By

Dr. Jay Altman, DVM

[Editors Note: This is the final post in a seven part series about horse digestive issues.]

Doctors, whether DVM’s or MD’s, are often faced with a case that includes some type of infection, and when we do the word antibiotics immediately comes to mind. So, of course we reach for the bottle or the prescription pad and get the therapy “rolling”; right? Well, many times it’s not quite that simple. There are many considerations in this decision when it comes to the horse as a patient. As veterinarians, we consider the implications of antibiotic resistance, the overall health status of the horse, and the effects that antibiotics will have on the digestive system.

The horse has a fermentation process that occurs in its cecum and large colon. This process relies on normal microflora or bacteria to digest fiber, the main foodstuff in the equine diet. As a hindgut fermentor, the horse is especially susceptible to the effects of antibiotics on its digestive system. To efficiently and properly digest, these bacteria must be in “balance”, which means that proper bacteria in the proper percentages must be populating the hindgut, and they must be healthy.

The bacterial health of the colon is dependent upon many factors including ph, growing medium (foodstuffs for the bacteria), and colonic motility or movement. When this environment for the bacteria is not correct, the normal bacteria may be low in numbers, have depressed activity, or be dead. Once any of these upsets to the bacteria occur, the environment may become preferential or conducive to the growth of unwanted and even toxic strains of bacteria.

One of the problems with antibiotics is that they are not very specific or targeted, which means they cannot just affect one strain of bacteria, and they do not just go to work at the site of infection. When a horse is placed on antibiotics, some change in the balance of the hindgut microflora is inevitable, due to the death of bacteria in the “fermentation vat.”

Many times, although a change is occurring in this bacterial population and digestive efficiency is reduced, the effects are not seen by the owner or the veterinarian attending the case. Occasionally, the effects can be significant enough that profound changes are seen, including diarrhea, colic, and in severe cases, there can be toxicity to the bloodstream caused by the overpopulation of “bad bugs”.

Many times veterinarians will recommend a probiotic to be fed orally, either while a horse is on antibiotics, or especially if a patient is exhibiting any signs of hindgut disturbance due to antibiotic therapy. Probiotics come in many forms and new developments in digestive health are proving that a combination of pre and probiotics including high quality yeasts are the most effective at maintaining or re-establishing colonic health. So, the next time your horse requires antibiotic therapy, you might consider discussing the effects to your horse’s digestive system with your veterinarian, and what precautions you can take while your horse is undergoing an antibiotic treatment.

Health Care You Can Count On!

About the author:

Dr. Altman specializes in equine dentistry and lameness, and enjoys working on medicine as well as surgical cases.

By

Dr. Jay Altman, DVM

[Editors Note: This is the sixth in a seven part series about horse digestive issues.]

Non-Steroidal Anti-inflammatory Drugs are a group of drugs commonly used in both human as well as equine medicine. Drugs such as Phenylbutazone (Bute), Banamine, Ketoprofen, Carprofen, and Naproxen, have been relied upon to help our equine athletes with all types of ailments. These drugs are as the name says anti-inflammatory, but they are also analgesic (moderate or control pain) in their operation and so the list of uses is quite long. Some of the most common uses for these drugs are aids in healing orthopedic conditions, controlling colic, and controlling fevers.

Just as in human medicine, veterinarians vary in the amount they use these drugs, since like many good things in life, excess can have its drawbacks. In the case of NSAIDS for horses, these drawbacks or toxicities have, due to their nature, meant that these drugs are sold as prescription only. The side effects of these compounds include gastric irritation and ulceration, colonic irritation and ulceration, and renal (kidney) toxicity.

Horses vary in their ability to tolerate these drugs without the deleterious side effects, and although there are some that can take repetitive full doses of these compounds for extended periods of time, the average horse cannot. On the other end of the sensitivity spectrum there are horses that even one or two small doses of these drugs will cause toxicity and possibly even clinical signs of discomfort or pain from the toxicity.

There are also some conditions that will exacerbate the toxicity issues any horse experiences. Pre-existing gastric or colonic irritation or ulceration can be especially concerning when using non-steroidal drugs, as these drugs inhibit the protective mechanisms of the stomach and colonic lining and the condition will usually worsen. Dehydrated horses or horses with pre-existing renal disease will be much more sensitive to the toxic effects of this class of drugs and special cautions should be taken to limit the dose and the number of doses administered in these situations.

