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Slaughterhouse inspections play a crucial role in the sanitary control of zoonoses and foodborne diseases. This study aimed to identify and analyze the frequencies of lymph node diseases in cattle slaughtered for human consumption, using the samples sent to the anatomic pathology service of the Federal Laboratory for Agricultural Defense ( Laboratório Federal de Defesa Agropecuária ), Minas Gerais, Brazil, from January 2015 to September 2022. In total, 2000 lymph node samples were analyzed, and additional information was individually retrieved. Lesions were most frequently identified in thoracic lymph nodes. Bacterial isolation and quantitative polymerase chain reaction (qPCR) were performed using samples suspected of tuberculosis. Tuberculosis cases accounted for 89.3% of the samples. Histopathology was more sensitive than other ancillary tests for diagnosing tuberculosis. Paraffin-embedded tissues from lymphoma cases were subjected to immunophenotyping using anti-CD3 and anti-CD79a immunohistochemistry. Frozen and/or paraffin-embedded tissues from lymphoma cases were used to identify the enzootic bovine leukosis (EBL) retrovirus through qPCR. Other diagnoses included primary (T- and B-cell lymphoma) and metastatic neoplasms (squamous cell carcinoma, pulmonary adenocarcinoma, undifferentiated carcinoma, undifferentiated adenocarcinoma, undifferentiated sarcoma, undifferentiated round cell tumor, mesothelioma, hepatic carcinoid, meningioma, and seminoma), actinogranulomas (pyogranulomatous lymphadenitis [actinobacillosis and actinomycosis]), idiopathic lymphadenitis (neutrophilic and/or histiocytic, granulomatous, and suppurative), and miscellaneous nonspecific lymphadenopathies (depletion/lymphoid atrophy, lymphangiectasia, erythrocyte drainage, parasitic eosinophilic lymphadenitis, follicular hyperplasia, and toxic granulomatous lymphadenitis). The combination of histopathology with complementary techniques is important for successful diagnosis, especially in complex cases of high epidemiological, economic, and zoosanitary importance, such as tuberculosis and EBL., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Neorickettsia helminthoeca (NH), the agent of salmon poisoning disease or canine neorickettiosis (CN), is a bacterial endosymbiont of the nematode Nanophyetus salmincola, and infections are spreading among specific fish-eating mammalians. This article describes the pathologic and immunohistochemical findings associated with spontaneous NH-induced infections in dogs from Southern Brazil. The principal pathologic findings were hypertrophy of Peyer patches and lymphadenopathy with lymphocytic proliferation, chronic interstitial pneumonia, and chronic enteritis associated with positive intralesional immunoreactivity to antigens of NH within macrophages and histiocytes. Positive immunoreactivity against canine parvovirus-2 (CPV-2) or/and canine distemper virus was not detected in the evaluated intestinal segments or in the samples from the cerebellum and lungs, respectively, from the dogs evaluated. These findings demonstrated that NH was involved in the enteric, pulmonary, and lymphoid lesions herein described, and provide additional information to confirm the occurrence of this bacterial endosymbiont within this geographical location. It is proposed that chronic pneumonia should be considered as a pathologic manifestation of NH-induced infections. Additionally, our results show that the occurrences of CN seem to be underdiagnosed in Southern Brazil due to the confusion with the incidence of CPV-2., (© 2019 Blackwell Verlag GmbH.)

