Veterinarian Dr. Andrew Dine, a Grosse Pointe Woods resident, has a very clear message to dog owners.

“If you do anything for your dog, give them the heartworm medication,” he said. “It’s more important than any of the vaccines. You can’t fix the damage a heartworm would do to your dog’s heart. Treating the damage will cost you between $500 and $800.

Heartworm is transmitted to dogs through mosquito bites. The monthly medication treats a dog for any transmission that may have occurred 4-6 weeks previous.

Depending where you purchase your dog’s heartworm medication, each pill or chewable can run between $5-$10. Dr. Dine said many vets recommend a 12-month medication schedule; he recommends May-November, as there are no mosquitoes in Michigan from November through March.

“If you give your dog preventative heartworm medication on May 1, that will protect him back to April 1,” Dr. Dine said. “The medication treats the larval stage only of the heartworm, so even if they have the larval stage on April 1, that pill on May 1 will kill it.”

Typical heartworm medication comes in three sizes, based on your dog’s weight: 1-25 pounds, 26-50 pounds and 51-100 pounds. If your dog has an adverse reaction to the medication, Dr. Dine recommends switching to another brand or type. The latest type is a liquid you can drop onto the skin on your dog’s neck. The amount of the actual medication in a chewable, for instance, is only about 6 micrograms. It cycles through the dog’s system quickly, and is not a time-release med.

“Heartworm is endemic in our area,” Dr. Dine said. “Not giving your dog the preventive medication is like playing Russian roulette with your dog.”

Many of the packages of medication come with stickers you can put on your wall calendar. When you give that month’s dose to your dog, put a check mark on it to confirm he or she was administered the medication. Most vets carry heartworm medication you can purchase immediately. You can also contact a reputable online store such as Petmeds.com for discounted medication, but it may take up to a week for delivery.