Epiphysitis and OCD - Developmental Bone Disease, and Feeding Broodmares by J Sinner/R Golob
As another foaling season passes and the current weanlings and yearlings grow and develop, our attention is often focused on joint problems. By simple definition, epiphysitis is an inflammation of the physes, which are the ends of the leg bones closest to the joints. OCD or osteochondritis dissecans is a necrotic lesion or death of a portion of the bone, usually in thejoint cartilage itself and the adjacent bone. OCD starts in utero, with improper cartilage formation. Together, they are classified as developmental orthopedic disease or DOD, and the economic losses from these conditions are a major concern in the equine industry. Foals who suffer from DOD are at risk for early arthritis and other unsoundness such as bone chips, spavin, ringbone or sidebone, and fractures as they are ridden and used, or if they suffer trauma such as a fall, kick, or accident. So how do we prevent the problems, or deal with them once they occur?
Let's look at causes first ...
Nutritional Studies in Europe, Australia and the USA point toward the importance of proper mineral intake in the broodmare from the very start of pregnancy and ideally long before. By the time the foal is born, it needs to have adequate copper and zinc stored in its liver to take it through the first 6 months of life. Without this storehouse of minerals, inadequate or unbalanced bone growth results. A recent study confirmed that feeding the foals supplemental copper and zinc or feeding the minerals to the nursing mares did not compensate for being born deficient. Of course we know that minerals in the chelated form, as in Dynamite products, are better utilized and safer from unwanted mineral reactions than are the inorganics. (Quick review: copper sulfate or oxide, zinc sulfate or oxide, etc. are inorganic and hence mostly indigestible minerals. Review Minerals: Right on Target!) We also know that supplementation must always be in balance, with a full spectrum of minerals, vitamins, and digestive aids to assure assimilation. Original formula Dynamite or TNT is my choice for broodmares and foals, due to the higher levels of copper, zinc, and vitamins A and D. Just feeding a mare supplements during the last trimester is a flawed logic, she needs supplementation from conception. The brain and nervous systems are formed very early in the pregnancy, and proper nutrition should be in place before the mare is even bred. If a mare has been debilitated or has come from a very unbalanced feeding program, you may be wise to postpone the breeding until she is healthy and in balance, or risk developmental problems with her foal. Most mares do not require much grain until the last couple months of pregnancy, and very fat mares will have a difficult time foaling, so use common sense and make sure she gets daily exercise or is turned out. Also, be cautious in worming or vaccinating in the first few months of pregnancy when the fetus is especially vulnerable. Vaccinologist Dr. Ronald Schultz of U of WI Madison recommends giving rhino shots only before a mare is bred,and not during pregnancy. Colorado State University now follows a program of not deworming mares until 100 days into the pregnancy. Alfalfa hay is very high in both molybdenum and zinc, which can suppress copper and create skeletal development problems. Alfalfa is also top-heavy in calcium, often containing a ratio of 5:1 calcium to phosphorus. The ideal ratio is 1.5:1, so you can see the problem here. Feed a high quality grass hay with possibly a smidge of alfalfa, not more than a pound or so for a weanling and up to a couple of pounds of alfalfa for a yearling. Free choice the grass hay. Alfalfa is also far too high in protein, often being 20 percent or more. I am really opposed to the philosophy of stuffing baby horses and broodmares with protein. If we follow Regan's philosophy that any mammal is not designed to have a protein level higher during its life than is present in its mother's milk, we find that the top limit for horses is 12 percent. Yet most commercial foal rations and some broodmare rations contain protein levels of 16-18 percent or even more!
Hint: foals fed high protein and calories do not get any bigger, they merely grow earlier but often end up unsound. The junior rations containing alfalfa, corn oil, animal fats etc., are not the way I choose to feed my horses. I have had amazing results with growth and body condition by feeding grass hay, a teeny bit of alfalfa, an ounce of Dynamite daily or the recommended dose of TNT, and the Pelleted Grain Ration which contains 12 percent protein. Whole organic extruded soybeans in this ration provide lysine and a great fat source, and the chemical free grains are awesome. You will be amazed at what just a couple of pounds of the PGR will do interms of size and condition. The last foal I bred and raised here exclusively on GrainRation looked like a two year old as a yearling, and when he shipped to his new owner at 15 months, the trainer was ready to climb on him thinking he was a coming three year old.
Feeding lots of grain is detrimental in another way as well. Large grain meals tend to trigger a rush of insulin followed by a blood sugar crash, which causes the glandular system stress. Since the thyroid and parathyroid glands control calcium metabolism, you are asking for trouble by pouring 10# of grain or more down a baby (or even 5#, depending on breed). You would be surprised how many people call me with babies who have cantaloupe-sized knees and confess to feeding even up to 20# of grain a day, especially of the high-octane junior rations. Sorry, folks, no futurity is worth a trashed foal. And remember from all the Regan columns on healthy human diet, grain is an acid-producing food. When any mammal has too much acid, the body will pull minerals from the bone to buffer the blood stream and keep the heart beating. One of our Directors who imports Dutch Warmbloods commented to me that she sees horses in Europe with impressive bone on the European diets of grass hay, carrots, and low grain, then comes home to the US to see "deer legs" on the siblings raised here on lots of grain and alfalfa hay. Remember, horses evolved in desert climes, where there was neither high protein nor lots of sugars in the forage. If we expect optimum health and soundness from our equines, we need to respect their inherent physiological needs.
