The types of parasites that infect your cat may also come in a wide variety, from single-celled protozoa to more complicated bacteria forms. While there are varying methods of infection, the majority of these parasitic blood infections are transmitted through ticks and fleas. To prevent these conditions, you should always work with your vet to develop an effective flea and tick control regimen for your pet.

Parasitic blood infections in cats include a variety of diseases in which parasitic organisms will invade your cat’s blood system. These diseases range in origin and severity. Some lead to mild sickness while others may cause severe anemia or even death. 

Exact symptoms of parasitic blood infection will vary, depending on which of the various types of infection your cat has contracted. Most of these, however, will have certain common characteristics that you should watch for.

There are a variety of parasitic blood infections capable of infecting your cat. Below is a short list of the most common specific conditions and their parasitic cause:

Caused by a parasite by the same name, this disease occurs naturally in wild cats in North America and is spread to domestic cats via tick bite.

Also called hemobartonellosis, this is one of the most common parasitic blood infections in cats. Infection is caused by a type of bacteria that enters the bloodstream via blood-sucking insects such as fleas and ticks, and can also be transmitted via scratches or fighting.

A tick-borne disease that is transmitted by the brown dog tick. The tick becomes infected when feeding on an infected host, but cats can only acquire the disease by eating the tick, not by being bitten.

Caused by an infection by trypanosomes, biting insects can transmit this disease between wild animals and domestic cats. This condition can also be transmitted to humans from their pets.

While the majority of parasitic blood infections in cats are spread by biting insects, there are a variety of other ways these conditions can be transmitted. Wild cats, or cats allowed to interact with wild or feral cats, may be especially at risk. Common causes include:

Diagnosis of parasitic blood infection in your cat will begin with a thorough physical examination by your vet and a review of your cat’s medical and symptomatic history. You should provide detailed information about your cat’s diet, whether it is an indoor or outdoor cat, and whether it has recently come into contact with any other wild or domesticated animals. You should also discuss whether or not your cat is on any flea and tick control regimen, as this could potentially help narrow down the organism causing the parasitic blood infection.

Your vet will thoroughly examine your cat’s gums to determine whether there are any signs of anemia. They will also inspect your cat’s coat to look for fleas, ticks, or any evidence of recent bites, scratches or fighting. The most definitive diagnostic tool will be a complete blood panel and a blood slide. In this test a small sample of your cat’s blood is withdrawn through a quick and painless needle stick. A drop is then placed on a slide and examined under a microscope for the presence of any abnormal cells. The shape and size of these objects will tell your veterinarian or laboratory just which of the numerous possible parasites are infecting your cat.

Treatment of parasitic blood infection in your cat will be two-fold. First, your veterinarian will stabilize your cat and deal with immediate life-threatening symptoms. This may include intravenous fluids, medicated baths to eliminate any fleas or ticks and, in some severe cases, blood infusion to counteract severe anemia.

The next step will be addressing the parasite, and treatment will depend on the exact organism that is identified in the diagnostic tests. It will be important for your veterinarian to identify the exact type of parasitic infection, since the medication of choice will vary greatly from parasite to parasite. In the case of most bacteria, antibiotics will be the preferred course of treatment. Anti-protozoal drugs will be used to treat parasitic infections of that nature.

Prognosis for full recovery in most cases of parasitic blood infections is good. It will be especially important to follow veterinarian instructions and administer the full course of medication as many of these parasites may return if not fully eradicated. Once eliminated from your cat’s system, there are typically no long term side effects. You should also work with your veterinarian to develop an appropriate flea and tick control program, as this will greatly reduce the possibility of most parasitic blood infections that are caused by biting insects.