Nerve Fiber Immunohistochemical Panel Discriminates between Nerve Sheath and Perivascular Wall Tumors.

Benign and malignant nerve sheath tumors (NST) pose a major challenge in routine diagnostic anatomic pathology because of shared histomorphological features with other soft-tissue tumors (STT). As a result, NST are often diagnosed as STT, a broad category that encompasses various entities including perivascular wall tumors (PWT) and that represents approximately 15% of all skin tumors in dogs. Immunohistochemistry (IHC) can assist the identification of histologic subtypes of STT.

Case Report: Neuroblastoma-Like Schwannoma in a Domestic Short-Haired Cat.

An axillary mass was detected in a 6-year-old, neutered, male, domestic short-haired cat during a wellness exam. Gross examination following surgical removal revealed a discrete, deep subcutaneous, discoid mass that was between 0.5- and 0.

Comparative Cytogenetic Analysis of Dog and Human Choroid Plexus Tumors Defines Syntenic Regions of Genomic Loss.

Choroid plexus tumors (CPTs) occur spontaneously in humans and dogs providing an opportunity for comparative cross species analysis of common tumor mechanisms. Large scale chromosomal copy number alterations are the hallmark of human CPTs and identification of driver genes within these regions is problematic. Copy number alterations in 12 spontaneous dog CPTs were defined using an Illumina 170 K single nucleotide polymorphism array and were characterized by highly recurrent whole chromosomal losses in up to 100% of cases with few chromosome wide gains.

Canine Nervous System Lymphoma Subtypes Display Characteristic Neuroanatomical Patterns.

Primary and secondary nervous system involvement occurs in 4% and 5%-12%, respectively, of all canine non-Hodgkin lymphomas. The recent new classification of canine malignant lymphomas, based on the human World Health Organization classification, has been endorsed with international acceptance. This histological and immunocytochemical classification provides a unique opportunity to study the histologic anatomic distribution patterns in the central and peripheral nervous system of these defined lymphoma subtypes.

Chromosomal Aberrations in Canine Gliomas Define Candidate Genes and Common Pathways in Dogs and Humans.

Spontaneous gliomas in dogs occur at a frequency similar to that in humans and may provide a translational model for therapeutic development and comparative biological investigations. Copy number alterations in 38 canine gliomas, including diffuse astrocytomas, glioblastomas, oligodendrogliomas, and mixed oligoastrocytomas, were defined using an Illumina 170K single nucleotide polymorphism array. Highly recurrent alterations were seen in up to 85% of some tumor types, most notably involving chromosomes 13, 22, and 38, and gliomas clustered into 2 major groups consisting of high-grade IV astrocytomas, or oligodendrogliomas and other tumors.

Molecular signalling pathways in canine gliomas.

In this study, we determined the expression of key signalling pathway proteins TP53, MDM2, P21, AKT, PTEN, RB1, P16, MTOR and MAPK in canine gliomas using western blotting. Protein expression was defined in three canine astrocytic glioma cell lines treated with CCNU, temozolamide or CPT-11 and was further evaluated in 22 spontaneous gliomas including high and low grade astrocytomas, high grade oligodendrogliomas and mixed oligoastrocytomas. Response to chemotherapeutic agents and cell survival were similar to that reported in human glioma cell lines.

Risk of false positive genetic associations in complex traits with underlying population structure: a case study.

Genome-wide association (GWA) studies are widely used to investigate the genetic etiology of diseases in domestic animals. In the horse, GWA studies using 40-50,000 single nucleotide polymorphisms (SNPs) in sample sizes of 30-40 individuals, consisting of only 6-14 affected horses, have led to the discovery of genetic mutations for simple monogenic traits. Equine neuroaxonal dystrophy is a common inherited neurological disorder characterized by symmetric ataxia.

Bilaterally symmetric focal cortical dysplasia in a golden retriever dog.

A 10-year-old golden retriever dog was referred with a 24-h history of generalized seizures. Magnetic resonance imaging of the brain found no abnormalities on 3 mm transverse sections and the dog was subsequently humanely destroyed. Microscopically there was bilaterally symmetrical focal disorganization of cortical grey matter within the tips of the right and left suprasylvian gyri of the temporal cortex.

Transmural ileal ganglioneuromatosis in a young Boer goat (Capra hircus).

A diagnosis of transmural ileal ganglioneuromatosis was made in a 15-day-old goat that was found dead following a period of diarrhoea and inappetence. Grossly, the entire length of the wall of the ileum was pale and firm with a variably segmental to transmural thickening. Microscopically, the ileal transmural thickening was due to a diffuse proliferation of both ganglionic and glial cells forming cell nests or packets that infiltrated the wall and into the mesentery surrounding a mesenteric lymph node.

Temporal and geographic clustering of polyomavirus-associated olfactory tumors in 10 free-ranging raccoons (Procyon lotor).

Reports of primary nervous system tumors in wild raccoons are extremely rare. Olfactory tumors were diagnosed postmortem in 9 free-ranging raccoons from 4 contiguous counties in California and 1 raccoon from Oregon within a 26-month period between 2010 and 2012. We describe the geographic and temporal features of these 10 cases, including the laboratory diagnostic investigations and the neuropathologic, immunohistochemical, and ultrastructural characteristics of these tumors in the affected animals.

Magnetic resonance imaging features of intracranial granular cell tumors in six dogs.

