedule once- or twice-a-year checks by an equine dentist or veterinarian, and watch for trouble signs: difficulty chewing, dropping food, a bad smell from the mouth.

Feed with care.
The simplest way to achieve good nutrition for your older horse is by providing a commercial feed specially formulated for senior horses. Feed such pellets in addition to forage (grass or hay); or, if the horse has severe dental problems, use the product as a complete feed, moistening with water as necessary.

Get him vet-checked.
Your vet can watch for conditions and diseases common to older horses, including digestive difficulties, Cushing’s disease, insulin resistance, melanomas, and kidney or liver problems. Schedule vet visits once or, even better, twice a year.

Watch for vulnerabilities.
Older horses have decreased reserves and increased susceptibility to serious infections and colic caused by dehydration or impaction. They’re also more attractive to biting insects, and may be more sensitive to temperature extremes (though you needn’t necessarily blanket your senior horse except in the most extreme cold— see below). Watch for signs of illness, and act promptly; provide adequate pest protection; and make sure your oldster has accessible shelter (where other horses won’t drive him away).

Ease the joint pain.
Work with your vet to address arthritis and other bone/joint difficulties. Joint-health supplements (containing glucosamine, chondroitin sulfate, and MSM) and judicious use of the nonsteroidal anti-inflammatory bute at your vet’s discretion may be helpful. (Note that the overuse of bute can cause kidney and gastrointestinal problems.)

Groom him.
A daily grooming promotes circulation, helps head off skin problems, and enables you to catch the start of small troubles before they become problematic. Especially during the winter, run your hand over your senior horse’s barrel regularly to check for ribbiness that might not show under a long haircoat.

A word about blankets:
If severe weather dictates that you blanket your older horse, be sure to remove and replace the blanket once a day to check for trouble. In my practice in the Northwest, I see more problems from older horses wearing blankets that never get removed— resulting in injuries and bad blanket rubs or sometimes severe undetected weight loss. Many older horses living in pastures with good shelters and plenty of fiber (the digestion of which helps generate warmth) don’t need blanketing. If you’re in doubt, ask your vet.

A mild winter with little snow, a warm and early spring—so far the year has been kind to horses (and people) in many northern states. But the good weather may have some unwanted effects on horse health, says Michigan State University Extension veterinarian Judy Marteniuk, DVM. Here are three risks to watch for:

• Disease-carrying insects. Early spring warmth gave insects a head start on the season, increasing the danger of insect-borne diseases like Lyme disease, carried by black-legged ticks, and West Nile virus, Eastern equine encephalitis and Western equine encephalitis, carried by mosquitoes. These insects were out and about, breeding and biting, weeks ahead of schedule. (New research also suggests that mild winters may move up the date at which disease-carrying mosquitoes shift from ­biting birds, their early season prey, to horses, people and other ­mammals.) To counter the threat, many horses were vaccinated against West Nile, EEE and WEE a few weeks earlier than usual. “The effect of the vaccinations lasts six to eight months,” Dr. Marteniuk says, “so these horses may need boosters in the fall if the mild weather continues.” Follow your veterinarian’s guidance.
• Internal parasites. The mild winter may have increased the risks from strongyles and other internal parasites. Adult strongyles (large or small) live in your horse’s large intestine and produce eggs that are passed in manure. In pastures (or wherever they land) the eggs hatch into infective larvae that horses ingest. Warmer-than-usual temperatures may have allowed more eggs to survive winter and hatch out early, Dr. Marteniuk says. “You don’t necessarily need to deworm more, but monitor closely to be sure parasites are under control,” she says. “Fecal evaluations should always be part of your program, and you may want to do an extra one this year.”
• Sand colic. Cases of sand colic have been higher than normal in her area this spring, Dr. Marteniuk reports. Lack of snow cover meant that turned-out horses nibbling for forage (or fed on the ground) took in quantities of sandy soil, which can build up in the gut and irritate the intestinal ­lining. Horses should be kept off barren, sandy soil and fed on mats to reduce the risk, she advises. Psyllium supplements, fed according to the manufacturer’s directions, may help move sand through the gut. But don’t expect quick results, Dr. Marteniuk says: “It can take weeks or months for sand to be moved out of the ­digestive tract, depending on the amount present.”

The Big Dry
Meanwhile, a prolonged drought has parched areas from Arizona east to North Carolina and northern Florida, and from Kansas south into Mexico. Last year Texas, in the heart of the stricken region, had the hottest and driest summer and the most destructive drought in its history, according to state officials. Pastures browned and stock tanks dried up. This year spring rains brought relief across parts of the Great Plains and along the Gulf Coast, especially in southeast Kansas, Oklahoma and northern and central Texas. But drought conditions persist in much of the Southwest and parts of the Southeast, and horse owners are dealing with the effects.

