Thoracic Tumor Associated with a Unilateral Empyema in a Beef Cow: A Case Report.

Tumors in cows are not frequently reported in the literature. They often represent unusual findings in live animals and are incidental at slaughter with rare positive therapeutic outcomes for farmers. A 9-year-old beef cow was referred to the hospital of ruminants of the National Veterinary School of Toulouse, France. The cow started to become sick 10 days prior, and major symptoms were anorexia, arched back, tachycardia, and tachypnea associated with significantly attenuated cardiac and pulmonary sounds upon right-sided auscultation. After specific investigations, a thoracic sarcoma associated with unilateral empyema was diagnosed. The empyema was treated, and supportive treatment was only performed for the tumor. Although the sarcoma remained, clinical improvement was significant, and the cow went back to her farm of origin. After the end of the withdrawal period, the cow recovered clinically but was culled by the owners for economic reasons. The present case report offers a continuum from the initial clinical signs motivating specific investigations to interesting laboratory findings, which were confirmed post-mortem.

Concurrent Mycobacterium genavense infection and intestinal B-cell lymphoma in a pet rabbit (Oryctolaguscuniculus).

A 6-year-old male intact pet rabbit was evaluated for chronic weight loss. A large mass was detected by palpation in the mid-abdomen and ultrasound examination suggested a jejunal location. Explorative laparotomy revealed a nodular mass within the jejunal wall. Histological examination of a biopsy revealed mycobacterial granulomatous enteritis with an atypical lymphoblastic proliferation suggestive of lymphoma. Neoplastic lymphocytes were immunopositive for Pax-5 but negative for CD3, which is diagnostic of a B-cell neoplasm. Numerous acid-fast bacteria were seen within histiocytes and identified by polymerase chain reaction as Mycobacterium genavense, which is a non-tuberculous and opportunistic mycobacterium with zoonotic potential. To the best of our knowledge, this is the first documented case of a concurrent B-cell lymphoma and M. genavense infection in a rabbit. Concomitant mycobacteriosis and lymphoma have been rarely described in animals and the coexistence of neoplasia and mycobacterial infection within the jejunum suggests a potential pathogenetic association. Interestingly, the rabbit owner worked in an anti-tuberculosis clinic, and an anthropic origin of the mycobacterial infection could not be excluded.

Multifocal cutaneous phaeohyphomycosis caused by Exophiala spinifera with clinical resolution in an immunocompromised cat.

Case summary: A 3-year-old neutered domestic shorthair cat with a long history of idiopathic immune-mediated haemolytic anaemia and thrombocytopenia treated with ciclosporin and prednisolone was referred 2 months after the appearance of nodular dermatitis. A single pigmented nodule was present in the lateral carpal region of the right foreleg. The lesion was 7 mm in diameter, non-exudative and cutaneous to subcutaneous. Fine-needle aspiration of the mass revealed the presence of pigmented fungal elements. Excisional surgery was planned; in the meantime, a plaque-like lesion developed in the interorbital region. Histopathological examination confirmed the presumptive diagnosis of phaeohyphomycosis, and Exophiala spinifera was identified as the aetiological agent. Itraconazole, given orally at a dose of 10 mg/kg for 8 weeks following surgery, enabled clinical resolution despite continued use of immunosuppressants. The follow-up was carried out over 14 weeks. Relevance and novel information: This case report provides the first evidence of multifocal cutaneous phaeohyphomycosis caused by E spinifera with clinical resolution after combined surgical and itraconazole treatment in an immunocompromised cat.

Cutaneous epitheliotropic T-cell lymphoma in a donkey - a case report.