Linguatula serrata is a cosmopolitan zoonotic parasite in which carnivores and herbivores serve as final and intermediate hosts, respectively. The aim of this study was to compare the L. serrata nymphal infection rate and intensity of infection (mean number of nymphs ± standard error) to the appearance and pathological changes of mesenteric lymph nodes (MLNs) infected with L. serrata using sheep slaughtered in Tabriz, Iran. In addition, the effect of age, sex, and season on the prevalence of L. serrata infection was evaluated. For this purpose, over a four-year period, 31,078 MLNs from 3199 sheep were examined, with 4972 (15.99%) MLNs infected representing 518 (16.20%) sheep. Collected MLNs were categorized by color as normal, red or black and by consistency as normal, soft or hard. L. serrata were found in 8.88% of normal-colored MLNs, 14.45% of red (hemorrhagic) MLNs and 44.57% of black-colored MLNs, with the difference being significant for infection and infection intensity (P < 0.0001). In regards to MLN consistency, 7.98% of normal, 31.52% of soft and 5.42% of hard lymph nodes were found to be infected with the infection rate and intensity in soft nodes being significantly different (P < 0.0001). Pathological changes in MLNs infected with L. serrata nymph with normal color and consistency had calcification of the L. serrata nymph, granulomatous inflammation around the nymph and some neutrophils. Granulomatous inflammation around the L. serrata nymph, haemosiderophage, macrophage and lymph node depletion from lymphocytes were observed in MLNs infected with L. serrata nymph with soft consistency. In addition, MLNs infected with L. serrata nymph with hard consistency and black color contained neutrophils in the capsule's wall, caseous necrotic mass and L. serrata surrounded by a thick capsule. In regards to prevalence, age, sex and season (autumn) were significant (P < 0.0001, P < 0.01, respectively). These study results suggest that targeted meat inspection and targeted animal interventions could be used to decrease human exposure to L. serrata and animal infection., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Nodular lymphoid hyperplasia (NLH) is one of the most common non-neoplastic splenic lesions in dogs, especially in old ones, showing a splenic enlargement. More recent studies have been focused on Contrast Enhanced Ultrasonography (CEUS) analysis of the spleen for establishing normal perfusion patterns and blood pool phase peculiarities of focal lesions. The aim of the study was to evaluate the qualitative and quantitative CEUS analysis of the canine splenic NLH, characterizing the CEUS pattern of this pathology on 20 clinical cases., Results: A prospective, observational study was performed using a system equipped with contrast-tuned imaging technology. Mechanical Index was set from 0.08 to 0.11; the contrast medium was a second generation contrast medium composed of sulphur hexafluoride encapsulated of a shell of phospholipids (SonoVue®). Qualitative and quantitative assessment of the enhancement pattern of splenic NLH were performed. Cytology and histology identified 20 splenic NLH. All of the benign hyperplastic lesions assessed were isoechoic with a homogeneous pattern than the surrounding normal spleen, during the wash-in phase (10-20 s) of the CEUS exam. Before finishing the wash-in phase, 20-45 s from the contrast medium inoculation, 19/20 benign nodules became markedly hypoechoic to the adjacent spleen. Sensitivity of hypoechoic pattern for NLH was 95%., Conclusions: These findings should prove useful in the evaluation of focal splenic masses in dogs. Since enhancement and perfusion patterns of NLH seem to coincide with some neoplastic lesions of the spleen previously reported, in clinical practice attention must be paid to the final diagnosis of canine splenic lesions using only the CEUS exam.

Background: Melanosis of lymph nodes in black pigs has generally been related to regression of congenital melanoma and, occasionally, to ingestion of acorns. The aim of this manuscript is to confirm the hypothesis of a possible acquired acorn-related pseudomelanosis in the Nero Calabrese pig, a swine breed belonging to the group of Italian native breeds and whose coverage area corresponds to the region of Calabria, southern Italy. This pig is characterized by slow-growing subjects, producing, however, high quality meat suitable for the production of sausages and fine hams. The study was carried out on 142 normally slaughtered pigs. All organs were examined. Lymph nodes and intestine (jejunum) were sampled. Histochemistry was performed on deparaffinized histological sections to identify the cell types involved and to characterize the pigment stored. To further confirm the pigmentation disorder, immunohistochemistry was carried out. Total phenolic substances were identified in acorns through the use of a biochemical reaction., Results: Lymph node pigmentation appears directly related to acorn ingestion, with a higher incidence in the group which was 70% natural fed (acorn of Quercus virgiliana). Moreover, findings obtained revealed how different amounts of phenolic substrates present in Q. virgiliana and Q. ilex acorns can influence the incidence of such exogenous pigmentation., Conclusion: The findings obtained in this study confirm the acquired nature of the melanin-like pigmentation detected in lymph nodes from acorn-fed swine. Acquired pigmentation must be differentiated from true melanosis as well as from melanosis related to tumor regression of congenital melanoma. This thesaurismosis can be proposed as a marker of wellbeing and quality, confirming that the pigs have been bred and fed in natural conditions.

