by Chris Hayhow, DVM, PhD
Diarrhea In rabbits may be caused by any number of factors such as change in diet, severe weather, or stress. It may also be associated with a number of serious intestinal problems such as Salmonella, coccidia, or hairballs. A sample of the stool should be checked by a veterinarian to determine the presence of intestinal parasites possibly causing the problem. If the sample is free of parasites, then close attention should be given to other possible disease problems. If parasites such as coccidian are diagnosed, they should be treated accordingly.
Any rabbit with diarrhea should have the feed removed for 24 hours. The rabbit should receive plenty of fresh water and be fed straw or coarse hay for 1 - 2 days, followed by a slow return of the regular diet. If you have changed feed and didn't do it gradually, now is the time to mix the new feed with the old feed to slowly adjust the herd over several days.
A sudden change in feed may disrupt the digestive balance in the intestinal tract and trigger diarrhea. Keep a close watch on your feed since different levels of protein and fiber can contribute to diarrhea if the rabbit is not adjusted to the new levels gradually. If the animal is not better in 36 - 48 hours, then it should be checked by a veterinarian.
Enteritis, or inflammation of the intestinal tract, is a common problem in weanling rabbits. Possible causes of enteritis include coccidiosis or other specific bacterial infections and possibly viruses, but enterotoxemia is the most common cause of death in rabbits of weanling age. The etiology is Clostridium spiroforme. Rabbits that are four to eight weeks of age are most at risk. It usually results in profuse diarrhea, dehydration and a rough hair coat. It can lead to death as quickly as 12 to 24 hours with no other signs observed.
When rabbits change from a milk diet to a pelleted diet the pH and the bacterial flora of the intestinal tract changes. When high energy rabbit feed is consumed in excess, it is not completely digested in the stomach and early intestinal tract. Excess energy can thus reach the cecum and provide the resident bacteria a source of energy. Certain bacteria multiply to high levels, and there is a toxin production. The diarrhea produced by these toxins can lead to dehydration, shock and ultimately death.
Prevention is the best treatment, since the case fatality rate may approach 100%. During an outbreak the energy intake (pellets) Should be decreased and the fiber intake (coarse hay or straw) increased. Water should be available at all times. Under certain conditions, the use of broad spectrum antibiotics may be indicated. Those animals that survive should be slowly adjusted to the diet.
Long term management changes are indicated. Stresses should be minimized. Increased sanitation in the rabbitry is a must. Plenty of clean, fresh water should be available at all times. The rabbits should be limit fed to discourage overeating. Fiber should be supplied so the rabbits will not have an empty stomach. The rabbits should be brought to full feed gradually so the bacteria in the intestinal tract are not presented with a sudden increase in nutrients, which may throw the delicate balance of intestinal bacteria out.
Coccidia are protozoan Parasites that infect the digestive tract. There are several species of Eimeria that can infect rabbits. Coccidia tend to be species specific, so they don't cross infect other animals or humans. There are two forms of coccidia commonly observed in rabbits. There is the hepatic form, caused by Eimeria stiedia, and the intestinal form caused by several other species of Eimeria.
The adult coccidia live in the lining of the intestinal tract, or in the case of hepatic coccidiosis in the lining of the bile ducts. Normally intestinal coccidosis is of little concern, but at times the infection can be severe. Most rabbits have some degree of intestinal coccidiosis. Livercoccidiosis, caused by Eimeria stiedia, is a problem. The damage induced in the bile ducts and liver can result in liver condemnation. Severe liver coccidiosis can be fatal to rabbits.
Clinical signs of intestinal coccidiosis include potbelly, rough hair coat, diarrhea, and decreased rate of growth. Signs of hepatic coccidiosis include diarrhea, potbelly, poor coat condition, poor body condition, and white spots on the liver on necropsy. Treatment is a continual battle in problem herds. Sulfaquinoxaline In the drinking water at 0.04% for two weeks, or in the feed at 0.025% for three weeks is effective. Other products are available such as Amprolium and other Sulfa formulations but they are not approved for use in rabbits in the U.S.
Long term control is best achieved by daily cleaning of the cages. Since the oocysts must sporulate outside the rabbit to be infective, daily cleansing of the cages help break the life cycle. This method of control can eliminate the problem.
HLRSC Official Guidebook - 5th Edition 2002