BACKGROUND: Cutaneous epitheliotropic T-cell lymphoma is a malignant tumour of the skin already reported in humans, dogs, cats, horses, and other species, but not previously in donkeys. The standard diagnosis is based on clinical, morphological and immunophenotypic data. Differentiation of malignant versus benign proliferation of lymphocytes is crucial; in ambiguous cases T-cell receptor gamma (TRG) molecular clonality should be tested. In the present paper, we report a case of mycosis fungoides diagnosed in a donkey whose diagnosis was based on clinical, histological and immunohistochemical aspects and a positive TRG clonality test. CASE PRESENTATION: A twenty-five-year-old donkey gelding was referred with a mildly pruritic, generalised and severe exfoliative dermatosis. Otherwise, the animal was clinically healthy, though mildly underweight. Dermatological examination revealed severe generalised alopecic and exfoliative dermatitis, occasionally eroded, with high number of large, thin, greyish scales. All mucocutaneous junctions except the hoofs were affected. Ectoparasites and dermatophytes were ruled out. The complete blood count and blood smear evaluation revealed mild normocytic normochromic anemia. The biochemistry panel showed mild hyperproteinemia with albumin within the normal range. Protein electrophoresis showed moderate polyclonal hypergammaglobulinemia. Histological findings were characterised by interface dermatitis with massive exocytosis in the epidermis of a homogenous population of lymphoid cells showing atypia. Clusters of neoplastic cells were present within the epidermis forming Pautrier "microabscesses". These findings are consistent with cutaneous epitheliotropic lymphoma. Immunohistochemical staining revealed uniform labelling of the neoplastic cells for CD3, and lack of expression of CD20 (a B cell lineage associated marker). Molecular clonality PCR (PARR) was performed using equine TRG primers; this revealed a clonal rearrangement in a heavy polyclonal background. Transmission electronic microscopy showed multiple lymphocytes with convoluted or cerebriform nuclei. CONCLUSIONS: This case report provides the first evidence of clinical, histopathological, immunophenotypic features, electron microscopy findings and molecular analysis of a cutaneous epitheliotropic T-cell lymphoma (mycosis fungoides) in a donkey. Our observations suggest that cutaneous T-cell lymphoma should be included in the differential diagnoses of exfoliative dermatitis, even those progressing in a chronic pattern and/or with few or no pruritus.

Multiple follicular abnormalities in a 1-year old cat consistent with basaloid follicular hamartomas.

BACKGROUND: In humans, basaloid follicular hamartomas are benign follicular tumours, that can be solitary or multiple, in which case they show autosomal dominant inheritance. HYPOTHESIS/OBJECTIVES: This study describes clinical and histopathological findings observed in a young cat, which could be consistent with basaloid follicular hamartomas. CASE DESCRIPTION: Multiple follicular abnormalities, consistent with cutaneous diffuse basaloid follicular hamartomas, were observed in skin samples from a one-year old neutered domestic short hair cat. Clinical signs were diffuse symmetrical alopecia with exaggerated skin markings (ventral abdomen, thorax and medial aspects of the limbs) and intense follicular-centred thickening (face and feet). Microscopic lesions were characterised by multiple proliferative follicular abnormalities in all samples. The epidermis showed a very irregular surface with the follicles filled with variably pigmented keratin. The epithelial walls of the follicles had multiple small hyperplastic basaloid cells foci. In the superficial dermis under the epidermis and around the follicles, fibroblastic spindle-shaped mesenchymal cells with a homogeneous moderate density were present in the collagenous connective tissue. The interfollicular epidermis was also abnormal with multiple small proliferating trichoblastic foci originating from the basal layer. RNAscope testing for feline papillomavirus was negative. CONCLUSIONS AND CLINICAL RELEVANCE: This case report provides the first evidence of clinical and histopathological findings of multiple follicular abnormalities, consistent with cutaneous diffuse basaloid follicular hamartomas in a cat.

De multiples anomalies folliculaires, compatibles avec des hamartomes folliculaires basaloïdes diffus cutanés, ont été observées dans des échantillons de peau d'un chat domestique à poils courts castré âgé d'un an. Les signes cliniques étaient une alopécie diffuse symétrique avec des marques cutanées exagérées (abdomen ventral, thorax et face médiale des membres) et un épaississement folliculaire intense (face et pieds).

