Infectious Canine Hepatitis (HCC) – What Dog Owners Need to Know

Where Is the Disease Found?

Infectious canine hepatitis (HCC), caused by canine adenovirus type 1 (CAV-1), is found worldwide. In Sweden and the Scandinavian countries the disease is very rare, with only a few cases reported annually. This low incidence is largely due to the high rate of vaccination among the scandinavian dogs, which provides effective protection.

Which Dogs Are Most at Risk?

The dogs most vulnerable to HCC are:

• Young puppies

• Unvaccinated dogs

• Newborns, especially if the mother was infected during pregnancy

These groups are particularly sensitive to infection and may experience severe symptoms or even sudden death.

How Is HCC Transmitted?

The virus spreads through all bodily fluids (saliva, urine, feces, nasal discharge) of an infected dog. After infection, a dog may continue to shed the virus in its urine for up to 6–9 months.

A major concern is that some dogs can carry and spread the virus without showing any symptoms—these are called asymptomatic carriers.

A Hardy Virus – Survives Outdoors

Another challenge in preventing the spread is that CAV-1 is highly resilient in the environment. It can survive for weeks outdoors, even in harsh conditions.

Most dogs are infected in everyday environments such as:

• Residential areas

• Parks and walking paths

• Dog parks

• Forests and fields

It can also be spread indirectly via:

• Hands and clothing of people

• Food and water bowls

• Blankets and toys

Importantly, only dogs can contract HCC—not humans or other animals.

canine adenovirus type 1 (CAV-1), the virus that causes infectious canine hepatitis (HCC), is a non-enveloped DNA virus, which makes it relatively resistant to many common disinfectants.

Effective Disinfectants That Can Kill CAV-1:

Here are disinfectants known to be effective against adenoviruses like CAV-1:

1. Virkon S or Virkon

• A broad-spectrum disinfectant used in veterinary clinics and kennels.

• Effective against viruses, bacteria, and fungi, including non-enveloped viruses like CAV-1.

• Must be mixed according to instructions (typically 1% solution) and allowed proper contact time (usually 10 minutes or more).

2. Sodium Hypochlorite (Bleach)

• Household bleach (5–6% sodium hypochlorite) diluted at 1:32 (approx. 1600 ppm) is effective.

• Requires cleaning first (to remove organic matter) and at least 10 minutes contact time.

• Corrosive, so not ideal for metal surfaces or soft materials.

3. Accelerated Hydrogen Peroxide (e.g., Rescue, Prevail)

• Safer for people and animals compared to bleach.

• Effective against non-enveloped viruses like adenoviruses.

• Often used in clinics, shelters, and grooming environments.

• Follow label directions for dilution and contact time.

4. Potassium Peroxymonosulfate (e.g., Trifectant)

• A high-level disinfectant often used in kennels and shelters.

• Effective against a wide range of pathogens, including CAV-1.

• Requires appropriate mixing and contact time.

Important Notes:

• Pre-cleaning is critical: Organic material (like dirt or feces) can inactivate disinfectants, so surfaces must be cleaned thoroughly before disinfecting.

• Contact time matters: Most disinfectants need 5–10 minutes of wet contact to work effectively.

• Outdoor use is limited: None of these disinfectants work well on soil, grass, or other outdoor environments — hence why vaccination is crucial for environmental protection.

• Allways read the instructions and keep pets and children away from the surfaces that you are cleaning

Why Vaccination Is Critical

Sweden has a strong tradition of vaccinating pets, which has helped keep many serious diseases rare. However, as these diseases become less visible, some dog owners mistakenly believe vaccination isn’t necessary.

If vaccination rates drop, diseases like HCC could resurface, especially in urban or high-density dog populations.

Symptoms of HCC

The course of illness can vary widely, especially depending on the dog’s age and immune status.

