Infectious Canine Hepatitis in Dogs – Symptoms, Diagnosis & Treatment

Medically reviewed for accuracy. This article is for informational purposes only and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult your veterinarian with questions about your dog's health.

What Is Infectious Canine Hepatitis?

Infectious canine hepatitis (ICH) is a highly contagious viral disease caused by canine adenovirus type 1 (CAV-1) that primarily attacks the liver, kidneys, eyes, and blood vessel linings in dogs. The disease ranges from a mild, barely noticeable infection to a rapidly fatal illness, and it can affect dogs of any age—though unvaccinated puppies are at the greatest risk. Thanks to widespread vaccination, ICH has become uncommon in many developed countries, but it remains a serious threat in areas where vaccination rates are low and in wildlife populations that serve as reservoirs.

CAV-1 belongs to the family Adenoviridae and is distinct from canine adenovirus type 2 (CAV-2), which causes respiratory disease. Once a dog is exposed—typically through contact with infected urine, feces, saliva, or nasal secretions—the virus enters through the mouth or nose and initially replicates in the tonsils and regional lymph nodes. Within days, it spreads through the bloodstream (a phase called viremia) to target organs, especially the liver (causing hepatitis), the kidneys (causing nephritis), and the vascular endothelium (the inner lining of blood vessels). This endothelial damage is responsible for many of the hallmark features of ICH, including hemorrhage, edema, and the characteristic "blue eye" opacity that can develop during recovery.

Symptoms of Infectious Canine Hepatitis in Dogs

The clinical signs of ICH vary widely depending on the severity of infection. Some dogs develop only a mild, subclinical illness, while others deteriorate rapidly. Recognizing the progression of symptoms can be critical for early intervention.

Early Signs

• Fever — An initial spike to 104°F (40°C) or higher is often the first sign, sometimes appearing within 1–2 days of infection.
• Lethargy and decreased energy — Your dog may seem unusually tired, reluctant to play, or slow to respond.
• Loss of appetite (anorexia) — Refusal of food or markedly reduced eating.
• Mild nasal or eye discharge — A clear, watery discharge from the nose or eyes.
• Increased thirst and urination — Early kidney involvement may cause changes in water intake and urination patterns.
• Swollen tonsils and sore throat — Difficulty swallowing or gagging, since the tonsils are among the first tissues affected.

Progressive Symptoms

• Abdominal pain and distension — Tenderness over the liver area (right side of the abdomen) and possible fluid accumulation (ascites).
• Vomiting and diarrhea — Often with blood, indicating gastrointestinal and vascular involvement.
• Jaundice (icterus) — Yellowing of the gums, whites of the eyes, and skin due to liver dysfunction.
• Enlarged liver (hepatomegaly) — Detectable on palpation or imaging.
• Petechiae and ecchymoses — Small or larger areas of hemorrhage visible on the skin, gums, or inside the ears, caused by blood vessel damage and clotting disorders.
• "Blue eye" (corneal edema) — A distinctive bluish-white cloudiness of one or both eyes, occurring in about 20% of naturally infected dogs, typically 1–3 weeks after infection. This results from immune complex deposition in the cornea and usually resolves on its own.
• Swollen lymph nodes (lymphadenopathy) — Palpable enlargement of lymph nodes throughout the body.

Emergency Signs

Seek immediate veterinary care if you observe any of the following:

• Collapse or inability to stand
• Uncontrolled bleeding from the gums, nose, rectum, or injection sites
• Seizures or disorientation — Indicating possible central nervous system involvement or hepatic encephalopathy
• Persistent, severe vomiting with blood
• Extreme abdominal distension with signs of pain
• Pale or white gums — Suggesting severe anemia or shock
• Sudden death — Peracute (hyperacute) ICH can kill puppies within hours, sometimes before any obvious signs appear

What Causes Infectious Canine Hepatitis in Dogs?

ICH is caused exclusively by canine adenovirus type 1 (CAV-1). The virus is remarkably hardy and can survive in the environment for weeks to months, particularly in cool, shaded conditions. Key risk factors include:

Transmission Routes

• Direct contact with infected dogs or wildlife (foxes, wolves, coyotes, bears, and other canids can carry CAV-1).
• Oral or nasal exposure to contaminated urine, feces, saliva, or nasal secretions. Recovered dogs can shed the virus in their urine for up to 6–9 months after infection.
• Fomite transmission — Contaminated food bowls, bedding, kennels, or equipment can harbor the virus.

