title: Anaemia in the cat with particular reference to infection with Haemobartonella felis
Creators: name: Bobade, Patrick Akin
Publisher: name: University of Glasgow
Year: 1980
Subjects: subject: Veterinary science.

description: This study was designed to investigate the prevalence and aetiology of anaemia in cats referred to Glasgow University Veterinary Hospital and to relate the prevalence to that of feline haemobartonellosis in these cats. A total of 84 male and 71 female cats, mostly domestic short haired, were examined. Their ages ranged from one month to 16 years. Anaemia was found in 41 (25.45%) of the 155 cats. It was slightly more prevalent in males than females and it increased with age reaching a peak at four to four and a half years. Marked anaemia (PCV less than 25%) occurred in 28 of the cases and the others were cases of mild anaemia (PCV 25-29%). The final diagnoses in the cases of anaemia were as follows. Concurrent Haemobartonella felis (H. felis) and feline leukaemia virus (FeLV) infections (12 cases), FeLV infection (7 cases), H. felis infection (3), concurrent H. felis and acute myeloid leukaemia (1), renal diseases (2), Heinz body anaemia due to intestinal intussusception(1) and feline infectious peritonitis (1). The diagnoses in the cases of mild anaemia were H. felis infection (5 cases),concurrent H.felis and FeLV infections (2), FeLV infection (1), renal diseases (2) severe flea infestation (1) and non-effusive peritonitis (1). No diagnosis was made in one case each of marked anaemia and mild anaemia. H. felis infection was detected in the blood of 36 (23.2%) of the cats examined and the prevalence of infection was slightly higher in males than females. The prevalence of infection increased with age reaching a peak at seven to seven and a half years. However the prevalence of the clinical disease as manifested by anaemia reached a peak at six to six and a half years. The prevalence of H. felis infection was significantly much higher (P &lt;0.001) in cats with external parasitism than other cats in the population sample, as well as in cats with FeLV infection compared with FeLV-free cats. Marked anaemia occurred in 16 of the cats infected with H. felis, mild anaemia in seven and the others were non-anaemic. Seventeen of the H. felis infected cats had concurrent FeLV infections. A much larger proportion of these cats were anaemic than the proportion of those with only H. felis infection. The anaemia due to concurrent H. felis and FeLV infection was generally more severe than that observed in cats with only H. felis infection and the mortality was much higher in the former group than in the latter. This study showed that H. felis infection on its own causes little or no clinical problem. However, when it is complicated by FeLV infection, a severe anaemia occurs in most cases. This suggests that FeLV infection may be more important in the pathogenesis of anaemia in clinical feline haemobartonellosis than the parasite H. felis itself. The anaemia due to concurrent H. felis and FeLV infections was usually so severe that compensatory regenerative responses were not adequate to produce remissions. Therefore the prognosis for anaemic cats with concurrent H. felis and FeLV infections should be regarded as poor. This study showed that acridine orange stain is more efficient in demonstrating H. felis organisms than the Romanowsky stains and that the May-Grunwald-Giemsa staining method is superior to the other Romanowsky stains in demonstrating H. felis organisms. However it also highlighted the need for developing a serological or immunological technique for the diagnosis of H. felis infection as all the aforementioned staining procedures at times failed to demonstrate the organism in the peripheral blood of infected cats. The H. felis organisms found in this study were mostly coccoid forms, with a few rod forms in two cases. The diameter of the coccoid forms ranged from 0.63mu to 1.73mu, while the length of the rod forms ranged from 0.79mu to 1.1mu and the diameter 0.17mu to 0.24mu. This study confirmed that H. felis organisms are chelated from the erythrocytes in blood samples stored in E.D.T.A. for some hours.