Feline Leukaemia Virus Testing

Sir, — Cat owners, cat breeders and veterinarians are now well aware that feline leukaemia virus (Felv) is a cause of serious disease in cats and also that Felv is involved in the pathogenesis of many diseases other than lymphosarcoma⁽⁸⁾. Epidemiological studies using a variety of techniques to detect virus and antibodies have defined populations of cats that are at risk from the effects of the virus and methods of control have been suggested^(2)(3)(4). All methods of control are based on separation cf Felv-infected cats from susceptible animals. To do this, viraemic cats need to be identified either by the demonstration of Felv-specific antigen in the cytoplasm of circulating leucocytes or platelets (by immunofluorescence on blood smears), demonstration of viral antigen in serum or plasma, or by isolation of virus from the plasma in feline cell cultures.     

Pax-7 immunoreactivity in the post-natal chicken central nervous system

In this immunocytochemical study on the constitutive expression of Pax-7 protein in the postnatal chicken brain, Pax-7 showed region and cell type specific expression. In the optic tectum, only cells in grey matter showed positive immunoreactivities (IRs), whereas those in the white matters did not show any IRs. In thalamic nuclei and several pontine nuclei, we also localized Pax-7 positive IRs. On the contrary, in the cerebellum, Pax-7 was mainly localized within the Bergmann glia, whereas Purkinje cells did not show any IRs. In double immunolabelling studies, most of the Pax-7 IRs did not originate from neuroglial cells such as oligodendrocytes, microglia or astrocytes, but from neurons, with the exception of Bergmann glia in the cerebellum. The presence of Pax-7 IRs in the adult chicken brain could suggest that Pax-7 might play a role in maintaining normal physiological function in some postnatal chicken brain cells.     

Correlation of Foxp3 positive regulatory T cells with prognostic factors in canine mammary carcinomas

Regulatory T cells (Treg) cells play a crucial role in tumor progression by suppressing anti-tumor immunity, but are not well-documented in veterinary oncology. To identify the characteristics of Treg cells in tumor microenvironments, the numbers of Treg cells were analyzed and compared with histological prognostic factors and molecular biomarkers in canine mammary carcinoma (MC) tissues (n=37). Abundant Treg cells were associated with high histological grade and lymphatic invasion. The numbers of Treg cells infiltrating intratumoral areas markedly increased in tumors with poor prognostic factors, such as high histological grade, lymphatic invasion, and necrosis. These findings suggest that Treg cells play a role in canine MC progression. Furthermore, Treg cell numbers in intratumoral compartments may provide a potential prognostic factor when assessing canine MCs, which may in turn lead to the development of new immunologic therapeutics.     

Efficacy of dog-appeasing pheromone (DAP) for ameliorating separation-related behavioral signs in hospitalized dogs

Dogs hospitalized in veterinary clinics are likely to show signs of separation-induced anxiety from hospitalization. The study assessed the effect of dog-appeasing pheromone (DAP) on 10 typical separation-related behavioral signs in hospitalized dogs. A DAP treated group (n = 24) was compared with a placebo control group (n = 19). There was overall amelioration of the signs without ‘vigilance’ and ‘anorexia’ in the DAP-treated dogs; marked decreases were noted in elimination (P = 0.038), excessive licking (P = 0.005), and pacing (P = 0.017). The results suggest that the use of DAP could decrease separation-induced anxiety, distress, and fear in inpatients, and possibly facilitate recovery in hospitalized dogs.     