Objectives Flow cytometry (FC) is becoming increasingly popular among veterinary oncologists for the diagnosis of lymphoma or leukaemia. It is accurate, fast and minimally invasive. Several studies of FC have been carried out in canine oncology and applied with great results, whereas there is limited knowledge and use of this technique in feline patients. This is mainly owing to the high prevalence of intra-abdominal lymphomas in this species and the difficulty associated with the diagnostic procedures needed to collect the sample. The purpose of the present study is to investigate whether any pre-analytical factor might affect the quality of suspected feline lymphoma samples for FC analysis. Methods Ninety-seven consecutive samples of suspected feline lymphoma were retrospectively selected from the authors' institution's FC database. The referring veterinarians were contacted and interviewed about several different variables, including signalment, appearance of the lesion, features of the sampling procedure and the experience of veterinarians performing the sampling. Statistical analyses were performed to assess the possible influence of these variables on the cellularity of the samples and the likelihood of it being finally processed for FC. Results Sample cellularity is a major factor in the likelihood of the sample being processed. Moreover, sample cellularity was significantly influenced by the needle size, with 21 G needles providing the highest cellularity. Notably, the sample cellularity and the likelihood of being processed did not vary between peripheral and intra-abdominal lesions. Approximately half of the cats required pharmacological restraint. Side effects were reported in one case only (transient swelling after peripheral lymph node sampling). Conclusions and relevance FC can be safely applied to cases of suspected feline lymphomas, including intra-abdominal lesions. A 21 G needle should be preferred for sampling. This study provides the basis for the increased use of this minimally invasive, fast and cost-effective technique in feline medicine.

Enlarged lymph nodes are frequently examined cytologically in dogs and metastatic lymphadenomegaly of various origin is a common cytological finding in these cases. In this study we aimed to examine epidemiological data, and to determine factors affecting the location of neoplastic metastases in the lymph nodes. Samples for cytological examination were obtained by fine-needle biopsy (FNB) of enlarged lymph nodes and stained with Giemsa solution. Cases meeting the following criteria were enrolled in the study: lymphadenomegaly detected in clinical examination, presence of primary mass confirmed by cytopathology or histopathology as a solid malignant tumour, and cytological diagnosis of metastatic tumour. Cytological pattern of lymph node involvement was classified as low, medium and massive. During study period 125 dogs met the eligibility criteria, with age ranged from 1.8 to 19 years. No sex predisposition to particular types of tumors was observed, except for adenocarcinoma which was diagnosed in females more often. Metastatic tumors were various in origin, with predominance of mast cell tumors, adenocarcinomas, and melanomas. Massive involvement predominated in all lymph nodes affected. Neoplastic lymphadenomegally is recognized usually in older dogs, with female predisposition related to dissemination of mammary cancers. Mast cell tumor, adenocarcinoma and melanoma are the most common causes of metastatic lymphadenomegaly, and in the vast majority of the cases massive lymph node involvement is observed., (Copyright© by the Polish Academy of Sciences.)