Múltiplas anormalidades foliculares, consistentes com hamartomas cutâneos foliculares basaloides difusos, foram observadas em amostras de pele de um gato doméstico de pelo curto castrado de um ano de idade. Os sinais clínicos foram alopecia simétrica difusa com marcações cutâneas exuberantes (abdômen, tórax e aspecto medial dos membros) e espessamento folicular central intenso (face e patas).

Se observaron múltiples anomalías foliculares, consistentes con hamartomas foliculares basaloides difusos cutáneos, en muestras de piel de un gato doméstico de pelo corto castrado de 1 año. Los signos clínicos fueron alopecia simétrica difusa con marcas cutáneas exageradas (abdomen ventral, tórax y cara medial de las extremidades) e intenso engrosamiento de la piel centrado en los folículos (cara y pies).

Opposite Outcomes of the Within-Host Competition between High- and Low-Pathogenic H5N8 Avian Influenza Viruses in Chickens Compared to Ducks.

Highly pathogenic avian influenza viruses (HPAIV) emerge from low-pathogenic avian influenza viruses (LPAIV) through the introduction of basic amino acids at the hemagglutinin (HA) cleavage site. Following viral evolution, the newly formed HPAIV likely represents a minority variant within the index host, predominantly infected with the LPAIV precursor. Using reverse genetics-engineered H5N8 viruses differing solely at the HA cleavage, we tested the hypothesis that the interaction between the minority HPAIV and the majority LPAIV could modulate the risk of HPAIV emergence and that the nature of the interaction could depend on the host species. In chickens, we observed that the H5N8LP increased H5N8HP replication and pathogenesis. In contrast, the H5N8LP antagonized H5N8HP replication and pathogenesis in ducks. Ducks mounted a more potent antiviral innate immune response than chickens against the H5N8LP, which correlated with H5N8HP inhibition. These data provide experimental evidence that HPAIV may be more likely to emerge in chickens than in ducks and underscore the importance of within-host viral variant interactions in viral evolution. IMPORTANCE Highly pathogenic avian influenza viruses represent a threat to poultry production systems and to human health because of their impact on food security and because of their zoonotic potential. It is therefore crucial to better understand how these viruses emerge. Using a within-host competition model between high- and low-pathogenic avian influenza viruses, we provide evidence that highly pathogenic avian influenza viruses could be more likely to emerge in chickens than in ducks. These results have important implications for highly pathogenic avian influenza virus emergence prevention, and they underscore the importance of within-host viral variant interactions in virus evolution.

Detection and Typing of a Fowl Adenovirus Type 1 Agent of Pancreatitis in Guinea Fowl.

Adenoviral pancreatitis has been amply described for decades in guinea fowl. Although its pathologic picture has been characterized fairly well, its etiology still remains only partially clarified. Based on several outbreaks diagnosed on commercial guinea flocks raised in France since 2017, we performed direct whole-genome sequencing from pancreatic lesional tissue by using the Oxford Nanopore Technologies (ONT) sequencing method. We generated 4781 viral reads and assembled a whole genome of 43,509 bp, clustering within fowl adenovirus type 1 (FAdV-1). A phylogenetic analysis based on a partial sequence of the hexon and short fiber genes on viruses collected in France showed 98.7% and 99.8% nucleotide identity, respectively. Altogether, these results confirm that an FAdV-1 closely related to chicken and other avian strains is the agent of pancreatitis in guinea fowl. This study illustrates the potential of ONT sequencing method to achieve rapid whole-genome sequencing directly from pathologic material.

