Oral fibrolipoma in dogs: Retrospective case series study and comparative review.

Fibrolipoma is defined as a typical lipoma transected by variable amounts of paucicellular and collagenous fibrous components. Oral and lingual fibrolipomas are well-recognized histological entities in human medicine that are slightly more prevalent in females, occur most commonly after the fourth decade, and arise from the buccal mucosa. The documentation of this neoplasm in the oral cavity is lacking in veterinary medicine. Through a multi-institutional retrospective compilation of cases submitted to diagnostic pathology services, here we describe the clinical and pathologic features of oral fibrolipomas in dogs. A total of 112 cases of oral fibrolipomas in dogs were retrieved. The mean age was 10.1 years (range 2-16 years, ±2.63 years standard deviation), with an average tumor size of 1.7 cm (range 0.2-8 cm, ±1.1 cm standard deviation). The most common location was the tongue (57.1%, 64/112), followed by the buccal mucosa (15.2%, 16/112), sublingual area (8.0%, 9/112), gingiva and lip (4.5%, 5/112 each), and palate (1 case). The anatomical location of oral fibrolipomas only differed significantly among the dog breeds (P < .001) but not among sex, age, anamnesis, or reason for submission. The tumor was most commonly reported in males (69.7%, 78/112), and in 62.5% (70/112) of the cases, the tumor was an incidental finding. Fibrolipoma should be considered a differential diagnosis when considering benign lingual and other oral soft tissue masses in dogs.

Cytokeratin AE1/AE3 immunolabeling in epithelioid hemangiosarcoma.

Epithelioid hemangiosarcoma (EH), a rare histological variant of hemangiosarcoma, is reported in various animal species, including humans, dogs, cows, horses, and cats. Epithelioid hemangiosarcomas are composed of highly pleomorphic epithelioid cells arranged in cords, islands, nests, or solid cellular areas, similar to epithelial neoplasms. Moreover, in humans, approximately 50% of EHs have cytoplasmic immunolabeling for cytokeratin AE1/AE3 (CK AE1/AE3), making it challenging to distinguish them from carcinomas. This retrospective study assessed the CK AE1/AE3 immunolabeling in canine EH cases from 5 veterinary institutions. Immunohistochemistry for CD31 and CK AE1/AE3 was performed on 30 cases. CK AE1/AE3 immunolabeling was detected in 43% (13/30) of cases, with cytoplasmic labeling ranging from 5% to 100% of neoplastic cells. All tumors consistently had membranous immunolabeling for CD31. The CK AE1/AE3 immunolabeling pattern in canine EHs closely resembled those documented in humans, indicating a similar diagnostic challenge. Therefore, it is recommended to include a vascular immunohistochemistry marker, such as CD31, whenever EH is suspected, particularly in small incisional cutaneous and subcutaneous biopsies.

Putative diagnosis of neuromuscular and vascular hamartoma: 2 cases in dogs and review of the veterinary literature.

Neuromuscular and vascular hamartoma (NMVH) is an infrequent gastrointestinal lesion described in human and veterinary medical literature. The histologic features of this entity are haphazardly arranged fascicles of smooth muscle, nerve fibers, scattered ganglion cells, and hemangiomatous blood vessels. Here we describe 2 putative cases of NMVH in a 1.7-y-old, intact female Anatolian mixed-breed dog and a 4-mo-old intact male Akita dog. Both animals had gastrointestinal clinical signs, including hematochezia, and on exploratory laparotomy, intussusception was confirmed. Histologic examination confirmed NMVH within the cecal wall in both cases using a panel of immunohistochemical (IHC) markers for vascular structures (CD31), smooth muscle (alpha-smooth muscle actin [α-SMA]), and nerves (glial fibrillary acidic protein [GFAP] and S100). The complete surgical excision of the lesion in both animals was considered curative without persistent clinical signs 14 mo and 12 mo, respectively, after surgery.

Coinfection by Mycobacterium marinum and Mycolicibacterium fortuitum in a captive adult diamondback water snake causing disseminated mycobacteriosis with acute cutaneous ulceration.