The drought has sharply curtailed hay production. As local supplies ran out last year, hay was trucked to Texas from as far away as Oregon, and prices shot up. Many horse owners turned to hay cubes, alfalfa pellets, beet pulp and other fiber sources to stretch their limited stores. This year, supplies have remained tight and prices high. In March, horse hay was listed for $10 to $20 per small bale and $90 to $100 per 4-by-5-foot round bale on the Texas Department of Agriculture’s Hay Hotline website.

The number of horses auctioned off, turned over to rescues or simply abandoned has risen in the drought-stricken regions, according to news reports. The drought was also said to be a factor in increased cases of some equine diseases, such as pigeon fever (a bacterial infection that causes abscesses, often in the chest and abdomen).

Scientists believe the weather phenomenon called La Niña was a major factor in the southern drought, and the National Weather Service’s Climate Prediction Center expects the current La Niña to end by summer. But many other forces drive weather patterns. For example, scientists report that rapid warming in the Arctic is altering the path of the jet stream, the major west-to-east air current over North America. That trend may make weird weather the new normal.

At Rancho Sierra Vista Equestrian Center in San Juan Capistrano, California, bad news came on the heels of the new year. “A little cough had been making the rounds of the barn, and we were on alert for that,” recalls trainer Cathy Hanson, who stables 30 horses at the 350-horse multidiscipline facility. “But in early January one horse developed neurological signs, and that prompted testing.”

The blood test came back positive for a form of equine herpesvirus-1 that can cause potentially fatal neurological disease in horses. “EHV is everywhere, and it’s super-contagious,” Cathy says. State animal health officials were called in, and on January 10 the facility was quarantined.

An outbreak of contagious disease is a nightmare at any barn, let alone a facility home to so many horses. This was the first such incident for Rancho Sierra Vista, but it was just one of several outbreaks that have put riders on edge around the United States in recent months. The list of disease-causing organisms that spread horse to horse includes viruses like EHV and equine influenza as well as bacteria like Streptococcus equi, which causes strangles. How can you protect your horse?

“We won’t be able to prevent all cases of these diseases,” says Josie Traub-Dargatz, DVM, MS, DACVIM, an equine disease expert at Colorado State University. But that doesn’t mean you’re helpless. In this article, Dr. Traub-Dargatz explains how you can ­assess—and reduce—the risks your horse faces. Those risks are greater if he lives at a big commercial boarding stable or is a regular on the show circuit than if he lives in your backyard and just makes a circuit of the pasture. But he faces some danger of infectious disease anytime he comes in contact with other horses.

Get the Facts First
Word of disease outbreak travels fast these days, via Facebook, Twitter, online forums, text messages, and email. “Social media can get information out extremely quickly,” Dr. Traub-Dargatz says, “but the accuracy of the information may be open to question.” To assess risk, you need to separate facts from rumors and exaggerations.

Some contagious equine diseases are reported to state animal health officials, and that makes it fairly easy to get reliable information about an outbreak. For example, in California, neurological cases caused by EHV-1 must be reported to the state Department of Food and Agriculture. During the San Juan Capistrano outbreak this allowed everyone to get frequent and accurate updates on the CDFA website, where outbreaks are categorized by county instead of by naming specific facilities. Reporting requirements for equine diseases vary state to state, so check with your state’s animal health officials to find out which diseases are reportable where you live.

Reporting requirements helped check a multistate outbreak in 2011, when more than 400 horses were exposed at a cutting-horse event in Utah and went home to barns in 19 states and Canada before the first case was recognized. State and federal officials worked closely to track the horses and get accurate, timely information to the public.

When the disease isn’t reportable to state animal health officials, getting information is much more complicated. For instance, California doesn’t require reporting for equine flu or common forms of EHV that cause respiratory disease in horses and abortion in pregnant mares. Where should you turn? Your veterinarian is the most likely source of reliable advice, but with no central clearinghouse for information it can be a challenge to get the facts.

The American Association of Equine Practitioners has formed a task force to develop a communications plan for disease outbreaks. (This is part of an effort by the American Horse Council to create a national equine health plan.) “The goal is to make sure owners and managers of events and horse facilities, industry associations, extension agents, horse councils and veterinary practitioners all have accurate information quickly, acknowledging that the source of that information may vary,” Dr. Traub-Dargatz says.

The task force will develop a draft plan and send it to the American Horse Council for industry input, so there’s an opportunity for horse owners and event organizers to get involved, she adds. “Think about what diseases you need to know about and what your concerns are. You can voice those concerns to breed or discipline associations or to your state horse council, which all communicate with the AHC.”

In the May 2012 issue, we reported that 87 percent of readers in our "Gallop Poll" had observed changes in climate trends where they lived. Read more about how those climate changes could affect your horse.

Climate change: The heating of the inner atmosphere, oceans, and land surfaces of the earth. The warming is associated with more intense extreme weather events and the altered timing, intensity, and distribution of precipitation.
—Paul R. Epstein, “Climate Change and Public Health: Emerging Infectious Diseases,” Harvard Medical School Center for Health and the Global Environment

You’ve been hearing about weird weather for a while: A historic drought in Texas... followed by regional flooding. Killer tornadoes in Alabama and elsewhere. A rare hurricane on the upper East Coast. Balmy weather in New Hampshire...in January. What gives?

