Detailed Explanation of Key Points for the Prevention and Control of Mink and Raccoon Dog Diseases

This disease is an acute, highly contagious infectious disease caused by a virus. The main characteristics of this disease are severe diarrhea, with grayish-white sloughed intestinal mucosa and fibrin mucous masses in the feces, a significant decrease in white blood cells, and severe gastrointestinal inflammatory changes.

1. Pathogen The pathogen of this disease is raccoon dog enteritis virus, which has the main characteristics of the parvovirus group. From the perspective of the virus, raccoon dog enteritis virus is related to feline panleukopenia virus, and the vaccines prepared from each can provide cross-protection to each other; however, protection against canine parvovirus enteritis is poor.

2. Epidemiological characteristics

The main sources of infection for this disease are sick raccoon dogs and raccoon dogs that have survived the disease (they carry the virus for at least one year and shed the virus for more than one year). Cats with panleukopenia, raccoon dogs with viral enteritis, and dogs with parvovirus enteritis can all cause viral enteritis in raccoon dogs. It is mainly transmitted directly or indirectly through the digestive and respiratory tracts, and can also be spread through the feces, urine, and saliva of sick raccoon dogs. Contaminated feed, water sources, equipment, and the environment cause susceptible animals to become infected.

This disease often occurs as an endemic outbreak in young raccoon dog populations, with a morbidity rate of 50%-60% and a mortality rate of up to 90%; in adult raccoon dogs, morbidity and mortality are generally around 20%, and most cases are chronic and latent infections. Recovered raccoon dogs can acquire relatively long-lasting immunity, but they still carry the virus and are the most dangerous source of infection.

This disease mostly occurs from June to October. If effective measures are not taken, it can cause an endemic outbreak and lead to recurrence in young raccoon dog populations around the time of weaning in the following year.

3. Clinical symptoms

The incubation period is generally about 5 days. In acute cases, death can occur the day after onset, with most cases occurring from 4 to 14 days, and after 15 days gradually turning into subacute or chronic courses.

The earliest symptoms in affected raccoon dogs are decreased appetite or complete loss of appetite, depression, rough and lusterless fur, increased thirst, and sometimes vomiting. The feces are initially soft and then thin and mostly mucous, grayish-white, with a few being bright red or reddish-brown, gradually becoming yellow-green and watery, and sometimes feces with streak-like blood traces are seen. As the disease worsens, the feces contain mucous of various colors; the sloughed mucous varies in thickness and is gray, yellowish-white, white, cream-colored, or black like coal tar. In severe diarrhea cases, tenesmus is often present, and in the later stage there is mostly extreme weakness and emaciation, sunken eye sockets, and finally death from exhaustion; in recovered raccoon dogs, recurrence mostly has a poor prognosis. White blood cells are significantly reduced, and most cases are aggravated by concurrent Escherichia coli and Salmonella infections.

4. Anatomical and pathological changes

Characterized by acute catarrhal, fibrinous, and hemorrhagic enteritis changes. The small intestine often shows acute hemorrhagic inflammation, the intestinal contents are mixed with dark red blood-like material, and the appearance is like bloody intestine; in some cases the intestinal contents are yellow-green and watery. In raccoon dogs that die from subacute or chronic courses, there are fibrinous necrotic lesions on the intestinal wall, most mesenteric lymph nodes are swollen, some spleens are enlarged, the gallbladder is full of bile, and the liver is earth-yellow and friable.

5. Diagnosis

Based on epidemiology, clinical characteristics, and a sharp decrease in white blood cells, a preliminary diagnosis can be made; for confirmation, specific hemagglutination and hemagglutination inhibition diagnostic techniques or virus isolation and identification can be carried out.

6. Prevention and treatment

Regular annual vaccination with antiviral enteritis vaccine should be used to control the occurrence of this disease.

In ordinary times, feeding and hygiene management must be strengthened, and the introduction of breeding animals from epidemic areas must be strictly controlled; breeding animals introduced from non-epidemic areas must also be isolated and observed, and only after being confirmed healthy can they be mixed into the group for rearing.

Raccoon dog viral enteritis vaccine can be used for emergency vaccination, and at the same time antibiotics combined with symptomatic treatment can be used for affected raccoon dogs, thereby controlling secondary bacterial infection.