Ask the Vet: General Equine Health

Answered by, Shanna Nelson, DVM, Fox Creek Veterinary Hospital, Wildwood, Missouri

Question: Could you explain how Omega-3 can help with hives? My soon to be 23-year-old mare has them from time to time beginning in the spring until late fall. She is not itchy, but rather can get very big different shapes all over her body. They tell me this might help if I start her on it now.

 Answer: I’m glad your horse isn’t itchy, as severe hives can certainly make a horse extremely miserable, especially in hot weather. Omega-3 fatty acids are sometimes recommended for the control of skin disease and other inflammatory conditions because they have anti-inflammatory properties. Briefly, Omega-3 and Omega-6 fatty acids are two types of “essential” fat, meaning they must be consumed in the diet to maintain health (and both are found in a horse’s usual food, in varying quantities). While Omega-3’s are often thought of as the “good guys” (anti-inflammatory) and Omega-6’s are considered the “bad guys” (pro-inflammatory), the truth is that both are required to support essential functions. The goal in supplementation is to increase the ratio of Omega-3 to Omega-6 in the diet, to tip the balance toward the anti-inflammatory side; however, we do not fully understand the ideal ratio. Several studies have shown potential benefit in horses receiving Omega-3 fatty acid supplementation in the management of equine asthma, osteoarthritis, and skin hypersensitivity. Often the supplements are used as adjuncts to other treatments and management changes, rather than as the sole therapy.

There are multiple commercial supplements that boast a healthy serving of Omega-3 fatty acids. Flaxseed and fish oil are other sources, but beware the added calories in fat supplements, particularly in horses that are already overweight.

Other treatments for hives, depending on the severity, include steroids, antihistamines, and desensitization (“allergy shots,” selected after appropriate testing based on either response to intradermal injection of allergens or assessment of the serum). Preventative measures include fly control, fly sheets, and avoiding potential contact triggers, such as irritating pasture plants or various topical sprays. Some horses, like some people, are just more sensitive than others.

Question: Are ponies more susceptible to founder than horses? I ask because I give my horses a grain supplement in the winter, along with hay, and I wonder if should provide this supplement for the pony.

Answer: The short answer to your question is yes: ponies are more susceptible to founder than horses. The long answer is a lot more complicated!

Most horses, if they are currently in adequate or overweight body condition, and if they are not in hard athletic work, will do well on a ration balancer and access to forage (hay/grass). I like ration balancers because they pack all of the essential vitamins and minerals into a compact volume, without adding a lot of calories. It is important to feed them according to the directions on the bag, rather than overfeeding. Many horses truly do not need grain, although performance horses and seniors are more likely to need the extra calories and energy. In the winter, additional hay can provide needed calories and “warmth.”

Laminitis (inflammation of the internal structures of the hoof) can lead to founder (sinking or rotation of the coffin bone), which can be debilitating and life-threatening. Laminitis can develop from myriad causes, including infection, toxins, overwork, and grain overload. Perhaps the most common cause is endocrine in origin, however.

We still do not understand the exact pathway that leads to laminitis and founder, but it involves elevations in insulin levels, triggered at least in part by sugary diet high in non-structural carbohydrates, which includes both lush pasture grass and many commercial grains, particularly sweet feed. Two conditions in equines predispose to excessive insulin secretion: Equine Metabolic Syndrome (EMS) and Pituitary Pars Intermedia Dysfunction (PPID or “Cushing’s Disease”). Ponies are affected by EMS and PPID at higher rates than full-sized horses, and they are also more likely to be obese in general, which contributes to the problem.

I recommend that all owners of ponies keep their animals at a reasonable weight, although it can be hard to keep a pony fit and trim! Minimizing pasture access (by using a grazing muzzle or spending time in a dry lot) can help, and exercise is ideal (and can actually help reverse insulin resistance). As stated earlier, most ponies probably don’t need a lot of grain in their diet, unless they have a specific health condition that calls for it. Stay on top of your pony’s farrier care, and ask your veterinarian whether testing for EMS or PPID is recommended.