Infectious hepatitis is a condition that most dogs are routinely vaccinated for. But vets are not always very good at explaining the reasons in detail as to why we vaccinate, or what the potential disease consequences are if we don’t. This is because 10–15-minute appointments never seem long enough!  

Don’t worry though, we’re going to cover it all here though. Let’s take a look at everything you need to know about infectious hepatitis in dogs, including just how serious it might be if your dog catches it. 

What is infectious hepatitis in dogs? 

Infectious hepatitis is a disease caused by canine adenovirus 1 (CAV-1). This disease is found worldwide and has been reported in foxes, wolves, bears and lynx, as well as domestic dogs. Thankfully we find it less commonly in areas where routine vaccination has become the norm.  

The virus is usually spread through oronasal exposure. Dogs can become infected by sniffing or licking infected urine, faeces or saliva, either directly from an animal carrying the disease or from a contaminated environment. The virus can survive for many months at room temperature waiting to infect its next host. It is also possible for ectoparasites like fleas or ticks to transfer the virus. Recovered dogs can shed the virus in their urine for up to 6 months, continuing to spread the disease. Parks, grooming parlours, boarding kennels and anywhere else dogs tend to congregate present the most risk. 

The virus targets blood vessel cells (endothelium) with a good blood supply, such as those found in the liver, spleen, lungs and kidneys. This means the disease can cause a variety of symptoms in dogs. Some may only develop mild symptoms, whereas it could be fatal for others.  

What are the symptoms of infectious hepatitis in dogs? 

Clinical symptoms can vary dramatically between different dogs. Some may only develop a mild fever whereas others could die. 10 – 30 % of dogs that are infected will die, with death rates being highest in very young dogs.  

The disease often starts with a fever but can progress to other symptoms as time goes on. Signs of infectious hepatitis may include – 

  • A fever – often more than 40oC and lasting 1-6 days 
  • Lethargy 
  • Reduced appetite 
  • Changes in thirst 
  • Elevated heart rate 
  • Enlarged lymph nodes and tonsils 
  • Conjunctivitis 
  • Nasal discharge 
  • Cloudiness of the eye surface (cornea) making it appear blue-tinged 
  • Abdominal pain 
  • Vomiting or diarrhoea 
  • Signs of blood clotting issues such as bleeding, small red dots on the gums or skin (petechia) and bruising 
  • Fluid swelling under the skin around the head and neck 
  • Neurological signs like tremors or seizures 
  • Death  

How is infectious hepatitis diagnosed in dogs? 

The vet will start by examining the affected dog to look for clues. Signs can be non-specific and found in many diseases, but a young puppy with a high temperature and cloudy eyes would certainly raise their suspicions of canine infectious hepatitis. Depending on their findings, and after taking a careful history from the owner, the vet may suggest some further tests.  

Blood tests are key to confirming a diagnosis. Biochemistry is recommended to look for signs of organ damage, checking liver and kidney values in particular. Haematology is also normally run to check red and white blood cell levels, flagging if there are any signs of anaemia and or infection. The vet may also need to run a coagulation profile if there are concerns about the dog’s ability to form blood clots. Serology tests can also analysed to help confirm the diagnosis of infectious hepatitis.   

Sometimes an ultrasound scan or X-rays may help to rule out other causes of disease and to assess the dog’s organs further.  

What is the treatment for infectious hepatitis in dogs? 

If your dog is diagnosed with infectious canine hepatitis, you should be aware that there is no direct cure. Some dogs may only have mild symptoms that go unnoticed, and these are likely to recover without intervention.  

But if your dog is unwell then supportive treatment will be recommended to give them the best chance of recovery. Hospitalisation is usually advised so that your dog can have the following care – 

  • Intravenous fluids (via a drip) to correct dehydration and support your dog’s blood pressure 
  • Oxygen therapy  
  • Antibiotics to prevent secondary infections from worsening their condition 
  • Anti-nausea medications to counteract vomiting 
  • Blood transfusion in cases that have severe clotting issues 
  • Anti-seizure medications 
  • Supported nutrition 
  • Pain relief 
  • Eye medications 
  • Repeat blood tests to check their progress 

During your pet’s time in the hospital, they will be barrier nursed. This means that staff will wear protective clothing and keep your dog isolated to prevent the spread of the disease to other patients.  

