While southern regions of the United States manage year-round mosquito activity due to persistently warm climates, New England’s season is shorter but intensely concentrated. The combination of heavy spring rainfall and high summer humidity leads to rapid population spikes, particularly for species like the Northern House Mosquito (Culex pipiens) and the Inland Floodwater Mosquito (Aedes vexans).
Heartworm disease, caused by the parasitic roundworm Dirofilaria immitis, is the most significant mosquito-borne threat to dogs, and occasionally cats. When an infected mosquito bites a pet, it transmits microscopic larvae into the bloodstream, which eventually mature and migrate to the heart and lungs. While heartworm is historically more prevalent in the warmer, southern United States, the disease is a persistent and growing seasonal risk in Massachusetts.
Southeastern Massachusetts is a known focal area for Eastern Equine Encephalitis (EEE) and West Nile Virus (WNV). While these viruses are primarily recognized for their severe impact on humans and horses, WNV can occasionally infect dogs and cats. Fortunately, domestic pets generally exhibit high natural resistance and rarely show severe clinical symptoms, though immunocompromised or older pets may be at higher risk.
Because heartworm larvae take several months to mature, pets often do not show immediate signs of infection following a mosquito bite. As the disease progresses, owners should monitor their pets for the following clinical signs:
Mosquitoes require stagnant water to breed and lay eggs. A standard summer storm in North Attleboro can leave behind enough standing water to produce thousands of mosquitoes within a week. Source reduction is a highly effective control method:
