Infectious hepatitis inflammation in dogs (Hepatitis contagiosa canis, CAV-1)
- Synonyms: Canine Adenovirus infection Type 1, Infectious Hepatitis in Dogs, Infectious Canine Hepatitis), Rubarth’s disease
- Occurrence: rarer
- Location of disease: General/Whole body
When to visit the vet?
Urgent see a veterinarian within 24 hours
If the condition worsens / symptoms persist, consult a veterinarian.
Definition
Infectious canine hepatitis (ICH), also known as canine contagious hepatitis, is a viral infection that primarily affects the liver of dogs. It is caused by Canine Adenovirus Type 1 (CAV-1) and can take both acute and chronic courses.
The most important facts at a glance
Infectious canine hepatitis (HCC) is caused by Canine Adenovirus Type 1 (CAV-1). This highly contagious virus spreads through direct Contact with infected animals or contaminated objects. It enters the body via the tonsils or pharynx and mainly affects the liver, but can also affect the kidneys, eyes, and vascular system. The disease manifests itself in symptoms such as Fever, weakness, loss of appetite, Vomiting, and Diarrhea. A definitive diagnosis is made by serological tests or PCR to detect the viral genome.
Since there is no specific antiviral therapy, treatment aims to relieve the symptoms. Fluid therapy, pain relievers, and anti-inflammatory drugs are some of the supportive measures. The prognosis depends on factors such as the age and immune status of the dog. Prevention is mainly through vaccination, which is part of the standard vaccination schedule. Good hygiene conditions and avoiding Contact with infected animals are also important.
Research focuses on new vaccines and therapeutic approaches to better understand and treat the disease. The development of safer and more effective vaccines is a priority, as is understanding the genetic and immunological mechanisms of the disease. Advances in these areas could reduce the impact of HCC on dogs worldwide.
Causes
ICH is caused by Canine Adenovirus Type 1 (CAV-1), which belongs to the Adenoviridae family. This virus is closely related to Canine Adenovirus Type 2 (CAV-2), which is responsible for respiratory diseases. CAV-1 is highly contagious and can be transmitted through direct Contact with infected animals or contaminated objects.
After infection, the virus enters the body via the tonsils or pharynx and spreads through the bloodstream. It primarily affects the liver, but can also impair the kidneys, eyes, and the dog’s vascular system. Viremia, i.e., the presence of viruses in the blood, leads to a systemic infection that is fought by the body’s immune system. The severity of the disease depends on the virulence of the pathogen and the dog’s immune status.
Common causes for the spread of CAV-1 include poor hygiene conditions, high animal density, and lack of immunity due to inadequate vaccination. Since the virus is relatively stable in the environment, it can be transmitted via contaminated surfaces, water, or feed. Infected dogs excrete the virus via saliva, urine, and feces, which increases the risk of infection for other dogs.
Symptoms
The symptoms of an HCC infection can vary depending on the course of the disease. In the acute phase, affected dogs often show Fever, loss of appetite, and lethargy. The liver is the main target organ, which is why symptoms such as Vomiting, Diarrhea, and Abdominal pain are common. Jaundice, recognizable by yellowish mucous membranes and eyes, can also be an indicator of liver involvement.
Another characteristic symptom is so-called “Blue Eye” (blue eye), a corneal opacity caused by immune-mediated inflammation of the cornea.
This can be temporary or, in severe cases, permanent. Some dogs also develop a Tendency to bleed, such as nosebleeds or pinpoint Bleeding on the skin and mucous membranes, which indicates impaired blood coagulation.
In severe cases, Convulsions, coma, and sudden Death can occur, especially in very young or immunocompromised animals. Chronic courses are also possible; symptoms may be milder and more nonspecific, but can lead to long-term liver dysfunction.
Therapy
The therapy for ICH depends on the severity of the symptoms and aims to alleviate the clinical signs and promote healing. There is no specific antiviral therapy against CAV-1, so the focus is on symptomatic and supportive therapy.
Fluid therapy is often necessary to correct dehydration and electrolyte imbalances. Pain relievers and anti-inflammatory drugs can be used to relieve Abdominal pain and Fever. In severe cases, corticosteroids can be administered to suppress the immune response and reduce inflammation.
Antibiotics may be required to treat secondary bacterial infections that result from the body’s weakened immune system. A special diet with easily digestible nutrients can support liver function and promote recovery.
Prognosis and follow-up care
The prognosis for HCC depends on various factors, including the dog’s age, immune status, and the severity of the disease. Dogs with a mild form of the disease usually have a good prognosis and can recover completely.
In severe cases, especially in young or unvaccinated dogs, the disease can take a critical course and even end in Death. However, early diagnosis and therapy can significantly improve the chances of survival.
Chronic courses can lead to permanent liver cirrhosis, which requires long-term medical care. Regular monitoring of liver function and an adapted diet are essential in such cases.
Prevention
The most effective method for the prevention of ICH is vaccination. The vaccine against CAV-1 is part of the standard vaccination schedule for dogs and offers reliable protection against the disease. As a rule, basic immunization is carried out in puppyhood, followed by regular booster vaccinations.