Detección y tipificación de un adenovirus aviar tipo 1 (FAdV-1), agente de pancreatitis en gallinas de Guinea. La pancreatitis adenoviral se ha descrito ampliamente durante décadas en gallinas de Guinea. Aunque su cuadro patológico se ha caracterizado bastante bien, su etiología todavía permanece sólo parcialmente aclarada. Sobre la base de varios brotes diagnosticados en parvadas comerciales de guineas criadas en Francia desde el año 2017, se realizó una secuenciación directa del genoma completo a partir del tejido de la lesión pancreática mediante el método de secuenciación desarrollado por Oxford Nanopore Technologies. Se generaron 4781 lecturas virales y se ensambló un genoma completo de 43,509 pb, que se agrupó dentro del adenovirus aviar tipo 1 (FAdV-1). Un análisis filogenético basado en una secuencia parcial de los genes hexón y de fibra corta de virus recolectados en Francia mostró identidades de nucleótidos de 98.7% y 99.8%, respectivamente. En conjunto, estos resultados confirman que un adenovirus aviar tipo 1 estrechamente relacionado con el pollo y otras cepas aviares es el agente de la pancreatitis en la gallina de Guinea. Este estudio ilustra el potencial de las tecnologías desarrolladas por Oxford Nanopore Thechnologies para lograr una secuenciación rápida de todo el genoma directamente a partir de material patológico.

Viral tropism and detection of clade 2.3.4.4b H5N8 highly pathogenic avian influenza viruses in feathers of ducks and geese.

Highly Pathogenic Avian Influenza viruses (HPAIVs) display a tissue pantropism, which implies a possible spread in feathers. HPAIV detection from feathers had been evaluated for H5N1 or H7N1 HPAIVs. It was suggested that viral RNA loads could be equivalent or higher in samples of immature feather compared to tracheal (TS) or cloacal swabs (CS). We investigated the suitability of feathers for the detection of clade 2.3.4.4b H5N8 HPAIV in ducks and geese field samples. In the six H5N8 positive flocks that were included in this study, TS, CS and immature wing feathers were taken from at least 10 birds. Molecular loads were then estimated using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) targetting H5 and M genes. In all flocks, viral loads were at least equivalent between feather and swab samples and in most cases up to 103 higher in feathers. Bayesian modelling confirmed that, in infected poultry, RT-qPCR was much more likely to be positive when applied on a feather sample only (estimated sensitivity between 0.89 and 0.96 depending on the positivity threshold) than on a combination of a tracheal and a cloacal swab (estimated sensitivity between 0.45 and 0.68 depending on the positivity threshold). Viral tropism and lesions in feathers were evaluated by histopathology and immunohistochemistry. Epithelial necrosis of immature feathers and follicles was observed concurrently with positive viral antigen detection and leukocytic infiltration of pulp. Accurate detection of clade 2.3.4.4b HPAIVs in feather samples were finally confirmed with experimental H5N8 infection on 10-week-old mule ducks, as viral loads at 3, 5 and 7 days post-infection were higher in feathers than in tracheal or cloacal swabs. However, feather samples were associated with lower viral loads than tracheal swabs at day 1, suggesting better detectability of the virus in feathers in the later course of infection. These results, based on both field cases and experimental infections, suggest that feather samples should be included in the toolbox of samples for detection of clade 2.3.4.4b HPAI viruses, at least in ducks and geese.

Multinodular Malignant Cutaneous Mast Cell Tumor in a Horse With Generalized Pruritus and Reactive Fibrosis: A Case Report.

Mast cell tumor (MCT) has long been considered as an uncommon neoplasm in horses. Cytological and behavioral evidence of its malignancy is usually lacking, and only a few reports have described MCT displaying malignant behavior. An 18-year-old Friesian stallion presented with a one-year history of intermittent and progressive skin lesions on the left forelimb associated with intense, generalized pruritus and apathy temporarily responsive to glucocorticoids and antibiotics. The horse was alert and responsive with poor body condition and marked generalized pruritus. The left forelimb was markedly enlarged and surrounded by numerous firm 2- to 20-cm masses that were ulcerated and focally necrotic. A 7-cm round firm mass was observed on the left dorsal neck. Dermatological examination revealed generalized moth-eaten alopecia and scaling with erosions and ulcers secondary to pruritus. A direct skin smear from the affected leg showed severe eosinophilic inflammation and neutrophilic inflammation with pleomorphic bacteria. Histopathology of the skin and biopsies of the underlying tissues revealed an abundant population of atypical mast cells consistent with a malignant MCT. The horse was euthanized and necropsy revealed a marked fibrous reaction on longitudinal sections of the affected limb, and the tumor could be detected on only a few histological slides. Diagnosis of equine MCT can be challenging because of the massive accompanying fibrous reaction. Mast cell tumor should be suspected in the presence of eosinophilic infiltration of the affected tissue and in cases of generalized pruritus not attributable to other causes.

