Heartworm is a parasitic disease that affects dogs.

The adult worm lives in the heart and the arteries to the lung. The worms are several inches long and cause much inflammation and irritation to the arteries and lungs as the disease develops.

The signs of the disease include coughing, breathing problems, exercise intolerance and weight loss. Treatment is expensive and risky and involves a stay in hospital.

If a dog is not treated it will develop heart problems and eventually die due to the worms in the heart.

The disease is caught by being bitten by mosquitoes that have already bitten another dog that has heartworm. The risk is therefore higher for dogs that are exposed to mosquitoes,

i.e. dogs in a village, or kept in a garden, or dogs that are exercised outside.

A simple blood test will show if your dog is positive for heartworm.

If positive we will advise treatment to kill the worms.

If negative we recommend preventative treatment to stop your dog catching the disease even if he is bitten by a mosquito carrying the disease.

This preventative treatment is called "Heartguard" and needs to be given every month to prevent your dog catching the disease. It must be given on time. If there is a gap then a blood test should be performed (after 3 months) to check that the dog has not caught the disease while off the tablets. We also advise a second blood test 3 months after the first to make sure that no adult heartworms have developed.

This product can only be bought from a veterinary surgeon, not from pet shops.

If your dog is five months or younger he can start "Heartguard" without a blood test first, as there has not been time for the adult worms to develop.

Heart worms are different from gut worms and a normal "dewormer" does not kill or prevent heart worms.

Cats can catch heartworm but it is much less common than in dogs.

We currently do not recommend prevention for cats.

The costs are as follows:

• Blood test $250 - $300
• Heartguard prevention for 6 months (according to weight)

Heartguard "Plus" contains dewormers against roundworms but not tapeworms.

We advise deworming with broad spectrum dewormers such as "Lopatol" every 3 months.