Adenovirus 1 or Hepatitis Blue Eye in Dogs

The term Blue Eye is used to describe a dog's corneas when they become cloudy due to them suffering from a serious viral infection. The infection is classed as a severe viral disease and it can affect dogs at any time during their lives. The virus attacks the liver as well as a dog's eyes which is why the condition is often referred to as Hepatitis Blue Eye. The infection is caused by the CAV-1 virus and is often referred to as Infectious Canine Hepatitis.

An Infectious Disease

Dogs pick up the virus when they come into contact with any faeces left by an infected dog and they can also pick up the virus from an infected dog’s saliva. However, a healthy dog with a strong immune system and enough antibodies in their systems would be able to fight off the infection in around two weeks or so. However, it’s worth noting the virus remains in a dog's kidneys for up to nine months and will be present in a dog's urine for that amount of time.

The condition is a viral disease that typically impacts a dog's upper respiratory tract causing serious infections. The virus also negatively impacts internal organs which includes a dog's liver, kidney and their eyes as well as what is known as endothelial cells which are cells that line the inner surface of blood vessels.

This virus first attacks a dog’s tonsils when they have been exposed to it, but it quickly spreads to the bloodstream and then on to the liver. Usually a dog's own system can defend itself against a virus, but this specific virus can spread rapidly because it can use a dog's own system to replicate and travel through the bloodstream. This is how the virus reaches vital internal organs so quickly. The cells in a dog's liver are negatively impacted and the virus is then passed out through their saliva and faeces which is when other dogs are most at risk of being infected.

As previously mentioned, dogs with healthy immune systems would be able to fight off the infection in around two weeks, but the virus will stay in their kidneys and therefore passed out every time a dog urinates for up nine months or longer. Should a dog be able to fight off the infection to a certain degree, they will typically suffer chronic hepatitis which is a very severe condition that negatively impacts their eyes and in particular the front of the eye which is known as the anterior uveitis. It is when this happens that a dog is referred to as suffering from hepatitis blue eye"" or infectious hepatitis.

Breeds Most at Risk

Studies have established that all breeds can be susceptible to suffering from the condition and that it is not a gender specific disorder either. Nor is it a genetic disease although research suggests that dogs usually develop the condition when they are under a year old which is typically when their immune systems are not fully developed and therefore weaker making it harder for them to fight off infections.

Symptoms to Watch Out For

The signs of there being something wrong will depend on how well a dog's system is coping with the infection and to what degree any internal organs have been affected. The symptoms associated with the various stages of the condition are as follows.

Percute is the very severe stage of the condition and when dogs will typically show the symptoms below:

• Fever
• Their central nervous systems begin to deteriorate
• Blood vessels collapse
• Dogs experience a condition known as DIC which is a blood coagulation disorder

When the infection has reached this stage, dogs usually succumb to the symptoms very quickly which is normally within hours.

Acute is the severe stage of the condition and dogs will typically show the following signs of there being something wrong:

• Fever
• Anorexia
• Lethargy
• Vomiting
• Diarrhoea
• An enlarged liver
• Abdominal pain
• A build-up of fluid in the abdomen
• Vasculitis which is an inflammation of blood vessels
• Skin has pinpoint red spots on it
• Skin appears bruised a condition known as petechia
• A blood coagulation disorder which is a condition known as DIC
• Enlarged and swollen lymph nodes which is a condition known as lymphadenopathy
• Occasionally, dogs suffer inflammation of the brain which is condition known as non-supportive encephalitis

Uncomplicated infections are less severe, but still a real concern and dogs typically show the following signs of there being something wrong:

• Lethargy
• Anorexia
• Transient fever
• Tonsillitis
• Vomiting
• Diarrhoea
• Lymphadenopathy
• An enlarged liver
• Abdominal pain

Late stage infection sees around 20% of dogs developing corneal swelling and inflammation of the eye which typically happens 4 to 6 weeks after they have been infected by the virus. If diagnosed and treated early enough, a dog with the condition will recover in a about 3 weeks, but if left untreated, the symptoms get progressively worse causing corneal ulceration and glaucoma.

Diagnosing the Problem

A vet would need to have a dog's full medical history and how the symptoms first manifested themselves. They would also need to know if a dog has been involved in any sort of incident that could have brought on the symptoms. A vet would need to thoroughly examine a dog suspected of suffering from the condition and would typically recommend carrying out the following tests which would help confirm a diagnosis:

• A complete blood profile
• A chemical blood profile
• A urinalysis
• An electrolyte panel
• Coagulation tests to see if a dog's blood is clotting correctly
• A serology to establish if a dog has enough antibodies to combat the CAV-1 virus
• A viral culture
• X-rays to check the size of a dog's liver and to see if there is a build-up of fluids in a dog's abdominal cavity
• An abdominal ultrasound which also would give a clearer picture of the size of a dog's liver
• A liver biopsy

The vet would need to rule out other conditions a dog might be suffering from which includes parvovirius and distemper.

Treatment Options

Providing the infection is caught early and it is the uncomplicated form of the disorder, a dog suffering from hepatitis blue eye can be treated as an outpatient. However, vets tend to keep dogs with the condition hospitalised so they can closely monitor their condition and its progress. It also allows vet to give dogs fluid therapy should this be deemed necessary. All too often a dog's magnesium and potassium levels are low when they have been infected by the virus and would need to be replenished as a matter of urgency. Should it be found that a dog is suffering from a coagulopathy disorder, they would need to be treated so their condition can be stabilised.

Dogs suffering from the condition would also need to be put on a course of antibiotics and it is essential for the full course to be completed for the treatment to be effective. Once a dog's system has fought off the viral infection or they have been successfully treated, their eyes usually clear and go back to normal a few weeks further down the line. However, if a dog is suffering from a severe infection, they generally succumb to their symptoms quite quickly.

Living with a Dog with Hepatitis Blue Eye

Once a dog has been allowed home, they would need to see the vet for follow-up visits to make sure a treatment is working and to keep an eye on their fluid, electrolyte levels. The vet would also want to ensure their blood is coagulating as it should. Dogs can suffer total kidney failure so it's essential for their condition to be closely monitored. Diet also plays a key role in a dog's recovery period and a vet would have typically recommended the sort of food they should be fed. Exercise would also need to be restricted as would any contact with other pets, making sure that any faeces are picked up immediately and disposed of safely.

Prevention

There is a vaccine for this disorder which puppies can be given when they are anything from 6 to 8 weeks old followed up by a booster which is given when they are a year old.

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