Clinical and histological recovery of non-thymoma-associated exfoliative dermatitis in a cat treated with ciclosporin A.

CASE SUMMARY: A 6-year-old neutered female European Shorthair cat was referred for chronic, moderately pruritic, alopecic and exfoliative dermatosis that was unresponsive to antiparasitic, antibiotic or steroidal anti-inflammatory drugs. The cat presented with truncular alopecia and numerous whitish adherent scales covering the whole body. Differential diagnoses included sebaceous adenitis, dermatophytosis, demodicosis, exfoliative dermatitis associated or not with thymoma, drug reaction, feline immunodeficiency virus- or feline leukaemia virus-associated dermatoses, epitheliotropic T-cell lymphoma, and Malassezia yeasts and/or bacterial overgrowth. Blood tests were within normal limits and the retrovirus tests were negative. Skin scrapings, fungal culture, coat brushing and skin cytology were negative for parasitic or microbial elements. Radiographs showed no signs of a thymic mass. Histological examination of skin biopsies revealed marked orthokeratotic hyperkeratosis, lymphocytic (CD3+) interface dermatitis and mural folliculitis with absence of sebaceous glands and occasional apoptotic cells in different epidermal layers. Clinical and histological findings were consistent with non-thymoma-associated exfoliative dermatitis syndrome. Ciclosporin A (7 mg/kg) was administered once daily. A dramatic improvement was observed after 3 weeks. Ciclosporin A intake was then progressively spaced out as the clinical signs diminished. Skin biopsies revealed resolution of hyperkeratosis, disappearance of the inflammatory infiltrate and recovery of the sebaceous glands. RELEVANCE AND NOVEL INFORMATION: T-cell infiltration with signs of epidermal cytotoxicity, in the absence of infectious agents or neoplastic process, suggests an immune-mediated process, and ciclosporin A, a calcineurin inhibitor, would be the drug of choice. This is the first report showing resolution of both the clinical and histological signs of non-thymoma-associated exfoliative dermatitis.

The Microbiota Contributes to the Control of Highly Pathogenic H5N9 Influenza Virus Replication in Ducks.

Ducks usually show little or no clinical signs following highly pathogenic avian influenza virus infection. In order to analyze whether the microbiota could contribute to the control of influenza virus replication in ducks, we used a broad-spectrum oral antibiotic treatment to deplete the microbiota before infection with a highly pathogenic H5N9 avian influenza virus. Antibiotic-treated ducks and nontreated control ducks did not show any clinical signs following H5N9 virus infection. We did not detect any significant difference in virus titers neither in the respiratory tract nor in the brain nor spleen. However, we found that antibiotic-treated H5N9 virus-infected ducks had significantly increased intestinal virus excretion at days 3 and 5 postinfection. This was associated with a significantly decreased antiviral immune response in the intestine of antibiotic-treated ducks. Our findings highlight the importance of an intact microbiota for an efficient control of avian influenza virus replication in ducks.IMPORTANCE Ducks are frequently infected with avian influenza viruses belonging to multiple subtypes. They represent an important reservoir species of avian influenza viruses, which can occasionally be transmitted to other bird species or mammals, including humans. Ducks thus have a central role in the epidemiology of influenza virus infection. Importantly, ducks usually show little or no clinical signs even following infection with a highly pathogenic avian influenza virus. We provide evidence that the microbiota contributes to the control of influenza virus replication in ducks by modulating the antiviral immune response. Ducks are able to control influenza virus replication more efficiently when they have an intact intestinal microbiota. Therefore, maintaining a healthy microbiota by limiting perturbations to its composition should contribute to the prevention of avian influenza virus spread from the duck reservoir.

