Mikihiko Tokuriki

First case of feline systemic Cryptococcus albidus infection

This paper, as best as the authors can determine, is the first to describe a documented case of systemic infection caused by Cryptococcus albidus in a cat. The patient had a history of paralysis of the hind legs and had been treated with prednisone for 1 month. Microscopic examination of a fine needle biopsy specimen from a right popliteal lymph node showed granulomatous inflammation with many encapsulated yeast cells. Moreover, microscopic examination of Indian ink preparations of the cerebrospinal fluid revealed encapsulated ovoid yeast cells. Thus this case was diagnosed to be cryptococcosis. However, the cat died after treatment for three days with voriconazole. Isolates recovered from samples of the cerebrospinal fluid, liver and spleen were identified as C. albidus by molecular analysis, as well as through morphologic and biochemical studies. Therefore, this case indicates that C. albidus should be considered as a potential feline pathogen.

Plasma thrombin- antithrombin complex concentrations in dogs with malignant tumours

IT has been suggested that coagulation abnormalities such as disseminated intravascular coagulation (DIC) might be caused by the excessive activation of coagulation in dogs with malignant tumours (O’Keefe and Couto 1988). Since excessive activation of coagulation leads to over-generation of thrombin, increased concentrations of thrombin measured in circulating blood would indicate an activation of coagulation. Thrombin-antithrombin complexes (TATs), which are formed rapidly after thrombin production, have been identified as a marker of coagulation activation (Pelzer and others 1988). The plasma TAT concentration has been reported to be useful for evaluating the activation of coagulation in dogs (Ravanat and others 1995), and is available as a marker of the hypercoagulable state in dogs with Cushing’s syndrome (Jacoby and others 2001). However, the plasma TAT concentrations in dogs with malignant tumours have not been reported. This short communication describes the plasma TAT concentrations in dogs with benign or malignant tumours and the incidence of a hypercoagulable state in dogs with malignant tumours. The plasma TAT concentrations of three groups of dogs were examined. Group 1 comprised 16 clinically healthy adult dogs; the dogs were considered clinically normal on the basis of physical examination, routine haematological examination and serum biochemical analysis. Group 2 comprised 11 dogs with benign tumours: five with an adenoma, three with a leiomyoma, two with a haemangioma and one with a lipoma. Group 3 consisted of 62 dogs with malignant tumours, this group was further divided into four subgroups: 27 dogs with epithelial tumours, 17 with mesenchymal tumours except haemangiosarcoma; 10 with haemangiosarcomas and eight with haematopoietic tumours. The dogs in groups 2 and 3 were referred to the Animal Medical Center of Nihon University and their tumours were diagnosed by histopathological examination. None of the dogs received any anticoagulants or blood products before blood sampling. Blood samples were collected into tubes containing 0·13M trisodium citrate (nine parts blood to one part anticoagulant) and centrifuged at 2000 g for 10 minutes, and the citrated plasma was frozen at –30°C until analysis. The plasma TAT concentrations were measured by enzyme immunoassay (TAT Test Kokusai-F; International Reagents Corporation). Mann-Whitney U tests were used to compare plasma TAT concentrations between the groups. For statistical analysis, plasma TAT concentrations undetectable by the assay method used (<0·4 ng/ml) were regarded as 0·4 ng/ml. To detect the incidence of a hypercoagulable state, a reference range of plasma TAT concentration was established as the mean (2sd) concentration obtained from group 1. Dogs with plasma TAT concentrations above the reference range were regarded as displaying a hypercoagulable state. The median (range) plasma TAT concentrations were 0·5 (<0·4 to 0·6) ng/ml in group 1, 0·4 (<0·4 to 6·3) ng/ml in group 2 and 1·3 (0·4 to 49·3) ng/ml in group 3; concentrations were significantly higher in group 3 than in group 1 (P<0·0001). However, there was no significant difference in the plasma TAT concentrations of groups 1 and 2 (P=0·8823) (Fig 1). Within group 3, the TAT concentrations were 0·8 (0·4 to 3·8) ng/ml for the dogs with epithelial tumours, 0·7 (0·4 to 49·3) ng/ml for those with mesenchymal tumours, 17·3 (4·4 to 42·5) ng/ml for those with haemangiosarcomas, and 8·2 (2·1 to 19·0) ng/ml for those with haematopoietic tumours. The plasma TAT concentrations were significantly elevated in all subgroups of group 3 (P<0·001, P<0·01, P<0·0001 and P<0·0001, respectively) compared with group 1 (Fig 2). The mean (2sd) plasma TAT concentration of dogs in group 1 was 0·49 (0·12) ng/ml, and thus dogs with plasma TAT concentrations in excess of 0·61 ng/ml were considered as disVeterinary Record (2005) 156, 839-840

Some behavioral aspects and proximate causes associated with emigration of young female Misaki feral horses

An investigation was carried out on 28 Misaki young female feral horses living in Misaki Island, Japan to explore the behavioral patterns, and proximate causes of emigration of these females when they left their natal band or mothers. All young females emigrated between 1 and 4 years of age. The age of emigration was significantly higher (P < 0.02) when the dam parity was lower. At the time of emigration, six behavior patterns of young females were observed. All the female offspring of mothers with lifetime stability (remained with the stallion permanently) had lifetime stability after their emigration. Hence, young females who lived in a stable band emigrated at an early age, which avoided mating with their sire, which would result in inbred offspring. Also the young females which had lifetime stability gave birth at an earlier time than unstable ones. Furthermore, these stable young females began their lifetime stability at the same age or earlier than their mothers. This suggests that the mothers have effective influence on their female offspring before and after their emigration. Of the young females, 28% emigrated because of the birth of a sibling. However, another 72% of the young females were forced to emigrate during their estrous period, or when they became pregnant and were close to parturition, or due to the death of their mothers. Therefore, if it was a clear external cause, this could be attributed to other causes such as the age of the young females, dam parity and dam stability at the time of emigration. These results provide a partial indication of which factor or combination of factors is necessary or sufficient to explain the emigration patterns.