rabbit pseudotuberculosis is transferable to humans
(Article published in the animal journal Tierwelt and graciously allowed to share here in MediRabbit.com by M. Gruaz)
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This sole and unique reason justifies that owners of rabbits should be informed about this disease, rare disease, yeti t is observed from time to time. It is important to recognize it as it is rather atypical.
For several years, I had 3 cases within few months’ of time, the author of this article can thus report about the clinical signs of the disease. It affects mostly adult animals, or those that are several years old. The rabbit eats less and less and, after a few days, eats only small amounts of fresh food, then stops eating. The droppings become increasingly smaller, as well as hard and sticky. The ventral abdomen is soft and during palpation, it is possible to feel that the content of the abdominal cavity decreases.
The animal loses weight rapidly. Death follows after a few days, unless the decision was taken to pts the animal. After presenting the pictures taken during necropsy to one veterinarian, and later to Dr. med. vet. Richard K. Hoop of the Institute of veterinary Bacteriology of the University of Zurich (Switzerland), the diagnosis was pseudotuberculosis. These persons warned the author about the risks of transference to man and to avoid bringing hands to the mouth after handling a sick rabbit. It should be noted that no further case has appeared among the rabbits of the writer.
According to Boucher et Nouaille the disease is rare in rabbits
Yersiniosis or pseudotuberculosis is rare in rabbit husbandry. It does, however, affect birds often, e.g. the common wood pigeon or rodents, including the guinea pig. When there is contact between these and rabbits, the latter can become infected. The disease is observed in farm rabbits living in hutches as well as in pet rabbits that live in the vicinity of birds infected by the bacterium. Wild rabbits and hares can also be a source of infection. Hares are very sensitive to yersiniosis. In this species the disease is frequently observed. It is the main cause of mortality in some regions of France and Germany. The disease is considered zoonotic, that is, it can be transferred to humans. It affects mainly boys aged 8 to 13. Signs are similar to those of appendicitis. They can be accompanied by skin inflammation and redness. Human beings and animals can be affected either by a generalized infection and severe septicemia, or by localized infections in the lungs or eyes. The septicemic form leads to death within 24 to 48 hours while the chronic form may become fatal after 2 or 3 months, although many survive.
A bacterium called Yersinia is causing the disease
This infection is caused by Yersinia pseudotuberculosis, a bacterium that was discovered in 1883 on a guinea pig inoculated with the nodule of a child that died of tuberculous meningitis. It is a small cosmopolitan Gram negative bacterium (rod shaped bacterium). This bacillus or bacterium is present in infected or healthy animal or human beings. Birds and rodents are the main reservoir. This bacterium can, however, also be found in the soil, in water or in food soiled with excrements of infected animals. In rabbits, the bacterium has been observed in fecals as well as in cecal droppings. It can survive over a year in the soil. It can even multiply at temperatures between 4 to 10°C. This ability may be linked to the rise of infected rabbits during the winter season. The ground is apparently is major source of contamination. Particular care should thus be given when burying a dead rabbit. Care should be taken when adding manure to the soil. Decay of bodies in a pile of manure should be avoided. The bacterium can get back to the soil this way.
After ingestion, the bacterium reaches the intestine where it will multiply. At 37°C, the bacterial population will grow rapidly and bacteria will start to invade lymphatic nodules associated to this organ. In the septicemic form of the disease, the rabbit will die rapidly, without noticeable clinical signs. In the non-septicemic forms, the rabbit appears tired, emaciated and exhausted. He stops eating and may suffer from diarrhea. During palpation, the nodules are hypertrophied. The liver has fairly hard nodules. The intestine can present necrotic regions. Kidneys and lungs are sometimes affected. Not all animals die.
Suspicion, onset and passing over of the disease
Necropsy can be indicative. Hypertrophy of the lymphatic nodules is observed and the spleen is twice to three times larger than normal. Kidneys, spleen and intestine have small white/yellowish nodules on their surface. These nodules resemble those observed with tuberculosis, hence the name pseudotuberculosis. A bacteriological examination of the affected organs (kidney, spleen, liver, intestine, bone marrow) is the sole diagnostic tool that enables to enables to obtain a conclusive diagnosis of the disease. It is necessary to teach basic hygiene measures to rabbit owners that possess birds, hamsters, guinea pigs or poultry living in the same barn than rabbits. The feeding of grains left over by birds living in hutches to poultry is a classical source of contamination of Yersinia bacteria in the barnyard. It is also important to look for possible contamination of the soil and plants. Contamination is often oral and digestive.
The incubation period is long and lasts an average of 15 days. The bacteria then reach the lymphatic system and nodules appear on different organs. After the ganglionic stage, the liver is invaded and becomes the starting point for septicemia.
Prevention is always more desirable than treatment
It is recommended to disinfect hutches, pens or the living environment of the rabbit and the soil. Walls can be washed clean. The water should be treated with an antibacterial product to kill the bacterium, before it is discarded. Accessories or hay should be burned. Those objects that can be soaked should be so during at least an hour in a bactericidal solution that can be found in drugstores. A drinking water chlorine-based disinfectant is added to the drinking water of the rabbits. Simultaneously riddance of rats is needed. Other breeding places should also be carefully inspected. Prophylactic measures should be taken. The treatment itself includes the administration of enrofloxacin (Baytril), 15 mg/kilo fresh weight during 8 days. After stopping the treatment during 10 days, a second antibiotic cure is given during an additional 8 days. A bacteriological study (antibiogram) allows determining the sensitivity of the bacterium to several antibiotics and can help find the efficiency of another molecule.
Maladies des lapins de Boucher et Nouaille
Textbook of Rabbit Medicine, Frances Harcourt-Brown, Oxford,
The Biology of the Laboratory Rabbit, Patrick J. Manning, Daniel H. Ringler and Christian E. Newcomer,
Zoonoses and Communicable Diseases Common to Man and Animals: Bacterioses and Mycoses v. 1 - PAHO Scientific Publications S. No. 580, Pedro N. Acha, Boris Szyfres.