So, are NSAIDS a friend or foe? The question as much of life is perspective, as an equine practitioner, working to improve the lives of horses; there is no question in my mind that these drugs are my friends. I can’t imagine how frustrated I would be if I could no longer use NSAIDS in my practice. Furthermore, my patients would be limited by medical conditions that there was no other reasonable therapy for.

This brings up the question of fear of using non-steroidals; no, I am not afraid of using this class of drugs. But yes, having seen the side effects and the toxicity issues, I do have a healthy respect for these drugs and try to prescribe a reasonable dose for a reasonable period of time, to effectively bring about improvement in the medical condition I am treating. In addition to moderating my dosing of these drugs, I also recommend alternatives to the drugs and or “protectants” from the toxicity issues where appropriate.

Some of the common alternatives I will employ to limit use of the drugs include rest, ice therapy, massage, intra-articular injections, acupuncture, chiropractics, and injectable as well as oral joint therapy compounds. When it comes to the issue of renal toxicity and or dehydration, I will either employ re-hydration tactics prior to use of the drugs or avoid them completely.

When it comes to protective strategies, I have historically used gastro-protectants such as omeprazole (Gastro-guard), ranitidine (Zantac), cimetidine (Tagmet), calcium carbonate, and magnesium and aluminum salts. The first three represent drugs that not only can treat minor symptoms, but when used properly can affect a cure to gastric ulcers.

The second three compounds are used for minor conditions, or as a strategy of maintenance for a horse that has had major problems with gastric ulceration, and I want to use a product for control of the ulcers and prevention of recurrence after treatment with one of the first three products. When it comes to colonic irritation and ulceration, these drugs do not seem to help. There is another gastro-protectant drug on the market called Sucralfate, which is suspected to help with issues in the hindgut or colon, but results with this therapy have been mixed. This strategy is usually employed in hospitalized horses, or horses with a severe problem.

Over the past few years my work in developing The Assure System®, and the Assure® product line has been to help with the issue of colonic irritation and ulceration, and the company’s research as well as clinical case load has shown this to be an effective strategy. Most recently we have developed a product know as Assure® Guard, that combines the effectiveness of the original Assure® product with the powerful antacid calcium carbonate (found in Rolaids and Tums).

Health Care You Can Count On!

About the author:

Dr. Altman specializes in equine dentistry and lameness, and enjoys working on medicine as well as surgical cases.

By

Dr. Jay Altman, DVM

[Editors Note: This is the fifth in a seven part series about horse digestive issues.]

Horses can suffer from two main categories of digestive ulcers. Both gastric (stomach) and colonic ulcers can be common in certain populations of horse. A Texas study of approximately 180 horses in a high stress environment showed over 95% of these horses had either gastric or colonic ulcers or both. In this article I would like to discuss some basic information on gastric ulceration, its diagnosis and treatments.

For the past 10 years the prevalence of gastric ulcers in performance horses has been well documented. The incidence of ulcers in racing Thoroughbreds is estimated to be about 90%. In other words, when groups or populations of these horses are screened for ulcers, approximately 9 of every 10 examined do have some level of gastric ulceration. Although it is known that this group of horses is among the most susceptible to gastric ulceration, we also know that horses of any breed can suffer from gastric ulcers, and the incidence is quite high.

Feeding of concentrates and high grain diets, combined with stress which can come in many forms, are known to contribute to the development and support of the debilitating condition. The degree of ulceration can range from mild gastric irritation, to erosive and bleeding lesions. These gastric ulcers can lead to poor performance, poor weight gain, anorexia, poor condition, excessive nervousness, poor attitude, and colic

For a definite diagnosis of gastric ulcers, we must look at the stomach through a gastroscope. For the horse this must be a 3 meter length scope. Due to the length of the scope and the high cost of the instrumentation, the gastroscopy is normally performed at an equine hospital, and therefore the horse must be transported to the hospital.

Occasionally as an alternative to performing the “scoping”, a horse will be placed on trial therapy to determine if gastric ulcers seem to be the problem. Of course trial therapy is not the preferred method, but on the other hand at times this method can be helpful, and can even be followed up with the gastro-scope. Assuming that the veterinarian performing the gastroscopy discovers ulcers, those ulcers are then graded on the basis of severity.