An adult male captive diamondback water snake (Nerodia rhombifer) was found dead after a 1-d history of lethargy and cutaneous ulcers. The snake had eaten 2 sunfish (Mola spp.) 5 d before death. Gross examination revealed white-to-tan nodules in the lung and liver and segmental intestinal impactions with digested fish. Histopathology confirmed disseminated granulomas with numerous intrahistiocytic acid-fast bacteria in the skin, skeletal muscle, lung, liver, and intestines. Mycobacterium marinum and Mycolicibacterium fortuitum were identified by culture of the hepatic granuloma, followed by PCR and rpoB gene sequencing. To our knowledge, this is the first description of M. marinum and M. fortuitum coinfection in this species. Although M. fortuitum has been isolated from reptiles, lesions associated with its presence in tissues have not been described previously. Interestingly, the mineralization within granulomas that we observed in our case is not reported in mycobacterial infection in reptiles, whereas this finding is common in mammals.

Beak fracture associated with leiomyosarcoma in a budgerigar (Melopsittacus undulatus): a case report and literature review.

A 2-year-old male budgerigar (Melopsittacus undulatus) died after a 1-day history of fracture of the rostral rhinotheca with pale mucous membranes, dyspnea, dull mentation, and ataxia. Histopathology revealed an infiltrative neoplasm composed of interweaving streams of spindle cells effacing the dermis and bone of the rostral upper beak as well as a ganglion and two cranial nerves. No visceral metastasis was observed. Neoplastic cells exhibited strong cytoplasmic immunolabeling for alpha-smooth muscle actin (α-SMA) and lacked immunolabeling for S100, Melan-A, PNL2, and cytokeratin AE1/AE3. These findings were consistent with a locally invasive leiomyosarcoma Leiomyosarcomas arise from the smooth muscle and are locally invasive with rare metastases. In birds, leiomyosarcomas are mostly reported to arise from the spleen, gastrointestinal, and reproductive tracts. In the case report herein, we describe the histological and immunohistochemical features of a primary beak leiomyosarcoma in a budgerigar associated with a fracture located at the rostral rhinotheca. Leiomyosarcoma arising from the beak has not been described in the literature.

Increased CCL-5 (RANTES) Gene Expression in the Choroid Plexus of Dogs with Canine Leishmaniosis.

Visceral canine leishmaniasis (CanL) can cause several clinical manifestations, including neurological lesions. Few reports have characterized the lesions observed in the central nervous system (CNS) during CanL; however, its pathogenesis remains unclear. The choroid plexus (CP) is a specialized structure responsible for the production and secretion of cerebrospinal fluid (CSF) and considered an interface between the peripheral immune system and CNS. It can allow the passage of inflammatory cells or pathogens and has the potential to act as a source of inflammatory mediators in several diseases. Thus, this study aimed to evaluate the role of CP as a possible route of inflammatory cells in the development of brain lesions in dogs with CanL, as well as its association with blood-CSF barrier (BCSFB) dysfunction. Samples were collected from 19 dogs that were naturally infected with CanL. We evaluated the histopathological lesions in the brain and investigated the gene expression of the cytokines. Capture enzyme-linked immunosorbent assay (ELISA) was used to evaluate the presence of the same cytokines in the CSF. Biochemical analysis was performed to compare the presence of albumin in the serum and CSF. Indirect ELISA was performed to measure the presence of anti-Leishmania antibodies in the CSF, which would suggest the disruption of the BCSFB. Histopathological evaluation of the dogs' brains revealed mild-to-severe inflammatory infiltrates, mainly in the CP and meninges. We also detected the presence of anti-Leishmania antibodies and albumin in the CSF, as well as Leishmania DNA in the CP. The gene expression of CCL-5 was increased in the CP of infected dogs compared with that of controls, and there was a tendency for the increase in the gene expression of CXCL-10. Thus, our findings confirm the disfunction of the BCSFB during CanL and suggest that the chemokines CCL-5 and CXCL-10 can be responsible for the recruitment of inflammatory cells found in CP.

Systemic Exophiala equina infection in an Eastern box turtle (Terrapene carolina carolina): a case report and literature review.

