The control of lymphosarcoma/leukaemia and feline leukaemia virus

This article discusses a removal programme designed especially for catteries and so–called multiple–cat households in an effort to control lymphosarcoma/leukaemia in cats and transmission of FeLV (feline leukaemia virus).
The removal programme calls for: annual testing of all stud cats; testing of all contacts of a FeLV–positive cat during the previous 2 years; testing of imported cats; and isolation of FeLV–positive cats or, if this is impossible, euthanasia. The FeLV antigen can be demonstrated in cats by the indirect immunofluorescence antibody (IFA) test.
The results of a removal programme carried out over a 4–year period in a large Dutch cat club are discussed. The percentage of FeLV–positive catteries decreased from 11 –5% during the first half of 1974 to 21% during the latter half of 1977; during the same period the percentage of FeLV–positive cats and stud cats decreased from 4–9% and 5–9%, respectively, to 1–2% and 1–0%, respectively.
It is concluded that the recommended removal programme can be carried out without difficulty and produces good results.     

Feline leukaemia virus status of Australian cats with lymphosarcoma

OBJECTIVE: To determine the FeLV status of sera and tumours from Australian cats with lymphosarcoma in relation to patient characteristics, tumour characteristics (tissue involvement, histological grade and immunophenotype), haematological and biochemical values. DESIGN: Prospective study of 107 client-owned cats with naturally-occurring lymphosarcoma. PROCEDURE: An ELISA was used to detect FeLV p27 antigen in serum specimens collected from cats with lymphosarcoma. A PCR was used to detect FeLV DNA in formalin-fixed, paraffin-embedded tissue sections containing neoplastic lymphoid cells. The PCR was designed to amplify a highly conserved region of the untranslated long terminal repeat of FeLV provirus. RESULTS: Only 2 of 107 cats (2%), for which serum samples were available, were FeLV-positive on the basis of detectable p27 antigen in serum. In contrast, 25 of 97 tumours (26%) contained FeLV DNA. Of the 86 cats for which both PCR and ELISA data were available, 19(22%) had FeLV provirus in their tumours but no detectable circulating FeLV antigen in serum, while 2 (2%) had FeLV provirus and circulating FeLV antigen. FeLV PCR-positive/ELISA-negative cats (19) differed from PCR-negative/ELISA-negative cats (65) in having fewer B-cell tumours (P = 0.06), more non B-/non T-cell tumours (P = 0.02) and comprising fewer non-Siamese/Oriental pure-bred cats (P = 0.03). CONCLUSIONS: The prevalence of FeLV antigen or provirus was considerably lower in our cohort of cats compared with studies of lymphosarcoma conducted in the Northern hemisphere. This suggests that factors other than FeLV are important in the development of lymphosarcoma in many Australian cats. No firm conclusions could be drawn concerning whether FeLV provirus contributed to the development of lymphosarcoma in PCR-positive/ELISA-negative cats.     

The presence of leukaemia (lymphosarcoma) and feline leukaemia virus (FeLV) in cats in The Netherlands

To study the presence and spread of feline leukaemia virus (FeLV) in The Netherlands, seven different groups of cats were examined. The indirect fluorescent antibody (IFA) test was used to detect FeLV-antigen in blood smears. Of cats with lymphosarcoma/leukaemia 73.2% were positive and 32.4% with infectious peritonitis were positive. Only one of sixty-six cats with other tumours–a cat with mammary carcinoma–was positive.
Forty-two (7.5%) of 557 cats with various complaints were positive for FeLV-antigen. The IFA-test appeared to be an important diagnostic supplement.
Of all stud males which had had contact with FeLV-positive cats 24.7% were positive for FeLV-antigen, whereas all stud males which had not had this contact, were negative.
There was a distinct difference between the percentages of FeLV-positive individuals in the groups of cats which had had (20.6%) and which had not had (0.4%) contact with FeLV-positive cats.
From the follow-up study it was found that 67.3% of the FeLV-positive cats died from, or were destroyed because of, FeLV-associated diseases within a period of 20 months.     

Lymphocytic leukemia and lymphosarcoma in a rabbit

Lymphocytic leukemia and lymphosarcoma were diagnosed in a rabbit with lethargy, emaciation, and pallor. The diagnosis was made on the bases of results of hematologic analysis, cytologic evaluation of a bone marrow specimen, and histologic examination. The lymphosarcoma was identified to be of T-cell origin. Leukemia is rarely diagnosed in rabbits, although lymphosarcoma is fairly common in this species.     

