More than a million pets in the U.S. have heartworms, and their humans don’t know it.*
April is heartworm disease prevention month, so we want to highlight a lovely story of one of our foster dog’s survival from this potentially fatal disease. But first, all of us pet lovers have heard of it, but what exactly is heartworm disease and how do our pets get it?
Heartworm disease starts with a single mosquito bite and if left untreated, results in severe lung disease, heart failure, other organ damage, and death. When a mosquito bites a dog infected with heartworm or drinks water contaminated with infected mosquito larvae, it’s transferred to an uninfected dog when the mosquito bites him a few days later. The worms are called “heartworms” because the adults live in the heart, lungs, and associated blood vessels of an infected animal. (Heartworms can also affect other pets like cats and ferrets. but they don’t survive for long or cause the damage quite like they do in dogs.) It takes about six months for the infective larvae in the dog to mature into adult heartworms. The adult heartworms mate and the females release their offspring into the dog’s bloodstream, completing the lifecycle. Surprisingly, a heartworm can live in a dog 5-7 years undetected. Adult heartworms range in size from four to 12 inches and look like strands of cooked spaghetti (eeewww!).
SVPP first time foster mom TzuFang Huang had just volunteered to foster Casper, a Chihuahua mix, when she learned he had heartworms during his initial vet check. “He was such a sweet, loving dog I couldn’t imagine why someone had abandoned him. After we got the diagnosis and the vet described what a costly, lengthy process it would be, I figured out why.” said TzuFang. A second test confirmed that Casper definitely had heartworms. TzuFang never questioned whether or not she would help Casper through what would be an intense four-month process. And what a Rockstar foster mom she was to have lovingly helped Casper without knowing exactly what to expect! After finding out Casper had heartworm, TzuFang had to then keep him calm for a month prior to getting the first of two shots that would slowly kill the heartworm. Keeping a young dog calm is no easy feat, but it’s meant to teach him to be more sedentary (i.e., no chasing squirrels or running through the dog park!).
The danger comes after the first shot when the worms start to die. They decompose inside the dog’s body, so the concern is that if they’re too active, those worms can get into certain vessels and endanger the pup. As a result, after Casper’s first shot, the doctor observed him onsite for the day then sent him home on a sedative. “I was scared when he came home that first day. He couldn’t walk straight. He’s usually really into eating, but he wouldn’t eat.” Turns out the sedative dose was a bit too strong,” said TzuFang. For the next month, Casper required medicine twice per day, then every other day, then daily plus heartworm medicine. After the second shot, Casper had to rest for another six weeks and follow the same medicine process. It was a long haul for Casper and his foster family!
Finally, after months of treatment, Casper made it! He was healthy, happy, and ready for adoption! But guess what? After caring for Casper through this traumatic experience, the dog mom relationship grew so strong that TzuFang gave him the best gift ever – she decided to keep him and become his new dog family! “We felt a connection and decided to keep him,” TzuFang said.
So, what’s the lesson learned from TzuFang’s experience with Casper? Heartworm disease prevention is key. The American Heartworm Society advocates to “Think 12." Give dogs 12 months of heartworm prevention and get them tested for heartworms every 12 months. It’s the easiest way to avoid heartworm disease. All require a veterinarian’s prescription. Most products are given monthly, either as a topical liquid applied on the skin or as an oral tablet. For more information, check out the American Heartworm Society.
Stacy St. Louis is one of our newest volunteers. With a career history in high tech Communications, she wanted to try her hand at writing for fun about a topic she loves – pets! Stacy is a born-and-raised Bay Area native who lives with her family (including Ruby the Maltese Yorkie) in Los Gatos.