Heartworms are a parasite transmitted by mosquitos to dogs and cats; dogs are more likely to contract heartworms than cats. Untreated heartworm infestation causes heart and lung disease and is fatal if left untreated. Because heartworm treatment is expensive, it is recommended to start prevention at 8 weeks but no later than 6 months of age (the sooner the better). Heartworm prevention is dosed by weight, and we have multiple products to choose from. A heartworm test is recommended yearly for dogs and every 2 years for cats to catch the disease as early as possible. Dog’s heartworm test also test for Lyme, Ehrlichia and Anaplasma tick disease, and the cat’s also includes feline leukemia and FIV (feline immunodeficiency virus). Year-round heartworm prevention is recommended, for more information on heartworms please see the heartworm article in our pet health library.
Dog’s Heartworm test and prevention rules:
- Puppies UNDER 6 months old are started on monthly heartworm preventative then tested at first annual exam and every yearly annual exam thereafter.
- If dog is OVER 6 months old, test then RETEST in 6 months.
- If dog OFF heartworm preventative for less than 2 months, then refill heartworm preventative and retest at next annual exam.
- If dog OFF heartworm preventative for less than 6 months, then refill ONLY Heartgard Plus and retest at next annual exam.
- If dog OFF heartworm preventative for more than 6 months, then test before refilling heartworm preventative.
- If dog is pregnant, should ONLY take monthly Heartgard Plus.