Risk Factors

• Vaccination status — Unvaccinated or incompletely vaccinated dogs are at the highest risk. This is by far the most important risk factor.
• Age — Puppies under one year are particularly vulnerable, especially between 3 and 12 weeks when maternal antibodies are waning.
• Immune compromise — Dogs with weakened immune systems (from concurrent disease, malnutrition, or immunosuppressive medications) face greater risk.
• Exposure to wildlife — Dogs in rural areas or those that contact wildlife are more likely to encounter CAV-1.
• Shelter and kennel environments — High-density housing increases transmission opportunity.
• Lack of environmental disinfection — CAV-1 is resistant to many common disinfectants, though bleach solutions (sodium hypochlorite) and steam cleaning are effective.

Breeds Most at Risk

Infectious canine hepatitis does not have a strong breed predisposition—any unvaccinated dog can contract CAV-1. However, certain factors make some groups more vulnerable:

• Puppies of any breed — Young, unvaccinated, or partially vaccinated puppies face the highest mortality rates.
• Working and sporting breeds with greater outdoor and wildlife exposure (e.g., Labrador Retrievers, German Shepherds, Beagles, Coonhounds) may encounter the virus more frequently due to their environments.
• Sled dog breeds (e.g., Siberian Huskies, Alaskan Malamutes) in regions where wildlife reservoirs are common.
• Immunocompromised dogs of any breed, including those undergoing chemotherapy or long-term corticosteroid therapy.

How Infectious Canine Hepatitis Is Diagnosed

Because ICH can resemble many other conditions—including leptospirosis, canine distemper, toxin ingestion, and other causes of acute hepatitis—accurate diagnosis requires a systematic approach.

Initial Examination

Blood Work

• Complete blood count (CBC) — May reveal leukopenia (low white blood cell count) in early disease, followed by leukocytosis during recovery. Thrombocytopenia (low platelet count) is common and contributes to bleeding.
• Serum biochemistry panel — Markedly elevated liver enzymes (ALT, AST, ALP), elevated bilirubin, and low albumin indicate liver damage. Elevated BUN and creatinine may suggest kidney involvement.
• Coagulation profile — Prolonged clotting times (PT, aPTT) reflect disseminated intravascular coagulation (DIC), a life-threatening complication.
• Estimated cost: $150–$400 for comprehensive blood panels.

Urinalysis

Specific Diagnostic Tests

• Serology — Paired serum antibody titers (taken 2–3 weeks apart) showing a fourfold rise confirm active infection. Single high titers may reflect vaccination rather than natural infection.
• PCR (polymerase chain reaction) — Detects CAV-1 DNA in blood, urine, or tissue samples. This is the most sensitive and specific test, with results typically available in 1–3 days. Cost: $100–$250.
• Virus isolation — CAV-1 can be cultured from blood during the viremic phase or from liver and kidney tissue, though this is primarily a research or reference lab technique.

Imaging

• Abdominal ultrasound — Reveals hepatomegaly, changes in liver echogenicity, gallbladder wall edema, peritoneal effusion, and kidney abnormalities. Cost: $200–$500.
• Radiographs — May show liver enlargement and fluid in the abdomen.

Post-Mortem Diagnosis

Treatment Options for Infectious Canine Hepatitis

There is no antiviral drug that specifically targets CAV-1. Treatment is entirely supportive, aimed at maintaining organ function and managing complications while the dog's immune system fights the virus.

Medical Management

• Intravenous (IV) fluid therapy — Aggressive crystalloid and colloid fluid support to maintain hydration, blood pressure, and organ perfusion. This is the cornerstone of treatment for moderate to severe cases.
• Anti-nausea medications — Maropitant (Cerenia) or ondansetron to control vomiting and allow nutritional support.
• Hepatoprotective agents — S-adenosylmethionine (SAMe), silymarin (milk thistle extract), and ursodiol may support liver recovery.
• Antibiotics — Broad-spectrum antibiotics (e.g., ampicillin, metronidazole) to prevent or treat secondary bacterial infections in the compromised liver and other tissues. Antibiotics do not treat the virus itself.
• Blood products — Fresh frozen plasma or whole blood transfusions to replace clotting factors and address DIC or severe hemorrhage.
• Gastroprotectants — Sucralfate and proton pump inhibitors to protect the GI tract.
• Vitamin K supplementation — If coagulopathy is severe and liver production of clotting factors is inadequate.
• Pain management — Appropriate analgesics (e.g., buprenorphine) for abdominal discomfort.

Surgical Options

Surgery is generally not applicable for ICH. In rare cases, surgical intervention may be considered for complications such as a ruptured organ or severe hemorrhage requiring exploratory laparotomy, but these situations are uncommon.

