Toxic Gut Syndrome: The Silent Killer

By Charles C. Kruger, DVM

Dr. Charles Kruger is a well-known veterinarian and breeder of champion show dogs.  His most celebrated achievement involves his work with Helen (“Scootie”) Sherlock and Judith Hale on Toxic Gut Syndrome (TGS), which had been killing many German Shepherd Dogs, including Ch. Karagin’s Crusader ROM.  Based on their analysis of Toxic Gut Syndrome, Dr. Kruger went on to develop his now-famous formula - Dr. Kruger’s Ultimate Supplement – that helps prevent the infection from taking hold in the first place, and offers many other health benefits as well.  Dr. Kruger is now retired from veterinary practice after more than 40 years as a small animal practitioner.  Here, in his own words, is the story of how Toxic Gut Syndrome was identified and controlled.

As a veterinarian and a breeder of German Shepherd Dogs and Pembroke Welsh Corgis for over 40 years, I have always been concerned with the medical and practical aspects of canine health.  My greatest challenge came, however, when circumstances turned me into a medical researcher.  It all began when I felt personally compelled to discover the cause and means to control a mysterious disease that was ravaging the champion German Shepherd Dog  population.  This disease, which we now know as Toxic Gut Syndrome, or Clostridial enterotoxemia, is an intestinal infection that affects several species of animals.  In the canine world, it primarily affects German Shepherd Dogs.  In 40 years of veterinary practice, I have seen a couple of cases of Toxic Gut Syndrome in other breeds – the Irish Setter and the Irish Wolfhound.  However, a related disorder, Clostridial enteritis, a lesser form of intestinal infection, is seen quite frequently in many breeds of dogs.

While veterinarians had long known of these conditions, around 1980 something unusual began happening with the German Shepherd breed.  Dogs would die suddenly, apparently from mesenteric torsion.  However, post mortem examinations yielded surprising results.  These dogs did not display the telltale twist at the mesenteric root.  After examining several dogs that exhibited this strange pathology, I went to work to discover what this new killer might be.  Library investigation turned up several references to a condition known as Clostridial enterotoxaemia , although very little scientific research was available on the subject.  I began to wonder if perhaps this might be the key to understanding this puzzling new condition.  Meanwhile, a promising solution to the problem presented itself.  In the 1980s, the German Shepherd breed was very heavily line-bred.  Very close breeding of this type is a two-edged sword, bringing out the best and the worst features of a breed.  I cannot say for sure that the breeding practices at that time prompted the frequency of Toxic Gut Syndrome, but we do know that close breeding can suppress proper immune system functioning. There were definite families of German Shepherds with a great propensity to develop Toxic Gut Syndrome.

After the deaths of several well-know champions, I had the sad opportunity to participate in the autopsies.  Again, while it was assumed by the attending veterinarians that there would be a twist at the mesenteric root indicating mesenteric torsion, there was no evidence of the expected lesions.  A team made up of myself, a friend (and laboratory technician) Judith Hale, and German shepherd authority Helen (“Scootie”) Sherlock, cultured the contents of the dead dogs’ intestines.  Judith was able to isolate very large numbers of Clostridium perfryngens bacterium - the very bacterium mentioned in the literature.

Clostridium is a virulent variety of bacteria that is a normal intestinal inhabitant in small numbers. Under certain environmental circumstances, it multiplies rapidly, giving off high levels of toxins that enter the dog’s blood stream, in effect, poisoning the dog and causing death.  According to my library research, Clostridium p. causes deaths in lambs, pigs and human babies in Papua, New Guinea that resembled the deaths I’d seen in German Shepherds.  The human form was given the name “pigbell”. 

Fortunately, an injection was developed that protected these babies, and another was successful in the lambs.  Now that we confirmed that the same bacterium was responsible for the deaths of the German Shepherds, our aim became stopping the infection’s progress in this breed.  At first we hoped the injections that protected the lambs or the human babies would be effective to protect the dogs.  To our disappointment, we found that the human drug was licensed in England and could not be brought to the United States.  We obtained the inoculation used to protect lambs.  We tried it on some dogs, but were disappointed again.  The tissue reaction in the German Shepherds was so severe and painful that it was not realistic to continue its use.  Clearly, we were not going to be able to cure this condition once it was already underway.  We needed to find a method of prevention rather than a remedy to stop this killer disease from ever taking hold.

