Veterinary Pathology

  • Multiple Histiocytic Foam Cell Nodules in the Tongue of Miniature Dachshund Dogs 15 aprile 2016
    Katou-Ichikawa, C., Izawa, T., Sasai, H., Kuwamura, M., Yamate, J.
    Miniature dachshund dogs are a common breed in Japan and are known to be predisposed to granulomatous diseases. Here we report the pathologic features of multiple lingual nodules in 7 miniature dachshunds. Seven dogs had multiple nodules of variable sizes mainly on the ventral and lateral surface of the tongue. In addition, 1 dog also had masses on the left oral mucosa. Three cases had recurrence after surgical resection. Histologically, the lingual nodules were composed of aggregates of foam cells with clear vacuolated cytoplasm that were negative for oil red O, PAS, and alcian blue. They stained positively for CD204 (macrophage scavenger receptor) and MHC class II and negatively for Iba-1, E-cadherin, adipophilin, cytokeratins, S-100, and nestin. These findings indicate that the multiple lingual nodules in miniature dachshunds are an unusual, unique lesion consisting of macrophage-derived foam cells, which does not correspond to canine lingual diseases reported to date.
  • Multisystemic Listeriosis in a Common Brushtail Possum (Trichosurus vulpecula) and Two Common Ringtail Possums (Pseudocheirus peregrinus) 15 aprile 2016
    Sangster, C. R.
    A single free-ranging common brushtail possum (Trichosurus vulpecula) and 2 captive sibling common ringtail possums (Pseudocheirus peregrinus) from a zoological facility in Sydney, Australia, were diagnosed with multisystemic listeriosis. The brushtail was found dead in an animal enclosure while the ringtails presented with signs of cardiovascular collapse and died shortly thereafter. All 3 animals were culture positive for Listeria monocytogenes and demonstrated focal suppurative lesions within the brainstem in addition to fulminant disease in other areas of the thorax and/or abdomen. Listeriosis in phalangeriformes species has rarely been reported, and brainstem lesions have not previously been described. It is speculated that access to the brainstem by the organism may have occurred hematogenously or via retrograde migration along cranial nerves. Sources of infection and the possibility of transmission between animals are also discussed.
  • The "Naked Truth": Naked Mole-Rats Do Get Cancer 15 aprile 2016
    Piersigilli, A., Meyerholz, D. K.
  • Lesions of Copper Toxicosis in Captive Marine Invertebrates With Comparisons to Normal Histology 15 aprile 2016
    LaDouceur, E. E. B., Wynne, J., Garner, M. M., Nyaoke, A., Keel, M. K.
    Despite increasing concern for coral reef ecosystem health within the last decade, there is scant literature concerning the histopathology of diseases affecting the major constituents of coral reef ecosystems, particularly marine invertebrates. This study describes histologic findings in 6 species of marine invertebrates (California sea hare [Aplysia californica], purple sea urchin [Strongylocentrotus purpuratus], sunburst anemone [Anthopleura sola], knobby star [Pisaster giganteus], bat star [Asterina miniata], and brittle star [Ophiopteris papillosa]) with spontaneous copper toxicosis, 4 purple sea urchins with experimentally induced copper toxicosis, and 1 unexposed control of each species listed. The primary lesions in the California sea hare with copper toxicosis were branchial and nephridial necrosis. Affected echinoderms shared several histologic lesions, including epidermal necrosis and ulceration and increased numbers of coelomocytes within the water-vascular system. The sunburst anemone with copper toxicosis had necrosis of both epidermis and gastrodermis, as well as expulsion of zooxanthellae from the gastrodermis. In addition to the lesions attributed to copper toxicosis, our results describe normal microscopic features of these animals that may be useful for histopathologic assessment of marine invertebrates.
  • A Comparative Review of Animal Models of Middle East Respiratory Syndrome Coronavirus Infection 15 aprile 2016
    Baseler, L., de Wit, E., Feldmann, H.
    Middle East respiratory syndrome coronavirus (MERS-CoV) was initially isolated from a Saudi Arabian man with fatal pneumonia. Since the original case in 2012, MERS-CoV infections have been reported in >1500 humans, and the case fatality rate is currently 35%. This lineage C betacoronavirus has been reported to cause a wide range of disease severity in humans, ranging from asymptomatic to progressive fatal pneumonia that may be accompanied by renal or multiorgan failure. Although the clinical presentation of human MERS-CoV infection has been documented, many facets of this emerging disease are still unknown and could be studied with animal models. Several animal models of MERS-CoV have been developed, including New Zealand white rabbits, transduced or transgenic mice that express human dipeptidyl peptidase 4, rhesus macaques, and common marmosets. This review provides an overview of the current state of knowledge on human MERS-CoV infections, the probable origin of MERS-CoV, and the available animal models of MERS-CoV infection. Evaluation of the benefits and limitations of these models will aid in appropriate model selection for studying viral pathogenesis and transmission, as well as for testing vaccines and antivirals against MERS-CoV.
  • Modeling Emergent Diseases: Lessons From Middle East Respiratory Syndrome 15 aprile 2016
    Meyerholz, D. K.
  • Six-Year Follow-up of Slaughterhouse Surveillance (2008-2013): The Catalan Slaughterhouse Support Network (SESC) 15 aprile 2016
    Vidal, E., Tolosa, E., Espinar, S., de Val, B. P., Nofrarias, M., Alba, A., Allepuz, A., Grau-Roma, L., Lopez-Soria, S., Martinez, J., Abarca, M. L., Castella, J., Manteca, X., Casanova, M. I., Isidoro-Ayza, M., Galindo-Cardiel, I., Soto, S., Dolz, R., Majo, N., Ramis, A., Segales, J., Mas, L., Chacon, C., Picart, L., Marco, A., Domingo, M.
