Colonic Hamartomatous Ganglioneuromatosis in a 4 Mo Old Puppy.

A 4 mo old male goldendoodle puppy was evaluated for chronic hematochezia with a history of recurrent rectal prolapse and tenesmus. A colo-colonic intussusception was diagnosed via abdominal imaging. Surgery was elected to reduce the intussusception, wherein a colonic mass was discovered. Colonic resection and anastomosis was performed, and the tissue were submitted for histopathological examination. The puppy was diagnosed with colonic hamartomatous ganglioneuromatosis based on the presence of markedly hyperplastic submucosal and myenteric plexi with infiltration and expansion of the mucosa and submucosa by Schwann cells and neuronal cell bodies. Ganglioneuromatosis is a rarely reported entity in the veterinary literature, and limited clinical follow up data is available for described cases. In humans, ganglioneuromatosis is associated with a PTEN genetic mutation, which confers increased susceptibility to the development of neoplasia of endocrine organs. Approximately 1 yr after the operation, this puppy appeared clinically normal with no abnormalities on repeated imaging. This case report describes the clinical presentation, surgical treatment, and histologic features of colonic hamartomatous ganglioneuromatosis with 1 yr postoperative clinical follow up data in a dog. Although uncommon, ganglioneuromatosis should be considered as a differential diagnosis list as a cause of gastrointestinal masses in puppies and young dogs.

Symmetrical parapagus diprosopus tetrophthalmos in a bovine calf, with computed tomography imaging, and review of craniofacial duplications.

Diprosopia, a congenital defect process also known as craniofacial duplication, is well-recognized in humans and has also been reported in numerous animal species. Here we describe a case of diprosopia in a live mixed-breed beef calf. We used computed tomography imaging to characterize internal and external abnormalities which, to our knowledge, have not been reported in any diprosopic veterinary species. Additional diagnostic tools included postmortem examination and histopathology. This case highlights distinct anatomic features associated with diprosopia and underscores the unique challenges associated with classifying and managing fetal malformations.

Unilateral invasive intraocular melanoma with choroidal and optic nerve involvement resulting in bilateral vision loss in a Labrador Retriever.

A 10-year-old male castrated Labrador Retriever cross was referred for evaluation of acute vision loss. Ophthalmic examination revealed mild left sided exophthalmos, bilateral resting mydriasis, an absent direct and reduced consensual PLR in the left eye and reduced direct and absent consensual PLR in the right eye. Examination of the cornea and anterior segment with slit lamp biomicroscopy was unremarkable. Indirect fundoscopy revealed a left optic nerve head obscured by a darkly pigmented lesion. Fundic examination in the right eye was unremarkable. Magnetic resonance imaging revealed a smoothly marginated, lobulated cone to irregularly shaped, strongly T1 hyperintense, T2 and T2 fluid-attenuated inversion recovery hypointense, strongly contrast enhancing mass closely associated with the entire left optic nerve, extending across the optic chiasm and into the right optic nerve ventrally. Full clinical staging revealed no evidence of metastasis. Exenteration of the left eye was performed. Histopathology revealed an unencapsulated, poorly demarcated, multilobulated and infiltrative pigmented mass that was effacing the posterior choroid and optic nerve. The mass was composed of a moderately pleomorphic population of heavily pigmented polygonal cells arranged in sheets and clusters, displaying moderate anisocytosis and anisokaryosis. The population of cells contained moderate amounts of abundant brown-black granular pigment consistent with melanin within the cytoplasm. Mitotic figures averaged approximately three per ten 400× fields (2.37 mm2 ). This is the first report of a melanocytic tumor invading along the optic nerve and tract to result in contralateral vision loss.

CSF from a puppy with a cerebral vascular hamartoma.

