Feline Infectious Anaemia

Desciption

An infectious disease of the cat caused by Mycoplasma haemofelis which until recently was known as Haemobartonella felis. The organism is found on the surface of erythrocytes and is considered an opportunistic infection that causes illness under predisposing causes. It is possible to be transmitted via bite wounds or biting arthropods. Recoverd cats become carriers of the organism.

Signalment

Almost half of the cats infected have concurrent Feline Leukaemia Virus (FeLV). The disease is common in roaming Tom cats 1-3 years old.

Diagnosis

The organism is intermittently seen microscopically on the surface of red blood cells on Giemsa-stained blood smears. Additionally Immunofluorescence of blood smears demonstrates the organism. When the organism is not found a presumptive diagnosis may be made with clinical signs of reduced packed cell volume, and other causes of a regenerative anaemia ruled out.

Clinical signs

The peracute disease is associated with severe anaemia and immunosuppression, and can be rapidly fatal.

Fever, anaemia, depression, weakness and jaundice occur in the acute form. In the chronic form animals present with anaemia, lethargy and weight loss. Cyclic fever may also occur during the transient period of parasitaemia. Recovery can occur with a regenerative bone marrow response however severe anaemia may occur in the presence of feline leukaemia virus (FeLV).

Treatment

Infected cats should be treated with doxycycline for 3 weeks twice daily. Enrofloxacin is also a good treatment choice especially in refractory cases when combined with doxycycline. A blood transfusion may be required in some severe cases of anaemia. As blood sucking endoparasites such as Fleas are thought to spread disease the animal should also recieve flea treatment.