Fatal diseases of dogs

There are four major infectious diseases affecting dogs today. Parvovirus, Distemper, Hepatitis and Leptospirosis. All are highly contagious and difficult and expensive to treat.

Canine Parvovirus

Parvovirus is perhaps the most common canine infectious disease.

It was first recognised in the late 1970's and rapidly became an epidemic. Many hundreds of dogs died before an effective vaccine could be produced. Sadly, this disease remains a major problem. Outbeaks still occur regularly across the country.

The disease is usually seen as bloody diarrhoea in young animals, with a characteristic offensive odour and severe dehydration. Many will die within hours of the onset of symptoms.

Once a dog becomes infected by parvovirus, the virus will invade the immune system and bone marrow. This leads to sudden and sever bleeding into the gut, resulting in shock and damage to the immune system. Death is common an frequently rapid unless emergency veterinary treatment is received.

Canine Distemper

Canine distemper, sometimes refferd to as 'hard pad', is caused by a virus very similar to the measles virus, although it is not a risk to humans.

Although less common than it was 20 or 30 years ago, outbreaks still occur, mainly in urban areas where a large unvaccinated population of dogs and foxes exists. These outbreaks tend to be 'explosive' in nature, causing death or permanent brain damage. Transmission of the virus is by inhalation and direct contact.

The distemper virus attacks most parts of the body, including the spleen and bone marrow. This makes it easier to catch secondary infections. As the disease progresses, the virus spreads to the lungs and gut, the eyes, skin and brain.

The classical signs are of a dog with a high temperature, a discharge from the eyes and nose, a cough and vomitting and diarrhoea. Hardening of the skin may occur in the nose and pads, hence the term 'hard pad'. The virus can reach the brain causing permanent damage, ranging from involuntary twitches to fits. Dogs that recover may be left with some permanent disability such as cracked pads and nose, epilepsy, and damage to the tooth enamel.

Once again, treatment is lengthy, expensive and most importantly, often unsucessful. 

As the incubation period is long - often about three weeks - it is usually too late to vaccinate when an outbreak occurs

Canine Hepatitis

As the name suggests, canine hepatitis attacks the liver. Some dogs may become infected and show no obvious signs, but in acute cases the death of your pet can occur within 24 - 36 hours.

The symptoms are very variable depending on the severity of the infection. Some animals may show a slight temperature and at the other extreme may die suddenly. Intermediate cases exhibit fever, vomiting, pale gums, jaundice, abdominal pain and internal bleeding. The less severe form of the disease has been associated with 'Fading Puppy Syndrome'.

Leptospirosis

Leptospirosis is caused by a bacteria that is spread in the urine of infected animals.

Two major forms of the disease exist in dogs. One (L.icterohaemorrhagiae) causes acute illness and jaundice and is usually caught from rats - either by the animal being bitten or coming into contact with rat urine. L.icterohaemorrhagiae infection usually produces a sudden disease with fever, vomitting and diarrhoea, thirst, bleeding, and jaundice. The outcome is usually fatal and death can occur within a few hours.

The other type (L.canicola) can also cause acute disease but frequently takes a more prolonged form.

This leads to the slow destruction of the kidneys and renal failure can occur many years after the original infection. Even animals that show no signs of illness may still go on to develop chronic disease.

Canine Parainfluenza

This virus is one of the pathogens responsible for disease known as 'kennel cough'.

Dogs with this disease suffer from a harsh, dry cough that can last for many weeks, causing distress for both the dog and the owner.