Recommendations for Heartworm Prevention

Heartworm is a rare disease in Melbourne, it occurs in 2 to 10 % of the dog population, our advice is that if you want the best protection for your Dog, then they should start on Heartworm prevention.

Ideally, puppies should start on Heartworm prevention at 12 to 14 weeks of age (i.e. the time of their second puppy vaccination). Preventatives cannot be given to puppies less than 8 weeks of age.

Older animals (or animals that have missed some doses of Heartworm tablets) can safely start on monthly Heartworm preventatives. These dogs may be carrying Heartworm infection, therefore we recommend that older animals start on Heartguard Plus monthly preventatives, as this medication will not only prevent Heartworm but will also kill 95% of adult Heartworms if it is used for at least 26 months continuously, i.e. from

http://www.veterinarypartner.com/Content.plx?A=610

a.. Ivermectin does not kill adult heartworms.
b.. Ivermectin does shorten the lifespan of adult heartworms.
c.. Ivermectin does sterilize adult heartworms.
d.. Ivermectin does kill microfilaria (keeping the dog from being a source of contagion)
e.. Ivermectin does kill L3 and L4 larvae (preventing new infections).

This means that if you opt to treat a heartworm positive dog with an ivermectin heartworm preventive only, you can expect the dog to remain heartworm positive for a good two years and the heartworm disease will be progressing during those two years.

The other Heartworm preventative products available (e.g. Proheart, Revolution, Sentinel etc.) are excellent preventatives but are not effective at killing adult heartworms.

Older animals should not start on any daily Heartworm prevention without first having a Heartworm test, as some daily preventatives can induce severe reactions in Heartworm positive animals.

Heartguard is safe in Ivermectin sensitive collies when given at the recommended dose rates.

Proheart (SR 12) injection can be given to animals over 6 months of age, we recommend starting monthly medication at 12 14 weeks of age, then if you choose, a Proheart injection can be given at 6 months of age, or alternatively at your dogs first yearly booster vaccination. This injection will provide Heartworm prevention for your dog for 12 months.

A note on Heartworm tests:

Because Heartworm disease is not common in Melbourne, many dogs that are infected are only infected with a few worms, these type of infections are not readily detectable with routine Heartworm tests. Because of this many dogs that are infected with Heartworm in Melbourne will actually have a negative test result. This is the reason that we no longer recommend Heartworm testing as a routine procedure. However your Veterinarian may recommend a Heartworm test in some circumstances.

Author KH