In regular veterinary practice, cases of bloat/torsion and mesenteric torsion are familiar.  In bloat/torsion, a twisting of the stomach follows a rapid accumulation of stomach gas.  In mesenteric torsion, there is a less significant buildup of gas, followed by a twisting of the entire small intestine at the attachment of the mesentery ligament. It now appeared to me that the three conditions – bloat/torsion, mesenteric torsion, and Toxic Gut Syndrome – have similar symptoms.   However, the diseases differ in their progress.  In bloat/torsion, dogs seem to blow up like a balloon before your eyes.  With mesenteric torsion dogs exhibit a strange, hunched-over posture.

In either case, the intestine loses its blood supply and the dog dies within a few hours due to toxins and shock.  Without surgery, both conditions are usually fatal.  While the cause of bloat/torsion is not clear, it is my opinion, however, an initial overgrowth of harmful, gas-forming bacteria in the digestive track is implicated.  With some research into the unique physiology of the German Shepherd intestine, it became obvious that prevention of Toxic Gut Syndrome required control of bacteria on a daily basis.

In general, the German Shepherd breed exhibits very low pancreatic enzyme production compared to other types of dogs.  As a result, intestinal pathogens responsible for Toxic Gut Syndrome can increase rapidly under certain conditions.  In dogs, pancreatic enzymes serve as a first line of defense, slowing down the progress of bacterial overgrowth.  German Shepherds lack this first line of defense.  Bacterial overgrowth is rapid and by the time the dog exhibits symptoms, the intestine has become paralyzed due to the toxins released from the bacteria.  At this point, the dog is beyond recovering and will die.

Preventing Toxic Gut Syndrome now seemed to depend on two control measures.  The first was limiting the number of pathogens in the intestine.  The second was increasing the number of friendly bacteria and enzymes to keep pathogens in check.    Supplementing the level of pancreatic enzymes, therefore, appeared to be one necessary step in preventing bacterial overgrowth.  The second control measure for pathogens is to increase the presence of good bacteria called Lactobacillus , which normally inhabits the healthy intestine.  Lactobacilli are found to thrive in milk products and are used to culture yogurt.  They also help control the growth of pathogenic bacteria and have a cleansing effect on the intestinal wall.

I then began to develop a supplement that would provide therapeutic amounts of enzymes and live acidophilus bacteria.  At first, I used live-culture yogurt and a commercial enzyme product made for large animals.  This seemed to help control bacterial overgrowth, but I wanted to find an even better supply of Lactobacilli and digestive enzymes.  At this point, I formulated the first stage of what was to become my Ultimate Supplement.  With additional study and experimentation, I decided to add vitamins, minerals (including trace minerals), some essential fatty acids and antioxidants to provide complete nutritional support.

Dogs and cats readily accepted this formulation, and it immediately became clear that it helped stop early death due to Toxic Gut Syndrome and help control even minor bacterial infections that cause diarrhea in puppies and older dogs. In my efforts to find a means to control the fast-acting Toxic Gut Syndrome, I seemed to have found a means to control the bloat/torsion complex as well. In addition, other benefits from the formula were realized.  We saw changes and improvements in skin and coat condition, less flatulence and dog body odor, reduced shedding, smaller, firmer stools and overall better digestion of food.  I have had numerous breeders who use the Ultimate Supplement and have found an increased effective reproduction rates. I was particularly impressed that it also controlled “nervous diarrhea” while transporting dogs.   After 20 years of administering the supplement with no deaths from toxic gut or the bloat/torsion complex in any dog using it, I feel confident in saying that this formulation helps control these diseases.  It is, however, absolutely necessary to give the prescribed amount everyday for the entire life of the dog, in particular while the dog is under stressful situations, such as in training with a handler or on a show circuit.

Experience has shown me that supplementation with a well formulated product provides many other benefits to dogs as far as enhancing their overall health and energy. In my forty years of breeding German Shepherds, I have never seen a dog react adversely to sensible supplementation.  The most dangerous situation is when one feeds excessively high protein content to puppies.  It is for this reason that manufacturer’s make different puppy foods for different size dogs.  The difference is the protein content.  Protein in dog food provides phosphorus; excessive phosphorus may contribute to developmental bone disease, especially in the growth plates.

There is absolutely no reason every dog cannot attain optimal health with the use of my Ultimate Supplement! Forty years of clinical practice has shown me that each dog has unique nutritional requirements.  This is obvious when you feed the same diet to a group of dogs.  Some will thrive while others will not.  My supplement is a “gap-filler” – it fills in the gaps to meet the individual nutritional needs of each dog.  I am certain that the lives of many dogs that were susceptible to these conditions as outlined in this article, have been saved as a result of using the Ultimate Supplement, a fact that I find personally rewarding.