Dynamite's 1to 1 and 2 to 1 FreeChoice products are bone, tendon and ligament builders containing chelated calcium, phosphorus, chelated copper and zinc, Ester C and sources of organic silica. Studies in France have proven that silica can be transmuted to calcium in the body, as needed. So I put out both products for the mares (from breeding on) and babies, and let their instincts indicate their consumption. Another great silica and trace mineral source is the Izmine, andI free choice that also. Regan has had great luck adding 1 teaspoon or up to 1 tablespoon of Izmine, to the Complete Grain Ration at weaning, depending on size and breed of foal. If you are feeding TNT, the Izmine is in there, as well as Free and Easy for prophylactic joint support.
University of Kentucky studies years ago proved that the addition of yeast cultures and lactobacillus products to the ration increased the absorption of phosphorus, and of course we have these in Dynamite products. I add a shot of Dyna Pro to assist with digestion, as babies don't have a mature hind gut until age two, and I figure they can use the additional digestive assist.
Watch ankles carefully in weanlings, and knees/hocks in yearlings. If you see any of these signs, midcourse correction is needed:
· Knobby or "figure eight" look to the ankles · Front or hind upright pasterns or "knuckling over" · Wobbling on the ankles or knees · Heat or swelling in fetlock, knee, hock, stifle · Babies who lie down a lot or have trouble rising · Babies who do not run and play · A preoccupied look in the eyes, wrinkled eyebrows · Club foot from joint soreness which causes uneven loading.
A formula option for existing epiphiysitis and OCD victims may be: Back off on protein, no alfalfa for a time, grass hay only. Plain rolled grain, no molasses, or ideally the Pelleted Grain Ration (PGR), only a pound or so a day. Ester C 3 tsp. per day, MSM 4 tsp. per day. 1to 1 and 2 to 1 Free Choice, 1 ounce regular Dynamite or TNT at the recommended level, DynaPro 3 cc per day. Results have been phenomenal, even on a filly diagnosed with a 9+ OCD lesion! As the problems resolve, gradually increase the grain to desired body weight. If the foal is still nursing, reduce the grain ration of the mare a bit, but make sure she still has her supplements. One note here, prevention is so much easier than treatment once a problem has occurred.
Environmental Horses were born to move, and motion is essential to proper development. Don't stall babies,other than to let them eat or during extreme weather, let them run outside to keep circulation to the physes consistent. Don't longe babies, work them loose in a big arena instead. Keep their feet trimmed often and keep the toes fairly short - make any corrections gradually. Chronic coughs or colds need to be addressed with Ester C, SOD or Hiscorbadyne . These conditions can cause body soreness and holding patterns that translate into upright pastems by tightening the muscles in the shoulders or hips. (Note - tendons can't and don't shorten, it is the muscles that they attach to which shorten! Selenium or magnesium deficiency can also cause muscle tightening especially in some of the heavily muscled breeds who require extra magnesium to keep those muscles more relaxed. Easy Boy at a low level can assist here. Selenium level should be fine if you are feeding regular formula Dynamite or TNT; if feeding Dynamite Plus in a selenium-deficient area, you may wish to do a blood selenium assay and use a little Dynamite E-Selenium if low.) Vaccines can cause body soreness and holding patterns - consider using single vaccines instead of multivalents, spacing them out, or using nosodes instead. Remember not to vaccinate and deworm, or wean, or castrate at the same time, or any combination of the foregoing.... space out the stresses by at least two weeks.
Keep growth rates constant. If you see a growth "spurt" starting, cut back on the calories a bit. Don't overworm, a toxic liver contributes to thyroid hormone deficiency since the T4 hormone is converted to T3, the more active form, in the liver. Remember that the thyroid and parathyroid glands regulate the loss/absorpfion of calcium in the body, so avoid thyroid inhibitors like alfalfa, molasses, flax or linseed meal. Don't feed oils to mares or babies, because they inhibit absorption of vitamins A and D, which are essential for calcium metabolism. Be aware of any genetic predisposition to DOD. I believe this is actually a phenomenon called "biochemical individuality," where the mare perhaps requires more copper than other mares, or the stallion tends to throw babies that grow big early and thus need more careful tending. (A fascinating fact regarding copper: Albion labs has proven that dark coated horses may require up to 8 times as much copper as a lighter coated horse). If you buy a stunted or deprived foal, don't just start socking the feed to it, go slowly. A rapid increase in nutrition triggers the growth spurts that can lead to problems. The same rule applies when fitting babies for show or sales, increase nutrition gradually.
As a breeder since the 1960s and a devoted Dynamite user for 18 years, I am on my fourth generation of Dynamite horses and they are awesome - if I do say so myself! Genetic potential is achievable, and minerals along with a safe and sane diet are the key. (For additional information, see Feeding Young Horses and Orphaned Foals)