Q. When is a horse most apt to colic?

The majority of the colics I attend to occur during changes in seasons.

The horse's metabolic rate increases during winter (to maintain body temperature), and water intake must increase as well. Consequently, mild dehydration leading to impaction colic is also a common problem.

Q. What supplements are recommended for a horse that's had EPM?

EPM (Equine Protozoal Myeloencephalitis) is a challenging disease. If horses recover from it, they can still be left with temporary or permanent deficits. Sometimes these deficits are mild (like a hind toe that drags) and don’t interfere much with riding. However, sometimes they’re more serious (like stumbling or incoordination) and result in a horse being retired from performance.

My first advice to you is work closely with your veterinarian to make sure the infectious organism (usually Sarcocystis neurona) has been completely eliminated. Use non-steroidal anti-inflammatory drugs (NSAIDs) such as phenylbutazone as directed to reduce any inflammation that treatment may have caused. Develop a physical therapy program that helps your horse regain his strength and coordination. This may include hill work, cavaletti, walking across different surfaces, massage and other rehabilitation techniques.

Supplements also play an important role in supporting a full recovery from a neuromuscular condition like EPM. As an antioxidant, Vitamin E protects tissues locally from damage by free radicals and supports a healthy immune system. Vitamin E works close with its partners Selenium and Vitamin C to safeguard the body from the oxidative stress of exercise, illness and certain medical conditions. However, only supplement with Selenium if this mineral is deficient in your particular area.

Ingredients known to fight inflammation naturally are also good choices for supplementing a horse being treated or recovering from EPM. Included in this category are Omega 3 Fatty Acids, MSM and herbs such as Boswellia, Yucca and Devil’s Claw. Depending on how much muscle atrophy your horse experienced, you may also want to consider supplements designed to build healthy muscle. Look especially for products with the essential amino acids lysine, threonine and methionine, the building blocks of protein.

Q. What supplement can be used as a bronchodilator for performance horses?

Unfortunately, there are no over-the-counter respiratory supplements with bronchodilator activity. The prescription medications Ventipulmin or Aeropulmin (clenbuterol) are the only FDA-approved solutions to relieve bronchospasm in the horse.

That’s not to say there aren’t some very good products to support healthy lung function in horses. One of the best ingredients for respiratory tissue is MSM, with proven antioxidant and anti-inflammatory activity. Vitamin C and N-acetyl cysteine also target the tissues that line the respiratory tract and provide excellent antioxidant support. Other potent antioxidants include Grape Seed Extract, Super Oxide Dismutase and Bioflavonoids, which are active substances in plants that protect cells from oxidative stress.

There are also some herbs that provide either soothing relief to airways or expectorant-like activity. Look for supplements containing plants such as licorice, garlic, elecampane and marshmallow. Note: some competitive riding associations forbid specific ingredients. If you are showing, please check with your association for rules and regulations.

Q. What would cause a horse to lose his "show coat"?

A horse's hair coat can be affected by a number of variables, including nutrition, parasites, illness and stress.  If a horse's hair coat suddenly changes, a physical examination, blood work and treating for parasites is a good approach, but your horse may have suddenly lost his coat simply due to stress. Although hair grows in cycles that are related to daylight and temperature, the quality and quantity of a coat is also affected by nutritional plane, certain health conditions and even stressful episodes.  Consult your veterinarian to rule out medical issues and assess proper nutrition for your horse, but realize he may just be reacting to changes in his environment.

Q. What research and/or advances are being made in treating/preventing moon blindness?

ERU, or Equine Recurrent Uveitis, is the most common cause of blindness in horses and one of the most frustrating eye conditions to treat. ERU is believed to be an auto-immune disease, which means the horse's own immune system inappropriately attacks the delicate tissues inside the eye (instead of attacking foreign invaders, like bacteria and viruses). The great mystery of ERU is how and why the immune system gets confused and starts to attack the inside of the eye. Some researchers believe that infection with Leptospirosis starts the process, while others believe that any type of infection within the body or trauma to the eye can initiate ERU. Regardless of the inciting cause, however, the end result is the same: self-perpetuation inflammation inside the eye that can lead to devastating intraocular disease and permanent vision loss.

