Written by: Horse-Canada.com

Get advice on a selection of common equine ailments from colic to thrush.

Thumbnail for Tackling Common Equine Ailments

Pam MacKenzie Photo

What is the best way to prevent colic?

Colic is scary word. It is the leading cause of death in horses, but it is not a disease. Rather, the term refers to abdominal pain resulting from a number of problems in the gastrointestinal tract. Some cases of colic resolve on their own, while others require medical or surgical intervention.

The following are common types of colic:

Impaction colic: occurs when a mass of ingesta (feed, a foreign object or even sand) causes an obstruction in the digestive tract. These cases are often resolved medically, but sometimes require surgery.

Displacement/torsion colic: is when a section of the intestines moves out of place, or gets twisted around itself, cutting off blood supply and killing parts of the organ. Immediate surgery is most often required.

Gas colic: is brought on by a build-up of excess gas. This can happen when a horse gets into the feed room and eats an overload of grain, for example. It can lead to displacement or twisting of the distended bowel, and sometimes gastric rupture, which is often fatal.

Spasmodic colic: is similar to indigestion in humans, whereby contractions or spasms of the intestines prevent anything from moving through the digestive tract. It is often triggered by stress or dehydration, but can also be caused by internal parasites.

Colic can be prevented by using careful and consistent management practices. Providing continual access to clean, fresh water and free-choice hay, allowing your horse free movement, and sticking to an appropriate deworming schedule can help keep his digestive tract running smoothly.

Equine Guelph offers a free online tool called the Colic Risk Rater, which can help you learn more about colic risk factors and ways to reduce the risk to your horse. Check it out at equineguelph.ca/Tools/colic.php.

What is the purpose of a fecal egg count test?

In a quest to adapt for survival, internal parasites are becoming resistant to deworming medications. Because of this, deworming protocols are evolving. A seasonal approach, using tried and true products on every horse in your herd may no longer be the best way to protect them.

Today, veterinarians are suggesting horse owners take an individualized approach to deworming, and that starts with fecal egg count testing, done on manure collected from each horse. The test will show which parasites are present in each individual. This will determine which horses need to be dewormed, for which parasites. Only “high shedders” – those with a significant number of parasites should be treated.

Ask your veterinarian to help you devise a deworming strategy that best suits your horses’ needs.

Equine Guelph’s Dr. Susan Raymond demonstrates how to collect manure for testing at: tinyurl.com/Fecal-Collection-Demo.

What should I do if my horse gets a puncture wound in his hoof?

If you come across a nail or similar object sticking out of your horse’s hoof, leave it as is, apply a protective bandage or put on a clean hoof boot and call your vet right away. The only way to know how far the object has penetrated the hoof, and which internal structures may be affected, is to take an x-ray; this goes for punctures to the sole, frog or bars.

The only exception to this rule is if the object sticks out past the bottom of the hoof, which would mean every time the horse takes a step, it is driven deeper into the hoof. If this is the case, your vet would likely recommend that you use a pair of pliers to smoothly pull it out as close to the entry point, and on the same angle as it punctured the hoof. Then, wrap the hoof to protect it from contamination, because whether the object is still in place, has fallen out, or has been pulled out, the hoof is vulnerable to invading bacteria, such as E. coli and clostridium tetani, once it has been punctured. Infection can set in within a couple of days.

After looking at the x-rays, your vet will decide if further tests are needed to determine the extent of the damage to internal structures. Depending on the severity, your horse may need to take a trip to an equine clinic for surgery, followed by intensive antibiotic therapy. More minor cases may involve your vet debriding (removing some of the hoof) to open up the puncture tract to allow drainage, followed by stall rest, poulticing the foot, a tetanus booster and a course of antibiotics.

How do I get rid of mud fever?

Commonly known as mud fever, or scratches, pastern dermatitis causes painful scabbing lesions on the back of a horse’s pasterns and fetlocks. It occurs due to a combination of predisposing factors, but the main culprit is a fungus-like bacteria called Dermatophilosis congolensis.

When the skin on a horse’s legs is damaged in some way – chapped or cracked from being housed in moist conditions, scratched from travelling through rough terrain or covered in insect bites – it is vulnerable to bacterial invasion.

The resulting infection causes inflammation and crusty sores that can be difficult to keep in check. Horses with white areas on their legs seem to get it the worst; it’s believed this may be related to photosensitization (a heightened reaction to sunlight).

The skin surrounding the scabs is often swollen and red, as well as warm, itchy and sensitive to the touch. Some horses even come up lame on the affected limbs.

If you notice this condition developing on your horse, get out some antibacterial soap or iodine scrub and a rough sponge, and find someone to hold your horse while you set to work removing the scabs and scrubbing the area clean. The goal is to get at the causal organisms under the scabs.

When the scabs are pulled from the skin, pus will be found underneath and tufts of hair will come away with them. You may also notice a clear fluid known as serum, which oozes from wounds and causes the hair to become matted. You might want to use an ichthammol ointment or zinc oxide cream to soften the scabs first, making them easier to remove. When you’re finished washing up, use clean towels to thoroughly dry the legs.