A 9-week-old puppy with refractory seizures and a dome-shaped head presented to the Mississippi State College of Veterinary Medicine Specialty Center for suspected hydrocephalus. Computerized tomography (CT) findings included transtentorial herniation and an intra-axial mass with dystrophic mineralization. Cerebrospinal fluid analysis revealed an increased nucleated cell count of 1100/µl (RI < 5/µl), erythrocyte count of 2.2 × 106 /µl, and markedly increased microprotein of 1939 mg/dl (RI < 30 mg/dl). On cytologic examination of the CSF, numerous erythrophagocytic, and hemosiderin-laden macrophages were observed, which indicated chronic active hemorrhage. Many neutrophils, macrophages, and lymphocytes that contained numerous intracytoplasmic, pleomorphic, bright yellow crystals were observed. Considering the ongoing hemorrhage, the crystals were presumed to be hematoidin. A biopsy with histopathology was performed on the intra-axial mass, and the results were consistent with a vascular hamartoma. We speculate that the formation of these crystals was related to the ongoing hemorrhage associated with the vascular hamartoma. Identification of these crystals may be useful to aid in the identification of chronic hemorrhage associated with vascular malformations or lesions within the central nervous system.

Pot-bellied Vietnamese pig with visceral mast cell tumors and mastocytemia.

An approximately 12-year-old female Vietnamese Pot-Bellied Pig was presented to the Mississippi State College of Veterinary Medicine Food Animal Service for anorexia of 2 days duration. On physical examination, the patient appeared depressed and lethargic with significantly pale mucus membranes, open mouth breathing, and nostril flaring. On abdominal palpation, the abdomen was tense and uncomfortable. A complete blood count (CBC) and chemistry profile were performed. The CBC revealed significant anemia and mild leukocytosis characterized by mild neutrophilia with a left shift. Mast cells were rarely observed. Hematocrit = 8.1% (RI 22-50), RBC = 1.25 × 106 /µL (RI 3.6-7.8), WBC = 19.85 × 103 /µL (RI 5.2-17.9), Neutrophils = 15.08 × 103 /µL (RI 0-11.4), and Bands = 0.993 × 103 /µL (RI 0-0.019). The chemistry profile was unremarkable with a mildly elevated BUN and slightly decreased total protein and albumin (BUN = 39 mg/dL [RI 4.2-15.1], total protein = 6.2 g/dL [RI 6.6-8.9], and albumin = 2.5 g/dL [RI 3.6-5.0]). An abdominal ultrasound revealed numerous hypoechoic nodules diffusely scattered throughout the hepatic parenchyma. An FNA of one of the hepatic nodules was performed. A mild suppurative component and numerous variably granulated mast cells were observed. A presumptive cytologic diagnosis of mast cell tumor was made. Histopathology was performed, confirming the cytologic interpretation.

High-grade mucoepidermoid carcinoma of the salivary gland in a bull.

Salivary gland neoplasia is uncommon in veterinary species and has rarely been reported in cattle. Adenocarcinoma, squamous cell carcinoma, and pleomorphic carcinoma have been described in the parotid gland of dairy cows. Here we describe a case of high-grade mucoepidermoid carcinoma in a bull. The bull had a chronic history of caudal mandibular soft tissue swelling. Postmortem examination revealed a 30 × 30-cm mass with a caseonecrotic center, hemorrhage and necrosis of the ipsilateral cervical musculature, osteolysis of the right paracondylar process of the skull and right horn base, pulmonary nodules, and enlarged tracheobronchial lymph nodes. Histology of the mass, lungs, and lymph nodes revealed an invasive neoplasm composed of epithelial cells arranged in nests and ductular structures supported by a spindle cell stroma, with frequent central necrosis. Immunohistochemistry revealed that epithelial cells were diffusely positive for pancytokeratin and p63 with multifocal vimentin positivity; stromal cells were diffusely positive for vimentin and α-SMA. A salivary gland mucoepidermoid carcinoma was diagnosed based on these findings. Although rare, salivary gland neoplasia should be considered a differential diagnosis for mandibular masses in cattle.

An Investigation of the Cause of Wild Turkey Mortality in Mississippi.

