Difference between revisions of "Feline Infectious Anaemia"
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Previously known as: '''Haemobartonellosis''' | Previously known as: '''Haemobartonellosis''' | ||
| − | Caused by: '''Mycoplasma haemofelis''' , previously known as '''Haemobartonella felis''' | + | Caused by: '''''Mycoplasma haemofelis''''' , previously known as '''''Haemobartonella felis''''' |
==Introduction== | ==Introduction== | ||
| − | Feline Infectious Anaemia, caused by '''Mycoplasma haemofelis''' (Mhf), is a regenerative anaemia of cats. The disease occurs worldwide and should be considered as a differential diagnosis for any cat presenting with anaemia. | + | Feline Infectious Anaemia, caused by '''''Mycoplasma haemofelis''''' (Mhf), is a regenerative anaemia of cats. The disease occurs worldwide and should be considered as a differential diagnosis for any cat presenting with anaemia. |
==Aetiology== | ==Aetiology== | ||
| − | Mhf is one of a group of organisms known as haemotropic mycoplasmas which infect several other domestic animal species. The causative organism was previously called Haemobartonella felis and thus the disease was known as haemobartonellosis. Polymerase chain reaction (PCR) assays allowing DNA analysis resulted in the reclassification of the organism in 2001. Two other haemotropic mycoplasmas ( | + | Mhf is one of a group of organisms known as haemotropic mycoplasmas which infect several other domestic animal species. The causative organism was previously called Haemobartonella felis and thus the disease was known as haemobartonellosis. Polymerase chain reaction (PCR) assays allowing DNA analysis resulted in the reclassification of the organism in 2001. Two other haemotropic mycoplasmas (''Candidatus M. haemominutum'' and ''Candidatus M. turicensis'') have been identified in cats but appear to be less pathogenic<sup>1</sup>. |
The mode of transmission of Mhf is poorly understood. | The mode of transmission of Mhf is poorly understood. | ||
Revision as of 10:56, 15 March 2012
Previously known as: Haemobartonellosis
Caused by: Mycoplasma haemofelis , previously known as Haemobartonella felis
Introduction
Feline Infectious Anaemia, caused by Mycoplasma haemofelis (Mhf), is a regenerative anaemia of cats. The disease occurs worldwide and should be considered as a differential diagnosis for any cat presenting with anaemia.
Aetiology
Mhf is one of a group of organisms known as haemotropic mycoplasmas which infect several other domestic animal species. The causative organism was previously called Haemobartonella felis and thus the disease was known as haemobartonellosis. Polymerase chain reaction (PCR) assays allowing DNA analysis resulted in the reclassification of the organism in 2001. Two other haemotropic mycoplasmas (Candidatus M. haemominutum and Candidatus M. turicensis) have been identified in cats but appear to be less pathogenic1.
The mode of transmission of Mhf is poorly understood.
Signalment
The major group at risk for Mhf infection are male cats who spend time outdoors. In many areas of the world an association has been shown between Mhf and retroviral infections1.
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).
Diagnosis
The best diagnostic test is a PCR, which is very sensitive and enables differentiation of the different species.
The organism can also be diagnosed on blood smears. The organism can be intermittently seen microscopically on the surface of red blood cells on Giemsa-stained blood smears. The organism stains blue and can look like rings or rods.
Erythrophagocytosis may be evident and parasitised erythrocytes will become spherical.
The organism must be differentiated from Howell-Jolly bodies and other parasites. Due to the cyclic parasitaemia the organism causes, negative blood smears will not rule out the disease.
Additionally Immunofluorescence of blood smears can demonstrate the organism.
Haematology will show a decreased packed cell volume and a low red blood cell count. The anaemia is usually regenerative. FeLV infection is associated with macrocytosis.
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 also be required in cases of severe anaemia.
As blood sucking endoparasites, such as Fleas, are thought to spread disease the animal should also receive flea treatment.
Prednisolone is also advised to treat the immune mediated mechanisms and to prevent further erythrophagocytosis.
Prognosis
Varied prognosis depending on the severity of the anaemia at presentation. If not treated 1/3 of affected animals will die. Antibiotics do not clear the infection so many cats become carriers of the organism however relapses are uncommon.
| Feline Infectious Anaemia Learning Resources | |
|---|---|
 Test your knowledge using flashcard type questions |
Small Animal Emergency and Critical Care Medicine Q&A 12 |
 Search for recent publications via CAB Abstract (CABI log in required) |
Mycoplasma haemofelis publications |
Full text articles available from CAB Abstract (CABI log in required) |
Diagnosis and management of Hemoplasma infections. Lappin, M. R.; The North American Veterinary Conference, Gainesville, USA, Small animal and exotics. Proceedings of the North American Veterinary Conference, Orlando, Florida, USA, 17-21 January, 2009, 2009, pp 655-656, 23 ref. |
References
Ettinger, S.J, Feldman, E.C. (2005) Textbook of Veterinary Internal Medicine (6th edition, volume 2)W.B. Saunders Company
Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition) Merial
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