Could one mosquito bite be deadly for your pet?
The answer is yes. One bite from an infected mosquito is just enough for it to inject deadly heartworms into your dog or cat.
And this summer, with warmer weather in the Pacific Northwest and travelers returning from humid Southern states, including Florida, Georgia and Texas, the danger of dogs and cats in the area contracting heartworm is higher than ever, said Dr. Jennifer Janes-Gonzales, a veterinarian at Banfield Pet Hospital in east Vancouver.
In fact, veterinarians are saying the prevalence of canine and feline heartworm disease has spiked in the Pacific Northwest in recent years, the doctor added.
Carol Hart of Vancouver visited South Florida in the late '90s with her husband. While driving down an interstate, she noticed a bloodhound staggering along the shoulder with a frayed rope hanging in a loop around his neck. Hart didn't waste time.
She pulled off the highway and jumped into action, inspecting the disoriented dog. "He looked lost," she said.
"He was completely skin and bones," she said. "I could see every one of his ribs."
Hart knew that something more was wrong with the suffering canine. The self-proclaimed dog lover took him to a local shelter. "The dog was diagnosed heartworm positive," she said. "I'm just glad I was there in time to help him."
The disease is typically uncommon in our cool, wet climate in the Pacific Northwest. However, Janes-Gonzales said the migration north by Southerners brings the disease to our area, and early summers allow mosquitoes to live longer .
With this extended lifespan, a mosquito can cultivate the deadly internal parasite in just six months , making your outdoor pet vulnerable to contraction upon contact, she said.
Heartworm disease starts when a mosquito bites a previously infected dog or cat and contracts the microfilaria parasite, creating infective larvae inside. As the mosquito bites other animals, it injects the larvae into their bloodstream, where they begin to migrate to the heart. As the larvae grow into adult worms, symptoms begin to appear, the veterinarian said.
Dry coughing and lethargic behavior are characteristics of the disease in dogs, while cats are often asymptomatic, making detection difficult based on behavior.
Janes-Gonzales said prevention is much less expensive than treatment.
"It's about $1,000 to treat a heartworm case, and anywhere from $8 to $24 a month to prevent it," she said. "Treatment is also very painful."
Because the medication kills adult worms, significant damage can be done to the heart and lungs, she said.
"I believe in the risk of contraction and the benefit of prevention. I always make sure to let my clients know that my own pets are protected," she said
Banfield Pet Hospital's aim is to create widespread awareness of the disease around Clark County . "Our goal is to have 35 percent of our clients on heartworm prevention," Janes-Gonzales said, "We have only seen one case since 2010, but our other hospitals in the area are beginning to see a couple a month."
Kimberly Dauphin, a veterinarian from Southern California, said she saw several heartworm cases per month while working in that region.
"Dogs have a high survival rate if the pet is treated before there is too much damage done to the heart," she said.
According to Dauphin, there is no surgery for heartworm disease, only an expensive medicine regimen. "It is hard to get the treatment medication, and this makes it not just more expensive but leaves less time to treat the disease," she said. "If a dog does undergo treatment, they are required to have at least four weeks of 'rest' in order to recover from the lung injury that comes along with all the worms dying."
Since cats often show no symptoms, their cases are often so advanced by the time of diagnosis that not much can be done. "Every heartworm-positive cat owner I have worked with elected to euthanize," Dauphin said.
Medication for heartworm protection comes in several forms.
"I always recommend injectable heartworm prevention such as ProHeart 6," Dauphin said. "It eliminates client responsibility to administer the medication or remain accurate with dosage. The prevention is cheap, safe, and effective while the treatment is expensive, dangerous, and difficult."
She added, "There is no question that the benefits of heartworm prevention far outweigh the risks of not preventing heartworm disease."
Janes-Gonzales tells every client that heartworm disease has been diagnosed in all 50 states, and cases are appearing farther north than ever before.
She recommends that pet owners speak to their veterinarians for more information and prevention options.
Ava Bartley writes for The Independent, Clark College's student newspaper.