강아지 바이러스성 간염(개 전염성 간염) 증상과 원인, 진단·치료와 관리 포인트 총정리

If Your Dog’s Eyes Turn Blue — Symptoms and Treatment Timing for Canine Infectious Hepatitis

Liver HealthDiseasesMeongsiljang Veterinary Advisory Board

Canine viral hepatitis is a contagious disease caused by adenovirus type 1, leading to liver damage and various symptoms. Early diagnosis and proper management are essential.

Canine Viral Hepatitis Is a Contagious Disease Caused by Adenovirus Type 1

A dog showing suspected symptoms of canine viral hepatitis

Canine viral hepatitis is an infectious disease caused by canine adenovirus type 1 (CAV-1). The virus is primarily shed in the urine and respiratory secretions of infected dogs, and even dogs that have recovered can continue to shed the virus for several weeks to months. Because adenovirus can survive in the environment for extended periods, contaminated surroundings themselves can serve as sources of infection. The disease typically presents with acute, severe symptoms in young puppies, causing damage to the liver and kidneys, and may be accompanied by respiratory signs or ocular manifestations known as "blue eye." The acute form progresses rapidly after onset and can be fatal, making early detection and vaccination paramount. The cornerstone of management is blocking transmission routes and avoiding high-risk environments.

The Cause of Infection Is Adenovirus Type 1 and Contaminated Environments

Canine viral hepatitis is caused by canine adenovirus type 1 (CAV-1). This virus is primarily shed in the urine and respiratory secretions of infected dogs, and even recovered dogs can continue to shed the virus for several weeks to months. Because adenovirus can survive in the environment for extended periods, infection can occur through contact with contaminated soil, water, or toys. Unvaccinated puppies are at the highest risk. The virus invades liver cells, causing inflammation and liver damage. The acute form can be fatal, with most cases either recovering or resulting in death within two weeks of onset. In some cases, the kidneys and eyes (resulting in "blue eye") may also be affected, so it is best understood as a systemic disease.

The canine adenovirus that causes infectious canine hepatitis can persist in contaminated environments.

Main Symptoms Include Fever, Vomiting, Diarrhea, and Abdominal Pain

The main symptoms of canine viral hepatitis include fever, loss of appetite, lethargy, vomiting, diarrhea, and abdominal pain. In young dogs, the disease often presents in an acute form, with high fever exceeding 40°C, rapid heart rate and breathing, and enlarged tonsils. The abdomen may swell due to liver enlargement, dehydration can progress rapidly, and vomiting blood or bloody stools may occur. Damage to the blood vessel lining can lead to bleeding disorders such as petechiae and ecchymoses, and during recovery, the cornea may become cloudy with a bluish tint, known as "blue eye." The acute form progresses quickly, with recovery or death occurring within two weeks of onset, so prompt action is crucial if symptoms appear.

Abdominal swelling and discomfort in a puppy with viral hepatitis

Emergency Symptoms Requiring Immediate Veterinary Visit

If your dog suddenly collapses, experiences severe vomiting, or passes bloody stool, you should go to the vet immediately. If a fever persists above 40 degrees Celsius, or if their eyes and lips become pale and their breathing becomes rapid, this is life-threatening and requires immediate emergency care. If there is suspicion of a blood clotting disorder due to liver dysfunction, blood transfusions or specialized treatment may be necessary.

Diagnosis Is Confirmed Through Blood Tests and Viral Antibody Testing

Diagnosing canine viral hepatitis involves blood tests and viral antibody testing. - Liver function tests: A sharp rise in ALT and AST levels suggests liver damage. - Antibody tests: These help accurately determine infection status and confirm the presence of the pathogen. - Complete blood count: Changes in white blood cell counts indicate an inflammatory response. - Ultrasound examination: This allows for visual assessment of changes in liver size or structural abnormalities. Early diagnosis is a key factor in significantly improving treatment success rates.