Alternative/Supportive Therapies

• Nutritional support — Small, frequent meals of a highly digestible, moderate-protein, low-fat diet to reduce hepatic workload. If the dog cannot eat voluntarily, nasogastric or esophageal feeding tubes may be placed.
• Plasma or serum therapy — Hyperimmune serum from recovered dogs has been used historically to provide passive immunity, though availability is limited.
• Corneal treatment — If "blue eye" develops, topical anti-inflammatory drops (under veterinary guidance) can ease discomfort while the condition resolves.
• Probiotics — May support GI recovery during antibiotic therapy.

At-Home Care

If your dog is recovering from a mild case or has been discharged from the hospital:

• Strict rest — Limit activity to allow the liver to heal. Avoid strenuous exercise for several weeks as directed by your vet.
• Isolation — Keep the infected dog away from other dogs. Remember, virus shedding in urine can continue for 6–9 months. Clean all areas your dog uses with a dilute bleach solution (1:32 dilution) or other veterinary-approved disinfectant.
• Medication compliance — Administer all prescribed medications on schedule.
• Nutritional management — Feed the veterinary-recommended diet in small, frequent meals.
• Monitor for relapse — Watch for recurrence of fever, appetite loss, jaundice, or bleeding, and contact your vet immediately if these appear.
• Follow-up bloodwork — Liver and kidney values should be rechecked as recommended (typically every 1–2 weeks initially) to confirm recovery.

Prognosis & Life Expectancy

The prognosis for ICH depends heavily on the severity of infection, the dog's age, and how quickly treatment begins.

• Peracute/hyperacute form — Primarily seen in very young puppies, this form progresses to death within hours, often before treatment can be initiated. Mortality in this form approaches 100%.
• Acute severe form — Dogs with significant liver failure, DIC, or multi-organ involvement face a guarded to poor prognosis, with mortality rates of 20–30% even with intensive care.
• Moderate form — With prompt, aggressive supportive care, many dogs recover fully within 1–2 weeks. Residual liver damage may occur but is often manageable.
• Mild/subclinical form — Many dogs recover without intervention, sometimes without the owner realizing infection occurred. These dogs develop strong, typically lifelong immunity.

With modern veterinary intensive care, overall survival rates for clinically affected dogs receiving treatment are approximately 70–80%. Dogs that survive the first 5–7 days generally carry a favorable prognosis for full recovery.

Prevention

Prevention is straightforward and highly effective through vaccination.

Vaccination

• The CAV-2 vaccine (included in the core DHPP or DA2PP combination vaccine) provides cross-protection against CAV-1 while avoiding the corneal and kidney side effects associated with the original CAV-1 vaccine.
• Puppy vaccination schedule: Initial doses at 6–8 weeks, 10–12 weeks, and 14–16 weeks of age, followed by a booster at one year.
• Adult dogs: Boosters every 3 years (per current AAHA and WSAVA guidelines) or as recommended by your veterinarian based on risk assessment.
• Vaccination is considered a core vaccine, meaning it is recommended for all dogs regardless of lifestyle.

Environmental Measures

• Disinfection — Regular cleaning of kennels, bowls, and living areas with dilute bleach or steam.
• Quarantine — Isolate new or potentially exposed dogs for at least 2 weeks.
• Avoid wildlife contact — Particularly in areas with known fox or coyote populations carrying CAV-1.

Breeding Considerations

• Ensure all breeding dogs are fully vaccinated.
• Puppies from vaccinated dams receive maternal antibodies that provide protection for the first several weeks of life, but this protection wanes and must be replaced with active vaccination.
• There are no genetic screening tests for ICH susceptibility, as the disease is infectious rather than hereditary.

Cost of Treatment

Treatment costs vary significantly based on disease severity and geographic location.

| Component | Estimated Cost | |---|---| | Initial examination and diagnostics (blood work, urinalysis) | $200–$500 | | Abdominal ultrasound | $200–$500 | | PCR testing for CAV-1 | $100–$250 | | Hospitalization with IV fluids (per day) | $300–$800 | | Blood transfusion or plasma therapy | $500–$1,500 per unit | | Medications (antibiotics, anti-nausea, hepatoprotectants) | $100–$300 | | Follow-up bloodwork and rechecks | $150–$350 per visit | | Mild case (outpatient) | $500–$1,500 total | | Moderate to severe case (hospitalization, 3–7 days) | $2,000–$7,000+ |

By comparison, the cost of a core DHPP vaccination ranges from $25–$50 per dose, making prevention vastly more affordable than treatment.

Frequently Asked Questions

Can infectious canine hepatitis spread to humans or cats?

Is infectious canine hepatitis the same as human hepatitis?

My dog is vaccinated—can they still get ICH?

What is "blue eye" and should I be worried?

How long should I keep my recovering dog isolated from other dogs?

Can a dog get infectious canine hepatitis more than once?

Is ICH still common today?

What should I do if I suspect my dog has infectious canine hepatitis?