West Nile virus and Usutu virus: a post-mortem monitoring study in wild birds from rescue centers, central Italy

West Nile virus (WNV) and Usutu virus (USUV) are mosquito-borne flaviviruses that have been associated with neurological diseases in humans and wild birds. Wild bird rescue centers are potential significant hot spots for avian infection surveillance, as recognized in the Italian Integrate National Surveillance Plan for Arboviruses. Here we report the results of a post-mortem active monitoring study conducted from November 2017 to October 2020 on animals hosted in five wild bird rescue centers of Central Italy. Five hundred seventy-six (n = 576) wild birds were tested by real-time polymerase chain reaction (RT-PCR) for the presence of WNV or USUV RNA fragments. No birds tested positive for USUV RNA (n = 0; 0.00%). Evidence of WNV RNA (Ct value = 34.36) was found in one bird (n = 1; 0.17%), an adult little grebe (Tachybaptus ruficollis subsp. ruficollis), that tested WNV positive in December 2019. This study highlights the strategic role of wildlife rescue centers in monitoring both the introduction and circulation of avian emerging zoonotic diseases. In addition, the presence of WNV during the cold season evidences the possible role of birds in overwintering mechanisms in the Italian territory and requires further investigation

Detection of Mycoplasma columbinasale in Cases of Respiratory Disease in Domestic Pigeons (Columba livia var. domestica)

In 2017, respiratory disease and low mortality were reported in domestic flying pigeons (Columba livia var. domestica) trained as hunting live bait in a breeding farm in Umbria, Italy. Clinically, open beak breathing, dropped wings, and pharyngeal and laryngeal hyperaemia were observed. Three birds were submitted for necropsy. Gross pathological evaluation revealed in all cases diffuses hyperaemia of the tracheal mucosa in association with mild emaciation and multiorgan congestion. Microscopically, diffuse epithelial hyperplasia of the trachea (n = 3) and diffuse lymphocytic infiltration of the lamina propria (n = 3) were observed. No lesions were reported in other organs. Based on reported clinical signs and lesions, Mycoplasma spp. were suspected, and molecular detection was performed on tracheal specimens leading to the identification of Mycoplasma columbinasale. Immunohistochemistry was subsequently performed to localize the microorganism within tissue lesions. Immunohistochemistry confirmed the presence of Mycoplasma species on the tracheal epithelial cells of all birds. Following tylosin administration, complete resolution of the clinical condition and lack of recurrence of clinical signs were reported in the breeding farm. These findings suggest that M. columbinasale could potentially have a role in the respiratory disease and low mortality in domestic pigeons

West Nile Virus and Usutu Virus: A Post-Mortem Monitoring Study in Wild Birds from Rescue Centers, Central Italy

West Nile virus (WNV) and Usutu virus (USUV) are mosquito-borne flaviviruses that have been associated with neurological diseases in humans and wild birds. Wild bird rescue centers are potential significant hot spots for avian infection surveillance, as recognized in the Italian Integrate National Surveillance Plan for Arboviruses. Here we report the results of a post-mortem active monitoring study conducted from November 2017 to October 2020 on animals hosted in five wild bird rescue centers of Central Italy. Five hundred seventy-six (n = 576) wild birds were tested by real-time polymerase chain reaction (RT-PCR) for the presence of WNV or USUV RNA fragments. No birds tested positive for USUV RNA (n = 0; 0.00%). Evidence of WNV RNA (Ct value = 34.36) was found in one bird (n = 1; 0.17%), an adult little grebe (Tachybaptus ruficollis subsp. ruficollis), that tested WNV positive in December 2019. This study highlights the strategic role of wildlife rescue centers in monitoring both the introduction and circulation of avian emerging zoonotic diseases. In addition, the presence of WNV during the cold season evidences the possible role of birds in overwintering mechanisms in the Italian territory and requires further investigations

LINEE GUIDA NAZIONALI PER LE AUTOPSIE A SCOPO FORENSE IN MEDICINA VETERINARIA

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The contribution of stem cells to epidermal and hair follicle tumours in the dog

Background -  Although cutaneous stem cells have been implicated in skin tumourigenesis in humans, no studies have been conducted to elucidate the presence and the possible role of stem cells in hair follicle tumours in the dog. Hypothesis -  Stem cell markers are expressed in canine epidermal and follicular tumours and can be used to better understand the biology and origin of these tumours. Animals and Methods -  In the present study, normal skin sections and 44 follicular tumours were retrospectively investigated for the immunohistochemical expression of keratin15 (K15) and nestin. In addition, 30 squamous cell carcinomas were evaluated for K15 expression. Results -  In normal skin, K15 and nestin were expressed in the outer root sheath cells of the isthmic portion of the hair follicle (bulge region), and K15 expression was also scattered in the basal cell layer of the epidermis. Infundibular keratinizing acanthomas, pilomatricomas and squamous cell carcinomas were mostly negative for K15, trichoblastomas were moderately to strongly positive, tricholemmomas were either negative or strongly positive, and trichoepitheliomas had heterogeneous staining. Nestin expression was generally faint in all follicular tumours. Conclusions and clinical importance -  Our results show that K15 can be a reliable marker for investigating the role of stem cells in hair follicle tumours of the dog, while nestin was judged to be a nonoptimal marker. Furthermore, our study suggests that hair follicle stem cells are present in the bulge region of hair follicles and could possibly play a role in tumourigenesis of canine tumours originating from this portion of the follicle, namely trichoblastomas, tricholemmomas and trichoepitheliomas. The loss of K15 expression in squamous cell carcinomas compared with normal skin suggests that this event could be important in the malignant transformation

