Ask the Vet

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General

What does it mean to float teeth?

Unlike dogs, cats and humans, a horses teeth keep growing throughout their life. Eating stemmy, fibrous food wears the teeth down, but uneven, sharp edges can develop that can cause sores on the cheeks and tongue.  Horses chew in a circular motion and their lower jaw is narrower than their upper jaw.  This leads to the upper teeth creating sores (ulcers) inside the cheek, and the lower teeth creating sores on the tongue.  As horses age the teeth run out of root length and gradually grow shorter.  This can lead to some teeth in the mouth being longer than others (wave mouth).  Add to this that horses may lose teeth, fracture teeth or be naturally born with conformational issues in their mouth, you can understand why a wide variety of problems may present that lead to difficulties chewing, dropping food or saliva, performance issues and weight loss.

Teeth floating, also known as mouth equilibration, means to remove the sharp edges, reduce the long teeth and balance the molar arcades to promote a normal and healthy chewing action.  During an oral exam your veterinarian can also look for evidence of cavities, gum disease and tooth abscesses.  On evaluation of the mouth the front teeth (incisors) should not be ignored as many problems can arise from these teeth.  Floating may be performed with hand equipment or motorized power equipment.  Please make sure you find an educated professional to take care of your horses teeth as the excessive use of power equipment can be dangerous to your horse.  At WECH we recommend that your horse should receive an oral exam 1-2x per year and should be "floated" when necessary to help your horse live a long and healthy life.

Should I vaccinate for tetanus?

Tetanus (lockjaw) is caused by a toxin-producing bacteria called Clostridium tetani that is ubiquitous in the soil. It gains entry to the body through wounds, especially puncture wounds. Horses are much more sensitive to the toxin than humans, which results in extreme muscle tension and spasms. It is a terrible, painful disease that is nearly impossible to treat and has a fatality rate close to 100%.

We vaccinate horses frequently for this disease because we cannot prove what titer (level of circulating antibodies to Clostridium tetani) will protect the horse should it become exposed. These levels are fairly well established in humans and less frequent booster shots have been proven to protect against the disease. Even then, you will usually get a tetanus shot if you go to the ER with a dirty cut.

The high frequency of contaminated puncture wound events in horses means that most are exposed several times during their lives. The tetanus toxoid vaccine is a very safe, reliable, and inexpensive vaccine compared to the terrible consequences of infection, so we tend to err on the side of caution, and recommend yearly vaccination or vaccination in the presence of a wound to prevent serious illness.

My horse developed swollen legs after eating second cut hay. Is the hay bad?

Occasionally a barn will have an epidemic of "fat legs" shortly after stocking a new hay. Nobody is sure exactly why this happens, but it is likely either the result of an unfamiliar plant in the new batch, or because the new hay is much richer and leafier than their usual ration. In this case, the change in diet probably causes a sudden shift in the bacterial populations in the gut, with slight leakage of inflammatory substances into the bloodstream. The good news is that this is not painful and usually resolves once they acclimatize to the new hay or are switched back to the old bales. It is a good idea to shift to the new hay the same way you would introduce a new grain - try mixing a flake of each type together for 7-10days prior to completely switching to allow their intestines to get used to the new hay rather than going "cold turkey".

What type of flooring is best in a stable?

Flooring is a very important consideration when building a stable. One must factor in cushioning, warmth, drainage, traction, and what type of bedding you plan to use. There are specialized stall mat systems that have built-in cushioning which is very comfortable for the horse, kind to the joints, and can cut down on bedding costs.

We are not huge fans of concrete as a flooring material for several reasons. Although it is inexpensive, durable, and easy to clean, it tends to be very cold in the winter and extremely slippery if not graded. We have found that no matter how much bedding we have put in the stall, there are some horses that still manage to work their way down to the floor, ending up with scrapes and sores from lying on the rough surface, as well as slipping when getting up. Over the long term, we believe that concrete causes more wear and tear on the limbs as well. We have seen groups of horses that have been housed long-term (years) on concrete with very little bedding, and they show signs of suspensory strain, puffy joints, and sore feet. They are also discouraged from lying down on the uncomfortable surface.

Concrete flooring is very commonly encountered, and with proper bedding management, many of the drawbacks can be minimized. Stall mats can also be placed over concrete to mitigate some of these effects.

Do I need to supplement selenium?

Selenium is an essential micronutrient for horses, but it carries a small margin of safety and overdoses can occur. Selenium toxicity is called "alkali disease" and is more common in areas with alkaline soils that have higher selenium levels, because edible plants will absorb excess amounts of the element. The most common external signs of chronic selenium overdose are lethargy, poor-quality flaky hooves and fragile haircoats. Acute selenium poisoning is called "blind staggers" and would only occur with a severe overdose of oral or injectable supplements.

