Heartworm in cats

Before heartworm was an infection which is only common to dogs. But, back in the year 1922, the first case of heartworm in the cat was reported in the United States. Since then, the infection has spread to various states. So, it’s something that every cat owners must be aware of primarily. This article will talk about how heartworm is transmitted, the causes, signs and the proper treatment.

What is Heartworm in Cat?

Dirofilaria immites cause feline heartworm, and it is a vector-borne helminths infection of Zoonotic. The adults stay in the right ventricle, pulmonary artery as well as vena cava. Microfilaria can be detected in any tissue specifically blood, lungs, and kidneys. Mortality because in this disease is rare.


Dirofilariasis is common in tropical and subtropical nations and temperate regions as well, which favor fast breeding of fly population. The feline heartworm is noticeable amongst the three to six years old ones.


Dirofilaria immites is a long thin roundworm that measures about 300 millimeters in length that can be readily determined in the right ventricle of the heart, vena cava, pulmonary artery as well as occasionally in lungs in heavy infections.

The Microfilaria measures about 286-349 millimicrons in length, and this can also be identified in both dry and wet blood smears in clinically affected animals.  The periodicity of microfilaria mainly at night has been reported.

Transmission of Heartworm

The life cycle of heartworm in a feline is indirect. In humid and hot weather, the illness is transmitted using a bit of mosquito and lice wherein the microfilaria develops into infective phase.

Symptoms of Heartworm in Feline

No clinical have been shown during life, and the illness usually happens as an apparent infection. Different indications of heartworm in the cat include:

  • Occasional coughing
  • Anorexia
  • Asthma-like symptoms
  • Lethargy
  • Increased respiratory effort
  • Vomiting


In general, the parasites are noticed at necropsy as an incidental finding. The same as microfilaria are also noticed during routine screening of blood smears of felids having normal health in endemic areas.

In heavy infection, the vena cava and pulmonary artery might be occluded with parasites that cause mechanical obstruction, occasional initial damage as well as passive hyperemia.


The illness in the domestic feline is generally detected through undergoing necropsy test. The illness can also be determined by an examination of blood smears and demonstration of characteristic microfilaria. Confirmative diagnosis can be made with the assistance of X-rays. The heartworm illness in domestic cats must be distinguished from Feline asthma as well as other pulmonary diseases.

Proper Treatment

In endemic parts of feline heartworm illness, Diethylcarbamazine citrate may be given after discussing with the veterinary. The efficiency of acetazolamide for adulticidal action as well as levamisole and ivermectin for antimicrobial activity is yet to be reviewed and evaluated perfectly.

Prevention and Control

Aside from lice and vigorous fly measures, periodic cure followed by serological monitoring as well as blood screening for microfilaria will be useful in controlling the disease in cats in endemic areas.

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