Lymphoproliferative disease virus (LPDV) is an exogenous alpharetrovirus that sporadically causes fatal lymphoid neoplasia in affected turkeys. Previous studies of wild turkeys (Meleagridis gallopavo) in the United States have demonstrated geographically widespread LPDV infection and frequent coinfection with avian poxvirus (APV) and reticuloendotheliosis virus (REV). This study was conducted to better understand health risks to Mississippi wild turkeys, including the relative importance of LPDV, APV, and REV in contributing to mortality. Thirteen wild turkeys, which died naturally or were euthanized due to illness, were submitted to Mississippi State University's Poultry Research and Diagnostic Laboratory for postmortem examinations. Birds originated from nine counties across the state over the past 5 yr. Carcasses were submitted as fresh (nonfrozen) or frozen. At autopsy, 9 of 13 turkeys had severe, proliferative cutaneous lesions on the head and neck, with diphtheritic or proliferative oral and esophageal lesions. Samples were collected for molecular diagnostic testing (LPDV and REV PCR), histopathology, and bacterial culture and isolation. External and internal parasites were preserved in formalin for identification. APV (cutaneous and/or diphtheritic forms) was diagnosed in 9 of 13 birds by identification of pathognomonic histologic lesions (including intracytoplasmic inclusion bodies). Interestingly, all birds with APV were also REV PCR positive. Furthermore, eight turkeys were positive for LPDV, and LPDV was commonly associated with coinfections with APV and REV.

El virus de la enfermedad linfoproliferativa (LPDV) es un Alfaretrovirus exógeno que esporádicamente provoca una neoplasia linfoide mortal en los pavos afectados. Estudios previos de pavos salvajes (Meleagridis gallopavo) en los Estados Unidos han demostrado que la infección por la enfermedad linfoproliferativa está geográficamente extendida y es una coinfección frecuente con el virus de la viruela aviar (APV) y el virus de la reticuloendoteliosis (REV). Este estudio se realizó para comprender mejor los riesgos para la salud de los pavos salvajes de Mississippi, incluida la importancia relativa de enfermedad linfoproliferativa, el virus de la viruela aviar y el virus de la reticuloendoteliosis en la contribución a la mortalidad. Trece pavos salvajes, que murieron naturalmente o fueron sacrificados por enfermedad, fueron enviados al Laboratorio de Investigación y Diagnóstico Avícola de la Universidad Estatal de Mississippi para exámenes post-mortem. Las aves provenían de condados de todo el estado durante los últimos cinco años. Las canales se enviaron tanto frescas (no congeladas) como congeladas. A la necropsia, 9 de 13 pavos mostraron lesiones cutáneas proliferativas graves en la cabeza y el cuello, con lesiones orales y esofágicas diftéricas o proliferativas. Se recolectaron muestras para pruebas de diagnóstico molecular (LPDV y REV PCR), histopatología y cultivo y aislamiento bacterianos. Los parásitos externos e internos se conservaron en formalina para su identificación. Se diagnosticó viruela aviar (formas cutáneas y/o diftéricas) se diagnosticó en 9 de 13 aves mediante la identificación de lesiones histológicas patognomónicas (incluidos los cuerpos de inclusión intracitoplasmáticos). Curiosamente, todas las aves con viruela aviar también fueron positivas a la presencia del virus de la reticuloendoteliosis por PCR. Además, ocho pavos fueron positivos para el virus de la enfermedad linfoproliferativa, y se asoció comúnmente con coinfecciones con viruela aviar y con el virus de la reticuloendoteliosis.

Nasal Rhinosporidiosis: Clinical Presentation, Clinical Findings, and Outcome in Dogs.

The purpose of this study was to describe the clinical presentation, imaging findings, and outcome in 10 dogs diagnosed with Rhinosporidium seeberi infections. Histopathology and cytology records were searched at a veterinary teaching hospital and a veterinary diagnostic laboratory to identify dogs with rhinosporidiosis. Medical records were reviewed for clinical, imaging, endoscopic, and surgical findings. Outcome was determined via evaluation of records and, where possible, telephone conversation with the primary care veterinarian and/or owner. Young to middle-aged large-breed dogs with an approximately equal sex distribution were represented. Unilateral signs predominated. Diagnosis was confirmed by histopathology in 9 cases, and cytology was diagnostic in only 1 of 3 cases. Histopathology was superior to cytology. Masses were soft tissue and contrast enhancing with no evidence of bony lysis on computed tomography (2 dogs). Direct or rhinoscopic (2 dogs) visualization revealed white to yellow pinpoint foci. Surgical resection (4 dogs) can result in long-term disease-free periods (up to 2659 days), although repeat surgery can be required. Dapsone was well tolerated in 1 dog, and relapse was not noted despite incomplete surgical resection (follow-up 749 days). Visualization of pale foci on a rostral intranasal mass in an endemic region should prompt consideration of rhinosporidiosis.

