Haematological and biochemical findings in cats in Australia with lymphosarcoma

Objective To describe, for the first time, haematological and serum biochem ical findings in cases of lymphosarcoma in Australian cats. Design A prospective multi-institutional study. Procedure Of 118 affected cats presented to the authors over a 18-month per iod, 97 were evaluated haematologically and 87 biochemically. Haematologica l analysis usually included determination of packed cell volume, haemoglobi n concentration, red blood cell and leukocyte counts, differential leukcocy te count, reticulocyte count and examination of buffy-coat smears for neopl astic cells. Serum biochemical analysis was done primarily with a discrete analyser and included a panel of commonly used analytes. Results Nonregenerative anaemia was present in 54% (52/97) of cats. Neutrop hilia, present in 65% (59/91) of cats, was commonly associated with lymphoc ytopaenia, eosinopaenia and monocytosis. Of the 13 cats with a secondary le ukaemic manifestation, only five had distinct lymphocytosis. Serum biochemi cal abnormalities either were nonspecific, such as hypoglycaemia in 37% (32 /87) of cats, or related to specific tissue involvement, such as hypoalbumi naemia in 76% (31/41) of cats with alimentary involvement and azotaemia in 60% (15/25) of cats with renal involvement. Conclusion It was shown for the first time that haematological and serum bi ochemical findings are of limited value in diagnosing lymphosarcoma in Aust ralian cats, except ii they are leukaemic. Although clinical pathological c hanges were common, they were nonspecific or related to specific tissue inv olvement. Their value in assessing response to therapy needs to be examined further. Patient characteristics such as age, breed and sex also had limit ed effect on laboratory findings and those observed were of little conseque nce. Additionally, histological and immunophenotypical variations in tumour type had little effect on laboratory findings.