Haemotropic mycoplasma infection
Also called Haemoplasmosis, feline infectious anaemia (cats)
Bacteria that cling to red blood cells. Many dogs and cats have no signs, but some develop anaemia, especially cats, dogs with weakened immunity and cats with FeLV or FIV.
Cause and spread
- Cause
- Hemotropic mycoplasmas: Mycoplasma haemofelis (the most disease-causing in cats), Mycoplasma haemocanis in dogs, and related types.
- How it spreads
- Thought to spread by fleas and other blood-sucking insects, bite wounds, and from mother to kittens.
Signs to watch for
- Often none in healthy adults
- Fever, weakness and depression
- Pale or yellow gums
- Poor appetite and enlarged spleen
- Weight loss in long-standing cases
Many diseases look alike. Only a laboratory test can tell them apart, so please see a veterinarian for any sick animal.
How it is diagnosed
Blood smears show the organisms only about half the time, because the number in the blood rises and falls and the organisms can detach in stored blood. PCR is therefore more reliable. A blood count shows the anaemia.
- Usually the first testComplete Blood Count (CBC)Shows anaemia.
- Confirms the diseaseMycoplasma haemofelis PCRDetects the main cat haemoplasma.
- Confirms the diseaseMycoplasma haemocanis PCRDetects the main dog haemoplasma.
- Supports the diagnosisBlood Smear ExaminationMay show the organisms on red blood cells, but can miss them.
Prevention and control
- Good flea and insect control
- Watch cats and dogs with other illnesses closely, because the infection can flare when immunity is low
Where this information comes from
- Hemotropic Mycoplasma Infections in Animals · Merck Veterinary Manual
General information for animal owners and veterinarians, last checked October 2026. It does not replace the advice of your veterinarian, who should decide which tests and treatment your animal needs.