Creepy Crawlies part 2

As I mentioned in Creepy Crawlies part 1, we will be discussing mosquitos and flies in part 2. In veterinary medicine, mosquitos are associated with heartworm disease and flies with maggot infestations.

To understand the role mosquitos play in spreading heartworm disease, it's helpful to understand the heartworm life cycle. It begins with adult heartworms reproducing in the heart of an infected dog. The offspring, microfilaria, circulate in the dog's bloodstream. A mosquito bites an infected dog and ingests microfilaria, which develop inside the mosquito into " infective stage" larvae over 10-14 days. After this time, when the infected mosquito bites another dog, the larvae enter the new host through the mosquito's bite wound. The infective larvae take approximately 6 months to migrate to the heart and mature into adults. Mature heartworms can live up to 5-7 years in dogs.

The adult heartworms live in the heart, lungs and associated blood vessels of the infected dog, causing lasting damage. The "worm burden" is determined by the number of worms in the heart, how long they have been there and how well the dog is tolerating them. Early signs of heartworm disease may be as vague as an occasional cough or tiredness after moderate activity. As the disease progresses, the cough becomes more persistent, and symptoms often associated with heart failure may be seen. Even mild activity leaves these dogs tired. If left untreated, heartworm disease will not only affect the heart and lungs but the liver and kidneys as well, eventually causing death.

Some dogs carry such a heavy worm burden that the worms block the flow of blood back into the heart. Called Caval Syndrome, this obstruction must be surgically removed. The surgery is very risky and most of these dogs die regardless.

When a dog is diagnosed with heartworm disease, the veterinarian first assesses the overall condition of the pet. The medications used to kill adult heartworms in the infected dog contain arsenic and are toxic. Sometimes, treatment causes life-threatening complications like blood clots to the lungs.

Considering the extensive damage caused by heartworm disease, the best approach is prevention. There are several heartworm preventatives available, and they all kill microfilaria circulating in the bloodstream. None of them kill adult heartworms. The current recommendation is to keep your dog on heartworm preventative all year round to avoid any gaps in protection and test annually. Most preventatives contain ingredients that help control intestinal parasites and fleas as well.

Fly strike is the veterinary term for the damage caused to our dogs by biting flies. It is seen primarily in dogs who are confined outdoors during the summer and fall months. Flies will seek out moist areas with exposed skin, like ears, vulvas and anuses, leaving behind painful bleeding sores. These wounds provide a good environment for the flies to feed and lay their eggs. In younger dogs, the wounds are often seen on the tips of erect ears or the leading edge of floppy ears. As our older pets become less diligent about grooming themselves, flies are attracted to urine and fecal residue on the hind quarters and will bite and lay eggs on vulvas and anuses. If the fly eggs are not removed immediately, they will hatch into maggots, who begin to feed on your dog's inflamed skin. Left unchecked, maggots cause extensive damage as they feed their way into healthy tissue. Treatment involves clipping and cleaning the wounds and removing as many maggots as possible. This procedure can be very painful so sedation is always recommended. As the wounds are healing, the dog must be kept indoors as much as possible to keep flies from re-infesting the wounds.

In addition to the disease these pests cause in our dogs, flies and mosquitos carry a large number of diseases that are life threatening to humans. Successful pest control requires understanding a little about the insects life cycles.

Female mosquitos lay their eggs in standing water, where the larvae hatch. Walk through the yard each day and empty standing water that collects in bowls, plant pots, gutters and other nooks and crannies. For larger bodies of water like ponds or pools, use a commercial larvacide and follow label directions. Run the water filter regularly. Cover pools at night and over the winter.

Flies are attracted to materials in which they can lay their eggs. They seek out rotting material like food waste and animal feces and manure. Secure household waste in garbage cans with tight fitting lids and empty often. Store food in airtight containers. Wash dishes immediately. Keep decaying yard waste and compost heaps away from your home. Scoop pet waste from the yard and litter pans often.

Both mosquitos and flies are attracted to bright lights at night so turn them off when not needed. According to the American Association for Advancement of Science, warm yellow LED lights are less appealing.

There are a wide variety of commercial bug zappers and bait traps available for both insects and can be used indoors and out. If you prefer DIY, you can make your own traps with common household items. Sealing gaps around doors and repairing screens will help keep both pests out of our homes. For the gardeners among us, there are several aromatic plants that repel flies and mosquitos, like basil, catnip, garlic, geraniums, lavender, lemongrass, marigolds, peppermint, rosemary and sage.

Insecticides have limited effectiveness against these winged pests. Their short life spans mean they develop resistance quickly. With populations numbering millions, insecticides only make a dent anyway and pose a threat to all life forms. Protect your family with mosquito repellants and your dogs with flea control products.