Phaeohyphomycosis is an infection caused by melanized fungi. This disease has been reported in several animal species including invertebrates, cold-blooded vertebrates, mammals, and humans. Melanized fungi have similar phenotypical features and confirmation requires culture and molecular diagnostics. To exemplify this we present a case of a 333 g adult of unknown age, free-ranging, male Eastern box turtle (Terrapene carolina carolina) that was referred to the Turtle Rescue Team at North Carolina State University for evaluation of multilobulated masses occupying the entire left orbit and at the right forelimb on the plantarolateral aspect of the foot. A fine needle aspirate cytologic examination of the mass on the right forelimb revealed large numbers of inflammatory cells and fungal organisms. Histopathology of the skin biopsies from the right forefoot was consistent with phaeohyphomycosis. A course of antifungal medication was started (Fluconazole 21 mg/kg loading dose IV then 5 mg/kg PO SID q 30 days). Due to concern for the patient's quality of life and the lack of a curative treatment plan, humane euthanasia was elected. Gross and histological postmortem examination confirmed the presence of multiple coelomic masses similar in appearance to those observed in the left orbit and right forefoot indicating disseminated phaeohyphomycosis. A swab of the periocular mass was submitted for fungal culture and phenotypic identification. The isolate was later identified as Exophiala equina through a combination of phenotypic characterization and sequencing of the ITS region of the nuclear rDNA. Exophiala is a genus in the family Herpotrichiellaceae, order Chaetothyriales and is considered an opportunistic "black yeast" causing infection in aquatic invertebrates, fish, amphibians, reptiles, and mammals including humans. Exophiala equina is infrequently reported in animals, with only three cases in the literature including the herein report.

Refractory shock, hypercoagulability, and multiorgan thrombosis associated with hypertrophic osteodystrophy in a dog.

OBJECTIVE: To describe the clinical findings and case progression in a dog presenting with severe systemic inflammatory response, refractory shock, progressive metabolic acidosis, and respiratory failure that was ultimately diagnosed with hypertrophic osteodystrophy (HOD). CASE SUMMARY: A 4-month-old male intact Mastiff presented with a 24-hour history of lethargy and generalized ostealgia. On examination, the dog was recumbent, febrile, and tachycardic with pain on palpation of the abdomen, right femur, and mandible. Appendicular joint radiographs showed changes consistent with osteochondrosis and ulnar-retained cartilaginous cores, with no overt evidence of HOD. Initial treatment included IV fluid therapy, multimodal analgesia, and broad-spectrum antimicrobials. Vasopressor therapy was initiated following hemodynamic decompensation. Synovial fluid cytological analysis and culture revealed nonseptic suppurative inflammation and no bacterial growth, respectively. Blood and urine cultures also yielded no growth. Viscoelastic testing was consistent with hypercoagulability. The dog initially had a metabolic acidosis with appropriate respiratory compensation that progressed to a mixed metabolic and respiratory acidosis despite aggressive therapies that included antimicrobials, vasopressors, positive inotropes, and corticosteroids. Humane euthanasia was elected approximately 32 hours after admission. Necropsy yielded a diagnosis of HOD. NEW OR UNIQUE INFORMATION PROVIDED: This is the first report detailing the occurrence of refractory shock and hypercoagulability associated with HOD in a dog without evidence of another identified comorbidity. HOD should be considered in any young, large-breed dog with generalized ostealgia and signs of systemic illness, even in the absence of classic radiographic abnormalities. Further investigation of coagulation status in dogs with HOD and a secondary systemic inflammatory response is warranted.

Heterologous vaccine immunogenicity, efficacy, and immune correlates of protection of a modified-live virus porcine reproductive and respiratory syndrome virus vaccine.