Most manufactured rations will have some selenium added, so you should examine the label carefully to determine how much more you need to add to your horses diet. In general, a 500kg horse should get about 1mg of selenium per day. There is a blood test available to check serum selenium levels if you are still unsure if your horse is getting the correct amount.

How can I keep a 19 year old TB mare in good weight but have her energy level manageable?

It can be difficult to keep weight on a peppy thoroughbred, especially when they are hitting an age at which a little extra condition can be beneficial. At WECH we find that fat based calories are the best source of "non-heating" energy. This can be as simple as adding soybean oil to the diet, in fact you can add up to two cups per day but work up to that slowly so you don't end up with diarrhea. There are also several excellent quality granular fat based supplements that can be added to the feed and are a little less messy.  Although nine hours of turnout a day is great for any horse, your horse may not be getting enough calories from the pasture at certain times of the year. It might help to bring your horse in at lunchtime to give them an extra meal of beet pulp, senior, and oil to boost their intake. Hay is the fundamental of any nutrition program, so if you are having trouble getting good quality first or second cut hay you may also want to add hay cubes to the diet. In addition, be sure that you have a thorough dental examination done as your horse may be reaching the age where the teeth may be loose, infected, or too smooth to grind adequately. We have on occasion pulled rotting teeth out with our fingers on older horses that were poor keepers, and they subsequently put on lots of weight. There were no external signs that anything was wrong in the mouth!

What causes acute lameness?

The sudden onset of laminitis in an otherwise healthy horse is always a mystery. Contrary to popular assumptions, a horse can develop acute laminitis without any other prior signs. One moment they are healthy and two hours later they can barely walk.

Laminitis is the inflammation of the laminae that attach the coffin bone to the hoof. Think of the attachments as similar to velcro. Inflammation causes the attachments to weaken, allowing them to be separated easily. The deep digital flexor tendon is attached to the bottom of the coffin bone in the heel area, and a healthy foot maintains an equilibrium between the bonds holding the bone to the hoof and the pull of the DDF tendon. When the bonds weaken, the pull of the tendon causes the bone to separate away from the hoof and rotate downward. This is similar to when a team is winning a tug of war match. A little lead suddenly cascades into the losing team being pulled over easily. The body under certain conditions will release chemicals that weaken the lamellar bonds, leading to laminitis. Both carbohydrate overload and septicemia can allow the large intestine of the colon to leak these damaging substances. Horses that suffer from metabolic diseases such as Cushing's syndrome and insulin resistance are also prone to laminitis, due to disruption of glucose uptake by the laminae. Excessive repetitive trauma can also lead to inflammation and deterioration of the laminae (often called road founder or mechanical founder).
Once your horse has laminitis it is necessary for your farrier and veterinarian to work closely together because your horse will need the expertise of both.

Why does my horse have bad breath?

My first question would be how old is your horse? As horses age, their cheek teeth continue to erupt so the grinding surface is constantly being renewed. As a result, the roots become shorter and the teeth can become unstable and prone to damage such as a fractured crown. This can lead to a foul odor as feed material becomes packed into the crack and infection develops. Another problem that can occur is feed material lodging in the spaces between the cheek teeth, called a diastema. If the gap is large, feed can move in and out easily, but if the gap is small and especially if the teeth still meet snugly at the crown, they can be very difficult to spot. Again, the smell comes from rotting food and gum infection. Any oral infection, such as those caused by foreign bodies imbedded in the tongue or gums, and periodontal disease, can also lead to bad breath due to the mixed population of bacteria involved (it is truly a jungle in there!). A thorough dental examination involving sedation, a speculum, and dental probes and mirrors may solve the mystery.

Other possible conditions that can give a horse bad breath is severe stomach ulcers or cancerous tumors in the lining of the stomach. Although carcinoma of the stomach is rare, the risk does increase as the horse gets older. Evaluation of the stomach with a gastroscope would reveal these problems.

What are capped hocks? Can they be treated?

A capped hock is a condition where extra synovial fluid is produced in the bursa that is present at the point of the hock. A normal horse has a small fluid pocket at the point of the hock. When extra fluid is produced, usually the result of trauma (e.g. a trailer accident, a kick, kicking walls), the soft tissue structures distend forming the "swelling" that is observed. The vast majority of these cases are purely cosmetic, as no lameness can be observed. This obviously would not be desirable however in horses whose appearance is judged (e.g. Halter horses). In a small number of horses, there could be a negative effect on performance especially if we are asking them to compete in upper level competitions where the horse needs to put out the utmost effort. If swelling in this area is observed and is associated with lameness, it may not be a capped hock and a thorough lameness evaluation may be indicated.

Those cases that respond to treatment, such as sweating, have intermittent insults and the soft tissue structures have not exceeded the point at which they cannot return to their normal shape. As the frequency of the insult increases, and the more times the area stretches, the less likely it is to return to the normal shape. Therefore horses that kick the walls frequently are more likely to develop a chronic capped hock condition vs. the horses who suffers a single trauma.