Failed detection of Bovine viral diarrhea virus 2 subgenotype a (BVDV-2a) by direct fluorescent antibody test on tissue samples due to reduced reactivity of field isolates to raw anti-BVDV antibody.

Bovine viral diarrhea virus 1 (BVDV-1) is associated with mild or subclinical infections, whereas BVDV-2 is frequently implicated in outbreaks of severe thrombocytopenia and acute fatal disease. In the present study, the carcass of a beef breed cow and tissue samples of a beef calf were received for laboratory diagnosis. Both animals exhibited severe clinical signs compatible with thrombocytopenia or hemorrhagic syndrome. Direct fluorescent antibody test (DFAT) failed to detect BVDV antigen in the tissue specimens of both cases. However, immunohistochemistry (IHC) revealed the presence of BVDV antigen in oral and esophageal mucosa and Peyer patches of the beef breed cow. Real-time reverse transcription polymerase chain reaction (real-time RT-PCR) detected BVDV-2 in selected tissues of both animals. Subsequently, BVDV was isolated from both cases and subjected to genetic and serologic characterizations. Mutations in the 5'-untranslated genomic region (5'-UTR) primer and probe binding sites and the E2 gene were associated with reduced efficiency of an established real-time RT-PCR assay and amino acid alterations in the E2 glycoprotein, respectively. Both viral isolates were classified by real-time RT-PCR and phylogenetic analysis as BVDV-2 subgenotype a. Unlike BVDV reference strains Singer and 125c, the isolates cross-reacted with anti-BVDV-1 and anti-BVDV-2 reference sera, indicating antigenic variations in field isolates. The isolates also showed reduced reactivity to porcine anti-BVDV antiserum (the raw serum used to produce BVDV DFA conjugate). In summary, data from the present investigation indicated that genetic and antigenic variations affected the performance of detection assays, especially DFAT, highlighting the need for regular evaluation and modification of BVDV tests.

Pilot Study: Colostomy and Urine Collection Protocol for Investigating Potential Inciting Causes of Hen Diuresis Syndrome.

Hen diuresis syndrome has emerged over the past 5 yr as a significant cause of mortality in the U.S. broiler breeder industry. The condition affects hens in production and is characterized by transient muscle weakness in the vent region, transient diuresis, and often urate deposits on the skin below the vent. Affected hens are often seen straining to lay an egg, which suggests oviduct contraction is also impaired. Related hen mortality, often reaching 1% or more a week, is believed to be primarily the result of male aggression of the vent region (Turner et al., "Investigating Causes of Excessive Urate Production in Broiler Breeder Hens Associated with Peritonitis and Cannibalism Mortality," Oral Presentation at The American Association of Avian Pathologists Annual Meeting, p. 139, 2010). The exact association between the cause of mortality and this syndrome is unknown, but it may be the consequence of transient partial to full oviduct prolapse, which predisposes or stimulates cannibalism and aggression. Based on unpublished work done prior to this study (Turner et al., ibid.), the evidence suggests the underlying problem is metabolic. We feel that urine collection and analysis is an essential component to understanding this condition. This study serves as a pilot study for future investigations that attempt to identify the nature and cause of the metabolic disturbance through paired urine and serum collection and analysis. For the purpose of this study, a small sample of 10 affected and 10 unaffected birds was used for sample collection. In order to collect pure urine, the birds were surgically colostomized. Colostomy did prove to be a useful means of collecting urine free of feces, and for the purposes of our study it yielded adequate urine samples for analysis. There were statistically relevant urine values observed. Affected birds had a higher presence of blood in the urine, a lower uric acid excretion rate (mg/hr), higher concentration (mEq/L) of urine Na+, and a lower concentration (mEq/L) of urine K+ than unaffected birds. This pilot study helps to address some of the pitfalls previously associated with colostomy and to determine when collection can begin postoperatively so that we can better understand when and how to begin our sampling in future trials to address the etiology of this condition.