Chemotherapy for canine lymphosarcoma.

Twenty dogs with naturally occurring lymphosarcoma were histologically diagnosed, clinically staged, and treated with combinations of drugs, including corticosteroids, alkylating agents, plant alkaloids and antimetabolities. Clinical response was categorized as complete, partial, or unsatisfactory. Of the 20 dogs, 17 responded to the chemotherapy completely or partially, with a mean objective remission duration of 104.8 days. The mean survival time for 19 dogs was 211.5 days, whereas the mean survival time for 16 dogs which responded completely or partially was 233.7 days.     

Bovine lymphosarcoma in twin calves.

Lymphosarcoma in twin female calves, apparently the first to be observed in Canada, is reported here. Peripheral blood and cultured mononuclear cells of one of the calves showed aneuploidy of the chromosomes. No hematological or serological evidence of bovine leukemia virus infection was observed in the other members of the herd. Bovine leukemia virus infection of the leukemic cells could not be detected by electron microscopy or by tissue culture procedures. There is a need to clarify the relationship of the calf form of the disease to the adult form of enzootic bovine leukosis.     

Cytology of canine cutaneous round cell tumors. Mast cell tumor, histiocytoma, lymphosarcoma and transmissible venereal tumor.

Sixty-four canine cutaneous round cell tumors were divided into 25 mast cell tumors, 15 histiocytomas, nine cutaneous lymphosarcomas and 15 transmissible venereal tumors. The final diagnosis was made from cytologic, clinical and histologic findings. Cytologic features were significantly distinctive in mast cell tumor, transmissible venereal tumor, and most cases of histiocytoma and lymphosarcoma to allow a diagnostic opinion. This opinion was supported by subsequent histologic examination. In some instances cytology was considered essential in rendering a diagnostic opinion even though histology was available.     

Immunodeficiency associated with lymphosarcoma in a horse.

Immune system dysfunction and immunoglobulin deficiency was diagnosed in a 2-year-old horse with disseminated lymphosarcoma. Prolonged (35 days) parenteral nutrition was delivered to support the horse during a period in which immune function studies could be performed. Correction of nutritional compromise by use of parenteral nutrition did not correct the immunoglobulin deficiency, and results of lymphocyte phenotype testing did not indicate abnormal proportions of leukocytes. Lymphoblast transformation studies were suggestive of a circulating immunosuppressive factor in the horse's serum. Normal cell function was detected when the cells were stimulated in precolostral equine serum.     

Hypereosinophilia in a horse with intestinal lymphosarcoma.

Paraneoplastic eosinophilia is reported in dogs, cats, and humans. Hypereosinophilia (an eosinophil count greater than 1.5 x 10(9) L) is often associated with metastasis and a poor prognosis. This report describes a case of paraneoplastic hypereosinophilia in a pony. Neoplasia should be included in the differential diagnoses in a horse with eosinophilia.     

A bovine lymphosarcoma

Abstract

Extract

A report in the recent literature of lympho-sarcoma in an Aberdeen Angus × Shorthorn × Guernsey heifer calf, 3 weeks old (Simon and Brewer, 1963 Simon, J. and Brewer, R. L. 1963. J. Amer. vet. med. Ass., 142: 1388–1388.  [Google Scholar]), has prompted the writer to record a case encountered in 1960.     

Malabsorption in the horse associated with alimentary lymphosarcoma.

Three horses suffering from malabsorption were shown to have alimentary lymphosarcoma predominantly affecting the small intestine and the associated lymph nodes. The diffuse cellular infiltration in two of the case produced marked changes in the villous architecture reducing the available mucosal surface area, and, with lowered or barely detectable disaccharidase activities, contributed to the impairment of digestive-absorptive processes. One of the horses maintained a voracious appetite and was not diarrhoeic, but failed to gain weight, indicating differences in the production and utilisation of energy sources absorbed from the small and the large intestines. A large proportion of plasma cells in the infiltrate, and the resulting morphological changes in two of the cases bore a striking resemblance to features of alpha chain disease, an immunodeficiency disease of man, although immunological studies were not conducted on these horses.