Hookworm life cycle – 2 charts and background information

The hookworm life cycle is set out below in a chart. I also have a page on deworming cat treatments and a page on cat parasites. Several species of hookworm can infect domestic cats. They are blood sucking endoparasites and one species, the most common in the USA can cause serious blood loss in young kittens.

Hookworm. Credit as per image.
Two useful tags. Click either to see the articles: Toxic to cats | Dangers to cats

Hookworms are small thin endoparasites about 0.25-0.5 inches long. The use their hooks to fasten onto the wall of the small intestines. They draw blood from the host. There are four species of hook worms that infest the domestic cat. They are not as common in cats as they are and dogs. They are more prevalent in geographical regions where the temperatures are higher and the humidity is also higher. In the USA this would be in the southern states. The conditions are favourable for the development and spread of the larvae.

RELATED: 95% of stray cats have worms and 57% scavenge potentially life-threatening refuse

The cycle starts by the cat acquiring the disease by ingesting infected larvae in soil or faeces or when the larvae directly penetrate the skin.

My book on home treatments for health conditions tells me that a recommended treatment in the US are the deworming medications: pyrantel pamoate and selamectin. They are said to be safe and effective. Milbemycin and ivermectin are also said to be effective dewormers but they are normally used on older kittens and adult cats. Please see your veterinarian about this. The information here is a guide only. Always be extremely cautious when home treating domestic cats.

For completeness, there are public health considerations. There is a disease in humans called cutaneous larvae migrans which is caused by hookworm species.

Hookworm Life Cycle – (ref: 2)

Larvae that are infective are either ingested by a cat or the larvae penetrate the cat’s skin.


The ingested larvae then travel to the small intestine. Larvae that have penetrated the skin travel to the intestine via the bloodstream to the lungs then coughed into the small intestine via the oesophagus.


In young cats the larva develop into adults in the small intestine and attach to the mucosa (mucous membranes are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion1). In some adult cats the penetrating larvae are stopped and deposited as encysted larvae in body tissues.


In young cats hookworms in the intestine feed on blood. This causes blood loss and feline anemia. In adult cats where the larvae remain inactive (see above) they do not cause disease.


Adult female hookworms that are attached to the mucous membrane produce eggs


Hookworm eggs are passed into the cat or kitten’s feces where they enter the outside environment.


Eggs hatch in warm and humid conditions. The larvae develop into infective stage after about one week.


Larvae that are infective are ingested by the cat or the penetrate the cat’s skin.

Since creating the above lifecycle, CDC have created their version which is below. Please click on the image to see it in a large format.

CDC hookworm lifecycle illustration
CDC hookworm lifecycle illustration.


1. Wikipedia authors

2. The Cat, Its Behavior, Nutrition & Health by Linda P Case

3. Original photo on Flickr

From Hookworm Life Cycle to Cat Health Problems

Useful tag. Click to see the articles: Cat behavior

Note: sources for news articles are carefully selected but the news is often not independently verified.
Useful links
Anxiety - reduce it
FULL Maine Coon guide - lots of pages
Children and cats - important
Scroll to Top