Heartworm Disease Testing and Prevention in Dogs

Heartworms are an actual worm- type parasite that lives inside the heart and blood vessels of the lungs of dogs. Heartworms cause inflammation and blockage of blood vessels in the lungs which causes coughing and difficulty breathing.

Heartworm disease is transmitted by infected mosquitoes.

Untreated heartworm disease can be fatal with severe damage occurring to the heart, lungs and other vital organs.

Preventing heartworm infection is easy with once a month preventative medications.

Treating a heartworm infection is difficult and costly! The process takes about 1 year and may cost over $1000!

Heartworms  are transmitted by mosquitoes. It takes 6 months from the time a dog is bitten by an infected mosquito until adult heartworms are present in the heart. The heartworm blood test detects adult heartworms in the heart.

Puppies less than 6 months of age cannot possibly have adult heartworms so they can be safely put on preventative without a heartworm test.   All puppies and dogs over 6 months of age must be tested at least once a year to ensure they do not have heartworms.  A monthly heartworm preventative must be started within 30 days of a negative heartworm test.

Rescued pets whose previous heartworm prevention and treatment may not be known should have a heartworm test immediately; then again in 6 months because it is possible they are incubating a new infection.

We recommend all dogs be on heartworm preventative medication year-round. Year-round preventative allows for protection even if winter weather is warmer than anticipated. Year-round preventative helps owners to stay in the habit of giving the medication. Most heartworm preventatives also treat or prevent intestinal parasite infections that are a risk year-round.

Heartworm preventative medications work by killing immature heartworms in the first 30 days after a bite has occurred from an infected mosquito. This is long before the immature heartworms are able to begin their migration to the heart.

If heartworm preventative is stopped in the winter the last dose must be given after all risk of mosquito activity has passed. If the weather is above 50 degrees Fahrenheit mosquitoes may still be active.

If heartworm preventative medication is stopped in the winter the dog must be retested to ensure no heartworms are present prior to restarting preventative medication. Giving heartworm preventative medication to a dog with adult heartworms can be fatal!

If you have any questions about heartworm disease or prevention please let us know.