Additional prevention measures include good hygiene practices, especially in environments with many dogs, such as kennels or animal shelters. Regular cleaning and disinfection of surfaces and objects that dogs come into Contact with can reduce the risk of transmission of CAV-1.
Contact with infected animals should be avoided to prevent infection. Owners should ensure that their dogs do not have access to potentially contaminated water sources or feeding places to minimize the risk of infection.
Outlook on current research
Canine contagious hepatitis (Hepatitis contagiosa canis, HCC) is a significant disease caused by Canine Adenovirus Type 1 (CAV-1). Research on HCC is currently focused on various areas, including the development of improved vaccines, the identification of new therapeutic approaches, and understanding the genetic and immunological mechanisms underlying the disease.
A major advance in research concerns vaccine development. Current studies aim to develop vaccines that not only provide longer immunity but are also safer. Researchers are exploring the possibility of developing genetically modified vaccines that use specific protein structures of the virus to induce a robust immune response without the risk of vaccine-induced disease.
Another area of research is the study of the pathogenesis of HCC. Scientists are working to better understand how CAV-1 infects liver cells and what immunological reactions this triggers. This research could lead to new therapeutic approaches that minimize or reverse the damage caused by the virus.
The development of antiviral drugs is also an active area of research. Researchers are identifying and testing various compounds that could directly attack the virus or modulate the host’s immune response to reduce the disease burden. These efforts could lead to new treatment options for dogs with HCC.
There are also studies dealing with the genetics of the virus itself. By sequencing and analyzing the genetic information of CAV-1, scientists are trying to understand the genetic variations associated with different degrees of virulence and infectivity. These findings could help identify specific viral strains associated with more severe disease courses.
Another important aspect of research is the monitoring and epidemiology of HCC. Scientists analyze the spread and frequency of CAV-1 infections in different geographical regions to identify patterns and trends that could be helpful in developing prevention strategies. Monitoring also helps to quickly detect and contain outbreaks.
Collaboration between research institutions worldwide has accelerated progress in these areas. By sharing data and resources, researchers can reach new insights faster and translate their findings into practice.
Overall, research on HCC remains a dynamic field with promising potential to improve the prevention, diagnosis, and treatment of this disease. Advances in vaccine technology, the discovery of new drugs, and a better understanding of virus biology promise to reduce the impact of HCC on dog populations worldwide.
Frequently Asked Questions (FAQs)
1. What is Hepatitis contagiosa canis (HCC)?
2. How is HCC transmitted?
3. What Symptoms: does a dog with HCC show?
4. Can HCC be treated?
5. How can I protect my dog from HCC?
6. Can HCC be transmitted to humans or other animals?
7. How is HCC diagnosed?
8. Can a dog fully recover after an HCC infection?
9. How long is the incubation period for HCC?
10. How long can the virus survive in the environment?
Literature
- Decaro, N., Martella, V., & Buonavoglia, C. (2008). Canine adenoviruses and herpesvirus. Veterinary Clinics of North America: Small Animal Practice, 38(4), 799–814. https://doi.org/10.1016/j.cvsm.2008.02.006
- Chouinard, L., Martineau, D., Forget, C., & Girard, C. (1998). Use of polymerase chain reaction and immunohistochemistry for detection of canine adenovirus type 1 in formalin-fixed, paraffin-embedded liver of dogs with chronic hepatitis or cirrhosis. Journal of Veterinary Diagnostic Investigation, 10(4), 320–325. https://doi.org/10.1177/104063879801000402
- Caudell, D., Confer, A. W., Fulton, R. W., Berry, A., Saliki, J. T., Fent, G. M., & Ritchey, J. W. (2005). Diagnosis of infectious canine hepatitis virus (CAV-1) infection in puppies with encephalopathy. Journal of Veterinary Diagnostic Investigation, 17(1), 58–61. https://doi.org/10.1177/104063870501700111
- Bulut, O., Yapici, O., Avci, O., Simsek, A., Atli, K., Dik, I., Yavru, S., & Hasircioglu, S. (2013). The serological and virological investigation of canine adenovirus infection on the dogs. The Scientific World Journal, 2013, 587024. https://doi.org/10.1155/2013/587024
- Wong, M., Woolford, L., Hasan, N. H., Hemmatzadeh, F., & others. (2017). A novel recombinant canine adenovirus type 1 detected from acute lethal cases of infectious canine hepatitis. Viral Immunology, 30(4), 258–263. https://doi.org/10.1089/vim.2016.0041
- Walker, D., Abbondati, E., Cox, A. L., Mitchell, G. B., Pizzi, R., Sharp, C. P., Philbey, A. W., & others. (2016). Serological and molecular epidemiology of canine adenovirus type 1 in red foxes (Vulpes vulpes) in the United Kingdom. Scientific Reports, 6, 36051. https://doi.org/10.1038/srep36051
- Mira, F., Dowgier, G., Purpari, G., Vicari, D., Di Bella, S., Macaluso, G., Gucciardi, F., Randazzo, V., Decaro, N., & Guercio, A. (2022). Study on the canine adenovirus type 1 (CAdV-1) infection in domestic dogs in Southern Italy. Pathogens, 11(11), 1254. https://doi.org/10.3390/pathogens11111254