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Abstract COVID-19 is a zoonotic disease caused by SARS-CoV-2. Infections of animals with SARS-CoV-2 have recently been reported, and an increase of severe lung pathologies in domestic dogs has also been detected by veterinarians in Spain. Therefore, further descriptions of the pathological processes in those animals that show symptoms similar to those described in humans affected by COVID-19 would be highly valuable. The potential for companion animals to contribute to the continued transmission and community spread of this known human-to-human disease is an urgent issue to be considered. Forty animals with pulmonary pathologies were studied by chest X-ray, ultrasound analysis, and computed tomography. Nasopharyngeal and rectal swabs were analyzed to detect canine pathogens, including SARS-CoV-2. An additional twenty healthy dogs living in SARS-CoV-2-positive households were included. Immunoglobulin detection by several immunoassays was performed. Our findings show that sick dogs presented severe alveolar or interstitial patterns with pulmonary opacity, parenchymal abnormalities, and bilateral lesions. The forty sick dogs were negative for SARS-CoV-2 but Mycoplasma spp. was detected in 26 of 33 dogs. Five healthy and one pathological dog presented IgG against SARS-CoV-2. Here we report that despite detecting dogs with α-SARS-CoV-2 IgG, we never obtained a positive RT-qPCR for SARS-SoV-2, not even in dogs with severe pulmonary disease; suggesting that even in the case of canine infection, transmission would be unlikely. Moreover, dogs living in COVID-19-positive households could have been more highly exposed to infection with SARS-CoV-2.

Fine needle biopsy (FNB) is an effective, minimally invasive and inexpensive diagnostic technique. Under computed tomography (CT)-guidance, lesions that have a difficult approach can be sampled to reach a diagnosis. The aim of this study is to describe the use of CT-guidance to obtain FNB from vertebral and paravertebral lesions in small animals. Ten dogs and one ferret that had undergone CT-guided FNB of vertebral and paravertebral lesions and had a cytological or a histological diagnosis were included in this retrospective study. The FNB samples were taken in four cases from the vertebra, in two cases from the intervertebral disc and in five cases from the intervertebral foramen. Two infectious and nine neoplastic lesions were diagnosed. The percentage of successful FNB was 91%. The percentage of samples with a cytological diagnosis was 80%. The percentage of complications was 9%. Limitations were the small number of animals in the study, the lacking complementary percutaneous biopsies for comparison, the lacking final histological diagnoses in some cases and the intervention of multiple operators. Computed tomography-guided FNB is a useful and safe technique for the diagnosis of vertebral and paravertebral lesions in small animals. However, a degree of expertise is important.

INTRODUCTION:In southern European countries, multicentric lymphoma and leishmaniosis are the main differential diagnoses in dogs presented with generalized lymphadenomegaly. The cytological examination is in some cases inconclusive and polymerase chain reaction (PCR) for antigen receptor rearrangement (PARR) has become a common method to confirm or rule out a lymphoproliferative neoplasia. According to the literature, leishmaniosis may lead to clonal arrangements and therefore to a false diagnosis of lymphoma, but this assumption is made from a single leishmania infected dog. Therefore, the objective of this study was to prospectively evaluate results from PARR in dogs with lymphadenomegaly due to clinical leishmaniosis at the moment of diagnosis. MATERIALS AND METHODS:31 dogs with a diagnosis of leishmaniosis based on the LeishVet guidelines were included in the study. Samples from enlarged lymph nodes were taken for cytological examination, clonality testing and Leishmania infantum PCR. RESULTS:All 31 dogs had medium to high positive antibody titers against Leishmania spp. and 30/31 had a positive Leishmania PCR from the lymph node. A polyclonal arrangement for B cells (immunoglobulin heavy chain gene) and T cells (T-cell receptor gamma chain gene) antigen receptors was found in 28/31 dogs. Two out of 31 dogs showed a monoclonal arrangement for Ig with high (1:2) and low (1:7) polyclonal background respectively; and one of the 31 dogs showed a monoclonal arrangement for T cell receptor with low (1:3) polyclonal background. CONCLUSION:Infections with Leishmania infantum resulted in clonal rearrangement, and therefore in a possible false diagnosis of lymphoma, in 3 out of 31 dogs (9.7%). Although, PARR is a useful method to differentiate lymphoma from reactive lymphoid hyperplasia in dogs with leishmaniosis, mono-/biclonal results should be interpreted carefully, especially in the presence of any degree of polyclonal background, and together with other clinicopathological findings.

Chemodectomas are low prevalence tumors with complex clinical management. Many present as an incidental finding however, in other dogs, they produce pericardial effusion and/or compression, leading to the appearance of severe clinical signs. There are currently several approaches: surgery, radiotherapy, stent placement and chemotherapy. This is the first description of percutaneous echo-guided radiofrequency ablation of aortic body tumors. This minimally invasive treatment is based on high frequency alternating electrical currents from an electrode that produces ionic agitation and generates frictional heat, causing coagulation necrosis. Five dogs with an echocardiographic and cytological diagnosis of chemodectoma underwent percutaneous echo-guided radiofrequency ablation. At the time of presentation, all the dogs showed clinical signs, such as ascites and/or collapse. There were no complications either during the procedure or in the following 24 hours. Rapid clinical improvement associated with a reduction in size and change in sonographic appearance of the mass were achieved with no complications. Six months follow-up was carried out in all dogs. A second percutaneous echo-guided RFA was performed eight months after the first procedure in one dog. Based on our experience, radiofrequency ablation seems to be a feasible and safe technique, making it a potential alternative therapeutic approach in the clinical management of aortic body tumors leading to severe clinical compromise.