Theories abound. But regardless of cause, changing weather patterns seem to be the new norm. Such weather-pattern changes may cause more than the typical weather-related problems, which can range from inconvenience to destruction. (Last year alone, the U.S. suffered a record-smashing 14 separate billion-dollar weather disasters.) They also may be affecting the spread of infectious disease (and more).

I’ve witnessed that firsthand in Texas, where I live. (See, “Outbreak!,” This Horse Life, page 10.) That led me to contact three experts in equine infectious disease: Dr. Craig Carter, of University of Kentucky, and Dr. Noah Cohen and Dr. Tracy Norman, of Texas A&M University. (See, “The Experts,” page 2.) I asked them how climate change might affect our horses’ health. Here’s what they had to say. Then read on to see how you can help protect your horses.

Dr. Craig Carter, University of Kentucky

Dr. Craig Carter: 'A scary thing to watch'
Climate-change scenarios project a shift in the spread of infectious disease, due to warming and associated weather extremes, such as flooding and droughts. “It’s a scary thing to watch,” says Dr. Carter. “My wife is a master gardener, so she keeps me up to date on plant zones. In the ’80s, Kentucky was a Zone 6. Today, the state is mostly a Zone 7, which indicates it’s warming. (Such zones, with 1 being the coldest, and 13 the warmest, are the U.S. Department of Agriculture’s indicator of whether a plant or tree will survive the winters in a given region.)

“Insect vectors (carriers of disease) are in concert with that trend,” he continues. “For instance, West Nile virus, which is transmitted by mosquitoes, appeared in Canada for the first time in 2002. Mosquitoes, ticks, flies, and other insects are moving northward as it warms. It’s not just horses (and people) at risk; crops are being affected, as are trees, due to beetle infestations. Climate change affects all forms of life.”

It doesn’t appear that the warming trend will end anytime soon.

“Ice caps are melting. I read one study done down on the Equator estimating that 2,000 plant and animal species are moving north at a rate of a mile per year,” Dr. Carter says. “We need to be ready, such as with vaccine development, better drugs, preventive measures—that all takes increased research dollars.”

Pigeon fever, which typically causes deep-muscle abscesses, is an example of an equine infectious disease on the move.

“Drought increased the biting-fly population in areas like Texas, Louisiana, and Colorado,” says Dr. Carter. “Flies can mechanically transmit Corynebacterium pseudotuberculosis, the cause of pigeon fever.” (More about that later.)

Leptospirosis is also on the move.

“We’re currently doing a study on equine leptospirosis at the University of Kentucky,” Dr. Carter says. “Interestingly, the horse is the only domestic animal that gets infected by lepto that doesn’t have a vaccine. Somehow it’s considered a ‘Kentucky’ problem. But our research team is seeing high blood titers (indicating exposure to the bacteria) all over the country.”

Leptospires are one cause of equine recurrent uveitis, an eye inflammation that eventually can cause blindness; lepto also can cause abortion in broodmares. “It’s a multi-species disease,” explains Dr. Carter. “Horses, cattle, dogs, and other animals pick it up from rodent urine in grass, contaminated hay, and other things in the environment. The Leptospira bacteria bore through the mucous membranes and infect the animal.” Outbreaks seem to follow wet years.

“Last year, Kentucky had the highest rainfall on record. We had 67" of rain; normal is about 40",” says Dr. Carter. “That’s resulting in a high prevalence of lepto this year. In 2006, another very wet year, we had 41 abortions confirmed in our lab alone, but that was only the tip of the iceberg. Yes, we predict 2012 will be another big lepto/abortion year.”

The economic impact on Kentucky farms alone is huge.

“In 2006, we attempted to trace back all the lepto abortions confirmed in our lab. We were only able to get good data from 20 of the affected farms. The value of the foals lost on those farms was $3.5 million. We can’t estimate the economic damage and suffering related to the uveitis syndrome. Again, that’s just the tip of the iceberg.

“We need more funding for research to better understand the epidemiology of this disease,” he states. “But we’re not going to give up until we have a vaccine for the horse.”

Dr. Carter says a recent graduate-student study at the University of Kentucky demonstrated that infected horses may be a risk factor for humans.

“Leptospirosis affects the kidneys in humans and can be fatal,” he says. “It’s a worldwide issue—it’s one of the most prevalent zoonotic (spreads to humans) diseases seen around the world.”

Unusual weather makes disease a moving target for veterinarians.

“Take equine herpes virus, a neurological disease that can be fatal, and one that’s highly contagious,” Dr. Carter continues. “It tends to follow cold-weather stress, which causes a horse’s immune system to be suppressed. EPM (equine protozoal myeloencephalitis), another neurological disease, has also been associated with cold stress. When a cold snap hits areas where horses aren’t used to it, they get stressed until they acclimate. They can come down with just about anything.”