What is Infectious Canine Hepatitis?

What is Infectious Canine Hepatitis?
January 10, 2017 kernow
border collie kernow

ICH is an infectious disease of dogs that (as you would expect from the name!) causes liver damage. It can also affect other organs, including the eyes and blood vessels, and is potentially fatal.

What causes it?

It is caused by a virus (Canine Adenovirus 1), that is closely related to one of the causes of Kennel Cough (CAV-2). The infectious viral particles spread from dog to dog via saliva and faeces; when the dog ingests or inhales the particles, the virus spreads in the bloodstream to infect the internal organs. Most dogs will mount an effective immune response and will recover; how severe the disease is depends on how well the immune system reacts.

What are the symptoms?

There are three distinct types of the disease – which set of symptoms a dog displays depends on how effective their immune system is, and how many viral particles they are infected by.

  • Peracute ICH is the most dangerous, but is fortunately quite incommon. It occurs where the dogâ’s immune system is rapidly overwhelmed resulting in sudden onset of severe symptoms, including:
    • Fever
    • Tremors and convulsions
    • Shock and bleeding under the skin
    • Death occurs in a matter of hours
  • Acute ICH is less sudden, but still very serious. Typical symptoms include:
    • Fever
    • Lethargy and loss of appetite
    • Vomiting and diarrhoea
    • Inflammation and pain of the liver
    • Jaundice
    • Abnormal bleeding
    • Swollen lymph glands
    • Occasionally, seizures or other brain damage may occur but it is rare.
  • Uncomplicated ICH is the most common form, causing:
    • Lethargy and loss of appetite
    • A short-lasting fever
    • Pain and jaundice
    • Vomiting and diarrhoea
    • Tonsillitis (a sore throat!)

Sometimes, there can be long-lasting complications after infection. The most common are:

  • Chronic hepatitis (long lasting ongoing liver damage,which occurs if their immune system is able to prevent the virus from spreading, but not clear it completely).
  • “Blue Eye” (damage to the front chamber of the eye, causing a blue colour and often blindness).

In most cases, the dogâ’s immune system clears the virus in 10-14 days (although the virus may still be shed in the urine for up to nine months).

How is it diagnosed – arenâ’t there other causes of liver disease?

Yes, there are many different causes of liver disease, many of which have very similar symptoms. Testing samples (urine, tonsils or fluid from the front of the eye) is usually the best way to confirm the presence of the virus – although there are blood tests, these may be confused by vaccination.

So how is it treated?

Unfortunately, there is no antiviral drug that can be used to kill the virus – the dogâ’s immune system has to do that. The mainstay of treatment is therefore supportive care, requiring hospitalisation and intensive care. Dogs with ICH are highly contagious, so suspected patients will usually be treated in an isolation ward, to protect other dogs visiting the practice. We will put them on a drip to prevent dehydration and to help support their heart and blood vessels. If their clotting system isnâ’t working normally, we may give them a blood plasma transfusion from another dog. Medications (such as maropitant) to prevent vomiting are often needed, and we will also usually use drugs to help support the liver, such as “urdox” (ursodeoxycholic acid), silybin and vitamin E.

How can it be prevented?

Very easily – by vaccinating your dog! ICH is one of the “core” vaccines recommended by the World Small Animal Veterinary Association – the primary course should be given to all dogs, and boosted regularly (the current recommendations are for a booster at one year old, followed by one every three years).

If you think your dog may be showing signs of liver disease, contact us urgently for advice.