Heartworm Disease

Heartworm Disease
Heartworm disease is a serious and potentially fatal disease. Left untreated, heartworm disease may result in heart failure and/or serious disease of the liver and kidneys. Prevention is the affective if properly given.

I. Transmission
A. Mosquito bites an infected dog
1. Harbors the microfilaria
2. Grows into larvae
B. Mosquito feeds on another dog
1. Larvae escape onto the skin
2. Larvae enter skin the migrate towards heart
II. Life Cycle
A. Microfilaria mature
B. Move into heart
C. Produce more microfilaria
III. Diagnosis
A. Pet Symptoms
B. Laboratory tests
1. Blood tests
2. X-rays
IV. Treatments
A. Pre-work up
B. Killing of Adult worms
1. Arsenic injections
2. Reduce activity
3. Follow-up exams
C. Killing of Microfilaria

V. Preventative
A. Daily
B. Monthly
VI. Diagnosis of heartworms in other animals
VII. Dogs vs. Cats




Heartworm infection is spread by mosquitoes. When a mosquito bites an infected dog, it takes up blood which may contain microscopic, immature worms called microfilaria. The mosquito harbors the microfilaria after about two weeks. During this time they become infective larvae. When the mosquito bites another dog, the infective larva is passed onto the dog’s skin. The larvae enter the skin and migrate toward the heart. This takes about three months.

The worms mature and travel to the right side of the heart through a vein and wait to reproduce. If male and female worms are present they will produce more microfilaria. Adult heartworms can reach 12 inches in length...