Upon discovering ulcers, there are a multitude of therapies for the veterinarian to choose from, and most often the prescription is accompanied by recommendations for management changes. The management changes are usually parallel to those recommended by gastroenterologists for humans, change of diet and reduced stress.

When it comes to drug therapy, there are three classes of drugs for the veterinarian to choose from. There are proton pump inhibitors, H2 blockers and antacids. The three classes vary in their ability to treat ulcers, with the proton pump inhibitors such as Gastroguard® being the most effective, and the antacids such as calcium carbonate, and aluminum silicate, being the least effective.

So, if the proton pump inhibitors are the most effective, why would H2 blockers such as Zantac® or the antacids even be a consideration for therapy? The answer is simple; cost. The cost of these therapies is proportional to their effectiveness, and so many times H2 blockers and antacids are used as part of a treatment protocol or as a prophylactic measure to reduce costs.

It is not uncommon for a treatment protocol to include Gastroguard® followed by one or both of the alternative drugs to make a complete program. Once the initial ulcer conditions are cleared up, many horses are maintained on antacid products to help reduce the risk of recurrence of the ulcer conditions.

Health Care You Can Count On!

About the author:

Dr. Altman specializes in equine dentistry and lameness, and enjoys working on medicine as well as surgical cases.

By

Dr. Jay Altman, DVM

[Editors Note: This is the forth in a seven part series about horse digestive issues.]

      
   
            
Colic is the most common medical ailment in the horse. Over the past 25 years there have been great strides in both the prevention and treatment of equine colic. Improvements in deworming products and schedules, equine dentistry, and management practices have helped to reduce the number of colic cases. Advances in veterinary knowledge and the development of new drugs and surgical techniques have helped to improve the survival rate for horses suffering with colic. Still today, each year 10-11% of the horse population suffers from colic.

One of the causes of colic, sand ingestion, can be a substantial risk to certain horses. Horses ingest sand either through grazing or eating hay or grain from the ground. The problem is most prevalent in the semi-arid west and southwestern states and the coastal states, although it can be a problem in any state. Soil or “dirt” consists of a certain amount of sand, which is a naturally occurring finely divided rock.

In fact, many soils not only contain sand, but also contain silt which is an even finer particle of rock and some contain gravel which are the rock particles that are larger than sand. The silt, sand and gravel ingested must travel through the digestive system of the horse to be removed within the feces. One of the problems associated with this situation is that the sand and gravel and to a lesser degree the silt can produce irritation within the digestive system. Additionally, in certain situations the sand can accumulate within the digestive system and the irritation can intensify due to this accumulation. As sand accumulates in the intestinal tract, a combination of the irritant effects and the weight of the sand can lead to impaired motility, reduced absorption of nutrients including water and thus, digestive upset.

If the accumulation of sand continues, the resultant digestive upset will eventually lead to poor condition, diarrhea and eventually colic. Making the situation even more troubling is the fact that clearance of the sand from the large colon, where most sand accumulates, requires adequate gastrointestinal motility. So once the sand begins to collect in the colon, any resulting reduction in motility will further add to the horse’s accumulation of sand and gravel.

As mentioned above the signs of sand accumulation can include poor condition, difficulty in maintaining weight, diarrhea and colic. Since none of these conditions are unique to a sand accumulation problem, the owner seeing any or all of these signs cannot assume that the cause is sand. Sand accumulation can at times be diagnosed and there are four methods for this diagnosis, two of which are not conclusive and two of which are.

The easiest of the methods, since the horse owner can perform it, is the fecal floatation test. With this method feces are collected from the horse and a standardized amount is added to a container with water. The water and feces are mixed so that any sand within the feces is suspended within the mixture and then allowed to settle to the bottom of the container. Once the sand has settled in the bottom of the container, the sand can be quantified. Although many veterinarians suggest this method and it has historically been considered to be one of the best in field tests, it has limitations.

