Intranasal mast cell tumors: Clinical, immunohistochemical, and molecular features in 20 dogs.

Mast cell tumors (MCTs) are an uncommon primary neoplasm of the nasal cavity in dogs for which there is a paucity of existing literature regarding their clinical behavior and molecular features. The objectives of this retrospective study were to examine the clinical findings, histopathologic and immunohistochemical features, and c-KIT mutation status of primary intranasal MCTs in dogs and identify potential prognostic factors. Canine biopsies submitted to a diagnostic laboratory in Colorado between 2010 and 2019 with intranasal neoplasms diagnosed as MCTs and no history of cutaneous or oral MCT were considered. Immunohistochemistry for CD117 and Ki67 and polymerase chain reaction (PCR) for internal tandem duplications at exons 8 and 11 of the c-KIT gene were performed. Twenty out of 1849 (1%) primary intranasal neoplasms were MCTs. Metastases were reported in 11/20 cases (55%), with the mandibular lymph node representing the most common site. One case had distant metastases to abdominal viscera. Of the cases with available outcome data, 6/14 (43%) died or were euthanized from MCT-related disease within 1 year of the onset of clinical signs. Only one case had a c-KIT mutation at exon 11. In our study, intranasal MCTs were prone to metastasize and had a generally poor prognosis, resembling the behavior of MCTs arising in other mucosal locations. While dogs with metastatic disease and survival times of <1 year tended to have atypical KIT localization, moderate to high Ki67 indices, and mitotic counts ≥8, definitive prognosticators could not be identified due to the limited number of cases with favorable clinical outcomes.

Natural Canine Distemper Virus Infection in Linnaeus's 2-Toed Sloths (Choloepus didactylus).

An outbreak of canine distemper virus in a private zoo in eastern Tennessee in July 2016 led to fatal clinical disease in 5 adult, wild-caught Linnaeus's 2-toed sloths (Choloepus didactylus). Clinical signs included hyporexia, lethargy, mucopurulent nasal discharge, and oral and facial ulcers. At necropsy, affected animals had crusts and ulcers on the lips, nose, tongue, and oral cavity. Microscopically, all sloths had widespread, random, hepatic necrosis; lymphoid depletion; and bronchointerstitial pneumonia. The central nervous system did not contain gross or histopathologic lesions in any of the 5 sloths, although immunoreactivity for viral antigen was present within vessel walls. Epithelial cells and histiocytes within numerous organs contained intranuclear and intracytoplasmic inclusions and occasional syncytial cells. Canine distemper virus was confirmed with immunohistochemistry and virus isolation. Viral sequencing identified the novel American-4 strain prevalent in eastern Tennessee wildlife. This is the first pathologic characterization of canine distemper virus infection in sloths (family Choloepodidae, order Pilosa) and emphasizes the significant morbidity and mortality in this species.

Imaging and clinical features of a true gastrogastric intussusception in a dog.

An 18-month-old male mixed breed dog was evaluated for acute vomiting and hematemesis. Clinical signs and initial radiographic findings shared commonalities with reported cases of pylorogastric intussusception in dogs. However, unlike previously reported cases, additional imaging [including ultrasound and computed tomography (CT)] revealed invagination of the gastric fundus into the gastric body, consistent with true gastrogastric intussusception. These findings were confirmed with histopathology and on necropsy. Key clinical message: Although extremely rare, gastrogastric intussusception should be included as a differential diagnosis for any patient presenting with acute vomiting, abdominal pain, dehydration, or tachycardia in combination with the diagnostic imaging findings described in this report.

Caractéristiques cliniques et d'imagerie d'une intussusception gastro-gastrique vraie chez un chien. Un chien mâle de race croisée âgé de 18 mois fut évalué pour des vomissements aigus et de l'hématémèse. Les signes cliniques et les trouvailles radiographiques initiales partageaient des similarités avec des cas rapportés d'intussusception pyloro-gastrique chez des chiens. Toutefois, contrairement aux cas rapportés précédemment, des examens d'imagerie supplémentaires [incluant l'échographie et la tomodensitométrie (CT)] ont révélé une invagination du fundus gastrique dans le corps de l'estomac, compatible avec une intussusception gastro-gastrique vraie. Ces données furent confirmées lors de l'examen histopathologique et de la nécropsie.Message clinique clé :Bien qu'extrêmement rare, l'intussusception gastro-gastrique devrait être incluse dans le diagnostic différentiel pour tout patient présenté avec des vomissements aigus, de la douleur abdominale, de la déshydratation ou de la tachycardie en combinaison avec les trouvailles en imagerie diagnostique décrites dans le présent rapport.(Traduit par Dr Serge Messier).

