All About Heart – Heartworm Awareness

Crash HW

Photo courtesy of Jackie Sheppard

With April being National Heartworm Awareness month, it is important to understand exactly what heartworm disease is and how you can prevent your dog from developing it. A common misconception about heartworm disease is that dogs who live in Chicago are not at risk. This map from the American Heartworm Society shows this is not the case!

How is heartworm disease transmitted?

Per the American Heartworm Society, “Adult female heartworms living in an infected dog, fox, coyote, or wolf produce microscopic baby worms called microfilaria that circulate in the bloodstream. When a mosquito bites and takes a blood meal from an infected animal, it picks up these baby worms, which develop and mature into “infective stage” larvae over a period of 10 to 14 days.” If the same mosquito then bites another dog after this timeframe, the infected larvae enter through the bite wound. After they enter the new host, it takes about 6 months for the larvae to become adults. If dogs are not routinely tested and treated, these mature heartworms can live in their heart, lungs and nearby blood vessels for 5-7 years, and can grow up to 12 inches long!

What are the signs of heartworm disease?

Most often dogs do not show any signs of being infected with heartworms until the disease has progressed to what is considered severe. According to the FDA, some signs dogs may exhibit in this stage are “difficulty breathing, coughing, tiredness, reduced appetite and weight loss, or lung, live, kidney or heart failure, leading to death.” Since many of these signs can be indicative of other problems or conditions, we recommend yearly heartworm testing.  

How often should heartworm medication be given?

We recommend administering heartworm prevention year-round to ensure your dog is completely protected. Per Vetstreet, “Today, since cases have been reported in all 50 states and because mosquitoes can live inside (even in winter), it’s recommended that no matter where you live, you give your dogs…heartworm prevention medicine year-round.” Especially with the warmer weather in the fall and winter, this means mosquitoes are just going to be around later in these typically cooler seasons!  In addition, these monthly preventatives are also deworming medications to protect your dog from roundworms, hookworms and whipworms; gastrointestinal parasites that can also transmit to people. We prefer to call heartworm preventatives now “parasite preventatives” for that very reason!

Dr. Natalie Marks, co-owner and veterinarian at Blum, said if you forget to give even just one month of heartworm prevention anytime during the year, we recommend bringing your dog in for a recheck heartworm test 6 months after the missed dose.

For more information about heartworm disease or to determine the best preventive for your dog, please call to speak to a Veterinary Care Coordinator at: (773) 327-4446. 

Written for Blum Animal Hospital by Jackie Sheppard.