Glucocorticoids, used in a wide range of pathologies thank to their therapeutical properties, are also illegally used as growth-promoters in animal breeding even if the European Union regulates their use to protect consumers' health from the adverse effects of residues in food. The first aim of the study was to establish the applicability of two histological parameters - atrophy and cortex-medulla ratio - to detect glucocorticoids misuse in calves. The second aim was to concurrently test the potentiality of both parameters to discriminate between treated and untreated animals. One hundred and seventy-two male Friesian veal calves were raised for six months and divided into two groups: Group A (106 calves) was given dexamethasone per os for twenty days (0.4mg/day), Group B (66 calves) used as control. Thymic samples were microscopically examined. Fat infiltration was evaluated and a degree of atrophy, ranging from 1 to 3 (mild, moderate, severe) was attributed; thymic cortex-medulla ratio was calculated too. Fisher's exact test and a Wilcoxon-Mann-Whitney test were performed to investigate the differences in thymic atrophy and cortex-medulla ratio between the groups. Results demonstrate that the thymic atrophy grading was significantly increased in group A (p=0,006), whereas the cortex-medulla ratio was decreased (p<0,004) when compared to group B; moreover, the parallel testing with fixed degree of atrophy and cortex-medulla ratio cut-off thresholds optimize the sensitivity (90%) in the detection of glucocorticoids anabolic treatments. These data suggest that microscopic thymus analysis represent a valid tool for the screening and monitoring of glucocorticoid illicit treatments., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Lymph nodal cyst-like lesions are occasionally identified during abdominal ultrasound in dogs. However, a study evaluating their prevalence and clinical significance is lacking. The aim of this observational cross-sectional study was to evaluate prevalence, most common location and concurrent diseases of cyst-like lymph nodes detected during abdominal ultrasound. Affected lymph nodes, patient signalment and concurrent diseases of dogs with cyst-like lymph nodal lesions having undergone abdominal ultrasound over a one-year period were recorded. Twenty-three affected lymph nodes were observed in 17/553 dogs (prevalence=3 per cent). The most commonly affected was the lumbar lymphocenter (7/23), followed by the coeliac (6/23), the cranial mesenteric (5/23) and the iliosacral (5/23). Twenty-three concurrent diseases were diagnosed in 17 dogs, among which 16/23 were non-neoplastic (70 per cent). The most common concurrent disease was renal insufficiency (8/23), followed by neoplasia (7/23), gastroenteropathy (3/23), benign prostatic disease (2/23), pancreatitis (1/23), peritonitis (1/23) and neurological disease (1/23). No statistical correlation existed between cyst-like lymph nodal lesion and a specific neoplastic or non-neoplastic disease. In conclusion, in the present study, cyst-like lymph nodal lesions have a low prevalence, involve different lymphocenters and were found in dogs affected by different diseases, including both non-neoplastic and neoplastic aetiologies., (British Veterinary Association.)

Background: Idiopathic purulent mesenteric lymphadenitis or lymph node abscessation, even though rare in dogs, are important diseases in which rapid diagnosis and treatment is critical. This study aimed to characterise the typical features of these conditions in dogs., Material and Methods: Archived records from 2005 to 2015 were retrospectively evaluated for the occurrence of idiopathic purulent mesenteric lymphadenitis or lymph node abscesses in dogs. History, physical and clinicopathological abnormalities, diagnostic tests performed, treatment and outcome were reviewed., Results: A total of 14 cases with histopathologic and/or cytologic confirmation were identified. Typically, there were gastrointestinal signs including abdominal pain and elevated body temperature. Blood analysis revealed non-specific inflammatory changes including elevated C-reactive protein. Half of the bacterial cultures from lymph nodes showed growth of various bacteria. A primary cause was not identified in any case. Out of 14 cases, 10 cases underwent surgery and all dogs were discharged from the hospital. Three suffered from a relapse between 1 and 5 months after discharge but were successfully managed with antibiotics., Conclusion and Clinical Relevance: Idiopathic purulent mesenteric lymphadenitis or lymph node abscessation are infrequent but clinically important diseases. Surgical, symptomatic and antibiotic treatment led to resolution of clinical signs in the evaluated cases. Thorough and standardised diagnostic workup and treatment of future cases are necessary to investigate possible pathogeneses and optimal therapeutic options. Outcome was favourable overall., (© 2016 British Small Animal Veterinary Association.)