CLINICOPATHOLOGICAL FEATURES OF TOXOPLASMOSIS IN FOUR RED PANDAS (AILURUS FULGENS).

Two geriatric red pandas (Ailurus fulgens) over a 4-yr period presented with vague clinical signs including anorexia, lethargy, and difficulty ambulating. Treatment protocols using enrofloxacin, steroids, and clindamycin were unsuccessful. Necropsy examination confirmed disseminated toxoplasmosis infection in these cases, and a modified agglutination test had been positive for a prolonged period of time before one panda showed signs of disease. A review of the Red Panda Species Survival Plan pathology database revealed two additional cases of disseminated toxoplasmosis in geriatric red pandas. Many organ systems were affected, but dissemination to the brain, lungs, and liver predominated. Immunohistochemistry or polymerase chain reaction was required to confirm a diagnosis in serologically positive animals, as well as in animals in which a histological diagnosis was suspected. This case series describes the clinical and pathological features of toxoplasmosis in geriatric red pandas.

Transcutaneous Detection of Intramural Microchips for Tracking the Migration of the Equine Large Colon: A Pilot Study.

Colic remains the number one cause of mortality in horses, and large colon displacement including colonic volvulus is one of the leading causes for equine hospitalization and surgery. Currently, there is not an adequate model to study the pathophysiology of this condition. The objective of this proof-of-concept study was to determine if subserosal implantation of bioinert microchips in the large intestine would be detectable by a RFID (radio-frequency identification) receiver when the implanted microchips were adjacent to the body wall, thus identifying the location of the colon within the abdomen. A horse with no history of gastrointestinal disease underwent a ventral midline celiotomy to implant twelve bioinert microchips into the subserosa at predetermined locations within the large colon and cecum. A RFID scanner was used to monitor the location of the colon via transcutaneous identification 1-3 times daily for a one-month period. Following humane euthanasia, a postmortem examination of the horse was performed to assess microchip implantation sites for migration and histologic assessment. Eleven out of the 12 implanted microchips were successfully identified transcutaneously at occurrences as high as 100%. Odds ratios were calculated for the likelihood of identifying each chip in a location different from its most common location. Microchips implanted into the subserosa of the equine large colon can be used as a means of identifying the approximate location of the equine large colon via transcutaneous identification with an RFID scanner.

Disease progression, pathologic, and virologic findings of an equine influenza outbreak in rescue donkeys.

BACKGROUND: Equine influenza virus is a common cause of respiratory disease in equids. Few reports describe clinical presentation and disease progression in donkeys. HYPOTHESIS/OBJECTIVES: Describe the clinical and diagnostic findings, outcome, and pathologic lesions associated with influenza pneumonia in donkeys. ANIMALS: Thirteen unvaccinated donkeys ranging from 1 week to 12 years of age and sharing clinical signs and exposure history. METHODS: Retrospective case series. Medical records from June to July 2020 at the Colorado State Veterinary Teaching Hospital and collaborating referring veterinary practices were reviewed. The diagnosis was confirmed by molecular testing, virus isolation, and partial genetic and phylogenetic analysis of the virus. RESULTS: Survival in donkeys <1 year old was 16.6% (1/6) whereas survival in animals >1 year of age was 85.7% (6/7). Hemagglutinin gene sequencing and phylogenetic analysis confirmed a contemporary clade 1 Florida sublineage H3 virus as the causative agent. CONCLUSIONS AND CLINICAL IMPORTANCE: Clinical signs of equine influenza virus infection in donkeys are similar to those observed in horses. Prognosis for survival generally is good, but deaths have been observed especially in foals born to seronegative dams. This finding emphasizes the importance of prenatal vaccination protocols in all equids, including donkeys.

Eimeria gilruthi-associated abomasitis in a group of ewes.

Nine of 23 (39%) research ewes with severe diarrhea and weight loss had histologic lesions consistent with Eimeria gilruthi infection in their abomasa. Gross anatomic lesions included hundreds of opaque 1-mm nodules in abomasal mucosa that corresponded microscopically to 200-300 µm diameter organisms surrounded by areas of necrosis. Analysis of fecal samples from 4 ewes demonstrated oocysts from typical ovine Eimeria species, none of which were E. gilruthi. Two separate PCR reactions were performed on abomasal tissue from 4 sheep to amplify the 18S ribosomal DNA (rDNA) and internal transcribed spacer (ITS) region of the rDNA, respectively. The resultant 18S rDNA nucleotide sequences shared 99% homology with multiple Eimeria species in GenBank. The ITS region shared 77% homology with E. ellipsoidalis in GenBank. Further studies are needed to understand the life cycle and pathogenicity of E. gilruthi. Our results underscore the inclusion of E. gilruthi in the differential diagnosis of diarrhea and weight loss in sheep.