Skip to main content

It's time to test for heartworm

by Dr. Kelly Wolfenson Guay

Spring is coming!  Time for great rejoicing after such a frigid winter, right?  Unfortunately, as spring arrives, so do many pesky critters that want to make you and your pets unhealthy, such as mosquitos, which can transmit heartworm disease, and ticks, which carry Lyme disease as well as other diseases.  Today we’ll focus on heartworm disease.  Cats and dogs are both susceptible to heartworm disease, which can be fatal and is preventable!

Heartworm larva live in the bellies of mosquitos and when they bite an animal, they are capable of transmitting these larva into their blood stream.  As the worms develop, they migrate to the lungs, heart, and pulmonary artery, where, if they are fortunate enough to be bunking with a worm of the opposite gender, they can set up shop and begin to breed.  Dogs that have died of heartworm disease look as if they have mounds of spaghetti living inside the chambers of their hearts, and cats that suffered the same demise may only have one or two small tendril-like worms in their lungs.  Ew, right?

Many products available by prescription from your veterinarian can protect your pets.  Typically, for cats, the best medication is a topical, systemically active spot-on, applied monthly, such as Revolution and Advantage Multi.  These medications also help to fight other external and intestinal parasites.  Most of these medications do not require cats to be blood tested prior to applying.  For dogs, it is a little more involved: a simple blood test is often required to make sure their systems are free from heartworms before beginning preventative care.  Many of the blood tests also test for Lyme disease as well as some other tick-borne diseases that can have serious consequences if left untreated.  If a dog is given heartworm prevention and already has the parasites, you risk a potentially fatal allergic reaction to dying adult worms.  This is why if there is more than a month or two lapse in monthly prevention in a dog, it is so important to test them first.  Common preventive medications for dogs include Triheart, Heartgard, or Sentinel.  Some of these protect from fleas and intestinal parasites as well.  These are all oral, monthly products, but there are topicals too, such as Revolution for dogs.  K9 Advantix is said to have mosquito repellent properties, but is not enough to protect your dog from heartworm disease.

Symptoms of heartworm disease in cats can range from none, to vomiting, asthma, or sudden death.  It is always sad when an animal dies, even more so when it is from a preventable cause.  Dogs, being generally larger than cats, often can have heartworm disease for years while the worms grow and grow.  Shortness of breath, gradual unexplained weight loss, or exercise intolerance may be the only symptoms of  this systemic disease that can affect the kidneys, heart, lungs, liver, and other organs.  Having an untreated pet is also a reservoir for infection of more mosquitos, and continues the cycle.

Spring is a great time to get your pets checked up, tested, and re-started on their year-round heartworm preventatives!- Save a life!


Dr. Kelly Wolfenson Guay
Dr. Kelly’s House Calls
find me on Facebook

Dr. Kelly has been in private practice and higher education for 15 years.  She runs a housecall business in Worcester County and would be delighted to see you and your pets in your home, where you and your pet are most comfortable and relaxed!  She will treat your pets as if they were her own!