The mainstay of controlling ERU outbreaks has always been topical and systemic anti-inflammatory drugs (i.e. Banamine), but new technology has become available in the past few years. Cyclosporine A (CSA) is a very effective drug and modulating the activity of the immune system, and North Carolina State University has developed a dissolvable plastic disc impregnated with CSA that can be surgically implanted underneath the sclera (the white of the eye). The disc slowly dissolves over two to three years, allowing the CSA to reach the inside of the eye and tell the immune system to stop attacking the inside of the eye. The long term success rates with decreasing the duration, severity and frequency of ERU episodes (and thus their blinding side effects) are excellent. A veterinary ophthalmologist can tell you if your horse is a candidate for this type of implant.

Other CSA-type drugs are also under investigation, but its too soon to tell if they will be as successful as the CSA implants in controlling ERU long term. ERU is a frustrating disease, and more research is needed about the cause so that we can design more effective treatments!

Q. What would cause a horse to colic intermittently or repeatedly?

Causes for a horse to repeatedly colic could be stress-induced, or it could be something even more problematic, such as sand in the intestines or even an enterolith (a mineralized foreign body that grows and enlarges within the digestive tract) or something else entirely. Knowing the horse’s age, breed, training program, geographic location, and diet would be helpful, as would knowing when does it show symptoms: right after it eats, right after or during exercise, only at shows, etc.

Contact your veterinarian every time your horse colics, as soon as it colics…before you give it any medication such as Banamine. Banamine is a useful medication; however, it only masks the signs of pain and reduces inflammation, it doesn’t treat the underlying cause of the colic and it can sometimes make it difficult for a vet during the diagnostic process. Until then, if your horse has had bouts of intermittent colic in the past, keep a detailed journal of this its training protocol including intensity, types, and times; as well as dietary information, including types, amounts, and times of feeding, when it is fed in relation to its exercise/training, etc. and then start comparing that to when it actually colics. This will be useful information that you can provide your veterinarian and will help them in the diagnostic process.

Q. What nutrition and supplements are recommended for a severely underweight horse?

It takes about two weeks before horses show weight changes up or down, and in the case of a starved horse, it can take longer since they have some repairing to do on the inside before muscle and fat can begin to be added on the outside.

Have your veterinarian examine your horse's his mouth for dental issues, his stool for parasite issues and his blood for organ issues. I would make your horse had an extensive physical examination to rule out any medical issues that may be impeding his weight gain.

Next, what breed is he? Some, like thoroughbreds, have a higher metabolism and are on the “hot” side. They may take longer to recover because they’re burning calories rapidly just thinking about things. Others, like quarter horses, morgans and ponies, have a slower metabolism and should have an easier time gaining and keeping weight. On a related topic, how are you housing this horse? Some horses do better alone but within sight of other horses while others prefer to mingle in a herd as soon as they’re strong enough to compete for food. Make sure he’s not losing precious calories stressing about his living situation or his next meal.

You may want to add some alfalfa to his diet—either as long-stem hay, hay cubes or even pellets—to whet his appetite and provide more nutrition. When it comes to forages, try soaked beet pulp for supplying calories and adding weight (it’s also a great mixer for supplements!), and you may want to add in some oats or a fortified grain product to see if that helps.

If you feel like he’s getting as much good quality hay as he can eat and you’re correctly balancing his forage-based diet with fortified grain or a ration balancer, then it may be time to add in supplements. I like to start one at a time so I know what helps and what doesn’t. Options include fat (there’s a separate Cool Calories product), protein (essential amino acids have been shown to improve the muscling of older horses), digestive support (probiotics, prebiotics and enzymes may help him digest and absorb his feed better) and even daily dewormers, which are advertised to provide a 40 percent improvement in feed conversion.