The best outcomes are achieved when treatment is started promptly 

Delays can increase the chances of complications, which could be fatal. If your dog is suffering from severe symptoms of disease and the chances of recovery are looking poor, your vet may discuss euthanasia with you.  

Dogs that recover from the disease may still develop corneal opacity in one or both eyes (cloudiness of the surface of the eye caused by corneal swelling or oedema), some 7 – 10 days later. This feature gives the disease it’s other name of ‘hepatitis blue eye’. This occurs in about 25% of affected dogs due to an immune response when fighting the disease. It usually resolves again by itself.  

Recovery from infectious hepatitis can be slow, and it may take time for your dog to regain any lost weight. Some dogs can also suffer from chronic kidney disease following their infection, reducing their lifespan.  

How can I prevent my dog from getting infectious hepatitis? 

One word – vaccination! This disease is serious and potentially fatal, but thanks to vaccination we see far fewer cases of it in the UK than we have in the past. This doesn’t mean we should become complacent, however.  

With disease carried in wildlife populations as well as being brought in from ever-increasing numbers of imported dogs, canine infectious hepatitis is still around. The best way to protect our dogs is by regularly vaccinating them.  

‘But what about herd immunity, surely my dog will be fine if I don’t jab them?’ 

Herd immunity occurs when the vast proportion of the canine population is vaccinated against a disease. This means there are fewer infected individuals spreading disease around, and less chances of outbreaks occurring. This helps to give protection to the small number of animals that don’t form an appropriate immune reaction (vaccine failure) or are unable to be vaccinated, for example very young puppies. But if more people choose not to vaccinate, we could soon see cases rise again. We have seen this play out in human medicine with rising cases of measles due to anti-vaccination movements.  

‘Why do I need to give my dog booster injections? It doesn’t seem necessary’ 

Protection can be given to puppies as part of their primary vaccination course. This immunity wanes over time and it will need to be boosted again at around a year of age. Thereafter, repeat vaccination is recommended every three years in line with manufacturer guidelines and consensus from the World Small Animal Veterinary Association (WSAVA). These vaccinations have been rigorously tested, and they are safely used on hundreds of animals each day in the UK.  

It is possible to do serology testing to check your pet’s antibody levels before giving a booster vaccination, however. Some dogs will form longer-lasting immunity, meaning that re-injection may not be needed at that point. This is also known as titre testing, and some owners choose to do this instead of following the generic vaccination protocol. However, owners should be aware that there are no reliable titre tests for leptospirosis and kennel cough, so annual booster vaccination for these is still recommended. This means you will still need to attend a yearly vet appointment. 

Summary 

Canine infectious hepatitis is indeed a serious disease, and it can be fatal for some dogs. Successful vaccination uptake means that cases are less likely than they have been in previous years. However, this could easily be reversed if uptake for booster injections declines.  

If you have any concerns about your pet or want to discuss vaccination protocols further, then make sure to book an appointment with your vet. They are ready to help support you and your dog’s health. 

FAQs 

Can canine infectious hepatitis in dogs be cured? 

There is no cure for canine infectious hepatitis. Recovery relies on your dog’s immune system and the supportive care they receive during this time. Even with treatment, this disease can be fatal for some animals. 

How do dogs get hepatitis?  

Dogs can catch canine infectious hepatitis by contacting an infected dog or an environment that they have contaminated with urine, faeces or saliva. Dogs that are unvaccinated and very young are most at risk from this disease.  

Can hepatitis in dogs be passed to humans? 

No, this disease is not zoonotic, meaning that humans cannot catch canine infectious hepatitis. However, your dog can infect other dogs and wildlife with this disease. Many infected dogs will shed the virus in their urine for up to 6 months.