They might sound harmless, but they aren’t. Heartworms (dirofilarial immitis) can cause serious disease in cats, dogs and ferrets resulting in severe lung disorders, heart failure and other major organ damage. It is carried by many species of mosquito, cannot be transmitted from animal to animal and is a worldwide problem.
When a mosquito takes blood from an infected animal and then feeds on another animal it deposits the heartworm larvae under the animal’s skin. Eventually they enter the animal’s bloodstream until they reach the heart where they grow into adult worms, reaching up to 12” long.
The female worm begins to produce microscopic offspring called microfilariae. These offspring continue to live in the bloodstream of the infected animal until they in turn mature. In dogs, the heartworms can lodge themselves in the heart and large blood vessels leading from the heart to the lungs, usually resulting in heart failure if left untreated.
Dogs may not show any visible sign of heartworm until a year after initial infection and it will often begin with a soft cough which leads to breathing difficulties, lack of usual energy levels and loss of appetite.
Cats are more prone to being affected in the lungs but overall are more resistant to the disease as the heartworm often dies before reaching full maturity.
Mauricio Diaz, owner of Vet Playa Centro, had this to say about the disease: “Because of its warm climate, the Riviera Maya attracts mosquitoes and I see three to four cases a month. A treatment to cure heartworm is between 1500-2000 pesos but prevention in the form of a monthly treatment is approximately 1000 pesos annually – a small price to pay for peace of mind. You never know which mosquito is carrying the disease.”
Diaz also says that “prevention is better than a cure and there is a range of commercial products on the market which your vet can advise you on. You can also take further steps to reduce the risk such as eliminating standing water in your surroundings, which is a perfect breeding ground for mosquitoes. Use mosquito repellant spray in your home but make sure that your pets are out for approximately 30 minutes when you do this. Spray the inside of outdoor bin lids where mosquitos like to lay their eggs and spray under the base too. These measures should not replace medically approved heartworm preventatives.”