San Francisco Climate

Is heartworm on the rise?

I've heard more than a few Bay Area pet owners say that they don't treat their pets with a monthly heartworm preventative because heartworm isn't a big issue — especially in San Francisco. We have so mosquitoes buzzing about, which are responsible for transmitting the disease.

After Alice's recent adverse reaction to Trifexis , I've been increasingly more wary of overmedicating my pooch, but recent reports seem to indicate that heartworm may be more prevalent, even here in the city, than we had previous thought.

According to a recent survey by the American Heartworm Society (AHS), heartworm-positive pets have been diagnosed in nearly every county and parish in every state in our country. The organization conducts the American Heartworm Incidence Survey every three years to track trends in heartworm incidence, using data from clinic heartworm testing and numbers of heartworm-positive dogs and cats. AHS gathered the 2010 data from more than 5,000 veterinary clinics across the country.

The infection rate in male dogs is as much as four times that of female dogs, and dogs housed outdoors are four to five times more likely to be infected than indoor dogs.

Treatment for heartworm infection is available, but is costly and requires strict supervision by both veterinarians and owners — and a month or more of cage confinement. The annual cost of prevention is roughly 10 percent of the cost of treatment. In addition, some heartworm medications treat other parasites as well.

The AHS recommends to both veterinarians and pet owners that pets be tested for heartworm each year and that dogs be put on heartworm prevention year-round. "Some owners, and even some veterinarians, question the necessity of following these recommendations, thinking that the cold or dry climate they live in makes such vigilance unnecessary," says says veterinarian and AHS President Wallace Graham. "However, we can cite case after case of heartworm-positive pets living in areas assumed to be low-risk. It only takes one bite from an infected mosquito for a pet to acquire a heartworm infection."

What is heartworm?

Heartworm disease is so named because the adult worms live in the right side of an animal's heart. Heartworm is a mosquito-borne parasite that is transmitted when an infective mosquito is feeding. The infected larvae enter the dog through the hole that is created in the dog's skin. Only a few of the many species of mosquitoes are significant vectors for hearworm. In Northern California, three species are thought to be the major carriers.

San Francisco Tops List of Climate-Friendly Cities | KQED News Fix

Canadian Business ranks among the three cities in California the top ten U.S.

The classification of new locations in San Francisco at number one because of its "political leadership and commitment" in the fight against climate change, the author of the study, Boyd Cohen, the impact of CO2, a Vancouver-based carbon offset company. The city also has a "proactive" university community, many active investors in clean technologies and the highest number of LEED certified buildings per capita in the country, he said.

Two other California cities made the top ten San Diego in the sixth, and ninth in San Jose.

Cohen said he based the rankings on political commitment, green buildings, university leadership, transit access and use, clean tech investment, and greenhouse gas emissions. He concedes that makes the term "climate-ready" something of a misnomer, as most of the rated activities are intended more for "mitigation" than "adaptation," that is more about reducing carbon emissions than actually preparing for the impacts of climate change. Cohen says rating cities on the latter is "tricky" because appropriate adaptation measures are different for every city.

Cohen, who says his firm works mostly in Latin America, says he has no client relationships with any cities on the list. He says he plans to continue with the national list and "make it more robust," and has plans to issue a global ranking next month.

Gretchen Weber is the Multimedia Producer for Climate Watch .