Diagnosis and treatment of infectious hepatitis in dogs

Canine infectious hepatitis is an acute and highly contagious septic infectious disease in dogs caused by canine adenovirus type I. it is characterized by circulatory disturbance, central necrosis of hepatic lobules, and nuclear inclusion bodies in liver parenchyma and endothelial cells. Dahe foxes are highly susceptible, and coyotes, raccoons and black bears are also susceptible. It can also infect people, but does not cause clinical symptoms.

Infectious canine hepatitis virus (IBV) belongs to adenoviridae, mammalian adenoviruses and has only one antitype. The resistance of the virus is so strong that it can survive on pollutants for 10 ~ 14 days, survive for 10 ~ 16 weeks at room temperature, remain infectious after 56 ℃ for 30 minutes, and kill for 3 ~ 5 minutes after 60 ℃. Tolerance to ether, chloroform and other lipid solvents. Phenol, iodine tincture and caustic soda are commonly used effective disinfectants.

Epidemiology the disease is widespread and can occur all the year round, regardless of age and sex, but it is most common in young dogs less than 1 year old, especially from 2 months to 3 months old. The incidence of the disease is high, and the case fatality rate ranges from 25% to 40%. The cured dogs can get lifelong immunity, but they can still carry the virus and detoxify from the urine for as long as 6 to 9 months. Sick dogs and convalescent dogs are the main sources of infection of the disease. the virus is excreted with vomit, saliva, feces, urine and other secretions and excretions of diseased dogs, polluting food, drinking water, utensils and the surrounding environment. Healthy dogs are infected through the digestive tract, and some are infected through the placenta.

The incubation period of clinical symptoms is usually 3 ~ 5 days, and the most acute cases often die within 12 ~ 24 hours after the onset of symptoms. The course of disease in most cases was 10 ~ 15 days. In acute cases, the initial dogs were afraid of cold and loss of appetite, and then the body temperature increased to 40 ℃ ~ 41 ℃. It decreased to normal temperature after 1 ~ 2 days, and increased again 4 ~ 5 days later. At this time, the sick dog has no appetite, thirst likes to drink, common vomiting, diarrhea, eye and nose serous mucous secretions, abdominal pain and moaning. Oral mucous membrane hyperemia, bright red, tonsil inflammation, obvious enlargement of submandibular lymph nodes, palpation of liver pain and swelling, sick dogs groaning in pain. Left anterior abdomen and splenomegaly were palpated. The symptoms of subacute cases were mild. The body temperature of the diseased dogs increased slightly, a few of them had edema of head, neck and lower abdomen, increased heartbeat and accelerated breathing. During the rehabilitation period, about 15% to 20% of sick dogs develop temporary corneal opacity in one or both eyes (ophthalmitis), commonly known as hepatoinflammatory blue eye disease, mostly temporary, and a few can cause permanent damage or even blindness. Most of them recovered or died within 2 weeks. The case fatality rate of puppies is about 20%. Most adult dogs have been able to do so.

The pathological changes were mainly systemic septicemia, common subcutaneous edema, and bleeding spots of different sizes could be seen in parenchyma, serosa and mucosa. Abdominal effusion, ascites blood color. The appearance of the liver is enlarged and the edge becomes blunt. The gallbladder is enlarged and filled with bile. The gallbladder wall is highly edematous, thickened and bleeding, showing black-red, which is a characteristic lesion. Kidney enlargement, mesenteric lymph node bleeding.

A preliminary diagnosis can be made according to clinical symptoms, epidemiological and pathological changes. Because the disease is often complicated with canine distemper, it should be treated carefully. Virus isolation and serological diagnosis are necessary for diagnosis. Artificial infection occurs in foxes and dogs, but not in ferrets.

Prevention and treatment measures vaccination: regular vaccination of dogs can effectively prevent the occurrence of this disease. The puppies were immunized for the first time at 45 days old and boosted once at 60 days old and 75 days old respectively. Every six months from the second year, each dog is vaccinated with one bottle of vaccine, big or small. The domestic canine vaccine has good immune effect against canine parvovirus, rabies, canine infectious hepatitis and canine parainfluenza, especially the immune protection rate against canine infectious hepatitis and canine parvovirus is close to 100%. According to expert estimates, the vaccination rate of canine vaccines is less than 10%, mainly because people have little awareness of vaccinating dogs. Therefore, to expand the coverage of canine vaccination and improve the immune density is the key to control the disease.

Treatment of sick dogs: the mortality rate of puppies with this disease is high, there is no specific drug treatment at present, and comprehensive treatment is usually used. The early stage of the disease was treated with hyperimmune serum or whole blood, serum or plasma or gamma globulin of convalescent dogs, subcutaneously injected once every other day for 2 ~ 3 times, which could inhibit the reproduction and spread of the virus. 5% glucose saline 150ml, plus Vc250mg, VBl2150mg~200mg, coenzyme A1 branch, ATP1 branch, inosine 1 branch, intravenous injection, once a day, to correct water and electrolyte disorders. 30% florfenicol 1m1, compound astragalus polysaccharide 2ml, intramuscular injection, once a day to control complications and secondary infection, Gantaile 2 ~ 3 tablets orally, three times a day to protect the liver and gallbladder.

Control measures: in the event of an epidemic, isolation measures should be strictly implemented to avoid direct and indirect contact between sick dogs and healthy dogs, and dead dogs should be burned and buried. Kennels, grounds and breeding utensils are disinfected with 3% sodium hydroxide solution. Newly introduced dogs should be isolated and observed for not less than 15 days. For healthy dogs, emergency immunization with five or six vaccines or subcutaneous injection of adult dog serum to young dogs less than 1 year old during the epidemic period of the disease, once a week, once a time, 3ml~5ml, can effectively control the epidemic situation.