Although porcine reproductive and respiratory syndrome virus (PRRSV) vaccines have been available in North America for almost 30 years, many vaccines face a significant hurdle: they must provide cross-protection against the highly diverse PRRSV strains. This cross-protection, or heterologous vaccine efficacy, relies greatly on the vaccine's ability to induce a strong immune response against various strains-heterologous immunogenicity. Thus, this study investigated vaccine efficacy and immunogenicity of a modified live virus (MLV) against four heterologous type 2 PRRSV (PRRSV-2) strains. In this study, 60 pigs were divided into 10 groups. Half were MOCK-vaccinated, and the other half vaccinated with the Prevacent® PRRS MLV vaccine. Four weeks after vaccination, groups were challenged with either MOCK, or four PRRSV-2 strains from three different lineages-NC174 or NADC30 (both lineage 1), VR2332 (lineage 5), or NADC20 (lineage 8). Pre-and post-challenge, lung pathology, viral loads in both nasal swabs and sera, anti-PRRSV IgA/G, neutralizing antibodies, and the PRRSV-2 strain-specific T-cell response were evaluated. At necropsy, the lung samples were collected to assess viral loads, macroscopical and histopathological findings, and IgA levels in bronchoalveolar lavage. Lung lesions were only induced by NC174, NADC20, and NADC30; within these, vaccination resulted in lower gross and microscopic lung lesion scores of the NADC20 and NADC30 strains. All pigs became viremic and vaccinated pigs had decreased viremia upon challenge with NADC20, NADC30, and VR2332. Regarding vaccine immunogenicity, vaccination induced a strong systemic IgG response and boosted the post-challenge serum IgG levels for all strains. Furthermore, vaccination increased the number of animals with neutralizing antibodies against three of the four challenge strains-NADC20, NADC30, and VR2332. The heterologous T-cell response was also improved by vaccination: Not only did vaccination increase the induction of heterologous effector/memory CD4 T cells, but it also improved the heterologous CD4 and CD8 proliferative and/or IFN-γ response against all strains. Importantly, correlation analyses revealed that the (non-PRRSV strain-specific) serum IgG levels and the PRRSV strain-specific CD4 T-cell response were the best immune correlates of protection. Overall, the Prevacent elicited various degrees of efficacy and immunogenicity against four heterologous and phylogenetically distant strains of PRRSV-2.

YERSINIA PSEUDOTUBERCULOSIS INFECTION IN LIONS (PANTHERA LEO) AT A ZOOLOGICAL PARK.

Two co-housed 17-yr-old male lions (Panthera leo) and one 15-yr-old female lion in an adjacent enclosure developed acute lethargy, depression, anorexia, and ataxia at a zoological park in central North Carolina, United States. One of the male lions and the female lion were found dead 5 and 4 d after the onset of clinical signs, respectively. The other male lion recovered without any clinical treatment. A third male lion housed with the female lion never developed clinical signs. Postmortem examination, microscopic evaluation, and bacterial culture of the liver from both deceased lions confirmed systemic Yersinia pseudotuberculosis infection. Susceptibility testing revealed resistance to amoxicillin-clavulanic acid and cefazolin. To investigate the extent of the outbreak, qualitative real-time polymerase chain reaction (PCR) for Y. pseudotuberculosis was performed on feces and substrate from 15 enclosures housing nondomestic felids and canids, resulting in a positive sample from one enclosure housing four asymptomatic lions. This enclosure was adjacent to housing of the deceased female lion. Enrofloxacin was administered to all animals in the vicinity at doses of 5 mg/kg in nondomestic felids and 10 mg/kg in nondomestic canids, orally q24h for 14 d. Repeated fecal PCR performed 1 wk after completing the antibiotic treatment protocol found no positive samples. The source of the infection was not identified despite PCR testing of environmental samples from all enclosures in the vicinity, the remains of a prey item fed out prior to the outbreak, and a single dead rodent found on grounds. No further clinical cases have occurred within the following year.

Case Report: Novel Disseminated Paecilomyces formosus Infection in a Dog.

A 2.5-year-old, 25.5 kg, spayed female Australian Shepherd dog had a 2-month history of shifting leg lameness in all limbs, tetraparesis, progressive lethargy, and severe pain. On the physical examination, fever (40.61°C), tachycardia, tachypnea, mild diffuse pelvic limb muscular atrophy, left prescapular and right popliteal lymphadenomegaly were observed. Due to the poor prognosis and difficult pain management, humane euthanasia was elected. Macroscopic and histological findings revealed multifocal to coalescing granulomas with central areas of lytic necrosis within the right femur, left humerus, left scapula, left biceps brachii, right semimembranosus muscle, liver, spleen, and lymph nodes. The necrotic areas contained myriad intralesional, intracellular, and extracellular negatively stained, non-pigmented, septate acute angle branching hyphae with parallel walls measuring 3-6 µm in width with polar bulbous projections measuring 7-13 µm in width. Fresh samples of the liver were submitted for fungal culture. Panfungal PCR targeting the major conserved genes-ITS, TUB, CAL-confirmed Paecilomyces formosus. Paecilomyces spp. are members of anamorphic fungi classified under the phylum Ascomycota. Paecilomycosis is an uncommon fungal infection caused by Paecilomyces spp with a disease reported in humans and animals ranging from superficial to systemic clinical forms affecting both immunocompromised and immunocompetent individuals. In dogs, disseminated paecilomycosis has been reported, but the species of fungi are not always determined. To our knowledge, this is the first case of disseminated paecilomycosis caused by P. formosus infection in a dog.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Physiological plasticity and acclimatory responses to salinity stress are ion-specific in the mayfly, Neocloeon triangulifer.

