Cytauxzoonosis

Cytauxzoonosis is caused by a tiny parasite called Cytauxzoon felis (North and South America, China) or Cytauxzoon spp in Europe. Infected cats can be severely unwell, and the disease affects both domestic cats and various species of wild cat.

The parasite is spread via ticks, which infect cats when they feed on them, having previously fed on an infected cat. The organism enters red blood cells causing illness. Cats with access outside are much more likely to be infected, and in some areas the disease is more common in summer months when there are more ticks around. The infection could also be spread via a blood transfusion.

The parasite enters the cat’s blood when the infected tick feeds. On entering the blood cells, the organism may cause damage to the blood vessels and red blood cells, resulting in blood clots. The body’s response may cause inflammation of various organs causing severe illness.

Cytauxzoonosis is a serious disease in pet cats. Often no signs are seen for 10-12 days after the tick bite and then your cat will become very unwell within 2-3 days. At the start of the illness your cat may have a high fever. This will make them feel unwell and they will often be lethargic and not willing to eat. As the disease progresses the destruction of red blood cells by the parasite causes anemia making cats pale and weak. Sometimes jaundice also results so you may notice your cat’s mouth looks pale or the membranes in the eye and mouth may become yellowed. The inflammation caused by the parasite might result in breathing difficulties, neurological signs, pain and sadly some cats may die.

The infection occurs in regions where infected ticks are found, so your veterinarian may suspect cytauxzoonosis having seen other cases in that region. Cases may be seen more commonly between May and September, when ticks are active. When a veterinarian examines your cat, they may notice pale or yellow gums and discover that your cat has a high temperature.

Your veterinarian will take blood samples which will show changes to the cells within the blood (red blood cells, white blood cells and platelets). In many affected cats their blood will not clot properly after a wound (your veterinarian may notice this when a blood sample is taken). In some cases, the parasite can be seen in red blood samples under a microscope. To confirm the diagnosis your veterinarian may want to do a PCR test to detect the parasite in your cat’s blood.

The parasite only affects cats and there have been no reported cases in people. The disease is spread through an infected tick so there is minimal risk from handling a sick cat with the disease. It is highly unlikely that there is any risk for you, pet dogs or other animals catching the disease from cats.

Sadly, infected cats may die despite treatment. However, if treatment is started in the early stages of disease it can be successful. Cytauxzoonosis reported in Europe may carry a better prognosis with some cats only showing mild signs of illness. Intensive care with fluids, blood transfusions, oxygen and drugs to kill the Cytauxzoon organisms is required. Cats surviving the disease may live with low levels of the parasite still within them. Tick prevention measures are the best way to prevent infection spreading.

The best way to protect your cat is to prevent contact with the ticks that might be carrying disease. This means keeping cats indoors or using treatment to prevent ticks biting the cat in the form of collars or other products. If you live in an area with this parasite, discuss prevention with your veterinary team.