EquiSearch's Ask the Vet: Weanling Joints

Find out how to prevent and treat inflammation in a weanling's bones and joints in this edition of EquiSearch.com's Ask the Vet by Dr. Joyce Harman.

Question: My weanling foal is becoming crooked in her front knees and seems to be a bit weak. Is there anything that I can possibly feed her or give her to help her joints grow strong and straight?

Answer: Last spring’s foals are now mostly out on their own and away from Mom’s milk. This is the time to carefully watch the joints and the area near the joints in the lower legs for any signs of swelling or odd-looking lumps. Also, carefully watch the angles of legs for any signs of crookedness and the feet for any odd shapes. Ask your farrier if he/she sees any stretching of the white line (thicker places) or flares forming. Changes in the feet can be an early sign of changes in the joints.

What we are looking for here is any sign of epiphysitis, which is an inflammation of the bone where it is actively growing. Each bone has an area next to the joint where the bone grows longer, while the area in the middle of the bone doesn’t add any length to the bone. Usually, if inflammation occurs, you will see a swelling or lump on both legs in the same place, though one side can be worse than the other. If you see a lump on just one leg, it may be from an injury. It is always wise to have a veterinarian check any unusual swellings.

To prevent and to treat epiphysitis examine your young horse carefully. Is he/she looking fat, or even just really round? A horse at this age should show a few ribs easily, especially if it is from one of the faster growing, large breeds of horse, such as a warmblood. I would much rather see a youngster looking skinny than fat. When horses go through growth spurts, they often look skinny for a few weeks until the growth spurt finishes, then they will look less skinny. Do not feed extra during that growth spurt. Horses being prepared for yearling sales or futurities are often overfed and sometimes under exercised. This is the worst combination of circumstances for a growing colt or filly’s bone and joint health.

What is the activity level of your youngster? Youngsters with epiphysitis often do not play as much as they should, since they can be in pain. This makes it easy for them to gain weight. Activity and exercise are important to help develop normal cartilage inside the joint. Play exercise is also important for babies to learn skills that will help make them better riding horses later in life, such as how to stay on their feet when the footing is not perfect. Controlled exercise of horses at this age (treadmills, hand walking) is good for teaching them life skills, but not good when it is the primary form of exercise. Lunging and round pen work are very stressful on growing bones at this age and should not be done.

Many foals are overfed grain. And many mares, while the foal is still nursing, are overfed, which makes their milk too rich for the baby. Mineral imbalances and overfeeding of high carbohydrate and sugary feeds can lead to inflammation. High protein diets may not be as bad as high carbohydrate diets, but they still are not needed by many youngsters. Inflammation then can lead to distortion of the bone (crooked legs), pain, lameness and distorted foot growth.

If your youngster is on the fat side, the first thing to do is decrease the amount of feed, protein and sugar being fed. No foal should be fed sweet feed: Research has shown that high levels of sweet feed and high carbohydrate diets trigger some bone growth problems such as epiphysitis and Osteochondrosis Dessicans (commonly known as OCD). Unless you have foals such as Thoroughbreds with a fast metabolic rate and a need for higher protein feeds, youngsters need little more than 12 percent protein. Many easy keeping breeds and some individual weanlings of any breed need very little grain, since they already have a tendency to be fat, even at this age. Grain was never fed to our wild horses; they just ate what Mom ate and drank her milk until the next baby came along. If your youngster needs more calories and is truly in need of more weight, it is better to feed a high fat diet than a high grain diet.

These young horses do need minerals. Conventionally (not organically) grown grains, hays and pasture grasses are generally deficient in available minerals. This is because the normal fertilizer is a salt and petroleum based product that actually binds the minerals in the soil and makes them unavailable to the soil microbes. The microbes (good bugs) are the creatures that actually feed the plants their minerals.

Research has shown that the minerals copper, magnesium, potassium, iron, manganese, zinc, iodine and selenium all are needed for healthy bone growth. The standard salt block, even the red mineralized salt block, has very little mineral available in it. The biggest factor with a salt block is that most horses of all ages eat limited amounts of salt. After almost 20 years of observing horses eating minerals, I find that horses eat minerals in preference to salt when offered a choice. So I feed minerals without salt and offer salt as a separate choice. Salt is a limiting factor in what animals will eat–just think how bad it tastes to have too much salt on your vegetables or excessively salty potato chips.

Growing horses eat minerals in spurts that correspond to their growth spurts. They may not eat any minerals for a few weeks or a month, then suddenly they consume several pounds. Look out, because the next thing that happens is some body part grows a lot. Notice how one day you look at your beautiful baby and his rear end is huge, his front end looks puny, his neck short and his head enormous. You wonder how you could have bred such an ugly creature. Then a few months later another growth spurt occurs, the back and neck look long, the head small and shoulders big. All these changes are normal and require minerals to grow the bones to make the frame bigger. Then the muscles catch up. Usually by the time the animal is about 3 years old they look more normally proportioned.

Some youngsters will eat dirt to try to get minerals, and if yours is doing that, it is a sure sign you need to add minerals to the feeding program. Look carefully at the ingredients to be sure there are trace minerals, and a balanced major mineral combination (calcium, phosphorus and magnesium). I have used minerals without salt for many years, and there are now other products on the market, I am sure.

Check out your hay situation also. Alfalfa hay can be very high in calcium which can throw your mineral balance off, but that varies depending on how it was harvested. Grains such as corn, oats and barley are high in phosphorus, so you need to have plenty of calcium to go with them. You can have your hay analyzed and figure out what you need to add. Or you can let them regulate the amount of minerals they eat. It is not necessary for even a growing youngster to have the minerals in front of them all the time. If you only go to the barn a few times a week and your horse is in a pasture with others, just offer the minerals when you visit.

Dr. Joyce Harman is a veterinarian and respected saddle-fitting expert certified in veterinary acupuncture and veterinary chiropractic; she is also trained in homeopathy and herbal medicine. Her Harmany Equine Clinic is in northern Virginia. Visit her online shop.

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