Hypercalcemia in cats with feline-leukemia-virus-associated leukemia-lymphoma

Three cases of hypercalcemia were recognized among 11 cats presenting with leukemia-lymphoma for ex vivo immunoadsorption therapy using Staphylococcal Protein-A-coated filters. In addition, the initial mean serum calcium concentration of cats with leukemia-lymphoma was significantly higher (P less than 0.005) than that of healthy control cats or feline-leukemia-virus-infected cats without malignancy. During immunotherapy of the hypercalcemic cats, objective reduction in the extent of the malignancies was associated with a small reduction in the serum calcium concentrations. This response to treatment, the lack of skeletal metastasis, and the absence of renal and parathyroid pathologic findings imply that humorally mediated mechanisms may have been responsible for the production of the hypercalcemia.     

Phenotypic characterization of Microsporum canis isolated from cats and dogs

To characterize strains of Microsporum canis that infect dogs and cats in S?o Paulo city, 30 isolates of this dermatophyte were tested for their ability to assimilate carbon and nitrogen sources, for proteinase and phospholipase secretion, for susceptibility to yeast killer toxins, and for susceptibility to the antifungals fluconazole, ketoconazole, itraconazole, 5-fluorocytosine and amphotericin B, in E test. All samples assimilated the nitrogen sources asparagine, ammonium sulphate, urea and sodium nitrate, as well as the carbon sources inulin, mannitol, trehalose, meso-erythritol, maltose, mannose, sorbitol, cellobiose, fructose and dextrin. Not all the samples assimilated adonitol, galactose, arabinose, rhamnose, raffinose, melibiose, ribose and sucrose, and none of them was capable of growing with dulcitol, lactose, or xylose as the only carbon source. Proteinase and phospholipase secretion was observed for most isolates. In the test of yeast killer toxin, 10 types could be identified, with four types exclusively observed in isolates from dogs and two types exclusively observed in isolates from cats. In the E test, all isolates were found to be resistant to the fluconazole and 5-fluorocytosine, while they were variably sensitive to amphotericin B, ketoconazole and itraconazole. When the data were submitted to the qualitative analysis in the matrix distance program FITOPAC, the similarity of the isolates could be assessed.     

Dermatophytoses in cats and humans in central Italy: epidemiological aspects

Two hundred hair/skin samples were collected from 2002 to 2004 from two groups of cats (privately owned and stray cats from a shelter) and 165 samples were obtained during the same period from persons in whom dermatophyte infection was highly suspected. The epidemiological data were statistically evaluated. Thirteen of the 100 privately owned cats (13%) and 100% of the stray cats were positive; of the 165 human samples examined 109 (66%) were positive for dermatophytes. Microsporum canis was the most common dermatophyte isolated in both cat groups while Trichophyton mentagrophytes was the most common in humans. Interestingly, a geophylic dermatophyte species (Microsporum gypseum) was found to be present and associated with clinical signs. Living in the countryside proved to be a risk factor for dermatophytoses in privately owned cats while in humans the main risk factor for M. canis was contact with animals followed by young age. None of the variables considered was associated with positivity for T. mentagrophytes while positivity for other fungi was correlated with life in the countryside.     

Carcinogenesis of N-nitrosodiethylamine (DENA) in chickens and domestic cats.

The environmental carcinogen N-nitrosodiethylamine (diethylnitrosamine, DENA) has been found to be carcinogenic in 18 animal species. In this study we demonstrate that, after intramuscular injection in chickens, it induces hepatocellular carcinomas of the liver and adenocarcinomas of the kidney. Oral administration in domestic cats causes malignant hepatomas and tumors of the esophagus and kidney. Since DENA is carcinogenic in all species in which it has been tested adequately it can be expected to be a human carcinogen, too.     

Human cancer in households containing cats with malignant lymphoma

Since feline malignant lymphoma is viral in nature, a retrospective case-control study was done to assess if there was any additional risk of cancer for human members in households with cats histologically diagnosed as having that disease. The 221 households identified as having owned cats that developed the disease were matched with control ones on the basis of index cat age, sex and breed. Various compared human demographic factors indicated close agreement in makeup between groups. Tests for association of human cancer with feline malignant lymphoma were negative. Association was sought in two ways: (1) by a case-control comparison, controlling human household cancer risk and length of time the index cat was in the household; and (2) by a comparison of the last five years' occurrence of human cancer in both groups compared to the expected. The expected numbers were calculated for the population-at-risk from human age- and sex-specific incidence rates published for this area. The specific occurrence of human cancers of the lymphatic and hematopoietic systems was examined. The validity of the study results and extension of these results to cat ownership in general were discussed.     

Occurrence of nervous-tissue tumors in cattle, horses, cats and dogs.

