Salmonella in You and Your Dog Cat & Other Pets

Ronald S. Hines DVM PhD 5/4/06

Salmonella are a group of bacteria that inhabit the intestinal tract of a large number of animals. In 1885 Daniel E. Salmon discovered them. When conditions are right, these bacteria can cause severe disease leading to food poisoning or death. There are about twenty species of salmonella and 2,300 serotypes. All can cause disease. In a normal intestine of a healthy animal, a multitude of “friendly” bacteria and yeast keep the number of salmonella and other “bad” bacteria at a constant low level. Too low a level to cause disease. If however, the animal is stressed or exposed to massive numbers of ‘bad” bacteria, the bacteria begin to produce toxic products and migrates into the blood stream causing a condition called septicemia or blood poisoning.

People are rather resistant to Salmonellosis. When we develop a case of it, it usually causes, chills, malaise, diarrhea and cramps. Dogs, horses, pigs and reptiles are also quite resistant to salmonella. A typical source of salmonella poisoning in people is the salad bar of fast food restaurants or the consumption of chicken that is under cooked. Salmonella is a tough organism that can live for several months at freezer temperatures. Because the organism colonizes the intestine, any case of the disease implies that fecal material was spread on improperly washed hands or utensils.

Salmonella is particularly severe in young, debilitated or stressed animals. In birds, a common source is Salmonella typhimurium from rodent droppings. Many mice and rats carry salmonella for years but appear healthy. When they contaminate the feed of parrots or chickens, sudden death occurs. A few of the sick birds recover and become chronic carriers themselves. Initially, animals with Salmonellosis run high fevers (105 – 107F). They quickly become depressed and dehydrated and die in a matter of hours. Often, the disease progresses so rapidly that antibiotics are not effective. Once the organism is present in a flock or herd, it is virtually impossible to get it out – short of depopulating the entire herd or flock. This is because despite vigorous antibiotic therapy, a few chronically infected animals will remain to spread the disease. . These carrier animals shed the organism only intermittently. The most famous salmonella carrier was Typhoid Mary Malone. From 1900 to 1907 she cheerily prepared wedding feasts in New York City, which were responsible for the sickness of Forty-seven guests and the deaths of three. She was a good cook and her services were in demand.

Within the last fifteen years it has become evident that virtually all reptiles carry salmonella in their intestines. A common salmonella carried by turtles, iguanas and snakes is Salmonella arizonae. Despite the popularity of pet reptiles, it is surprising how few human cases of this disease have been traced back to reptiles. A disturbing development is that many strains of salmonella have become resistant to the chloramphenicol, nitrofurans, ampicillin and fluroquinolone antibiotics formerly used to treat them.

Some things you can do to prevent Salmonellosis:

1) Prevent rodent contamination of food ingredients

2) Avoid introducing new animals into a herd or flock. The farmer’s axiom “all in – all out” prevents the introduction of disease. When you do set up a new flock or herd, choose animals from a certified salmonella-free source.

3) Heat all food ingredients to a minimum of 185 F. This temperature kills salmonella.

4) Avoid sharing utensils between animals. Soaking utensils in a solution of one part household bleach and twenty parts water will kill salmonella provided that heavy organic soiling is not present (pre-wash the utensils).

5) Do not feed raw eggs or meat. Avoid “triple D” meats and rendering house products.

Consult With Dr. Hines

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