The test by design will inform you the horse is passing sand through his digestive system. The test will not tell you if the horse is accumulating sand within the digestive system. If some amount of sand is detected in the feces, it could be that the rate of ingestion and the rate of sand passage is equal and the horse is not accumulating any appreciable amount within the colon. On the other hand, if the rate of ingestion over a period of time outweighs the rate of sand passage, the horse begins to accumulate sand within the colon. Once this accumulation begins there is a likelihood that the sand will impair motility within the colon and additional accumulation will ensue. If no sand is detected using this test method one must then wonder if the horse is accumulating sand, because none of it is being passed in the feces. If very large quantities of sand are detected within the feces one can assume that the horse does have a sand problem. So although this test is used, the results are often hard to interpret and should always be scrutinized.

The second method, which is most commonly performed by a veterinarian, is to listen for sand in the colon. Utilizing his stethoscope your veterinarian can listen to the contractions of the colon within the abdomen and under certain conditions can actually hear the sound of sand moving within the colon. When the veterinarian discovers this sound and diagnoses a sand condition the results are reliable. Where this method encounters a shortcoming is when the sound is not detected, yet there is actually sand within the bottom of the colon. This can occur if the sand load is not moving either because the sand has impaired motility of the colon itself, or the normal motility within the colon does not have the force to move the sand and thus create the sound.

The two methods that are completely reliable for sand detection are not readily accessible and are both quite expensive. The first method is to radiograph the abdomen and diagnose the sand load based upon the radiograph results. Equine abdominal radiographs must be performed in a hospital or clinic, with a radiograph generator that is powerful enough to penetrate the equine abdomen.

Although this method is non-invasive it is inconvenient and incurs considerable expense. Furthermore, although considered to be reliable, some doctors have questions as to the sensitivity (ability to detect the sand) of this test, when the sand is spread over 70-100 feet of intestines. The last method although possibly the most reliable, is not only impractical for many reasons, but it is also invasive and expensive. Exploratory abdominal surgery although totally reliable in detecting sand, is only chosen with a horse ill enough to undergo colic surgery to relieve the condition.

It is recommend that if your horse is exposed to eating sand or dirt, the first step is to control the consumption through management changes. These changes include feeding, both grain and hay, only out of feeders, feeding off the ground and using mats in the feeding area. These steps will all help to control the sand intake. When feeding outside in a dry lot or a sparsely vegetated pen or pasture, covering a large area with mats, will help control both the eating area and the surrounding area where the horse is likely to browse for every last morsel of hay.

These control measures will help in many cases, yet there are situations in which it is either hard or impossible to control the consumption of sand including herd pasture management, dry-land pasture grazing, and various other housing arrangements. For horses that do consume some quantity of sand, if complete control of sand intake is not possible, sand removal treatment with psyllium is a viable option.

Historically there have been four problems with most psyllium treatments, not enough psyllium within the product administered, not enough product administered at each dosing, not a long enough or regular enough treatment period, and the lack of clearance due to altered colonic motility. There is a new, pelleted psyllium product that has just become available, called Assure Plus®, and this product works to overcome the common shortcomings of prior psyllium protocols. The investment in management changes and Assure Plus® treatment can result in a healthier and less colic prone horse.

Health Care You Can Count On!

About the author:

Dr. Altman specializes in equine dentistry and lameness, and enjoys working on medicine as well as surgical cases.

By

Dr. Jay Altman, DVM

[Editors Note: This is the third in a seven part series about horse digestive issues.]

Colic is the term used for abdominal distress that horses commonly encounter. The incidence of colic in horses is quite high. It is estimated that 10-11% of the horse population undergoes a bout of colic every year. This is a startling number when one considers that colic is still the condition that accounts for the most deaths in horses each year. For equine veterinarians colic is, by far, the most common cause for emergency calls and distressed horse owners. Although there have been great strides in equine medicine and surgery over the past 25 years, and the ability to treat and cure many colic conditions has drastically improved, there is no single answer or drug that will end all colic.

What causes colic, or even what are the various causes of colic, can be a confusing topic for the horse owner. When discussing the causes of colic it is helpful to try and separate the anatomical and physiological conditions that may be involved in the colic and the trigger mechanisms that may have prompted the condition. For instance, a large colon impaction may be the anatomical and physical cause of the pain associated with your horse’s colic, but lack of fresh water and resulting dehydration may have been the cause of the colic.

The equine abdomen contains approximately 100 feet of small and large intestine. Problems relating to colic may occur at any point in this vast digestive system, including the stomach, the small intestine, the cecum, the large intestine, the small intestine and the rectum. Naturally, many horse-owners consider the stomach when talking about colic, and the recent popularization of information regarding gastric ulcers has helped to reinforce this thought process. But, the stomach plays a minor role as a site of colic pathology.