A significantly increased incidence of pleural mesothelioma in Biancavilla (Sicily, Italy) has been attributed to exposure to fluoro-edenite (FE), a fibrous amphibole extracted from a local stone quarry. The lymph-nodes draining the pulmonary lobes of sheep grazing around the town were examined, to gain insights into fibre diffusion. The pasture areas of six sheep flocks lying about 3km from Biancavilla were located using the global positioning system. The cranial tracheobronchial and one middle mediastinal lymph-node as well as four lung tissue samples were collected from 10 animals from each flock and from 10 control sheep for light and scanning electron microscopy (SEM) examination. The lymph-nodes from exposed sheep were enlarged and exhibited signs of anthracosis. Histologically, especially at the paracortical level, they showed lymph-follicle hyperplasia with large reactive cores and several macrophages (coniophages) containing grey-brownish particulate interspersed with elements with a fibril structure, forming aggregates of varying dimensions (coniophage nodules). Similar findings were detected in some peribronchiolar areas of the lung parenchyma. SEM examination showed that FE fibres measured 8-41µm in length and 0.4-1.39µm in diameter in both lymph-nodes and lung tissue. Monitoring of FE fibres in sheep lymph-nodes using appropriate techniques can help set up environmental pollution surveillance., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Medial retropharyngeal lymph node (MRLN) mass lesions are a common cause of cranial cervical masses in dogs and cats, and are predominantly due to metastatic neoplasia, primary neoplasia, or inflammatory lymphadenitis. The purpose of this retrospective cross-sectional study was to test the hypothesis that clinical and magnetic resonance imaging (MRI) characteristics for dogs and cats with MRLN mass lesions would differ for inflammatory vs. neoplastic etiologies. Dogs and cats with MRLN mass lesions that had undergone MRI and had a confirmed cytological or histopathological diagnosis were recruited from medical record archives. Clinical findings were recorded by one observer and MRI characteristics were recorded by two other observers who were unaware of clinical findings. A total of 31 patients were sampled, with 15 in the inflammatory lymphadenitis group and 16 in the neoplasia group. Patients with inflammatory lymphadenitis were more likely to be younger and present with lethargy (P = 0.001), pyrexia (P = 0.000), and neck pain (P = 0.006). Patients with inflammatory lymphadenitis were also more likely to have a leukocystosis (P = 0.02) and segmental neutrophilia (P = 0.001). Inflammatory masses were more likely to have moderate or marked MRI perinodal contrast enhancement (P = 0.021) and local muscle contrast enhancement (P = 0.03) whereas the neoplastic masses were more likely to have greater MRI width (P = 0.002) and height (P = 0.009). In conclusion, findings indicated that some clinical and MRI characteristics differed for dogs and cats with inflammatory vs. neoplastic medial retropharyngeal lymph node masses. Although histopathological or cytological diagnosis remains necessary for confirmation, these findings may help with the ranking of differential diagnoses of future cases., (© 2015 American College of Veterinary Radiology.)