Calcium electroporation: The bioelectrochemical treatment of spontaneous equine skin tumors results in a local necrosis.

Electrochemotherapy (ECT) is an anticancer bioelectrochemical therapy where electrical field pulses (electropermeabilization) increase intracellular concentration of antitumor drugs. The procedure is very effective against skin tumors. The restrictive regulations concerning anticancer drugs in veterinary medicine limit use of ECT. Electroporation with calcium (Electroporation Calcium Therapy)(ECaT) was proved to be effective in vivo on induced tumors in laboratory animals. This study evaluated the effects of ECaT in equine sarcoids (spontaneous skin tumors) on an animal cohort. Pulse parameters for ECaT were choosen for using skin contact electrodes. ECaT was applied under general anesthesia. The tumors were removed at different days after the treatment and analyzed by histology. The study assessed the volume fraction of necrosis that was >50% for 9 of 13 sarcoids. Sixteen sarcoids in 10 horses were treated with ECaT. Macroscopic changes (a crust) were observed in 14/16 tumors. The main microscopic changes were necrosis, ulceration,hemorrhages, calcifications and thrombosis. The adverse effect was an inflammatory local reaction. Surrounding tissues were not affected. This targeted effect can be explained by its control by the field distribution in the tissue and on the interstitial diffusion of the injected Ca2+.

Pathogenesis, Host Innate Immune Response, and Aerosol Transmission of Influenza D Virus in Cattle.

The recently discovered influenza D virus (IDV) of the Orthomyxoviridae family has been detected in swine and ruminants with a worldwide distribution. Cattle are considered to be the primary host and reservoir, and previous studies suggested a tropism of IDV for the upper respiratory tract and a putative role in the bovine respiratory disease complex. This study aimed to characterize the pathogenicity of IDV in naive calves as well as the ability of this virus to transmit by air. Eight naive calves were infected by aerosol with a recent French isolate, D/bovine/France/5920/2014. Results show that IDV replicates not only in the upper respiratory tract but also in the lower respiratory tract (LRT), inducing moderate bronchopneumonia with restricted lesions of interstitial pneumonia. Inoculation was followed by IDV-specific IgG1 production as early as 10 days postchallenge and likely both Th1 and Th2 responses. Study of the innate immune response in the LRT of IDV-infected calves indicated the overexpression of pathogen recognition receptors and of chemokines CCL2, CCL3, and CCL4, but without overexpression of genes involved in the type I interferon pathway. Finally, virological examination of three aerosol-sentinel animals, housed 3 m apart from inoculated calves (and thus subject to infection by aerosol transmission), and IDV detection in air samples collected in different areas showed that IDV can be airborne transmitted and infect naive contact calves on short distances. This study suggests that IDV is a respiratory virus with moderate pathogenicity and probably a high level of transmission. It consequently can be considered predisposing to or a cofactor of respiratory disease.IMPORTANCE Influenza D virus (IDV), a new genus of the Orthomyxoviridae family, has a broad geographical distribution and can infect several animal species. Cattle are so far considered the primary host for IDV, but the pathogenicity and the prevalence of this virus are still unclear. We demonstrated that under experimental conditions (in a controlled environment and in the absence of coinfecting pathogens), IDV is able to cause mild to moderate disease and targets both the upper and lower respiratory tracts. The virus can transmit by direct as well as aerosol contacts. While this study evidenced overexpression of pathogen recognition receptors and chemokines in the lower respiratory tract, IDV-specific IgG1 production as early as 10 days postchallenge, and likely both Th1 and Th2 responses, further studies are warranted to better understand the immune responses triggered by IDV and its role as part of the bovine respiratory disease complex.