There are treatment options available, which include injections, systemic anti-inflammatories and wrapping, to reduce the swelling and fluid production, however an important aspect is also stopping the behavior (e.g. using kicking chains, putting a stall bumper up). Therefore aggressive treatment at the first instance of a capped hock is important prior to having the structures stretched to have the best chance of avoiding a chronic condition. If you have a horse that you suspect is having issues with capped hocks, give your veterinarian a call.

What anti-inflammatories are safe for ulcer prone horses?

A good initial strategy would be to try to prevent the use of non-steroidal anti inflammatories for as long as possible. Although we have not had trouble with oral glucosamine supplements in ulcer prone horses per se, it is a good idea to minimize the addition of supplements that may discourage picky appetites. Instead of oral joint supplements you could try monthly shots of Adequan or Hyaluronic Acid to preserve joint health. Keeping your horse exercised regularly and regular hoof trimming will help them to stay loose and comfortable. If your horse happens to experience an injury, alternative methods for pain relief including cold therapy, laser, ultrasound, acupuncture, and manual adjustments can provide significant relief. If you do need to give your horse more powerful medications, there are NSAIDS that are easier on the stomach than bute, particularly Equioxx (Firocoxib). Steroidal anti-inflammatories including dexamethasone, as well as opiods such as butorphanol are also potent pain relievers that have minimal effect on gastric mucosa. Veterinarians also have several other drugs on hand for particular medical situations that can be used with a lower risk of aggravating an ulcer problem. Should you have an emergency situation on your hands be sure to inform the treating veterinarian of your horses'sensitive stomach so they can make the best medical choices. Of course, the stress of chronic pain is a significant risk factor for the development of ulcers so every treatment decision must consider that factor also.

What is the prognosis for a bowed tendon?

There are many factors to consider when assessing a tendon injury and giving a prognosis for return to athletic use. "Moderate" is in the eye of the beholder, and what may be considered mild for one type of horse could be quite severe in another. In general, I take in to account the age, breed, body type, use of the horse, and how the injury occurred. When evaluating the ultrasound, factors such as size, severity, and location of the lesion are important as well as additional factors such as concurrent injuries and health conditions (for example, older horses with cushings disease tend to heal soft tissue injuries more slowly).

 

While sufficient rest and careful return to exercise are the only "treatments" that I consider absolutely essential, there are several additional therapies available that may accelerate healing and lead to a stronger finished product. This includes shockwave therapy, surgery, intralesional injection of bone marrow, a-cell, stem cells, platelet rich plasma and other substances, therapeutic laser and ultrasound. Your veterinarian has likely already discussed these options with you.

 

In my experience, the reoccurrence rate of soft tissue injuries depends a lot on the original damage, and what the horse is used for. The more physically demanding the sport, the greater the likelihood of re-injury. The second injury typically occurs at the bottom or top of the original tear, where the healthy, stretchy uninjured tendon melds into the stiffer scar tissue of the old lesion. There is a lot of stress at this transitional area and it is usually the first spot to let go. Lots of horses are able to continue performing as athletes after a bowed tendon but I caution riders to never forget that the injury had occurred. Any increase in heat, pain, or swelling should be investigated immediately. To answer your specific question, sticking to your vets advice, giving your horse enough time to heal, and carefully bringing him back to work will give him his best chance to stay sound.

My horse is foaming at the mouth, what could be causing this?

When examining a horse that is foaming at the mouth, there are several possibilities that come to mind. Oral problems are at the top of the list. Most often the problem is a fractured tooth or some foreign material (usually grass awns or twigs) embedded in the gums or tongue, or feed material packed into a pocket between two teeth that has rotted and caused infection. A thorough oral examination with a speculum and good light source should reveal the problem.

Other causes of foaming at the mouth include choke, but this is usually accompanied by retching, feed material coming out of the nostrils, and signs of distress. Most cases of choke are mild and resolve fairly quickly on their own, but stubborn situations can be treated by your veterinarian with sedation, anti-inflammatories, and gentle lavage with a stomach tube.
An uncommon cause for an "outbreak" of drooling in a barn is a certain plant containing a toxin called slaframine that is found on pasture and in hay containing clover. The condition, accurately named "slobbers", clears up when the offending forage is removed with no lasting effects. Some horses that are receiving oral medications will get very pouty and hold the drug in their mouths for a long period of time rather than swallowing it. These animals will appear to foam because they are not swallowing the copious amounts of saliva that is naturally produced. Foals with gastric ulcers will occasionally drool as well.

 

Finally, one must consider disorders of the pharynx including abscessation and neurologic dysfunction, as well as certain diseases such as rabies and encephalitis.
If thorough rinsing of the mouth and a (careful!) finger check around the cheeks and lips doesn't reveal the problem, give your vet a call.