Heartworm Disease & Our Dogs

What is Heartworm Disease?

Heartworm is a serious and potentially fatal disease caused by parasitic worms that are transmitted to your pet as larvae by mosquitoes. These worms are found in the arteries of the lungs or heart. Dogs are considered the most common host for heartworms.

How can my dog catch Heartworm Disease?

When a mosquito infected with heartworm larvae bites your dog, larvae can enter through the bite wound and a new heartworm infection is established. Over the next few months, these larvae develop in tissues into mature worms that migrate to the heart and blood vessels of the lungs. Adult heartworms can be as long as 30cm and live from five to seven years with some dogs infected by as many as 250 worms at a time.


Why is heartworm prevention important for my dog’s health?

Heartworms interfere with circulation and cause damage to tissues, potentially causing heart failure and death. Treating a heartworm infection is difficult and not without risks. PREVENTION is the best approach.

How can I protect my dog from heartworms?

It is almost impossible to prevent some mosquito bites. Therefore to ensure your dog is protected from heartworm disease you need to kill heartworm larvae from mosquitoes before they develop into harmful adult worms inside the body. This is easily done with medication in the form of tablets/chews, ‘spot on’ treatments or injections, that can be administered daily, monthly, or annually.

What product should I use?

  • ProHeart SR-12 annual injection (lasts for 12 months)
  • NexGard Spectra monthly chews (also most intestinal worms, fleas & ticks)  ** a single tapewormer tablet will still need to be given once every 3 months
  • Interceptor monthly tablets (also controls most intestinal worms)
  • Sentinal Spectrum monthly tablets (also controls fleas & most intestinal worms)

Talk to your vet about the appropriate heartworm prevention for your dog.

When should I start heartworm prevention for my puppy?

Puppies can be bitten by mosquitoes just like any other dog therefore heartworm prevention is recommended from 6 weeks of age and continued for life to ensure protection from disease. Up to 6 months of age monthly prevention is usually recommended after which the ProHeart annual injection may be more convenient.

What if my dog has not had heartworm prevention before?

If your dog is older than 6 months, talk to your vet about blood tests that should be done PRIOR to commencing preventative medication. This is important to establish if there is an existing heartworm burden as heartworm prevention will not kill adult heartworms and may cause side effects.

What if my dog is not up to date with heartworm prevention?

If your dog has not been given preventative medication for less than 6 months, resume treatment with the ProHeart annual injection or monthly heartworm control and be sure to continue it monthly for at least 12 months. If it has been longer than 6 months we advise having your vet do a blood test to determine of your dog has an existing heartworm infection before recommencing prevention.

What if my dog has Heartworm Disease, is it treatable?

There is some risk involved in treating for heartworms although fatalities are rare. Dogs with poor liver or kidney function are at a higher risk of complications from treatment and severe or long-standing heartworm disease may have caused irreversible damage to the organs.

An injectable drug is given for two days that kills the adult worms over a period of a month. Complete rest is essential after treatment as the dead worms will often lodge in the lungs and be slowly reabsorbed by the body. This is a hazardous period although serious reactions are uncommon. 4 weeks later the dog must then be administered a drug to kill the microfilariae (baby worms) in the blood stream. Finally, 4 weeks after this the dog is tested for the presence of microfilaria to ensure treatment was effective after which heartworm prevention should begin.

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During this time the puppies will meet new friends and owners learn new skills to teach when at home, on walks, around at a friends place or just general living with your newest furry friend.

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