Retrospective study of 103 presumed cases of tick (Ixodes holocyclus) envenomation in the horse

Objective Review 103 cases of presumed tick envenomation in horses. Design Retrospective study. Method Variables, including date of presentation, age, breed, weight, presence of ticks, gait and respiration scores, duration of recumbency, treatment, outcome and complications were recorded. A series of univariable screening tests were performed and used in a multivariable logistic regression model. Results There were a total of 103 cases affecting 10 breeds, aged between 1 week and 18 years of age. Horses >6 months old and weighing >100 kg had a higher odds of death than those <6 months old and <100 kg. Cases were seen from North Queensland to the central coast of New South Wales and were more likely to present in the warmer months. There was no association between the number of ticks found on an animal and death. Horses with a higher respiratory score had higher odds of dying, but there was no association between gait score and survival. Horses recumbent >120 h after presentation had higher odds of dying. Complications were reported in 35% of horses. The odds ratio for survival was higher for horses receiving >0.5 mL/kg of tick antiserum. Overall, 74% of horses survived. Multivariable modelling was limited by the small sample size. Conclusion In general, tick envenomation in horses follows the geographic distribution of Ixodes holocyclus. Tick antiserum administered at >0.5 mL/kg increases the odds of survival. It would appear that the complications associated with managing a recumbent horse increase the odds of death.     

Characteristics of 18F-FDG and 18F-FDOPA PET in an 8-year-old neutered male Yorkshire Terrier dog with glioma: long-term chemotherapy using hydroxyurea plus imatinib with prednisolone and immunoreactivity for PDGFR-β and LAT1

An 8-year-old neutered male Yorkshire Terrier dog presented with head pressing, vestibular ataxia, neck tenderness, and no oculocephalic reflex. A demarcated lesion in the pons was identified on MRI. The patient was tentatively diagnosed with a glioma and was treated with hydroxyurea plus imatinib and prednisolone. After 30 days of therapeutic treatment, the patient showed a clear improvement in neurological signs, which lasted for 1117 days. On day 569 after the initiation of treatment, ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) was performed with no significant findings on visual analysis. The average and maximal standardized uptake values (SUVs) were 1.92 and 2.29, respectively. The tumor-to-normal-tissue (T/N) ratio was 0.97. The first evidence of clinical deterioration was noticed on day 1147. On day 1155, 3,4-dihydroxy-6-[¹⁸F]-fluoro-l-phenylalanine (¹⁸F-FDOPA)-PET was performed. High uptake of ¹⁸F-FDOPA was observed in the intracranial lesion. The mean and maximal SUVs of the tumor were 1.59 and 2.29, respectively. The T/N ratio was 2.22. The patient was euthanized on day 1155 and histopathologic evaluations confirmed glioma (astrocytoma). This case shows that chemotherapy with hydroxyurea plus imatinib may be considered in the treatment of canine glioma. Furthermore, this is the first case describing the application of ¹⁸F-FDG and ¹⁸F-FDOPA in a dog with glioma.     

Clinical,pathologic, and toxicologic characterization of Salvia reflexa (lance-leaf sage) poisoning in cattle fed contaminated hay

Salvia reflexa (lance-leaf sage)-contaminated alfalfa hay was fed to ~500 mixed-breed beef cattle. Within hours of exposure, nearly half of the cattle developed lethargy, anorexia, depression, and recumbency, followed by bellowing, colic, and death. Even though the uneaten contaminated hay was removed the first day, nearly 100 animals died within the first 48 h. Three of these cattle were examined postmortem, and tissues and hay samples were collected for microscopic and chemical analysis. Several days later, a smaller number of the clinically poisoned cattle developed neurologic disease with aberrant behavior, aggression, icterus, blindness, exhaustion, and death. A total of 165 cattle were fatally poisoned. Poisoned cattle had swollen, dark, mottled livers that had a prominent nutmeg-like lobular pattern on cut section. Histologically, there was severe centrilobular-to-panlobular hepatic necrosis with marked hepatocellular swelling, degeneration, and necrosis. The surviving cattle developed liver disease characterized by altered serum biochemical analyses and microscopic hepatocellular degeneration and necrosis. In subsequent biopsies and analysis, these lesions resolved within 6–7 mo. After confirming toxicity of the hay in cattle, goats, and mice, followed by a mouse bioassay–guided chemical fractionation process, Salvia reflexa was identified as the contaminant in the hay responsible for the hepatotoxicity. S. reflexa has not been reported previously to cause fatal hepatotoxicity in livestock in North America, to our knowledge.