HEARTWORM IN DOGS

WHAT IS HEARTWORM DISEASE?

Canine heartworm disease is caused by a parasitic worm called Dirofilaria immitis which lives in the heart and pulmonary artery of dogs and can cause signs of cardiac failure and lung disease.

HOW IS HEARTWORM DISEASE SPREAD?

Heartworm cannot be spread directed from dog to dog but must spend part of its lifecycle in a mosquito before being injected into the dog. The larvae injected into the dog with a mosquito bite take about 6 months to develop into adult heartworm.

HOW WILL I KNOW IF MY DOG HAS HEARTWORM?

It may take up to 2 years after infection before dogs will show signs relating to heartworm disease. These signs may include coughing, shortness of breath, reduced ability to exercise and abdominal distension.

Infection with heartworm can only be detected once adult heartworm are present i.e 6 months after infection has occurred. A simple blood test will detect the presence of the worm at this stage.

CAN I PREVENT MY DOG GETTING HEARTWORM DISEASE?

There are a number of heartworm preventative medications available which act by killing the immature larvae injected by the mosquito before they develop into adults. These medications will NOT kill adult heartworm once established.

Daily heartworm tablets are available without prescription, the active ingredient in these is DEC  (diethylcarbamazine). These are effective if given on a regular daily basis but can be easily forgotten. If DEC is given to a dog with adult heartworm present it may cause a shock-like reaction which can be severe, it is recommended that a heartworm test is carried out before starting DEC therapy in dogs >6 months of age

Monthly heartworm tablets containing ivermectin, milbemycin or moxidectin are given on a monthly basis and are safe and effective, combinations of these drugs are available with worming and flea preparations included.

All heartworm preventatives must be given on a regular basis throughout the life of the dog, erratic dosing will be ineffective as it is difficult to predict when mosquitoes will bite and a heartworm blood test should be carried out 6 months after any lapse in dosage regime.

WHAT IF MY DOGS GETS HEARTWORM DISEASE?

 You will be notified immediately of  a positive heartworm blood test and we will arrange another check up with the vet. Dogs with no symptoms of cardiac disease can be admitted for treatment with injections of a drug which will kill the adult heartworms and may then go on a course of tablets at home to minimise side-effects while the heartworm die over the next month.

Older dogs or those with signs of significant heartworm disease may need to have further blood tests, xrays and other drug treatments prior to killing the heartworm. These will be discussed if needed.