Help! Does my dog have heartworm, New Farm Vet?
What causes heartworm disease, New Farm Vet?
Heartworm (Dirofilaria immitis) is a parasite that is spread by mosquitoes (Culex or Aedes spp.). The heartworm's lifecycle starts inside a mosquito, gaining entry into your pet’s body via a mosquito bite. The juvenile parasites then enter the blood stream after spending some time in the muscles and tissues. Eventually the parasites migrate into the heart and lungs where they grow into adult worms.
When should I start heartworm preventive medication, New Farm Vet?
Heartworm preventive medication should start from 8 weeks of age. However, it is extremely important that you are certain that your pet is free from heartworm disease before starting medication. Hence, if your furry kid is more than 6 months old and has not been on preventive medication, or you are thinking of recommencing preventive medication after a break in treatment (usually greater than 6 months), then you will need a heartworm test. This is crucial as potentially life-threatening reactions can occur if preventive medication is given to a pet that has heartworms.
When in doubt - have your vet give your dog a heartworm test even if the interval between treatments is less than 6 months.
How can heartworm disease be prevented, New Farm Vet?
The following chart lists out some of the more popular active ingredients used in several brands that are effective in preventing heartworm infection.
Active Ingredient
|
Route
|
Brands
|
Diethylcarbamazine
|
Daily oral pills. If more than 48hrs of treatment is missed, then a heartworm test should be performed prior to recommencing medication. Alternatively, a dose of ivermectin can be given and continued monthly (i.e. adopting the alternative treatment below).
|
Dimmitrol
|
Macrolides
(Ivermectin, moxidectin, selamectin and mibemycin)
|
Monthly prevention. Oral or “spot on” applications available. Most commonly used ingredient. Frequently combined with other ingredients to act as a wormer and flea control. Do not give ivermectin to Collie breeds (Border collies, Sheepdogs, Shelties and Aussie Shepherds).
|
Heartgard, Interceptor Spectrum, Sentinel Spectrum, Revolution, Advocate, Proheart, Milbemax.
|
Moxidectin
|
Annual injection. This is a slow-release preparation (not a vaccine!). Start from 12 weeks of age.
|
Proheart SR 12
|
What if my dog has heartworm disease, New Farm Vet?
The most important point to consider is that your vet must be certain that your pooch really has a heartworm infection. If a single test returns positive, further diagnostic tests, especially radiographs of the thorax, are recommended. There are 4 classes of heartworm infection and each class has their own recommended therapy. Melarsomine is the drug of choice to kill adult heartworms. Speak to your vet if you are concerned.
