Heartworm disease & prevention
Heartworm disease is a serious disease that is becoming more common throughout the US. This disease can cause significant and sometimes irreversible damage to the heart and lungs. The good news is that it is easily preventable!
Heartworm disease can affect dogs, cats, ferrets and other mammals with each species developing different signs. Cases have now been reported in all 50 states with more cases in the northern states every year. When an infected mosquito bites a dog, the “juvenile” stage enters the pet’s bloodstream. This grows over time to become a worm which migrates to the heart and blood vessels of the lungs. There, these worms produce more worms and cause damage over time. Signs of heartworm that are most commonly seen include persistent cough, unwillingness to play, getting easily tired, weight loss and decreased appetite.
Since we are not able to prevent mosquitos from biting our pets, we need to give them preventative medications that kill the heartworm if they become infected. These medications are very safe and very effective. Some even have other benefits like treating intestinal worms. To start these medications, your veterinarian needs to verify that your pet does not currently have heartworms. This is accomplished with a simple blood test in hospital or sometimes sent to the lab with the results returning the next day. This test is commonly included in your pet’s yearly bloodwork.
Prevention of this disease usually involves a once monthly chewable treat, topical medication or an injectable medication. These medications should be started no later than 8 weeks of age. The American Heartworm Society recommend year-round preventative even in the northern states that experience cold weather and snow. The reason for this is that mosquitos are starting to adapt to cold weather more and some even survive during winter in homes. The intestinal deworming benefit of these products also plays a part in the recommendation of their year-round use. Please contact your veterinarian to discuss this topic further and to see what preventative is right for your pet. For more information on this topic, please go to
Dan VanSteenkiste DVM