Heartworm is a small worm which lives in the bloodstream of dogs and less commonly cats.  It can cause serious, chronic and fatal disease.  It is transmitted by mosquitoes and is a common cause of heart and lung disease in unprotected dogs.  Humans can occasionally be infected with serious consequences.

All dogs in Cairns should be on regular heartworm preventatives.

Treatment for heartworm is complicated and expensive, and many infected dogs die in spite of treatment.  Therefore using regular prevention in heartworm endemic areas such as Cairns is essential.

Heartworm prevention

There are several effective preventatives on the market.  We recommend yearly Proheart Injections because it is easy to remember, and also Interceptor or Sentinel monthly tablets.  We can also advise you of other products which may be sutiable for your pet.

It is important to make sure you also use effective intestinal worm products at least 3 monthly.  Interceptor and Sentinel treat both heartworm and intestinal worms.

Please note that most supermarket and pet store wormers are ineffective against common tropical worms, especially the cat tapeworm.  Talk to your vet about effective intestinal wormers.

Adult heartworm lives in the dog's heart and the blood vessels going to the lungs. These worms are about 20cm long and 1mm in diameter. They produce larval offspring called microfilaria that floats around in the bloodstream. Mosquitoes suck blood containing microfilaria from infected dogs and transmit these larvae from dog to dog. After infection these larvae take 6 months to develop into adult worms residing in the dog's heart.
Clinical signs of heartworm disease are many and varied but basically the heartworm physically block the heart and lungs, thereby reducing the function of these organs.

In dogs that are showing symptoms of heart/lung compromise, it may first be necessary to stabilise the patient before killing any heartworm. Dead worms aren't voided from the body. Because they are in the heart, blood flow pushes the dead worms into the lungs. These dead worms can cause lung pathology.

Never give daily heartworm tablets to a dog which may have heartworm (has missed treatments or not been on heartworm preventative).  If you dog has missed treatments, speak to your vet about testing and a suitable treatment: some preventatives like the heartworm injection will kill young heartworm even if you have missed a few treatments.
 

Treatment of Heartworm infections

Dogs with symptoms and positive blood tests for heartworm should be treated.  There are a number of effective treatments depending on your dog's symptoms and test results.  Treatment can be expensive and dangerous, especially if there are many worms.  If you are worried your dog may have heartworm,  take them to a vet, as there are other causes of similar symptoms.