When diagnosed and treated in the early stages, Lyme disease is actually easily curable. Unfortunately, usually by the time most horses are definitely diagnosed as suffering from Lyme disease, the illness is well established and may not respond as quickly, or as completely, to treatment. For most of these horses, the disease becomes chronic, meaning it will never truly go away.
The first step after diagnosis is a course of antibiotics, usually intravenous tetracycline, oral doxycycline, or a combination of the two. If you’re fortunate, your horse will return to normal and stay that way.
For some, though, the horse either responds well initially but relapses or never completely recovers. Even in people, who are often diagnosed and treated much sooner, treatment failure rates - defined as continued or recurrent symptoms - run from about 10 to 30%.
Recurrent Lyme symptoms in people and animals that are relatively normal between ’attacks’ tend to have symptoms return on a cyclical basis, with intervals of between six to 12 months.
Some veterinarians think this time span actually represents new Lyme infections rather than chronic relapses, which may be the case in some. But, even where there is no chance of repeated infection, the cyclic relapse pattern appears.
Treatment And Management
Horses experiencing relapses should be on antibiotics, especially oral doxycycline (5 to 10 mg/kg, twice a day). A typical course is about three weeks, although in human-medicine cases, especially in people with late cases of Lyme and arthritis, longer treatment periods are more beneficial.
Another option, although infinitely more expensive and less convenient to use, is intravenous therapy, either with oxytetracycline or with ceftiofur. Owners of horses that have repeated episodes of Lyme-related pain and arthritis should talk to their veterinarians about keeping the horse on a longer course of therapy.
This is especially true if the horse’s condition worsens within four to six weeks of stopping antibiotics. When antibiotics are given in sufficient dosages for a sufficiently long period of time, the chance of the horse having a relapse drops.
Most problematic of all, however, are those horses that don’t respond completely to antibiotic therapy and/or have periodic recurrences of the Lyme symptoms. Long courses of antibiotics have been tried in people with ’treatment-resistant Lyme,’ but a recently completed large study showed they make no difference. Guidance regarding how to keep these horses more comfortable and in work is sorely lacking.
Dealing with the discomfort of a Lyme flare-up can be a real challenge, since the pain may be of several origins - joints, bursae, muscle, or nerve irritations. The Lyme horse also typically shows a pattern of migrating joint pain, from leg to leg and from joint to joint. However, you can help make him more comfortable:
• Avoid formal exercise but, if possible, keep the horse in a large paddock or field where he is free to move around at will, has sufficient shelter and a bedded area to lie down.
• Try an herbal pain/inflammation supplement, such as BL Solution, instead of NSAIDs like bute or aspirin for the horse that is sore all over.
• If muscle pain is obvious, experiment with rubs using the herbal liniment Sore No-More or using warming/mentholated muscle rubs to see if they bring relief. Applying warm, moist towels on top of the liniment, and then covered with a layer of plastic (a plastic shower curtain from the dollar store works well for this) and a blanket can greatly enhance the effect. The plastic will hold the heat for at least 30 minutes. If necessary, use a sheet or blanket to keep the muscles warm.
• For areas of obvious joint or bursa swelling carrying heat, try hosing the area with cold water several times a day, or applying wraps soaked in witch hazel that have been cooled in the freezer.
Change the wraps when they warm up or refresh them by pouring on more cold, fresh witch hazel. When you can’t treat this intensively, we suggest rubbing in Sore No-More for acute flare-ups, every four hours or so. DMSO could also be tried, but it may cause skin scurffing if inflammation is active.
• For stiffness during the recovery phases, or stiffness that persists between flare-ups, Sore No-More is still a good choice or you could try a capsaicin cream or liquid, applied 30 minutes before work and at night. Allow two to three days to see the maximum effect from this.
There are two schools of thought regarding non-responders. One theory is that they’re still infected, but the organisms are ’hiding’ from the antibiotics and the immune system inside the horse’s cells.
Another commonly believed theory is that the infection is no longer present, but the arthritis is coming from an autoimmune reaction, somewhat similar to rheumatoid arthritis.
Since only synovial biopsies are truly accurate in determining if a horse is still infected or not, there’s really no way to tell whether the organisms are ’hiding’ or an autoimmune reaction is occurring. This is an important point, however, since treatments of the two causes are vastly different. Persistent infection calls for immune system support and stimulation, while autoimmune reactions require it be quieted down.
Because of veterinary medicine’s inability to determine the cause, a middle-road approach is usually chosen, which might involve:
• Prolonged daily oral antibiotic therapy or pulse antibiotics, such as high doses given for three days a week, then rest, then resume again the next week. By prolonged, we mean months of treatment.
• Nutritional anti-inflammatory support, including:
• Omega-3 fatty acid sources (4 to 6 oz. of ground, stabilized flaxseed or 1 to 2 tablespoons of flaxseed oil).
• Vitamin E (1500 IU/day) and selenium (2 to 4 mg/day).
• Copper and zinc, as dictated by the horse’s dietary needs, but a safe ballpark about 75 mg/day copper and 225 mg zinc.
• Magnesium supplementation up to a Ca:Mg ratio of 1.5:1 for the total diet to control inflammatory responses and calm muscles. You can try five to eight grams of magnesium/day to evaluate the effect, but for long-term use, you should make sure you are at the appropriate Ca:Mg ratio.
• MSM at 20 grams/day.
• Joint nutraceuticals, such as glucosamine, chondroitin, hyaluronic acid, alone or in combination with anti-inflammatory/anti-arthritic herbs, like boswellia, curcumin, tumeric.
The question of whether to use immune stimulation or not must be addressed on a horse-by-horse basis. With acute cases or chronic/recurrent symptoms where synovial biopsy or rising titers (blood tests indicating the amount of Lyme organisms present in the blood) can be documented, assuring the infection is still present, immune stimulants may definitely help.
However, if your chronic Lyme horse is suffering continued pain because of an autoimmune reaction, not persistence of the Lyme organisms, immune stimulants may make things worse. Certainly any horse that worsens or appears to worsen on immune stimulants should have their use stopped immediately.
In addition, regular, long-term of use of NSAIDs like phenylbutazone should be avoided because of the potential for adverse effects on joint cartilage, tendon, muscle blood flow and the immune system.
For more information on Lyme, see Horse Journal back issues: April 2002 ”Neurological Symptoms Can Be Misleading,” and June 2001 ”Lyme Disease Calls For Prompt Action.” You can purchase these through our back-issues department at 800-424-7887 or online at our website, www.horse-journal.com.
Also With This Article
Click here to view ”Smart Moves.”
Click here to view ”Symptoms of Chronic Lyme.”
Click here to view ”Doxy Before Shows.”
Click here to view ”Get Ticked Off at Ticks.”
Click here to view ”Yankee Does More Than Live With Lyme.”