Feline low-grade alimentary lymphoma: an emerging entity and a potential animal model for human disease.

BACKGROUND: Low-grade alimentary lymphoma (LGAL) is characterised by the infiltration of neoplastic T-lymphocytes, typically in the small intestine. The incidence of LGAL has increased over the last ten years and it is now the most frequent digestive neoplasia in cats and comprises 60 to 75% of gastrointestinal lymphoma cases. Given that LGAL shares common clinical, paraclinical and ultrasonographic features with inflammatory bowel diseases, establishing a diagnosis is challenging. A review was designed to summarise current knowledge of the pathogenesis, diagnosis, prognosis and treatment of feline LGAL. Electronic searches of PubMed and Science Direct were carried out without date or language restrictions. RESULTS: A total of 176 peer-reviewed documents were identified and most of which were published in the last twenty years. 130 studies were found from the veterinary literature and 46 from the human medicine literature. Heterogeneity of study designs and outcome measures made meta-analysis inappropriate. The pathophysiology of feline LGAL still needs to be elucidated, not least the putative roles of infectious agents, environmental factors as well as genetic events. The most common therapeutic strategy is combination treatment with prednisolone and chlorambucil, and prolonged remission can often be achieved. Developments in immunohistochemical analysis and clonality testing have improved the confidence of clinicians in obtaining a correct diagnosis between LGAL and IBD. The condition shares similarities with some diseases in humans, especially human indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. CONCLUSIONS: The pathophysiology of feline LGAL still needs to be elucidated and prospective studies as well as standardisation of therapeutic strategies are needed. A combination of conventional histopathology and immunohistochemistry remains the current gold-standard test, but clinicians should be cautious about reclassifying cats previously diagnosed with IBD to lymphoma on the basis of clonality testing. Importantly, feline LGAL could be considered to be a potential animal model for indolent digestive T-cell lymphoproliferative disorder, a rare condition in human medicine.

Plasma-Mediated Bipolar Radiofrequency Ablation of Overlong Soft Palate in the Dog: A Pilot Study.

The objective of this study was to compare the clinical, biological, macroscopic, and histologic outcomes after resection of the soft palate by plasma-mediated bipolar radiofrequency ablation (PBRA) or traditional incisional techniques (incisional soft palate resection [INC]) in dogs. Ten dogs were divided in two groups. In the INC group, the soft palate was incised with scissors and the wound was sutured in a continuous pattern. In the PBRA group, a wand was used to ablate the desired portion of the soft palate, without suture. Clinical, biological, macroscopic, and histologic assessments were scheduled over 14 days. The duration of surgery was significantly shorter for the PBRA group. The C-reactive protein concentrations were significantly higher in the PBRA group at 6 hr and on day 3 (P < .05) but with values very close to the baseline. C-reactive protein concentrations were maximal, but with low values (<25 mg/L), at day 1 for both techniques. The irregularity scores for the soft palate caudal border on days 1, 3, and 14 were significantly higher in the INC group than in the PBRA group (P < .05). The main histopathologic changes were the presence of superficial granulomas and a significantly greater depth of tissue damage in the INC group (2.5 ± 0.3 mm) compared with the PBRA group (1.5 ± 0.1 mm; P < .05). PBRA compared favorably with the traditional technique in terms of ease, duration of surgery, and depth of tissue damage. Future studies are warranted to validate its effectiveness for treating brachycephalic airway obstruction syndrome in dogs.

Presence of neural progenitors in spontaneous canine gliomas: A histopathological and immunohistochemical study of 20 cases.