Blood test procedures for diagnosing canine viral hepatitis

Treatment Focuses on Symptom Management and Supportive Care

Since there is no specific antiviral medication for canine viral hepatitis, treatment focuses on symptom management and supportive care. Intravenous fluids are administered to prevent dehydration, while antiemetics and gastrointestinal protectants are used to control vomiting and soothe the stomach. Nutritional supplements are provided to support liver function recovery, and in severe cases, blood products may be given to address coagulation disorders. The treatment period typically lasts one to two weeks, and liver function tests should be monitored even after recovery.

A puppy receiving intravenous injections during treatment for viral hepatitis

Home Care: Fluid Supplementation and Rest Are Most Important

During the recovery phase of canine viral hepatitis, it is important to provide a quiet environment for rest and consistently supply small amounts of fluids and nutrients. If your dog has no appetite, use liquid nutritional supplements or oral rehydration solutions to maintain hydration. Avoid meat and fatty foods, and instead offer soft, easily digestible meals. Completely prevent contact with infected dogs and thoroughly disinfect the environment with a disinfectant. Even after recovery, limit outdoor activities for 2 to 4 weeks.

Home care for a dog during the recovery phase of viral hepatitis

Breed-Specific Precautions: Poodles, Terriers, and Others Have Higher Risk

It is not definitively established in veterinary textbooks that specific breeds are more susceptible to viral hepatitis. However, unvaccinated puppies are more prone to developing severe acute symptoms, so extra caution is warranted. Therefore, timely vaccination is the most effective preventive measure. Even after recovery from infection, liver dysfunction may persist, so regular monitoring of liver enzymes (ALT and AST) and bilirubin levels is recommended to check for long-term damage. Combining this with good hygiene practices and preventing exposure to contaminated environments can further reduce the risk of infection.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Can canine viral hepatitis be transmitted to humans?

No, canine infectious hepatitis is not transmitted to humans. This virus affects only dogs, so people cannot become infected.

When should I start getting my pet vaccinated?

Vaccinations typically begin at 6 weeks of age, with 2–3 doses administered at 2–4-week intervals to ensure effectiveness. Please consult your veterinarian to schedule the appropriate vaccination plan.

Is testing still necessary after recovery?

Yes, it’s important to check for any long-term damage by performing liver function tests even after recovery. We recommend follow-up testing in 1–2 months.

Can I live with an infected dog?

No, you should absolutely avoid contact with infected dogs. Since the virus can survive in the environment for extended periods, thorough disinfection is required, followed by a minimum one-month quarantine.

What side effects can occur after vaccination?

Mild fever, lethargy, and decreased appetite may occur temporarily. Severe reactions are rare, but if symptoms persist or difficulty breathing develops, seek veterinary care immediately.

Comparison Table of Vaccines for Canine Viral Hepatitis

Item	Vaccination Type	Timing	Duration of Efficacy	Precautions
First vaccination	Modified live CAV-2 vaccine (prevents infectious canine hepatitis via CAV-1 cross-protection)	From 6 weeks of age	1 year	In high-infection-risk environments, a second dose is needed 2 weeks later
Second vaccination	Combination vaccine (CAV-2 based, includes infectious canine hepatitis)	10 weeks of age	1 year	Restricting activity within 24 hours after vaccination is recommended
Booster shot	Revaccination after 1 year	After 12 months	3 years	Per veterinary judgment based on individual circumstances

Modern vaccines use a modified live CAV-2 vaccine rather than CAV-1 and provide excellent cross-protection against CAV-1. Vaccination is recommended by the veterinarian according to the dog's health status and environment, and a pre-vaccination checkup is essential.

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References

[1] Clinical Medicine of the Dog and Cat, 4th Ed, 2021

[2] Plumb's Veterinary Drug Handbook, 9th Ed, 2022

[3] American Veterinary Medical Association (AVMA) Guidelines on Canine Infectious Diseases, 2023