In Puppies:

• Sudden death

• Stillborn puppies (if the mother was infected during pregnancy)

In Older Dogs:

• Nausea

• Vomiting

• Diarrhea

• High fever

• Swollen lymph nodes and tonsils

• Bleeding or bruising under the skin (especially on the neck and head)

• Pale or yellow-tinged gums and mucous membranes (jaundice)

The virus targets blood vessels and vital organs like the liver, kidneys, and spleen. In some dogs, long-term damage can occur in the kidneys or eyes due to immune complex deposits.

One characteristic sign is a bluish cloudiness in the eye, known as “blue eye”, which can develop in some infected dogs.

Some infected dogs, especially adults, may only show mild symptoms, such as a slight cough, but can still transmit the virus to others.

How Can I Protect My Dog?

Vaccination is the most effective way to protect against HCC.

• It not only shields your own dog but also protects vulnerable dogs (such as young puppies or immunocompromised dogs who can’t be vaccinated).

• It is a simple, affordable way to guard against a potentially fatal disease.

Do Vaccines Have Side Effects?

Serious side effects from modern dog vaccines are very rare.

Most common reactions are mild and temporary, such as:

• Minor swelling at the injection site

• Slight fatigue after vaccination

Compared to the diseases they prevent, the risk of side effects is minimal.

It’s crucial to share accurate information about vaccines and disease risks. In recent years, social media has tended to focus on rare side effects while downplaying the seriousness of preventable diseases. This may lead some owners to avoid vaccinating, increasing the risk of outbreaks.

Remember: before vaccines were available, many dogs died from these illnesses.

Is My Dog Protected Against HCC?

Check your dog's vaccination record (vaccination card or passport). It lists the vaccine names and the diseases they protect against.

For example, a common vaccine is Nobivac DHPPi:

• D = Distemper (Valpsjuka)

• H = Hepatitis (HCC – Infectious Canine Hepatitis)

• P = Parvovirus

• Pi = Parainfluenza (Kennel cough)

Vaccination Schedule – What You Need to Know

Basic vaccination plan:

1. First dose: ~8 weeks of age

2. Second dose: ~12 weeks of age

3. Booster: at 1 year old

This is called the primary vaccination series. After that:

• Vaccination for HCC, parvo, and distemper is recommended every 3 years.

• The kennel cough vaccine is often given annually, especially for social dogs (doggy daycare, dog parks, boarding, etc.).

If you’re a breeder or your puppies are at higher risk (e.g., local cases of HCC), a third puppy dose at 14–16 weeksmay be recommended. However, this is usually not necessary in Sweden.

⚠️ Important: Your puppy isn’t fully protected immediately after the second vaccine at 12 weeks. It takes 1–2 weeks for the immune system to build proper protection. During this period, avoid exposing your puppy to high-risk environments.

Additional Advice for Dog Owners

• Travel and HCC risk:
  If you're traveling abroad with your dog, especially to countries with lower vaccination rates, your dog may be at a higher risk of exposure. Make sure all vaccines are up to date before traveling.

• Kennels and dog gatherings:
  Many boarding facilities, training centers, and dog shows require proof of vaccination. Even if not required, vaccinating helps protect your dog and the entire dog community.

• Understanding “blue eye”:
  The “blue eye” symptom is not just cosmetic—it can signal immune system complications and may affect vision. It often appears days or weeks after infection.

• Don’t delay treatment:
  If your dog shows symptoms like vomiting, lethargy, pale or yellow gums, see a veterinarian immediately. Prompt treatment can save your dog’s life.

Did You Know?

• HCC was once a leading cause of death in puppies before vaccines were introduced.

• The disease can progress very quickly, sometimes within 24–48 hours.

• HCC is still common in many countries, especially in areas with low vaccination rates.

• The CAV-1 virus (which causes HCC) is not used in vaccines today. Instead, a related virus (CAV-2) is used, which is safer and still provides strong protection against HCC.

If you’re unsure whether your dog is adequately protected or need help reading the vaccination record, contact your veterinarian for guidance. They can ensure your dog has the protection it needs against serious but preventable diseases like HCC.

Foto Jametlene Reskp