Q. What treatments are available for a horse with corneal ulcers?

First, a complete ophthalmic examination should be performed. This complete exam should include an evaluation of the horse in the darkest place possible (in most barns, this is in a stall with all windows/doors closed). A veterinarian is better able to visualize subtle eye problems when they use a bright, focal light source in a dark place. This is something to keep in mind when designing a new barn! As part of a complete exam, the entire eye, including the retina (the light-sensing structure at the back of your eye) should be examined. The pupils may or may not need to be dilated using dilating eye drops, depending on the horse's suspected eye condition. Fluorescein application to the surface of the eye as part of the eye exam is the best way to diagnose a corneal ulcer, or scratch on the surface of the eye. An ulcerated cornea will have fluorescein stain adhere to the ulcerate area and cause a distinct yellow/green glow.

The treatment for corneal ulcers varies by the appearance of the ulcer. Most simple, superficial ulcers will be treated with a broad-spectrum topical antibiotic ointment. The purpose of the antibiotic is to prevent infection of the cornea. Bacteria and fungus love the wet, warm, tasty collagen than makes up 90 percent of the horse cornea! Other treatments for a simple, superficial ulcer may include atropine ointment, which dilates the pupil and relieves pain, and an oral pain medication like phenylbutazone (Bute) or flunixin meglumine (Banamine), or even a topical antifungal medication (if you live in an area of the country where fungal corneal infections are common). Most simple ulcers need treatment for approximately a week.

Unfortunately, even simple ulcers, which properly treated can get infected, or the initial injury may be more severe. Any time an ulcer shows sign of infection or is deep into the cornea, more aggressive treatment is warranted. Your veterinarian may consider referral to a veterinary ophthalmologist at this point. Sometimes a subpalpebral lavage tube may be placed to make it easier for you or the hospital staff to treat the horse. A subpalpebral lavage tube is a very small, flexible plastic tube that is inserted under the eyelid, then draped over the forehead and down the neck. It allows injection of the medication near the shoulder which then travels up the tube and into the eye. This allows for more potent medication to be delivered to the eye more frequently without handling the eye itself.

As you can tell, trying to decide if an ulcer is simple or complicated is definitely something that a veterinarian needs to assess. Any possible eye injury should be considered an emergency and be examined by a veterinarian as soon as possible.

Q. What is the relationship between genetics and Anterior Segment Dysgenesis (ASD)?

p>Multiple Congenital Ocular Anomalies (MCOA) is the new name for Anterior Segment Dysgenesis (ASD). The disease was renamed because ASD involves a specific pattern of cornea and lens abnormalities (seen most often in humans and rarely in dogs) not identified in horses with MCOA. MCOA is seen most commonly in Rocky Mountain horses but can also be seen in other breeds. The most common ocular signs are cysts of the iris and ciliary body (the ocular structure right behind the eye that produces the aqueous humor within the eye), small pupil size, resistance of the pupil to dilation, prominent eye position/shape and retinal abnormalities (including retinal detachment). Horses are generally considered to fit into one of three categories: unaffected, horses with only cysts and horses with cysts and other abnormalities. A recent scientific publication journal (BMC Genetics) has demonstrated that the gene responsible for the development of cysts alone or the development of MCOA is on equine chromosome 6q and is linked to the markers UPP5, PMEL117ex11 and UPP6. This chromosome region is the same one where the gene for the silver coat color (PMEL117) resides.

While finding genes can be really difficult, finding a marker that is linked to the gene is often easier and makes developing a test to identify the disease is carrier horses much simpler. Interestingly, mutations in the PMEL117 gene results in the silver coat color that is so frequently (but not always) associated with cysts and MCOA, however the researchers do not believe that the gene that causes the coat color silver is the same gene that causes MCOA. Not all horses with MCOA are silver in color (and thus homozygous for the silver gene). Hopefully, we will see more information about the genetics of this disease published soon, followed by a genetic test that will allow breeders to make more informed breeding decisions.