Equine Wellness - Jan 2016

TALKING WITH

DR. HANNAH MUELLER

Dr. Hannah Mueller is a 2004 graduate of Oregon State University, College of Veterinary Medicine. She strives to provide the best care possible for her patients and believes her unique holistic approach allows her to do so. Dr. Hannah has a solid foundation in sports medicine and lameness. This, along with her training in acupuncture, chiropractic, stretch exercises, massage techniques and other hands on healing modalities, allows her to rehabilitate horses to their fullest potential. CedarbrookVet.com

Question:

My mare keeps getting blisters and sores on her nose, presumably from a plant in her pasture (she's not prone to sunburn). We've walked the pasture and mowed it to try to eliminate any serious plant issues, but it keeps happening - her pasture-mates don't seem to have a problem (or they are staying away from the plant). How would you treat the sores?

Answer:

Before a treatment plan can be made, it's important to find the underlying cause. Start with a veterinary exam. If the blisters are found on white (pink skin) areas, it could be sunburn even if she is not usually prone to it. Horses can suddenly develop photosensitization (increased risk of sunburn) from certain plants (St. John's wort, Alsike clover, etc.), or from liver disease. Bloodwork may be needed to get a diagnosis. Make sure there are no chemicals being sprayed on the pasture that could cause a skin reaction.

The cause will determine the treatment, aside from treating the likely secondary infection. To treat the latter, use a topical product that has antibacterial and antifungal properties. Vetericyn is a good option, but you can also try a natural product such as Schreiner's Herbal Solution or Zephyr's Garden Anti-Fungal Salve. If the sores are crusted over, then the salve is a better choice as it will help soften the crusts so they can be gently removed. If the treatments do not touch the underlying skin, they will not be effective.

Question:

I am having a hard time keeping weight on my Cushing's horse. He is on Pergolide, and on pasture all day with a grazing muzzle. He also gets free choice grass hay, and a few cups of oats twice a day. I'm afraid to change his feed too much - I've been warned I'll cause him to founder. Is there anything else I could safely be feeding him?

Answer:

The warnings you have received are likely because horses with Cushing's disease often become insulin resistant and are sensitive to non-structural carbohydrates (NSCs). The overall NSC level of the feed for these horses should be less than 10%; which is why we first maximize the fiber and fat in the diet, then add carbs/grains only if absolutely needed.

It sounds like your horse's hay is free-choice at night, but limited during the day, if he is out to pasture with a grazing muzzle on. Grazing muzzles are great for overweight horses as they keep the animals from consuming too much while still allowing them to continually eat small amounts. With a NSC-sensitive horse, grazing muzzles are helpful only if he is at a good weight and can tolerate a little bit of pasture. Some of these horses have to have the hole plugged in their muzzles so they can have turnout but not eat any green grass at all. If the horse is thin, the grazing muzzle is limiting overall feed intake by too much, causing problems gaining weight.

The trick is to increase the overall feed intake, but not increase NSCs - so don't turn your horse out without a grazing muzzle. Unfortunately, you'll have to minimize or eliminate pasture turnout so you can maximize the time he spends eating low-NSC feeds (hopefully you have a large paddock, dry lot, or arena for alternate turnout). Make sure your hay has been tested and is low carb (if you are unsure, soak it for 30 minutes and rinse/strain it to lower the carb level) and feed it truly free choice so it is always available. Make sure another horse isn't out-competing him for the food - if he is with a buddy, the feed will have to be free choice for both of them or the buddy will need to wear the grazing muzzle.

Eliminate the oats and instead add in a low-NSC feed such as LMF Low Carb Stage 1, or Haystack Special Blend Pellets. You can also feed beet pulp and grass hay pellets free choice; just make sure all pelleted feeds are soaked into a mash so they are completely soft before feeding, or there is risk of choke. An additional fat source such as one cup of veggie oil twice a day can help. Make all food changes slowly over one to two weeks to help avoid colic. Probiotics can be fed to help with a food change and to assist GI tract function in general. Be sure your horse is current on dental care and routine blood work from your veterinarian so that any underlying problem has been ruled out.

Question:

When are nosebleeds in horses a cause for concern?

Answer:

Most nosebleeds in horses are not problematic and resolve on their own after 20 to 30 minutes. They are usually due to minor wounds/trauma in the nasal passage, or can arise from irritation caused by dry conditions, dust or allergens. If the nosebleed is in one nostril, and is a slow trickle that resolves quickly and doesn't recur, it is probably from one of these causes and not a cause for concern, but look for signs of head trauma in case there is more than just a nosebleed going on.

Bleeding from both nostrils after exercise may be EIPH (exercise induced pulmonary hemorrhage), a condition caused by overexertion that's often seen in racehorses. This condition has treatment options but can be serious. Ethmoid hematomas and guttural pouch mycosis (a fungal infection) cause steady nosebleeds that recur or do not resolve quickly, and are cause for concern. When in doubt, an endoscopic examination should be done during a bleed to follow the blood to the source and make a diagnosis. Surgical intervention may be necessary to prevent a fatal bleed in these rare cases.

Question:

In horses with advanced ringbone, can some of the lameness result simply from reduced joint movement, rather than a pain response? I have an older mare whose quality of life we are trying to assess going into winter. She is on Previcox or Bute for pain management, depending on her symptoms. However, even on anti-inflammatories she is still quite lame. Otherwise she seems healthy - good weight, good appetite, wanders with her friends outside. We are struggling to determine how much pain/inflammation is causing the lameness versus reduced mobility of the joint.

Answer:

A horse with his pastern surgically fused because of high ringbone does not show lameness, so the reduced joint movement is not significant enough to notably change the gait. Low ringbone, on the other hand, is in the coffin joint, which is difficult to get to for fusion; and being a higher motion joint than the pastern, it's not commonly fused. With low ringbone, I think there could be some minor gait abnormality due to the decreased range of motion.

To answer your question, the bulk of your horse's lameness arises from pain, not restricted range of motion in the pastern or coffin joint. If you are questioning her quality of life, it sounds like it is time to try other treatment options in addition to the oral NSAIDs. Talk with your veterinarian about options such as fusing the joint (high ringbone), joint injections (unless the arthritis is so advanced a needle can't fit into the joint space), shockwave therapy, Adequan and Cosequin ASU (joint supplements), acupuncture, Back on Track wraps, Theraplate, and x-ray guided corrective trimming/shoeing. Have your veterinarian give you a lameness grade (1 to 5 scale) and use that along with her attitude as your guide. If she is depressed, losing weight, or lying down excessively, it may be time to let her go. If her lameness grade is 1 to 2 out of 5, she should be doing okay overall. If she is at a 3, then she's probably doing all right if she's healthy and happy overall. If she is at a 4 or 5, then things are serious and her quality of life may be significantly compromised. Things can change day to day and can be weather-dependent, so keeping a daily pain score chart may be helpful in developing an overall picture to discuss with your veterinarian. Good luck with your decision and I hope for the best!