Mature B cell neoplasms cover a spectrum of diseases involving lymphoid tissues (lymphoma) or blood (leukemia), with an overlap between these two presentations. Previous studies describing equine lymphoid neoplasias have not included analyses of clonality using molecular techniques. The objective of this study was to use molecular techniques to advance the classification of B cell lymphoproliferative diseases in five adult equine patients with a rare condition of monoclonal gammopathy, B cell leukemia, and concurrent lymphadenopathy (lymphoma/leukemia). The B cell neoplasms were phenotypically characterized by gene and cell surface molecule expression, secreted immunoglobulin (Ig) isotype concentrations, Ig heavy-chain variable (IGHV) region domain sequencing, and spectratyping. All five patients had hyperglobulinemia due to IgG1 or IgG4/7 monoclonal gammopathy. Peripheral blood leukocyte immunophenotyping revealed high proportions of IgG1- or IgG4/7-positive cells and relative T cell lymphopenia. Most leukemic cells lacked the surface B cell markers CD19 and CD21. IGHG1 or IGHG4/7 gene expression was consistent with surface protein expression, and secreted isotype and Ig spectratyping revealed one dominant monoclonal peak. The mRNA expression of the B cell-associated developmental genes EBF1, PAX5, and CD19 was high compared to that of the plasma cell-associated marker CD38. Sequence analysis of the IGHV domain of leukemic cells revealed mutated Igs. In conclusion, the protein and molecular techniques used in this study identified neoplastic cells compatible with a developmental transition between B cell and plasma cell stages, and they can be used for the classification of equine B cell lymphoproliferative disease., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Imaging studies in humans with anal and rectal cancer indicate that magnetic resonance imaging (MRI) is a more sensitive technique than abdominal ultrasound (AUS) for the detection of abdominal lymphadenopathy. The purpose of this retrospective study was to directly compare the efficacy of these two techniques in detecting abdominal lymphadenopathy in dogs with apocrine gland adenocarcinoma of the anal sac (AGAAS). Six dogs with histologically confirmed AGAAS and histopathologic confirmation of metastasis to abdominal lymph nodes (LNs) had AUS and abdominal MRI. AUS identified lymphadenopathy in two of six dogs, whereas MRI identified lymphadenopathy in all the six dogs. Lymphadenopathy was predominantly sacral in location, with involvement of the medial iliac and hypogastric LNs in only two cases. These data suggest that MRI is more sensitive than AUS for detecting sacral abdominal lymphadenopathy in dogs with AGAAS. As such, MRI could be considered in any patient with AGAAS for initial staging of this disease., (© 2013 Blackwell Publishing Ltd.)

Objectives: The aim of this study was to determine common reasons for lymph node fine needle aspirates, cytological diagnoses reported and the frequency and reasons for non-diagnostic samples from dogs and cats., Methods: Retrospective study of computerised records of fine needle aspirate samples submitted to NationWide Laboratories (UK) between April 2009 and May 2011 to identify lymph node samples. Reason for sampling, sample quality, diagnosis achieved and reason for non-diagnostic samples were assessed., Results: A total of 1473 records were available for review. Of 1274 canine samples, 928 (72 · 8%) were diagnostic and 346 (27 · 2%) were non-diagnostic. Of 199 feline samples, 171 (85 · 9%) samples were diagnostic and 28 (14 · 1%) were non-diagnostic. The most common reasons for sample submission in both species were investigation of lymphadenopathy (alone or in combination with other clinical signs) or tumour staging. In dogs, the most common diagnosis was lymphoma (351, 27 · 5%), and in cats, reactive hyperplasia (63, 31 · 6%). Absence of cells, cell disruption and low yield were the most common causes of non-diagnostic samples. Submission of the history did not affect the probability of reaching a cytological diagnosis., Clinical Significance: Lymph node cytology is a useful diagnostic procedure but educating veterinarians to improve sampling and smearing may increase diagnostic yield., (© 2014 British Small Animal Veterinary Association.)

Microbubbles have shown potential as intralymphatic ultrasound contrast agents while nanoparticle-loaded microbubbles are increasingly investigated for ultrasound-triggered drug and gene delivery. To explore whether mRNA-nanoparticle loaded microbubbles could serve as theranostics for detection of and mRNA transfer to the lymph nodes, we investigate the behavior of unloaded and mRNA-loaded microbubbles using contrast-enhanced ultrasound imaging after subcutaneous injection in dogs. Our results indicate that both types of microbubbles are equally capable of rapidly entering the lymph vessels and nodes upon injection, and novel, valuable and detailed information on the lymphatic structure in the animals could be obtained. Furthermore, additional observations were made regarding the dynamics of microbubble lymph node uptake. Importantly, neither the microbubble migration distance within the lymphatics, nor the observed contrast signal intensity was influenced by mRNA-loading. Although further optimization of acoustic parameters will be needed, this could represent a first step towards ultrasound-guided, ultrasound-triggered intranodal mRNA delivery using these theranostic microbubbles.