In fact, some retrospective studies have shown that only 3-4% of colic cases are due to pathology, such as ulcers, in the stomach. The vast majority, 64-68%, of colic disease states are related to the hindgut, including the large colon, small colon, cecum, and rectum. Additionally, a study of 180 performance horses published in March of 2005 showed that 97% of the horses had ulcers of either the stomach, the colon, or both, and 63% of this population had colonic ulceration. Some of the pathological causes of colic include gas accumulation and distention, feed impaction, sand impaction, vascular compromise, motility disturbances, colitis (inflammation of the colon), adhesions of tissues, displacement of a section of colon, and torsion or volvulus of a section of colon.

What causes these pathological conditions? This question, posed by many clients, is one that equine veterinarians are confronted with on a daily basis. Although in many cases it is impossible for you or your veterinarian to know the exact cause of the colic, in other cases an inciting cause can at least be suspected. Since a large percentage of colics are related to management, there is an advantage to knowing, or at least having a hypothesis as to what caused the colic. Theoretically, there is some item or items in the horse’s management that can be identified, to help reduce the risk and or incidence of future episodes of the same type of illness.

Discussing all of the causes and management mistakes that can lead to a colic situation is almost impossible. Instead it is valuable to review the management practices that can positively influence and reduce the risk of colic. The following list of management strategies should help the horse owner to review his or her current management and determine if they are doing their utmost to reducing colic risks.

1. Implement an effective internal parasite reduction program. This includes management of the premise to reduce the environmental load, as well as a rotational deworming program tailored to each horse and region of the country.
2. Match the horse’s natural diet as closely as possible.
3. Maintain a well balanced diet.
4. Schedule feeding to simulate eating patterns in nature.
5. Limit changes in feed and make any changes in feed gradual.
6. Feed only high quality hay and concentrated feeds.
7. Provide constant access to clean, fresh water and regulate water temperature in extreme cold.
8. Reduce stress for the horse by eliminating changes in housing and activity levels.
9. Maintain good dental health through regular examinations and dentistry by your veterinarian.
10. Manage the horse’s environment by providing clean, safe areas with adequate protection from the elements.
11. Pay close attention to your horse, so that disease and or illness can be detected and attended to in a timely fashion.

Each of these strategies is a complex and detailed topic. Furthermore, for most horse owners several of the most important strategies can be difficult to maintain. It should also be apparent that many of these guidelines relate to the horse’s diet and therefore, gastrointestinal health. The second major category of management involves stress. Stress for horses can come from many different types of management situations and changes. Environment and housing, trailering, changes in surroundings, changes in horse population, changes in feeding schedules, and changes in exercise schedule can all be considered stressors. Horses and horse breeds vary in their ability to handle stress and, just as in people, what constitutes a stress to one horse may not be a stressor to another horse.

Maintaining your horse’s natural diet requires feedstuffs that consist predominantly of roughage or high fiber plant material. It is difficult for many horses to maintain adequate weight on a diet consisting of only roughage, since the energy expended, when in work, is higher than the calories provided by this type of diet. Adding a higher calorie concentrated ration to the horse’s roughage requirement becomes essential to maintaining weight and energy.

The problem with this feeding regimen is that the concentrated rations provide a high level of non-structural carbohydrates, which alter the gastric and colonic ph and environment. These changes to the gastrointestinal physiology lead to an environment that for many horses predisposes them to gastric and colonic irritation and ulcers and therefore many types of colic and in some cases significant issues with diarrhea.

A combination of high grain diet, nervous personality and management stresses can place some horses in the high-risk category when evaluating the chances of colic. There have been some efforts over the past few years on the part of both the veterinary community and the feed industry to try to alleviate these conditions. By altering the concentrated feeds that are used to maintain horses, and developing add on products that will help to counteract the negative effects of high grain diets and stress, the industry is attempting to better address the gastrointestinal requirements of the horse. It is important that horse owners analyze their horses management routine and diet to help reduce the individual’s risk of colic.

Health Care You Can Count On!

About the author:

Dr. Altman specializes in equine dentistry and lameness, and enjoys working on medicine as well as surgical cases.