Heartworm Prevention Steps

Posted by bmedia on Tuesday, February 2, 2016


Heart worm can be a serious issue in dogs. However, without in-house testing capabilities, we can tell within minutes if your dog is infected and begin steps toward treating the disease. Read an excerpt from this American Heartworm Society (AHS) study about early heartworm prevention:

The domestic dog and some wild canids are the normal definitive hosts for the heartworm, Dirofilaria immitis, and thus serve as the main reservoir of infection. Cats and ferrets occasionally have low-level, transient microfilaremia and therefore may serve as a limited source of infection for mosquitoes. A clear understanding of heartworm transmission, development, prepatent period, and the susceptibility of the different life stages of the parasite to available pharmaceutical drugs is critical.


The AHS recommends year-round heartworm prophylaxis for maximal effectiveness. If seasonal treatment is chosen, administration should begin at least one month prior to the anticipated start of heartworm transmission and depending on the product used, may need to be continued for up to 6 months after transmission typically ceases (see section on Lack of Efficacy).The prescription of heartworm chemoprophylactic medication requires authorization by a licensed veterinarian having a valid relationship with the client and patient. If records of past treatment and testing do not exist, it is necessary to test the patient before dispensing or prescribing chemoprophylaxis. Options for effective chemoprophylaxis include several drugs administered monthly either orally or topically, or parenterally at 6-month intervals. Puppies should be started on preventives as early as possible, and no later than 8 weeks of age. Puppies started on a heartworm preventive after 8 weeks of age should be tested 6 months after the initial dose, then annually thereafter. Before initiating a preventive regime on dogs 7 months of age or older, antigen and microfilariae testing should be performed immediately, then 6 months later, then again in 6 months and annually thereafter. This will avoid delays in detecting subclinical infections and the potential confusion concerning effectiveness of the prevention program if a pre-existing infection becomes evident after beginning chemoprophylaxis.

SRC: Read the full AHS study here: www.heartwormsociety.org/images/pdf/Canine-Guidelines-Summary.pdf