Magnetic resonance (MR) imaging characteristics of intracranial granular cell tumors (GCTs) have been previously reported in three dogs. The goal of this retrospective study was to examine a larger number of dogs and determine whether distinctive MR characteristics of intracranial GCTs could be identified. Six dogs with histologically confirmed intracranial GCTs and MR imaging were included.

Genome-wide association analysis identifies a mutation in the thiamine transporter 2 (SLC19A3) gene associated with Alaskan Husky encephalopathy.

Alaskan Husky Encephalopathy (AHE) has been previously proposed as a mitochondrial encephalopathy based on neuropathological similarities with human Leigh Syndrome (LS). We studied 11 Alaskan Husky dogs with AHE, but found no abnormalities in respiratory chain enzyme activities in muscle and liver, or mutations in mitochondrial or nuclear genes that cause LS in people. A genome wide association study was performed using eight of the affected dogs and 20 related but unaffected control AHs using the Illumina canine HD array.

A prospective on farm cohort study investigating the epidemiology and pathophysiology of drunken lamb syndrome.

Drunken lamb syndrome (DLS) is a fatal disease of unknown aetiology affecting young lambs. In 2011, a prospective on farm cohort study was carried out to investigate the epidemiology and pathophysiology of DLS. Ten cases from a cohort of 1635 crossbred and pure Welsh Mountain lambs were identified as having DLS on the basis of characteristic clinical signs.

Clear cell ependymoma in a dog.

A 13-year-old, mixed breed dog presented with a 1-month history of seizures. Magnetic resonance imaging of the brain revealed a 2.2 × 1.

Pedigree analysis and exclusion of alpha-tocopherol transfer protein (TTPA) as a candidate gene for neuroaxonal dystrophy in the American Quarter Horse.

Background: Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (NAD/EDM) is a neurodegenerative disorder affecting young horses of various breeds that resembles ataxia with vitamin E deficiency in humans, an inherited disorder caused by mutations in the alpha-tocopherol transfer protein gene (TTPA). To evaluate variants found upon sequencing TTPA in the horse, the mode of inheritance for NAD/EDM had to be established.

Hypothesis: NAD/EDM in the American Quarter Horse (QH) is caused by a mutation in TTPA.

Enteritis in an alpaca (Vicugna pacos) associated with a potentially novel adenovirus.

Adenovirus-associated enteritis was diagnosed by histopathology of small intestine in a 2-year-old alpaca (Vicugna pacos). Electron microscopy confirmed intracytoplasmic and intranuclear adenoviral particles within enterocytes. Nucleic acid was extracted from paraffin-embedded tissue sections, and a pan-adenovirus nested polymerase chain reaction (PCR) assay was employed to target a partial sequence of the polymerase gene.

Case study of copper poisoning in a British dairy herd.

Following the initial diagnosis of chronic copper poisoning (CCP), the copper (Cu) status of a British dairy herd was investigated. Eight fatal cases of CCP were identified over a 17-month period, from December 1999 to May 2001, involving seven Jersey cows and one Holstein-Friesian; seven cows were dry when CCP occurred. Case diagnostic criteria were necrotising hepatopathy associated with abnormally high liver and kidney Cu concentrations.

Aberrant E-cadherin, β-catenin, and glial fibrillary acidic protein (GFAP) expression in canine choroid plexus tumors.

Expression of E-cadherin and β-catenin has been widely studied in various human and canine epithelial tumors and has been correlated with dedifferentiation, invasiveness, and metastasis. Choroid plexus tumors (CPTs) are of epithelial origin, and the most important prognostic factor in human medicine is the tumor grade. Limited information is available regarding E-cadherin and β-catenin expression in human CPTs, and no information is found in the veterinary literature.

Equine degenerative myeloencephalopathy in Lusitano horses.

Background: Equine degenerative myeloencephalopathy (EDM) is a neurodegenerative disorder that has been previously associated with low vitamin E concentrations.

Objective: To describe the clinical, electrophysiologic, and pathologic features of EDM in a group of related Lusitano horses.

Animals: Fifteen Lusitano horses.

TP53 mutations in canine brain tumors.

The p53 tumor suppressor gene (TP53) is the most frequently altered gene in human cancer. Mutation of the gene has been shown to be an important mechanism of p53 pathway inactivation in a variety of human brain tumors, particularly those of astrocytic origin. Genomic DNA from a series of 37 glial and 51 nonglial canine brain tumors was sequenced to determine the frequency of TP53 gene mutations involving exons 3-9.

Evaluation of epidemiological, clinical, and pathological features of neuroaxonal dystrophy in Quarter Horses.

Objective: To describe epidemiological, clinical, and pathological features of neuroaxonal dystrophy in Quarter Horses (QHs) on a single farm.

Design: Prospective case series. Animals-148 horses.

Controlling tuberculosis in a llama (Lama glama) herd using clinical signs, tuberculin skin testing and serology.

An outbreak of tuberculosis (TB), caused by Mycobacterium bovis, was investigated in a small herd of llamas (Lama glama). Based on three ante-mortem diagnostic methods (clinical signs, tuberculin skin test reactions, and 'Rapid Test' serology), 12 llamas were selected for examination post-mortem. Grossly visible lesions suspicious of TB were observed in eight animals, four of which had exhibited clinical signs, one was a skin test 'reactor', and three had been seropositive.