Gliomas are the most common primary brain tumours in humans and are associated with a poor prognosis. An accurate animal model of human glioma tumorigenesis is needed to test new treatment strategies. Dogs represent a promising model because they develop spontaneous diffusely-infiltrating gliomas. This study investigated whether spontaneous canine gliomas contain cancer stem cells previously identified in all grades of human gliomas. Twenty spontaneous cases of canine gliomas were graded according to the human WHO classification. The expression of different markers of lineage differentiation was evaluated with immunohistochemistry as follows: nestin and CD133 for neural stem cells, doublecortin for neuronal progenitor cells, Olig2 for glial progenitor cells, glial fibrillary acidic protein, vimentin and S-100 for mature glial cells, and NeuN and ßIII-tubulin for mature neurons. Gliomas were characterised as follows: five grade II (oligodendrogliomas); nine grade III (seven anaplastic oligodendrogliomas, one anaplastic astrocytoma, one anaplastic oligoastrocytoma); six grade IV (glioblastomas). Immunohistochemical evaluation revealed that (1) nestin and CD133 were expressed in all grades of gliomas with a higher proportion of positive cells in high-grade gliomas; (2) the expression of S-100 protein and Olig2 did not differ substantially between astrocytic and oligodendroglial tumours, and (3) all gliomas were negative for mature neuron markers. The results demonstrated the presence of undifferentiated neural progenitors in all grades of spontaneous canine gliomas, confirming the relevance of this animal model for further studies on cancer stem cells.

A mycobacterial coinfection in a dog suspected on blood smear.

A 4-year-old neutered female crossbred Shepherd was referred for a history of 10 days of anorexia, polyuria, polydipsia, polyadenomegaly, and diarrhea. On physical examination, the dog appeared quiet, responsive, and apyretic, with generalized and severe lymphadenomegaly. Hematologic abnormalities included neutrophilic leukocytosis with left shift, and lymphopenia. Blood smears revealed intracytoplasmic bacilli negatively stained with May-Grünwald-Giemsa in neutrophils and monocytes. Lymph node smears revealed pyogranulomatous adenitis with calcified deposits and many negative-staining rod structures, both within the cytoplasm of neutrophils and macrophages, and free in the background. An acid-fast stain (Ziehl-Neelsen) confirmed the diagnosis of mycobacterial infection. The dog was euthanized for public health and ethical reasons, and the postmortem examination revealed severe and generalized granulomatous and necrotizing lymphadenitis, panniculitis, and hepatitis, and infiltration of epithelioid macrophages in the lungs, colon, and spleen. Numerous acid-fast bacilli, consistent with mycobacterial infection, were observed both in the cytoplasm of epithelioid macrophages and giant cells, and free in the background. Mycobacterium bovis was first confirmed by conventional PCR of organ extracts. Mycobacterium avium was detected in a culture of the same organs. Further PCR amplifications and sequencing revealed a coinfection with 2 different species of mycobacterium, one belonging to the Mycobacterium avium complex and the other to the Mycobacterium tuberculosis complex.

49-month survival following caval venectomy without nephrectomy in a dog with a pheochromocytoma.

An 11 yr old spayed female Labrador retriever was diagnosed with a right adrenal tumor. At surgery, adhesions to the right kidney were dissected, allowing the right kidney to be preserved. The tumor showed extensive invasion into the suprarenal vena cava. It was felt that thrombus removal via venotomy could not be performed. Instead, the vena cava was ligated caudal to the liver and cranial to the right renal vein. The neoplastic gland was then excised en bloc together with the portion of the invaded caudal vena cava. Hind limb edema had developed preoperatively and increased transiently in the first days postoperatively. The animal was discharged 6 days postoperatively with no other clinical disorders, and hind limb edema resolved over time. Histopathology identified a pheochromocytoma. The dog died 49 mo later. A neoplastic thrombus of the vena cava may require venotomy to allow thrombus removal. Occasionally, removal of the thrombus by venotomy may prove impossible. In such a situation, en bloc removal of the concerned portion of the vena cava may be performed with a good long-term outcome provided that gradual occlusion of the vena cava by the thrombus has allowed time for collateral circulation to develop.