09/07/2025
❤️ Heartworms are called heartworms because they migrate around the body in the blood vessels but prefer to settle right near the heart.
❤️ Heartworms can infect: dogs, cats, ferrets, foxes, coyotes, seals, raccoons, wolves, and more.
❤️ Heartworms are spread by mosquitoes everywhere (even Alaska). The baby heartworms are picked up from a mosquito feeding on an infected animal and then transferred to the next pet they feed on where they develop into juvenile and adult worms and then reproduce.
❤️ Heartworms go through multiple life stages, and prevention only works on certain larval life stages. Once they are in the body, they burrow through tissues like lungs, liver, kidney, and blood vessels and cause irreversible damage to those tissues the longer they are left untreated.
❤️ When you give preventative heartworm medications, the medicine acts like a dewormer for the heartworms that might have been picked up in the last 30 days. The monthly dose is such a micro-dose that the medication does not have negative side effects to 99.9% of dogs. This is why you do NOT stop giving monthly heartworm meds or skip even one month. If you skip December 1st dose and your pet was bitten on November 3rd, then the larvae mature into juvenile and adult worms before your January 1st dose is given. The preventative medication works on the larvae, not the juvenile and adult life stages. In this scenario, the only thing to get rid of the heartworms now is injection treatments.
❤️ "Slow kill" heartworm treatments only limit further exposure to new heartworm larvae and let the pets' body essentially wait out the heartworms lifespan while they continue to damage the body over their 5-7 year life cycle. In the meantime, the worms won't die off from the preventative medication, but their exposure to it monthly makes them and their offspring more resistant to the preventative medication (drug resistance).
❤️ Because of factors like missing only 1 dose of prevention in the last year, puking after eating the prevention, or spitting it out after you thought they ate it, or drug resistance, we require a yearly blood test to screen for heartworms for all dogs. This yearly test also screens for tick borne diseases like Lyme disease. The sooner your vet knows your pet has heartworms, the sooner treatments can be started and we can minimize side effects from heartworms burrowing through your pets body causing lifelong damage.
❤️ Parasites like heartworms are preventable and treatable in dogs and preventable in cats. Your pets can't take their own medication, so its up to you to protect them. Please talk to your veterinarian if there is an issue with getting your pet to take the medicine, remembering to give it, if your pet has a reaction to medications, or if you have any other concerns.