Ask the Vet: General Equine Health

Question: Does a horse ever get over a stifle? Answer: Stifle injuries in the horse range from minor to very severe. If your horse is locking its patella, the prognosis is very good with proper treatment.

 Answered by: Manuel Himenes, DVM, Kailua, HI 

If If your horse has ruptured ligaments or a torn meniscus, the prognosis is more guarded and will likely require surgery. OCD cysts of the stifle can be successfully treated if there is no arthritis present. Arthritis of the stifle has a poor prognosis for athletic soundness.

Your veterinarian will be able to determine the type of injury and prognosis.


Question: Does improper hoof trimming (long toes, short heels) contribute to white line disease? 

Answer: Unbalanced hooves result in uneven forces along the ground surface of the foot. This unevenness create a shearing force along the laminae of the hoof creating separation of the white line. This separation allows a secondary infection (white line disease) to occur.


Question: I have a 10-year-old Connemara mare with Cushing’s disease. Can you please tell me about the use of Pergolide when she is in foal? She is due to foal in May.

Answer: Pergolide is considered safe in pregnant mares. Uncontrolled Cushing’s disease is far more dangerous to her pregnancy than any pergolide side affect.


Question: I have concerns for over vaccinating my horse. Does checking titers tell a complete story? Is Mercury used in all vaccines? 

Answer: The question of vaccine titers is a controversial one. There is conflicting data on the protective titer level. Vaccine titers are available for the following diseases: Equine herpes III (rhino), Potomac horse fever, Equine encephalitis (EEE, WEE, VEE), Equine viral arteritis, Equine influenza, Rabies titer (RFFIT: non export), West Nile virus antibody titer, Strangles and Lyme disease. Titers for influenza and equine herpes virus drop off very rapidly and will often result in revaccination. It is often best to determine the disease risk for your horse then vaccinate accordingly. For example, if your are in a rabies free area, rabies vaccine may not be necessary.

Many vaccines do contain mercury as a preservative. The modified live vaccines usually do not. Most tetanus vaccines do have mercury. You can find out if a vaccine has mercury by looking at the company web sight for the technical information they must list contents there by law.


Question: My horse cannot see at night and has trouble with depth perception in the day. What might be her problem?

Answer: Vision in the horse is hard to access. I would first begin by having a veterinarian examine your horse’s eyes and verify the the pupils can dilate. Sometimes if a horse has had an eye injury, the iris will stick to the cornea or lens and not allow the muscles of the iris to dilate the pupil. The pupil must dilate in low light conditions in order to allow more light into the eye. If one eye lost the ability to dilate this may cause the loss of telescopic vision required for depth perception. Also, be sure that your horse does not have any other diseases of the eye like uveitis, which can cause a loss of vision in one eye.

Careful examination of your horse’s eyes can also rule out the eyes as a problem. Your horse may have other neurological or musculoskeletal problems that are not related to the eye itself. Good luck with your horse and I hope that the problem can be defined with a positive outcome.