Diagnosis of Deerpox virus infection in a white-tailed deer (Odocoileus virginianus) fawn.

A 3-month-old fawn from a group of 12 captive white-tailed deer (Odocoileus virginianus) displaying cutaneous lesions was presented to the Mississippi Veterinary Research & Diagnostic Laboratory for necropsy. Postmortem examination identified multiple discrete, round, alopecic, flat, proliferative dermal lesions scattered along the skin of the lips, muzzle, pinna, ventral thorax, medial limbs, and most notably the abdomen. Multiple ulcers were present on the commissures of the lips, dorsal surface of the tongue, and left caudal buccal surface of the oral cavity. The abdomen was filled with fibrinopurulent exudate and ruminal contents. Multiple to coalescing transmural ulcers were identified in the rumen. Histopathological evaluation of the skin revealed markedly thickened epidermis and focal areas of superficial dermal fibrosis, intracytoplasmic, eosinophilic inclusions in swollen keratinocytes and lymphocytic and plasmacytic perivascular dermatitis. The rumen ulcers were surrounded with necrotic cellular debris mixed with fibrin, bacteria, hemorrhages, and a collection of mixed inflammatory cells. Some swollen ruminal mucosal epithelia had eosinophilic intracytoplasmic inclusions. Poxvirus was isolated from the skin and rumen tissue specimens. Electron microscopy detected viral particles with poxvirus morphology. Polymerase chain reaction assays detected A21, a gene conserved within family Poxviridae, in the skin and rumen tissues. Phylogenic analysis of the A21 sequences indicated that the viral isolate (M10-9055) was closely related to known members of genus Cervidpoxvirus. In conclusion, findings indicate that Deerpox virus can produce extensive lesions in white-tailed deer.

A hospital outbreak of diarrhea due to an emerging epidemic strain of Clostridium difficile.

BACKGROUND: Increased Clostridium difficile-associated disease (CDAD) in a hospital and an affiliated long-term care facility continued despite infection control measures. We investigated this outbreak to determine risk factors and transmission settings. METHODS: The CDAD cases were compared according to where the disease was likely acquired based on health care exposure and characterization of isolates from case patients, asymptomatic carriers, and the environment. Antimicrobial susceptibility testing, strain typing using pulsed-field gel electrophoresis, and toxinotyping were performed, and toxins A and B, binary toxin, and deletions in the tcdC gene were detected using polymerase chain reaction. Risk factors were examined in a case-control study, and overall antimicrobial use was compared at the hospital before and during the outbreak. RESULTS: Significant increases were observed in hospital-acquired (0.19 vs 0.86; P < .001) and long-term care facility-acquired (0.04 vs 0.31; P = .004) CDAD cases per 100 admissions as a result of transmission of a toxinotype III strain at the hospital and a toxinotype 0 strain at the long-term care facility. The toxinotype III strain was positive for binary toxin, an 18-base pair deletion in tcdC, and increased resistance to fluoroquinolones. Independent risk factors for CDAD included use of fluoroquinolones (odds ratio [OR], 3.22; P = .04), cephalosporins (OR, 5.19; P = .006), and proton pump inhibitors (OR, 5.02; P = .02). A significant increase in fluoroquinolone use at the hospital took place during the outbreak (185.5 defined daily doses per 1000 patient-days vs 200.9 defined daily doses per 1000 patient-days; P < .001). CONCLUSIONS: The hospital outbreak of CDAD was caused by transmission of a more virulent, fluoroquinolone-resistant strain of C difficile. More selective fluoroquinolone and proton pump inhibitor use may be important in controlling and preventing such outbreaks.