The contribution of stem cells to epidermal and hair follicle tumours in the dog

Background -  Although cutaneous stem cells have been implicated in skin tumourigenesis in humans, no studies have been conducted to elucidate the presence and the possible role of stem cells in hair follicle tumours in the dog. Hypothesis -  Stem cell markers are expressed in canine epidermal and follicular tumours and can be used to better understand the biology and origin of these tumours. Animals and Methods -  In the present study, normal skin sections and 44 follicular tumours were retrospectively investigated for the immunohistochemical expression of keratin15 (K15) and nestin. In addition, 30 squamous cell carcinomas were evaluated for K15 expression. Results -  In normal skin, K15 and nestin were expressed in the outer root sheath cells of the isthmic portion of the hair follicle (bulge region), and K15 expression was also scattered in the basal cell layer of the epidermis. Infundibular keratinizing acanthomas, pilomatricomas and squamous cell carcinomas were mostly negative for K15, trichoblastomas were moderately to strongly positive, tricholemmomas were either negative or strongly positive, and trichoepitheliomas had heterogeneous staining. Nestin expression was generally faint in all follicular tumours. Conclusions and clinical importance -  Our results show that K15 can be a reliable marker for investigating the role of stem cells in hair follicle tumours of the dog, while nestin was judged to be a nonoptimal marker. Furthermore, our study suggests that hair follicle stem cells are present in the bulge region of hair follicles and could possibly play a role in tumourigenesis of canine tumours originating from this portion of the follicle, namely trichoblastomas, tricholemmomas and trichoepitheliomas. The loss of K15 expression in squamous cell carcinomas compared with normal skin suggests that this event could be important in the malignant transformation

A case of orbital extra-adrenal paraganglioma in a quarter horse

Paragangliomas are tumors originating from paraganglia cells which represent a considerable constituent of the dispersed neuroendocrine system. Rarely these tumors are found within the orbital region. This report documents a case of primary extra-adrenal paraganglioma in a 15-year-old female quarter horse, diagnosed on the basis of clinical signs, gross anatomopathological, histopathological and immunohistochemical investigations. Clinical diagnostics led to full appreciation of the severe tumor invasiveness and to an informed decision by the owner for euthanasia. Gross inspection confirmed the previous clinical assessments of exophthalmos consequential to pressure from the orbital neoplasia, revealing a mass infiltrating into surrounding tissues. Histopathology and immunohistochemistry allowed for the final diagnosis of paraganglioma. Histology sections showed a partially encapsulated infiltrative mass with multifocal angiotropic growth, and composed of polygonal cells organized in nests, packets, and bundles supported by a fibrovascular stroma. The lobules were lined peripherally by spindle cells. The tumor was highly vascular with blood-filled lacunae and multifocal to coalescing areas of liquefactive necrosis. The polygonal cells were characterized by indistinct borders, lightly eosinophilic cytoplasm with moderate amount of granules, round or oval central nuclei with stippled chromatin (“salt and pepper” appearance) and inconspicuous nucleoli. Immunohistochemistry aided in the diagnostic discrimination of paraganglioma from neuroendocrine carcinoma and in the assessment of tumor differentiation. Orbital paraganglioma holds low likelihood for animal survival, but may have good prognosis when timely addressed

Mural Endocarditis and Embolic Pneumonia Due to <i>Trueperella pyogenes</i> in an Adult Cow with Ventricular Septal Defect

Bacterial endocarditis represents one of the most frequently acquired cardiac diseases in adult cattle. Congenital heart diseases as a ventricular septal defect can facilitate bacterial endocarditis as a consequence of turbulent blood flow through the defect, causing damage to the endocardium. We describe a case of mural endocarditis associated with a ventricular septal defect in an eight-year-old female Holstein Friesian cow. The cow’s history revealed that she had presented dysorexia and a sudden decrease of milk production in the last 10 days prior to the examination. On clinical examination, jugular pulses, tachycardia with irregular heart rate and tachypnea with harsh bronchovesicular sounds were evident. Electrocardiographic examination allowed the diagnosis of an atrial fibrillation with high ventricular response rate. Transthoracic echocardiography revealed a large vegetation originating from the endocardium between the tricuspid and pulmonic valves in the right ventricle outflow. On post-mortem examination, a small muscular septal defect under the right coronary cusp of the aortic valve and a mural vegetative endocarditis were found. An abscess in the chondro-costal junction of the third right rib and metastatic pneumonia were also observed. This case report describes a rare consequence of a small ventricular septal defect that had not been previously diagnosed in an adult cow