In the middle of a cold and bitter winter, many pet owners might be tempted to forego their dog’s heartworm preventative treatments until the weather warms and insects come out again. However, the American Heartworm Society and many vets across the country are urging owners to think again and treat their dogs with heartworm preventative all year.
First, you might be asking why your dog needs heartworm preventative and how the disease is spread. Heartworms are spread by mosquitos carrying infected blood and larvae can begin to develop after a single mosquito bites and infects your pet. The larvae go through multiple stages of development before they reach adult-hood and migrate to the heart and the lungs. As the disease progresses, more larvae are produced and it becomes more life-threatening for the pet. In these instances, infected pets require immediate veterinary attention before damage could progress.
Now back to heartworm preventatives. Preventatives do not stop the infection of heartworms in your pet, but rather break the life cycle so adults do not develop. When you give your dog a preventative medication, the medication clears the dog of all heartworm larvae in its system it may have acquired from the past 30 days. The medication does not stay in the dog’s system for 30 days but rather, it is given on a 30-day cycle basis as it takes 6 months for adults to develop from initial infection. The reason why preventatives should be given all year is because the medication is only effective against heartworm larvae, adults are resistant and will continue to develop.
If owners decide to skip heartworm preventative treatment in the winter months, or they accidently miss several doses, they must test their dog in the spring before resuming preventative treatments. A quick test with a few drops of blood is effective in determining if the dog is infected with heartworms and if it is safe to use heartworm preventative treatment. Here at Palmer Animal Hospital, if your dog is on preventative all year, we will test them every other year and we will test them once a year if they are not on preventatives continuously. The reason behind this is if one dose is accidently missed, or the dog spits up or vomits the medication they could be unprotected for a period of time potentially allowing adult heartworms to develop.
Cases of heartworm have been on the rise in recent years so it is important to protect your pet against the disease. Even in the colder winter months, it is important to give your dog a heartworm preventative all year so they are well protected and don’t spread the disease.