Meddleton Equine Hospital

Give the appropriate dose by weight of Marquis (Ponazuril) orally once daily. The label dosage is for 28 days. Treating for 2 consecutive 28 day periods has been associated with an increase the effectiveness of the treatment and reduction in the likelihood of relapse.

The addition of Sulfadiazine and Pyrimethamine (ReBalance) to the treatment has also been associated with an increase the effectiveness of the treatment and reduction in the likelihood of relapse. This can be given concurrently with the Marquis given after the Marquis is finished. Either way plan to give the ReBalance for 6 months.

The best way to determine the length of treatment is to re-evaluate the neurologic status of the horse following each stage of treatment.

• Vitamin E should be supplemented a rate of 9,000 IU per day. This acts as an antioxidant and helps in neurological repair.
• Day 7 and Day 21: Give an Immune Stimulant (Equimune IV).
• Day 24-26: Schedule a neurological examination.
• Day 28: Continue Marquis until Neurological signs have resolved or remained static for 2 weeks, or treat for an additional 28 days.
• Day 52-56: Schedule a neurological examination.

Because of the side effects of the medications, I recommend that you monitor your horse's blood count and liver and kidney function by running monthly blood tests (CBC, Chemistry), especially if you are treating for more than one month.

• Take temperature daily and report any rise over 1.5 ° F
• Check the digital pulse (over the sesamoid bones) on both front feet each morning. If increased, stop treatment and report immediately. Call if your horse appears to have sore feet (laminitis / founder).
• Loss of Appetite: Call if your horse goes of feed.

During the treatment, as the protozoa are killed, the neurologic signs sometimes get worse for a day or two, this is perfectly normal. Call if this occurs to have the horse treated for inflammation. However if horse is unable to keep its balance or unable to rise, report immediately.

• Report any colic or diarrhea.
• Report if any other medication is given during this period. Tetracyclines are best avoided
• Report if there is no change in the horse’s neurologic status for a ten day period.
• Report when the horse seems back to normal, with no neurologic signs.

Achieving high enough levels of the medication in the central nervous system (spinal cord) to kill the protozoa without causing toxicity to the horse is difficult. Many questions remain as to whether the medications are killing the protozoa or just suppressing it. Therefore it is advisable to do what you can to help stimulate your horse's immune system, and to minimize stress!

Therefore:

• Do not give corticosteroids! (Joint injections, hives, allergies, inflammation, etc.).
• Do not trailer, move, show, compete, or other stressful activities: REDUCE STRESS!

• Immune System Stimulants: Vitamin E, B vitamins, Equimune, EqStim, Levamsole, alpha-Interferon, Echinacea, Hilton Herbs, Garlic, Chiropractic, Acupuncture.
• Anti-Inflammatory/Antioxidants: Vitamin E, Vitamin C, Omega 3 fatty acids, Branched Chain Amino Acids, Flax Seed, Hilton Herbs.

Riding your horse with EPM, while showing any neurological deficits, poses a greater risk of injury to both you and your horse. Ride at your own risk!

After re-exam days, if the horse is rideable, that is: there is no history or suggestion of tripping or falling when ridden or on the longe and it seems to be adequately coordinated. If there is any question about safety, do not ride, but rather longe the horse for 10 to 20 minutes daily in a large (50 foot) circle. Ride on the flat in a good balance for up to 20 min daily. Avoid extreme collection, tight turns at anything but a walk, and no galloping. Generally the walk and canter (lope) is affected the most. Many of these horses do not use their hind legs normally and there is a significant chance of developing hind suspensory disease or other problems. Therefore the work must be controlled.