    Meat inspection has the ultimate objective of declaring the meat and offal obtained from carcasses of slaughtered animals fit or unfit for human consumption. This safeguards the health of consumers by ensuring that the food coming from these establishments poses no risk to public health. Concomitantly, it contributes to animal disease surveillance. The Catalan Public Health Protection Agency (Generalitat de Catalunya) identified the need to provide its meat inspectors with a support structure to improve diagnostic capacity: the Slaughterhouse Support Network (SESC). The main goal of the SESC was to offer continuing education to meat inspectors to improve the diagnostic capacity for lesions observed in slaughterhouses. With this aim, a web-based application was designed that allowed meat inspectors to submit their inquiries, images of the lesions, and samples for laboratory analysis. This commentary reviews the cases from the first 6 years of SESC operation (2008–2013). The program not only provides continuing education to inspectors but also contributes to the collection of useful information on animal health and welfare. Therefore, SESC complements animal disease surveillance programs, such as those for tuberculosis, bovine cysticercosis, and porcine trichinellosis, and is a powerful tool for early detection of emerging animal diseases and zoonoses.
  • Cytologic Diagnosis of Heterobilharzia americana Infection in a Liver Aspirate From a Dog 15 aprile 2016
    Le Donne, V., McGovern, D. A., Fletcher, J. M., Grasperge, B. J.
    Heterobilharzia americana is a trematode of the Schistosomatidae family that infects dogs, raccoons, and other mammals as definitive hosts. This parasite is considered endemic in the southern Atlantic and Gulf coasts; however, only a few cases are reported. A 7-year-old dog from Louisiana was referred for persistent hypercalcemia, hyperglobulinemia, and weight loss. Abdominal ultrasound revealed diffuse hyperechogenicity of the liver with several hyperechoic nodules of varying size. Cytologic examination of fine-needle aspirates of the liver revealed few ovoid to round basophilic thin-walled eggshell fragments and rare ciliated miracidia. H. americana eggs were identified on fecal sedimentation.
  • Receptor Tyrosine Kinase Expression Profiles in Canine Cutaneous and Subcutaneous Mast Cell Tumors 15 aprile 2016
    Thompson, J. J., Morrison, J. A., Pearl, D. L., Boston, S. E., Wood, G. A., Foster, R. A., Coomber, B. L.
    The receptor tyrosine kinase (RTK) KIT is a major focus of current research into canine mast cell tumors (MCTs). Little is known about the role of other RTKs, such as vascular endothelial growth factor receptors (VEGFRs) and platelet-derived growth factor receptors (PDGFRs). These RTKs are dysregulated in many human and animal cancers and are key regulators of tumor angiogenesis. The aims of this study were to assess the expression and activation (phosphorylation) status of KIT, VEGFR2, and PDGFR (α and β) in canine MCTs and to examine associations with various clinical outcomes. c-KIT mutational status and KIT cellular localization pattern were also evaluated for these tumors. Twenty-seven MCTs, consisting of 5 subcutaneous and 22 cutaneous tumors, from 25 dogs were evaluated. MCT biopsies, cultured mast cells, and skin from the surgical margin were analyzed through Western blotting. MCT biopsies were also used for KIT immunohistochemical labeling and polymerase chain reaction for c-KIT mutational analysis. MCT had heterogeneous expression profiles for all 3 RTKs, which varied in intensity and activation status. Statistical analyses showed phosphorylated KIT, VEGFR2, and KIT cellular localization to be predictive of decreased survival time, disease-free interval, and increased metastatic rate. Expression of VEGFR2 and KIT diffuse cytoplasmic labeling were also significantly associated with increased rate of local recurrence. The results of the study show that phosphorylated KIT, KIT, VEGFR2, and PDGFRβ, in addition to KIT localization, may be valuable prognostic determinants in MCTs and should be further studied to improve diagnostic and therapeutic modalities.
  • Foot Lesions in Farmed Mink (Neovison vison): Pathologic and Epidemiologic Characteristics on 4 Danish Farms 15 aprile 2016
    Jespersen, A., Hammer, A. S., Jensen, H. E., Bonde-Jensen, N., Lassus, M. M., Agger, J. F., Larsen, P. F.
    The aim of this study was to evaluate gross and histologic lesions and epidemiologic factors of foot lesions in farmed mink. The feet of 1159 mink from 4 Danish farms were examined and lesions described. Swabs from the lesions were taken from 27 mink for microbiology, and tissue samples from a representative spectrum of feet with and without lesions (n = 22) were examined histologically. Feet were grouped according to gross inspection: no lesions (55.1%), hair loss (7.1%), hyperkeratosis (35.8%), and crusting (5.3%). Lesions were predominantly located in plantar metatarsal skin (98.1%). Staphylococci were the most prevalent microorganisms cultured from the lesions. There was a significant association between presence of lesions and sex (P < .0001), age (P < .0001), and color type (P = .023). Lesion size was significantly different between hair loss and crusts and between hyperkeratosis and crusts (P < .0001). Histologically, lesions included varying degrees of orthokeratotic to parakeratotic hyperkeratosis and granulomatous to pyogranulomatous dermatitis with trichogranulomas as a dominant feature in all mink. The gross and microscopic lesions were comparable to physically induced changes in other species that develop as a response to repetitive friction or pressure. The condition may have an impact on animal welfare in mink production.