From 11 North American veterinary university hospitals and clinics, 248 animals were a confirmed diagnosis of nervous-tissue tumor were identified; 7 tumors were found in cattle, 28 in horses, 14 in cats, 199 in dogs, and none in other species. Tumors were divided for analysis into three categories-glial, meningeal, and peripheral nerve. In cattle and horses, all tumors involved peripheral nerves, the risk of which, in horses, reached a plateau at 4-6 years of age and remained constant thereafter. In cats, the tumors were equally distributed among the three tumor categories whereas, in dogs, twice as many glial tumors as meningeal and peripheral nerve tumors were found. The risk for glial tumors in dogs reached a peak at 10-14 years of age, for meningeal at 7-9 years, and for peripheral nerve at 2-3 and 7-9 years. Three canine breeds-English bulldog, boxer, and Boston terrier-had an excessive rish of glial tumors. Except for an excess of skin tumors in dogs with peripheral nerve tumors, there was no unusual occurrence with second primary neoplasms for any species. There was no detectable predisposition by sex for any of the categories of nervous-tissue tumors among any of the four species. The role of genetic abnormalities associated with nervous-tissue tumors and other etiologic factors (e.g., chronic hypoxia) may be clarified by further studies involving canine breeds of "bulldog" ancestry.     

Molecular typing of Sporothrix schenckii isolates from cats in Malaysia

Epidemiological data on the aetiologic agents of feline sporotrichosis in Malaysia have not been reported, though human sporotrichosis in Malaysia is reported to be transmitted primarily via cat scratch. To the best of our knowledge, the present report is the first study of the molecular epidemiology of Sporothrix schenckii isolates from cats with sporotrichosis in Malaysia. In the present work, we characterised 18 clinical isolates from cats in Malaysia based on molecular properties, including sequence analyses of the calmodulin gene and the rDNA ITS region and selective PCR of mating type (MAT) loci. In this study, isolates from feline sporotrichosis were identified as a S. schenckii sensu stricto by sequence analyses of the calmodulin gene and the internal transcribed spacer (ITS) region. Notably, phylogenetic analysis of the ITS confirmed assignment to clinical clade D (and not C) of S. schenckii sensu stricto. Therefore, clinical clade D of S. schenckii sensu stricto appeared to be the prevailing source of feline sporotrichosis in Malaysia. The ratio of MAT1‐1‐1:MAT1‐2‐1 in these Malaysian isolates was found to be 1 : 0. This result suggested that a clonal strain of S. schenckii is the prevailing causative agent of feline sporotrichosis in Malaysia.     

Blood-brain barrier dysfunction in cats following recombinant interleukin-2 infusion

The effects of systemic human recombinant interleukin-2 (rIL-2) infusion upon blood-brain barrier status and cerebral vascular ultrastructure were examined in cats. Each of eight animals received a single bolus i.v. infusion of rIL-2 (100,000 units/kg). Six control animals were infused with rIL-2 excipient only. Following a 1-h postinfusion survival time, the brain tissue of five rIL-2 infused and three excipient infused animals was processed and examined by light microscopy and electron microscopy for evidence of altered cerebrovascular permeability to systemically circulating horseradish peroxidase. The brain tissue of three additional rIL-2 infused animals and three excipient infused animals, sacrificed 4 h postinfusion, was examined at the light microscopic and electron microscopic levels for the presence of extravasated endogenous IgG. All animals infused with rIL-2 and four of six excipient infused animals showed increased cerebrovascular permeability to the probe used. Altered blood-brain barrier permeability, when present, was recognized in multiple loci throughout the brain, being most prominent within white matter regions. Horseradish peroxidase and IgG were observed within perivascular basal laminae and within the interstices of the brain parenchyma. Numerous endothelial lesions were observed as was flooding of endothelial cytoplasm by horseradish peroxidase or IgG. Every animal studied, regardless of permeability status, showed, within the perivascular brain parenchyma, numerous disrupted neuronal and glial processes as well as expanded intercellular spaces. This study suggests that a single systemic infusion of rIL-2 profoundly alters blood-brain barrier integrity and cerebrovascular morphological integrity. The data also suggest that some of the observed cerebrovascular effects of systemic rIL-2 infusion are due to components of the vehicle for rIL-2.     

Antibody to feline oncornavirus-associated cell membrane antigen in neonatal cats

Antibodies to a feline oncornavirus-associated cell membrane antigen have been found in newborn kittens whose mothers had previously nursed litters of kittens injected with feline leukemia virus (FeLV). These antibodies, which were apparently obtained passively from the mother, seem to protect the kittens from the development of progressive tumors following the injection of various amounts of feline sarcoma virus (FSV). That these mothers were apparently able to passively transmit immunity suggests that they became infected with FeLV in a horizontal manner while nursing previous litters and resisted the development of progressive tumors, but mounted an immune response which resulted in the production of humoral antibody. It also suggests that some degree of cross-protection exists in vivo between the feline leukemia and sarcoma viruses used in this study.