It’s also a good idea to let your vet know what you’re dealing with so that he or she can help you identify and manage any contributing factors, rule out other possible infections or conditions, and direct you in a treatment plan specific to your horse. If not treated correctly, it can become serious, persisting for months.

Plus, for some horses the condition is so painful, they need to be sedated before they can tolerate letting you touch, pick at or scrub the area. Painkillers, antibiotics, corticosteroids or other topical ointments may be prescribed. If your vet has given you an ointment, use clean wraps on his legs to make sure the medication has a chance to work, and to prevent exposure to the elements.

It takes time and vigilance to rid your horse of mud fever. It is advisable to keep the affected area clipped to prevent hair from matting in the festering sores. Use caution when doing so, and be sure to disinfect the clipper blades when you’re done.

To prevent mud fever, keep your horse’s legs clean and dry. Reduce moisture in his environment, eliminating mud and standing water, and avoid excessive bathing, which can predispose him to the condition.

My horse is scratching his mane bald. Can horses get lice?

Yes, horses can become infested with these external parasites, which come in two forms – sucking and chewing (or biting) lice. They can show up on any horse, since they are easily transmitted through horse-to-horse contact, or by sharing grooming equipment or blankets. However, they most often affect horses that are stressed, malnourished or suffering from some other illness.

Sucking lice are up to four or five millimetres long and have a pointy nose, which they use to pierce the skin and suck blood. Chewing lice are smaller, with a wide head. They feast on skin debris and dandruff on the surface of the skin.

Since they are so small, it can be hard to see lice. Their eggs are tiny white spheres that stick to the hair. They tend to hang out near the head, mane, tail and back. Horses with lice scratch these areas a lot, and, depending on the degree of infestation, may even rub themselves raw.

Some vets may suggest a dose of oral ivermectin to get rid of sucking lice, but this is an “off label” recommendation, and won’t do anything about chewing lice. Treatment typically involves application of a topical pyrethroid insecticide, administered through sprays or dusts, which should be repeated two weeks later to get any eggs that were left behind.

How can I tell if my horse has thrush?

You can tell your horse has thrush if you discover a black, tarry substance when picking out his hooves, which smells far worse than any compacted dirt or manure ever could – usually a strong, cheesy odour.

It is primarily caused by the anaerobic bacterium Fusobacterium necrophorum, which eats away at the tissue of the frog. Other anaerobic bacteria, which thrive in damp, dark conditions and can be killed by exposure to oxygen, have been implicated in cases of thrush, along with the fungus Candida albicans. It can be painful and, depending on how far the infection has progressed, can lead to lameness.

If you notice your horse’s frog is decaying and his feet smell terrible, start treatment right away. Take him to a clean, dry spot, and thoroughly pick out his hooves. Then, scrub them with antiseptic soap, formulated to kill a variety of bacteria and fungi – Betadine® is a good go-to. Carefully remove any loose frog tissue with a hoof knife to allow air and cleansers access to the affected areas.

There are many products on the market designed to take on thrush, as well as several home remedies. With active ingredients including copper napthenate, iodine and gentian violet, commercial products come in many forms, such as liquids, pastes, creams, aerosols and hoof packings. You may feel more comfortable choosing one after speaking with your farrier or vet.

It can take several weeks to eradicate thrush, with daily monitoring and consistent treatment. Be sure to start with a clean hoof every time and apply the product directly to the affected area. Some farriers recommend using a syringe to help hit your target neatly and efficiently. For hard to reach spots, try soaking a small piece of gauze or cotton in your preparation and using a hoof pick to push it into the crevices.

Picking your horse’s hooves out daily, to remove debris and expose the tissue to air, can help keep thrush away. Regular trims, good nutrition and exercise to promote healthy hoof growth are also recommended. Eliminate breeding grounds for bacteria by removing manure and mud from paddocks.

Can horses get cataracts?

When you hear the word cataracts, you likely think of it as a geriatric human complaint. In fact, cataracts can affect horses (and humans) of all ages, robbing the sufferer of vision.

Cataracts are cloudy areas in the lens inside the eye – which is normally clear – causing blurry or obscured vision that may result in spooking or impaired performance.

Horses can be born with them or develop them over time. There can also be a hereditary component, with some breeds being more prone than others. However, acquired cataracts, which can form as the result of injury to the eye or other imbalances in the body, are far more common.

If your horse has begun to spook or shy uncharacteristically, resist performing certain tasks, squint in bright light, or has developed a white spot on his eye, get your vet in to do an eye exam.

There is no medical solution for cataracts; the only option is surgery. Your vet will help you determine whether this is right for your horse, taking a number of factors into consideration including your horse’s overall health and temperament, possible complications, follow up care and, of course, costs.

Veterinary literature reports that surgical outcomes are initially good, but vision still reduces over time. This may improve as techniques evolve.