Eosinophilic bronchopneumopathy is a disease characterized by the infiltration of the lung and bronchial mucosa by eosinophils. The aim of the present study was to describe the CT findings in a large series of dogs with confirmed diagnosis of eosinophilic bronchopneumopathy. Computed tomographic scans of 15 dogs with confirmed diagnosis of eosinophilic bronchopneumopathy were evaluated retrospectively by two boarded radiologists who reached a consensus. Abnormalities were identified in 14/15 (93%) dogs, including pulmonary parenchymal abnormalities in 14/15 (93%) dogs, bronchial wall thickening in 13 (87%) dogs, which was considered marked in eight (53%), plugging of the bronchial lumen by mucus/debris in 11 (73%) dogs, and bronchiectasis in nine (60%) dogs. Pulmonary nodules were identified in 5/15 (33%) dogs including one dog with a mass. All dogs with a nodular lung pattern had additional abnormalities. Lymphadenopathy was present in 10 dogs (67%). Lesions associated with eosinophilic bronchopneumopathy are variable and heterogeneous and encompass a wider variety of computed tomographic features than reported previously. Computed tomographic images were abnormal in the majority of affected dogs, hence CT is a useful modality to characterize the nature and distribution of thoracic lesions in dogs with eosinophilic bronchopneumopathy., (© 2014 American College of Veterinary Radiology.)

A 12-year-old neutered male domestic shorthair cat presented for chronic, localized, swelling and crusting of the left upper lip, weight loss, sporadic vomiting, and focal alopecia between the scapulae was diagnosed with hyperthyroidism and regional eosinophilic lymphadenitis. Treatment with methimazole exacerbated an underlying hypersensitivity disorder leading to marked generalized lymphadenopathy that histologically mimicked lymphoma.

Medical records of dogs diagnosed with oral papillary squamous cell carcinoma between December 2008 and April 2011 were reviewed. Information abstracted included signalment, tumor location, tumor size, computed tomographic (CT) features, evidence of metastatic disease based on cytologic examination of lymph node aspirates and thoracic radiography, treatment, surgical margins, histologic features, and treatment outcome. Dogs included in the study were all sexually altered, predominantly large breed dogs with a mean age of 3.9-years (range, 0.5 to 9.0-years). The most common location was the rostral maxilla. Invasion of underlying bone and lymphadenopathy were evident on CT imaging in most dogs. No evidence of metastasis was found on mandibular lymph node cytology and thoracic radiography. Histologic analysis revealed similar morphologic findings for all surgically resected tumors. Surgical excision with 1-2 cm margins was complete in all cases, with a mean tumor-free interval of 12.1-months.

Juvenile meagre Argyrosomus regius (Asso, 1809) maintained in experimental conditions developed lateral and/or bilateral circular-shaped sarcoma within the opercular cavity. The sarcoma was dense, reddish and its growth from the branchial arch exerted pressure on the operculum forcing it to open. Histologically, the neoplasm exhibited marked proliferation of mesenchymal connective tissue composed largely of fusiform cells, which developed in a solid pattern accompanied by abundant mononuclear cell types. Multifocal areas of discrete necrosis were also observed, compatible with a sarcomatous proliferation. The immunological parameters analysed suggested an inflammatory response. No bacteria were isolated from the hematopoietic organs. However, Vibrio species, components of the normal seawater flora, were isolated from the tumour, which may have had a role in eliciting the immune response. No evidence of viral pathogens was found by electron microscopy. In order to look for cytogenetic alterations often linked to sarcomas, the diploid number and karyotype of this species were determined for the first time. An increase in the aneuploidy level was observed in sarcoma cell metaphase stages compared to other tissues. The aetiology of this tumour remains unknown.

