A condition resembling Chastek paralysis in cats

Abstract

Extract

The design of a national mastitis survey, the methods used and the results have been described in Parts 1 and 2 of this series (Elliott et al., 1976 Elliott, R. E. W., Tattersfield, Jean G. and Brookbanks, E. O. 1975. New Zealand National Mastitis Survey: 1965–6. 1. Preliminary Studies. N.Z. vet. J., 24: 18–20.  [Google Scholar]; Tattersfield et al., 1976 Tattersfield, Jean G., Elliott, R. E. W. and Brookbanks, E. O. 1976. New Zealand National Mastitis Survey: 1965–6. 2. Measures of Mastitis Prevalence. N.Z. vet. J., 24: 40–54. [Taylor &; Francis Online] , [Google Scholar]).     

Crystal-associated cholangiopathy associated with the ingestion of Panicum spp. and other plants

Several panicoid grasses and some other plants throughout the world have been associated with a crystal-associated hepatopathy causing photosensitisation in ruminants. We have prepared sheep with reentrant bile duct cannulae and fed them on Panicum dichotomiflorum from the Waikato region. Bile from these sheep has been collected and crystals harvested by centrifugation and Percol density gradient techniques. These sheep, when slaughtered after showing elevations of serum bilirubin and enzymes indicating liver injury, had the typical cholangiohepatopathy of Panicum spp. toxicity. The crystals have now been identified as calcium salts of epismilagenin glucuronide. Likely precursor saponins of the sapogenin have been identified in Panicum dichotomiflorum. While we regard these findings as an important step forward in the understanding of these diseases, we are now investigating the factors, including known hepatotoxins, responsible for the occurrence of these hepatopathies.     

Loss of retinoblastoma protein, but not p53, is associated with the presence of papillomaviral DNA in feline viral plaques, Bowenoid in situ carcinomas, and squamous cell carcinomas

Although papillomaviral (PV) DNA is frequently present in feline cutaneous squamous cell carcinomas (SCCs), a causative association cannot be proven. Oncogenic human PVs cause neoplastic transformation by inhibiting retinoblastoma (pRb) and p53 activity. Therefore, absence of pRb and p53 immunostaining, along with increased p16 immunostaining, indicates a PV cause in some human SCCs. If PVs cause cutaneous feline SCCs, it was hypothesized that a similar immunohistochemistry profile, along with PV DNA, would be detectable. This was investigated using 5 feline viral plaques, 10 Bowenoid in situ carcinomas, 19 SCCs from ultraviolet-exposed (UV-exposed) skin, and 11 SCCs from UV-protected skin. Papillomaviral DNA was amplified by polymerase chain reaction from 30 of 45 lesions. Reduced pRb immunostaining was present in 26 of 45; increased p16 immunostaining was in 30; and p53 immunostaining was in 19. Both reduced pRb immunostaining and increased p16 immunostaining were more frequent in lesions containing PV DNA. In contrast, no association was observed between p53 immunostaining and the presence of PV DNA. SCCs from UV-protected skin more frequently contained PV DNA, reduced pRb, and increased p16 than UV-exposed SCCs. UV exposure was not associated with p53 immunostaining within the SCCs. These results suggest that feline PVs alter cell regulation by degrading pRb. Unlike oncogenic human PVs, there was no evidence that feline PVs degrade p53. These results provide further evidence that PVs may cause feline cutaneous SCCs, especially those in UV-protected skin, and they suggest a possible mechanism of this oncogenic action.     

Histology and immunohistochemistry of seven ferret vaccination-site fibrosarcomas

The anatomical location, histology, and immunohistochemistry of 10 ferret dermal and subcutaneous fibrosarcomas were examined. Seven of the 10 tumors were from locations used for vaccination. All fibrosarcomas contained spindle-shaped cells surrounded by variable quantities of connective tissue stroma. However, vaccination-site fibrosarcomas (VSFs) subjectively contained a higher degree of cellular pleomorphism. Multinucleated cells were present in three of seven VSFs but not in any of the nonvaccination-site fibrosarcomas (NVSFs). Large histiocytic cells, interpreted as macrophages, containing intracytoplasmic basophilic granular material were observed in two VSFs but not in any of the NVSFs. Five VSFs contained peripheral lymphoplasmacytic aggregates. Immunohistochemically, three VSFs stained with anti-smooth muscle actin antibodies and one stained with antibodies against desmin. No expression of muscle cytoskeletal filaments was observed in any NVSF. Filaments interpreted as actin were visible in both the VSFs examined ultrastructurally. One of the VSFs examined ultrastructurally contained intracytoplasmic crystalline material. The preferential development of subcutaneous fibrosarcomas in vaccination sites suggests that, as in cats, vaccination may promote local sarcoma development in ferrets. Additionally, some of the histologic, immunohistochemical, and ultrastructural features of these tumors are similar to those reported for feline vaccine-associated sarcomas. To the authors' knowledge, vaccination has not previously been reported to be oncogenic in any species other than cats.     

Demonstration of schizogonous stages of Sarcocystis gigantea in experimentally infected sheep

Sarcocystis-free lambs were orally dosed with 1 X 10(6) sporocysts of Sarcocystis gigantea. Schizonts were found in endothelial cells of capillaries and arterioles of the brain, lung and kidney of lambs 7 and 14 days post-inoculation (d.p.i.). Between 21 and 35 d.p.i. there was extensive multi-focal encephalitis; however no organisms were detected in association with these lesions.