Infectious Canine Hepatitis (ICH)

Infectious canine hepatitis (ICH) is a viral disease that primarily affects the liver but can also impact other vital organs in dogs. The disease is caused by the canine adenovirus type 1 (CAV-1), a member of the family Adenoviridae, and the genus Mastadenovirus. ICH poses significant health risks to canines worldwide and requires attention from veterinary researchers. BioVenic has been engaged in ICH-related research for many years and has formed profound insights. We can provide our customers with diagnostic and preventive solutions and tools for ICH.

Etiology

The diameter of CAV-1 is approximately 80 nm, and its morphological and structural features closely resemble those of other animal adenoviruses, characterized by an icosahedral stereo-symmetric structure. The spheroid exhibits hemagglutinin on its surface, facilitating the binding of the virus to cell receptors during cell infection. Notably, CAV-1 demonstrates a remarkable environmental survival capability, particularly in the urine, saliva, and feces of infected dogs, rendering it highly contagious.

Fig. 1 Schematic diagram of the structure of CAV-1.¹

Geographical Distribution

ICH exhibits a global distribution and is widespread in various countries, including the United Kingdom, Denmark, Norway, Australia, Canada, and the United States. It is not constrained by a specific season, sex, or breed, and can affect any infected dog. The prevalence of ICH may vary regionally, influenced by differences in vaccination coverage and the population density of susceptible animals.

Susceptible Animals

CAV-1 has a high susceptibility in dogs and foxes, with coyotes, raccoons, and black bears also being prone to infection. Dogs of all ages and breeds can be affected by CAV-1, but puppies, particularly those under one year of age, exhibit a higher susceptibility due to their immature immune systems.

Transmission

CAV-1 mainly infects dogs through the digestive tract. Infected dogs pollute the surrounding environment through eye and nose secretions, feces, urine, etc., and then infect other healthy dogs. In addition, the virus can also be transmitted through the placenta.

The main source of CAV-1 infection is sick dogs and infected dogs after recovery, especially virus-infected dogs can still detect the virus from the urine within 6-9 months of recovery.

Pathogenesis

Once the CAV-1 enters the body, it replicates in the tonsils and regional lymph nodes. From there, the virus spreads to the bloodstream, leading to viremia. The liver is a primary target organ, resulting in hepatic necrosis and subsequent damage. The virus can also affect other organs, such as the kidneys, spleen, lungs, and eyes, leading to a range of clinical signs and symptoms.

Signs and Symptoms

In the early stage of ICH, its clinical symptoms are similar to canine distemper. Affected dogs may exhibit all or some of the following symptoms:

Diagnosis

• Laboratory tests such as complete blood count (CBC), serum biochemical profiles, and coagulation tests can unveil abnormalities indicative of liver dysfunction.
• Veterinary immunodiagnostics, such as ELISA and immunohistochemistry (IHC) prove effective in detecting the presence of CAV-1 antibodies or antigens, thereby confirming exposure or active infection.
• For veterinary molecular diagnostics, advanced techniques like PCR, NGS, and LAMP can be employed to detect CAV-1 genetic material.
• We are fully capable of developing CAV-1 diagnostic kits for you based on the above principles.

Treatment and Prognosis

There is no specific drug for ICH.

Medications such as antiemetics, analgesics, and hepatoprotective drugs may be administered based on the dog's condition. Severely affected dogs may require hospitalization and intensive care, including plasma transfusions for coagulation abnormalities. The prognosis for ICH varies depending on the severity of the disease, timely intervention, and the individual dog's response to treatment.

Prevention and Control

The main measures to prevent the occurrence of ICH are regular immunization and strengthening feeding management.

Vaccination

• Regular vaccinations are recommended for all dogs as part of a comprehensive vaccination program.
• Since CAV-1 and CAV-2 are immunologically crossed, the CAV-2 vaccine can make it resistant to CAV-1, and it will not cause eye disease and nephritis. The protection can be produced 2 weeks after vaccination, so the CAV-2 attenuated vaccine is commonly used to immunize dogs against CAV-1 infection.

Other Prevent Measures

• Ensure that both the kennel and the dog are kept clean and hygienic.
• It's important to ensure proper ventilation in the kennel and maintain consistent disinfection practices.
• It is strictly forbidden to mix with other dogs.
• Timely isolation of sick and suspicious dogs, and timely disinfection to avoid CAV-1 contamination of the environment.

As a professional veterinary diagnostics CRO, BioVenic is dedicated to promoting the health and well-being of dogs. We contribute to the early detection of ICH through the development of advanced diagnostic tools and methods. Additionally, we help veterinary researchers meet challenges by advancing the development of more effective vaccines. If you are interested in working with us, please feel free to contact us.

Reference

1. Sykes JE. "Infectious Canine Hepatitis." Canine and Feline Infectious Diseases. 2014: 182-186.