Diagnosis and treatment of pasteurellosis and brucellosis in rabbits

From May to July 2002, a kind of epidemic disease characterized by rhinitis and acute death occurred in a rabbit farm. After laboratory bacteriological examination, it was diagnosed as rabbit pasteurellosis. The report is as follows:

1. Basic situation the rabbit farm is located in * * Chabqal County Dairy Farm. Since 2000, the farm has been built. Now it raises California rabbits, Belgian rabbits and other breeds, with a total of more than 1000 rabbits, all caged and unvaccinated. There has been no major epidemic in the past two years. In late May 2002, after continuous heavy rain, due to the epidemic disease caused by low temperature and humidity in the rabbit house, more than 10 young and adult rabbits died of acute disease. after that, most of the rabbits showed chronic process, and more than 80 rabbits died slowly one after another.

2. Some of the diseased rabbits with acute death of clinical symptoms did not show any clinical symptoms and died suddenly, the course of disease was longer than 3mur6 days, the body temperature of the diseased rabbits increased to about 40 ℃, and there was a purulent secretion from the nasal cavity. Shortness of breath, frequent sneezing, sometimes dysentery, hypothermia before death, limb convulsions and death. Chronic cases, mainly showing the symptoms of rhinitis, began to flow out of serous rhinorrhea, and then turned to mucus-purulent rhinorrhea. Commonly used front claws to wipe the nose, so that the hair around the nostrils is moist and shedding, and the skin of the upper lip and nostrils is red and inflamed. As sick rabbits often grasp the nose, bacteria can be brought to the eyes, ears or subcutaneous, causing suppurative conjunctivitis, otitis media and subcutaneous abscess, severe dyspnea, frequent sneezing, coughing and sometimes dysentery. Several sick rabbits die in the rabbit farm every day.

3 pathological changes in nasal cavity: multiple mucus-purulent secretions, nasal mucous membrane hyperemia or bleeding, edema; larynx and trachea mucous membrane congestion, bleeding, and a large amount of red foam; pulmonary edema, congestion or hemorrhage; acute death rabbits can see liver deformation and necrotic spots; lymph nodes, splenomegaly, bleeding; intestinal mucosa sometimes can see congestion and bleeding. Most of the female rabbits showed uterine empyema after autopsy, some diseased rabbits had subcutaneous abscess, and individual male rabbits saw testicular enlargement or orchitis.

4. Bacteriological diagnosis

4.1 the liver, spleen, lung, kidney, uterine empyema and subcutaneous abscess were taken from the rabbits. Gram-negative bipolar bacilli were found by smear, Gram's and Wright staining and microscopic examination.

4.2 isolation and culture: the above diseased materials were inoculated on blood Agar medium by inoculating cyclobacteria. After 24 hours of culture at 37 ℃, gray and moist viscous colonies grew without hemolysis, and a large number of gram-negative bipolar microbacilli were still found by colony smear, staining and microscopic examination.

4.3 biochemical reaction: in order to distinguish Pasteurella multocida from Bordetella, the following biochemical experiments were done: from the detection to the colony of bipolar coloring bacteria, the aseptic operation of inoculation needle was inoculated into glucose, fried sugar, lactose, raffinose and rhamnose, 37 ℃ in biochemical reaction tube, the results showed that glucose and dark sugar produced acid discoloration (no gas production), but lactose, raffinose and rhamnose did not change.

5. Prevention and control measures

5.1 the rabbits in the whole field were examined one by one, and the rabbits with runny nose, sneezing, damp nose hair or other clinical symptoms were isolated and treated separately, without contact with healthy rabbits. Healthy rabbits were injected with rabbit plague-Pasteurella multocida vaccine.

5.2 to do a good job of disinfecting the rabbit farm, first thoroughly remove the rabbit feces, bedding grass, remaining feed and other dirt, and disinfect the ground with 10% Rich 20% lime milk. Rabbit cages and utensils are disinfected with 5% murine 10% bleach. The feces of diseased rabbits, bedding grass and other dirt were burned and some of them were buried deeply.

5.3. each rabbit was injected with Antibacterial King (Basik) injection with a dose of 0.5mg/kg body weight. Twice a day for 4 days.

5.4 healthy rabbits were given enrofloxacin in drinking water for 5 days per 5g/100kg of water.

5.5 strengthen the feeding and management, give full-price feed according to the standard, meet the nutritional needs, and pay attention to the environmental hygiene of the rabbit house. When there are conditions, the rabbit house should be cleaned, washed and disinfected regularly to avoid the appearance of damp condition. When there are major changes in the weather, such as continuous heavy rain and a sudden drop in temperature, strengthen the protection of rabbits and improve their immunity.

After taking the above measures, except for a few deaths, most of the clinical symptoms disappeared and no new cases occurred.

6. Summary

6.1 after the above clinical symptoms and bacteriological examination, it can be confirmed that the epidemic disease in the rabbit farm is rabbit pasteurellosis. The clinical symptoms of this disease are very similar to those of brucellosis in rabbits. It is also very similar in terms of bacterial morphology and culture characteristics. But Pasteurella can ferment glucose while Bordetella can't. From the above bacterial biochemical reaction, it can be confirmed that the bacteria is Palmiella rather than Bordetella.

6.2 Pasteurella multocida is a conditional pathogen. The occurrence of Pasteurella multocida is closely related to weather changes and feeding and management conditions. The author believes that the direct cause of the occurrence of Pasteurella multocida in the rabbit farm is the continuous heavy rain in May, the drop in temperature, the dampness of the rabbit house and poor feeding and management. To prevent the occurrence of this disease, we must do a good job of heat preservation, rain and moisture protection of the rabbit house, and strengthen the feeding and management at the same time.