Freshwater salinization is a rapidly emerging ecological issue and is correlated with significant declines in aquatic biodiversity. It remains unclear how changing salinity regimes affect the physiology of sensitive aquatic insects. We used the parthenogenetic mayfly, Neocloeon triangulifer, to ask how ionic exposure history alters physiological processes and responses to subsequent major ion exposures. Using radiotracers (22Na, 35SO4, and 45Ca), we observed that mayflies chronically reared in elevated sodium or sulfate (157 mg L-1 Na or 667 mg L-1 SO4) had 2-fold (p < 0.0001) and 8-fold (p < 0.0001) lower ion uptake rates than mayflies reared in dilute control water (16 mg L-1 Na and 23 mg L-1 SO4) and subsequently transferred to elevated salinities, respectively. These acclimatory ion transport changes provided protection in 96-h toxicity bioassays for sodium, but not sulfate. Interestingly, calcium uptake was uniformly much lower and minimally influenced by exposure history, but was poorly tolerated in the toxicity bioassays. With qRT-PCR, we observed that the expression of many ion transporter genes in mayflies was influenced by elevated salinity in an ion-specific manner (general upregulation in response to sulfate, downregulation in response to calcium). Elevated sodium exposure had minimal influence on the same genes. Finally, we provide novel light microscopic evidence of histomorphological changes within the epithelium of the Malpighian tubules (insect primary excretory system) that undergoes cellular degeneration and necrosis secondary to calcium toxicity. We conclude that physiological plasticity to salinity stress is ion-specific and provide evidence for ion-specific toxicity mechanisms in N. triangulifer.

Case Report: Pulmonary Conidiobolomycosis in a Vietnamese Pot-Bellied Pig.

An adult castrated male Vietnamese pot-bellied pig had a 1-week history of acute dyspnea and lethargy. Minimal diagnostic testing was authorized by the owner, resulting in treatment with a third-generation cephalosporin and a non-steroidal anti-inflammatory drug. Partial improvement was observed after a week; however, the pig died 2 weeks after the initial onset of clinical signs. Macroscopically, ~90% of the left lung was effaced by large masses with a caseonecrotic center. Histologic examination revealed eosinophilic granulomas with myriad, intralesional, negatively staining hyphae highlighted by "sleeves" of hypereosinophilic material (Splendore-Hoeppli material). Infection with an oomycete or "zygomycete" (i.e., organisms of the order Entomophthorales or Mucorales) was initially considered. Pan-fungal PCR and sequencing performed on formalin-fixed, paraffin-embedded lung tissue identified Conidiobolus spp., consistent with a diagnosis of primary pulmonary conidiobolomycosis. There are only a few reports of infections with Conidiobolus spp. (and other members of the order Entomophthorales) in swine. Unlike humans and other animal species, conidiobolomycosis in pigs presents more commonly as a primary pulmonary disease rather than rhinofacial or nasopharyngeal disease.

Myxosarcoma Associated with the Kidney in a Cat: Case Report.

A 12 yr old spayed female domestic shorthair with a history of lethargy, anorexia, and a pendulous abdomen was referred after a cranial abdominal mass was palpated on physical examination. Thoracic radiographs and an abdominal ultrasound revealed a mass associated with the kidney and moderate hemoperitoneum. Exploratory laparotomy revealed abdominal hemorrhage originating from a right renal mass that was adhered to the caudal vena cava. Following a right nephrectomy, histopathology diagnosed the mass as a perirenal/renal myxosarcoma. Based upon thoracic radiographs and abdominal ultrasound, the patient remains disease free at 14 mo postoperatively.