 What
causes heartworm disease and how do they get into the heart?
 Heartworm
disease know as Dirofilariasis, is a severe and potentially
deadly disease in dogs. It is caused by blood-borne parasites
called Dirofilaria immitis. Heartworm is transferred
from mosquito to dog.
As many as 30 species of mosquitoes can
transmit heartworms. The female mosquito bites the infected dog
and ingests the microfilarie during a blood meal. The
microfilariae develop further for 10 to 30 days in the mosquito and then
enter the mouthparts of the mosquito. The microfilariae are now
called infective larvae because at this stage of development, they will
grow to adult when they enter a dog. the mosquito usually bites
the dog where the hair coat is the thinnest. However, having long
hair does not prevent a dog from getting heartworms.
When fully developed, the infective
larvae enter the bloodstream and move to the heart and adjacent vessels
where they grow to maturity in two to three months and start
reproducing, thereby completing the full life cycle.
Where are heartworms found?
Canine heartworm disease occurs all over
the world. It has been found in all 50 states. Valencia
County has more cases of heartworm in 2001 that any other county in New
Mexico.
How do dogs get infected with them?
The disease is not spread directly from
dog to dog. An intermediate host, the mosquito, is required for
transmission. Spread of the disease therefore coincides with
mosquito season. The number of dogs infected and the length of the
mosquito season are directly correlated with the incidence of heartworm
disease in any given area.
What do heartworms do to the dog?
Adult Heartworm:
Adult heartworms cause disease by clogging the heart and major blood
vessels leading from the heart. they interfere with the valve
action in the heart. By clogging the main blood vessels, the blood
supply to other organs of the body is reduced, particularly the lungs,
liver and kidneys, leading to malfunction of these organs.
Signs of heartworm disease in a dog?
The signs of heartworm disease depend on
the number of adult worms present, the location of the worms, the length
of time the worms have been present, and the degree of damage to the
heart, lungs, liver, and kidneys from the adult worms and the
microfilariae. The most obvious signs are a soft, dry cough,
shortness of breath, weakness, nervousness, listlessness, and loss of
stamina. All of these signs are most noticeable following
exercise, when some dogs may even faint. There may also be
evidence of weight loss, poor condition, and anemia.
How is heartworm infection diagnosed?
A simple blood test can determine if your
pet has this disease.
How are dogs treated for heartworms?
There is some risk involved in treating
dogs with heartworms, although fatalities are rare. A newer drug
is now available that does not have the toxic side-effects. We can
now successfully treat more than 95% of dogs with heartworms.
With the safe and affordable heart
preventatives available today, no pet should ever have to endure this
dreaded disease. |
