Hookworms in Cats

Hookworms can cause anemia, small intestine inflammation, internal blood loss and bleeding at the site of the bite. Because of this, hookworms can be fatal if left untreated. Fatalities are most common in young kittens.

Ancylostoma hookworms are small, thread-like parasites that attach to the walls of the small intestine in cats, feeding on the blood of their host. Both Ancylostoma tubaeforme and Ancylostoma ceylanicum worms are known to invade cats. Hookworms are fairly common, infecting an estimated 10 to 60 percent of all cats at some point in their lives.

Symptoms are often mild in older cats and more pronounced in younger cats. These symptoms include:

• Small lesions on the bottom of the foot pads and in-between toes
• Pale mucous membranes in the lips, gums and nostrils
• Poor coat
• Diarrhea that may contain blood
• Weight loss
• Constipation
• Black, tarry stools
• Loss of appetite
• Cough
• Breathing difficulties
• Wheezing

Hookworm eggs are passed through the stool where they hatch into larvae. Cats become infected with the larvae either through skin contact with an infected cat's stool in the dirt, sand or litter box, through the ingestion of other animals that are infected with hookworms, or by drinking water that is infested with the larvae. Kittens can become infected with hookworms by drinking their mother's milk. Once inside of the cat's body, the larvae migrate to the lungs and then into the small intestine. While in the small intestine, the larvae will attach themselves to the intestinal wall, feed on the cat's blood and mature into adult worms that can reproduce eggs that will then pass through the cat's stool. It takes approximately two to four weeks from the initial infestation for the cat to be able to pass on the hookworms to other cats, animals and humans. Outdoor cats, hunters, and cats in overcrowded shelters are most likely to become infected with hookworms.

Because adult hookworms are typically 1/2-inch or less in size and produce small eggs and larvae, they are difficult to see in the stool with the naked eye. It's important to watch for the symptoms in cats in order to catch and treat hookworms before complications occur. 

The veterinarian will need to know the cat's complete health history, which will include a detailed list of the symptoms, an approximate date when the symptoms first began and if any other animals in the household have recently been diagnosed with hookworms. The veterinarian will suspect hookworms if other kittens in the litter have recently died. 

Hookworms are diagnosed by the veterinarian examining the cat's stool sample under a microscope. The stool specimen will be mixed with a solution that allows the eggs to float up to the top of the sample, making them easily visible under the microscope. Because hookworms typically reproduce daily, infestations are easily detected.

Cats who have been diagnosed with hookworms will have several labs drawn, which will include a complete blood count and a urinalysis. These labs will look for low hemoglobin levels that are indicative of anemia and low kidney function as a result of dehydration.

Medication

A deworming medication will be prescribed to the cat. This medication will either expel the worms or kill them. Fenbendazole is a common ingredient in deworming medications and may cause vomiting. The medication will need to be given to the cat for three to five days to ensure that all of the hookworms have been expelled.

Pregnant cats should begin medication two weeks after breeding and continue until two to four weeks after giving birth in order to prevent the hookworms from being passed on to the kittens. Kittens should receive medication after they have reached three to four weeks of age and continue once a month to ensure that all of the hookworms have been expelled.

Supplements

Cats who are severely anemic may need to receive iron and nutritional supplements until their iron levels are back to normal.

Fluid Therapy

If the cat is extremely dehydrated, hospitalization may be needed. Fluids will be given intravenously during hospitalization. The veterinarian will run frequent labs to ensure the cat's heart and kidneys are responding well to the fluid therapy.

When caught early, the prognosis is good for cats who receive thorough treatment. The cat will need to follow up with the veterinarian as recommended to ensure that re-infestation does not occur. Though there is no vaccination available to prevent hookworms, there are medications available through prescription to prevent the parasite from infecting the cat. It's important to prevent future infestations by properly and frequently cleaning the cat's litter box and living area. Outdoor cats should be protected by paying close attention to areas where water gathers, such as small ponds, containers, and low-lying areas. 

Because hookworms can be passed to humans, it's important to take care when caring for the cat and cleaning its litter box by wearing gloves and with thorough hand washing.