A Comprehensive Analysis of the Prevention and Treatment of Infectious Canine Hepatitis

Infectious canine hepatitis is an acute infectious disease caused by canine adenovirus infection. It is characterized by mainly affecting puppies under 1 year of age and often causing acute necrotizing hepatitis, and it is frequently complicated by mixed infection with canine distemper in clinical practice. This disease occurs almost everywhere in the world and is a common infectious disease of dogs, but it is often overlooked or misdiagnosed by breeders; therefore, adopting comprehensive prevention and control measures against this disease is very important for the healthy development of the dog-breeding industry.

1 Outbreak situation

A dog-breeding household in Zhaoyuan County purchased 12 meat-purpose growing dogs from elsewhere on July 16, including 8 Saint Bernards and 4 Great Danes, and it was unclear whether they had been vaccinated against canine hepatitis. After being brought back, they were not placed under isolation observation but were instead mixed and raised with the originally kept dogs. On July 28, 1 Saint Bernard became ill and died the next day; on July 30, another Saint Bernard and 1 Great Dane became ill and were brought to the station for treatment; on August 4, another Saint Bernard became ill.

2 Clinical symptoms

The early symptoms of the sick dogs were very similar to those of canine distemper, manifesting as depression, poor appetite, significantly increased thirst, vomiting, and diarrhea. The abdominal circumference increased, and palpation revealed fluctuation; percussion produced a horizontal dull sound, and abdominal puncture drained a large amount of pale red fluid. Body temperature rose above 40°C and persisted for 3 to 5 days. The sick dogs had pain in the xiphoid cartilage area; the corneas were cloudy and disappeared after treatment 3 days later. Among the treated sick dogs, 1 dog had scrotal edema, and another dog had blood in its vomit and feces and died the next day.

3 Pathological changes

Necropsy of the dead dogs showed fluid accumulation in the abdominal cavity, a layer of fibrin covering the mesentery and liver surface, enlarged and pale liver, edematous and thickened gallbladder wall, congested and enlarged mesenteric lymph nodes, and pinpoint-sized hemorrhagic spots visible on the liver surface.

4 Laboratory testing and diagnosis

4.1 Bacteriological examination: The heart and liver of the dead dogs were separately inoculated onto ordinary agar medium and cultured at 37°C for 48 hours before observation, and no bacterial growth was seen.

4.2 Histopathological examination: After frozen sections of liver tissue were fixed and stained with alkaline fuchsin, microscopy revealed multinucleated giant fused cells in the hepatocyte nuclei as intranuclear inclusion bodies, with thickened and deeply stained nuclear membranes and transparent gaps between the nuclear membranes and the inclusion bodies.

4.3 Comprehensive diagnostic analysis: Based on the above clinical symptom manifestations, necropsy changes, and laboratory tests of the sick dogs, a comprehensive judgment confirmed that the 4 affected dogs were suffering from infectious hepatitis.

5 Comprehensive prevention and control

5.1 Prevention and control

Through the diagnosis and treatment of the above 3 sick dogs and analysis of the onset situation and causes of death of the early dead dogs, based on the actual situation of disease prevention and control in the dog-breeding industry and our many years of experience in animal epidemic prevention work, for dog-breeding households, especially large-scale dog-breeding farms (households), the following four points should mainly be done well in the prevention and control of dog diseases,

① Strengthen feeding management, feed and water complete compound feed and clean water at fixed times and in fixed amounts, and enhance the body's own disease resistance. Do a good job of hygiene in the kennels and of the dogs themselves, keep the kennels well ventilated, and keep the environment clean; ② Breed, raise, and keep dogs by oneself to reduce or eliminate externally introduced diseases; ③ Carry out immunization with relevant vaccines (bacterins) on time, which is the key measure for preventing infectious diseases; ④ Isolate sick dogs promptly, feed them separately, and treat them as early as possible; at the same time, urgently vaccinate healthy dogs with vaccines (bacterins) related to the occurring disease.

5.2 Treatment

5.2.1 Puncture drainage: Perform abdominal puncture drainage on sick dogs with relatively large amounts of abdominal effusion. However, be careful not to drain it all at once, so as to avoid a sharp drop in abdominal pressure, causing congestion of abdominal organs and massive fluid loss that may lead to collapse of the sick dog. After the fluid is completely drained, inject 6 to 8 g of Xianfeng VI diluted with water for injection into the abdominal cavity through the puncture needle.

5.2.2 Oral diuretics: Choose amphenpyrimidine, 5 mg daily, taken orally in 2 divided doses. Other diuretics should be chosen cautiously to prevent hepatic coma. When taking diuretics, pay attention to stress reactions such as anorexia, vomiting, and dry mouth; if these are found, the dose may be reduced to 1.0 to 1.5 mg daily and maintained for 3 to 4 days.

5.2.3 Blood transfusion therapy: Select healthy, immunized dog blood and conduct a three-drop test and a normal saline ratio test with the sick dog to find a suitable blood type, then transfuse 40 to 60 mL per day to the sick dog for 3 consecutive days.

5.2.4 Fluid replacement therapy: Per kg of body weight, mix 1.0 mL of 5% glucose, 8 to 10 mL of normal saline, 0.1 to 0.5 mL of 10% Vc, 0.1 mL of 2.5% VB6, and 0.2 g of Xianfeng VI for 1 intravenous injection, once daily for 3 consecutive days. For severely collapsed sick dogs, an additional 0.5 g of hydrolyzed protein may be infused and insulin injected intramuscularly.

6 Summary

For dogs with infectious hepatitis, after the above treatment, the symptoms are significantly alleviated in about 4 days. At this point, blood transfusion and fluid replacement can be stopped, but general symptomatic treatment should be adopted until recovery.

Practice has shown that there is no other specific effective therapy for infectious canine hepatitis. During treatment, medication should be given symptomatically according to clinical symptoms and with reference to blood indicators, liver function changes, and so on. For severe sick dogs whose condition continues to worsen during treatment, such as oliguria, bleeding, and coma, unfavorable factors must be eliminated promptly to prevent secondary infection with other diseases and the occurrence of serious consequences such as hypoglycemia and coagulation disorders. Time must be gained as quickly and to the greatest extent possible for the recovery of liver function and the regeneration of liver cells.