Tracheobronchial lymphadenomegaly is commonly associated with lymphosarcoma and disseminated mycotic infection. Available data also suggest other pathologic causes of enlarged tracheobronchial lymph nodes. Our objective was to establish the distribution and prevalence of diseases that cause radiographically evident tracheobronchial lymphadenomegaly in a large population of dogs. Patients were divided into groups based on the methods of diagnoses with 25 having confirmed diagnoses and 85 with presumptive diagnoses. Of the 110 dogs in the study, 92 (84%) had neoplasia and 18 (16%) had infectious diseases. Infections were attributed to Coccidioides (12, 67%), Aspergillus (3, 17%), and 1 each (6%) to Nocardia, Penicillium, and Mycobacteriosis. Tumors were characterized as lymphoma (66, 60%) or nonlymphoid (26, 23.6%). Nonlymphomas in Group 1 included histiocytic sarcoma complex (16%), carcinoma (12%), adenocarcinoma (8%), osteosarcoma (8%), chemodectoma (4%), ganglioneuroblastoma (4%), and neuroendocrine (4%). The number of dogs with tracheobronchial lymphadenomegaly scores 1, 2, 3, 4, or 5 (with 5 being the greatest) was 8 (7%), 15 (14%), 30 (27%), 15 (14%), and 44 (38%), respectively. The results suggest that in addition to diagnoses of lymphoma and fungal infections, other neoplasms and in particular histiocytic sarcoma and metastatic adenocarcinoma, should be considered when tracheobronchial lymphadenomegaly is identified radiographically in dogs. When comparing the degree of tracheobronchial lymphadenopathy by disease category, there was no significant affiliation (P = 0.33)., (© 2012 Veterinary Radiology & Ultrasound.)

Infection of the Bursa of Fabricius with Cryptosporidium baileyi was diagnosed in a group of hand reared Red-breasted Merganser (Mergus serrator) ducklings during one breeding season in a German zoological garden.The birds had died in an emaciated and anaemic state after problems with spontaneous feeding. The bursae were infected with moderate to high numbers of cryptosporidia, which were associated with hyperplasia, degeneration and sloughing of the affected epithelial cells and mild heterophilic bursitis, lesions typically seen in bursal cryptosporidiosis in other avian species. In addition, lymphatic tissue was nearly absent, which was probably caused by chronic stress and malnutrition related to the rearing of these highly stress-sensitive birds in an artificial environment. Companion ducklings from stress-resistant, spontaneously feeding species from the zoological collection were used to calm the Mergansers, but may have introduced the cryptosporidia into the rearing boxes. Another possible source for the introduction of C. baileyi were adult mallards (Anas platyrhynchos), which were used to increase the hatching rate by a phase of natural breeding in the middle third of the incubation period of the Merganser eggs.

In this retrospective study, radiographically enlarged sternal lymph nodes (LNs) were evaluated in 71 dogs and 13 cats for average size, location, and most representative radiographic view. Concurrent clinical diagnoses were also noted and grouped into one of three following categories: neoplastic, inflammatory, or hematologic. There were no statistically significant differences in LN size between lateral views within each species. Enlarged sternal LNs were more cranially positioned in dogs than cats. No statistical difference was noted between right and left laterals, as to on which projection the enlarged sterna lymph nodes was seen best. Neoplastic disease (78.9%) was the most prevalent condition seen in association with LN enlargement in dogs, followed by primary infectious or inflammatory diseases (14.1%) and various hematologic conditions (7.0%). In cats, neoplasia was also most common (69.2%), followed by inflammatory diseases (30.8%). No hematologic conditions were noted in cats. The most common etiologic agent seen concurrently with enlarged sternal LNs in both dogs (33.8%) and cats (38.5%) was malignant lymphoma. The results of this study provide a clinically useful representation of the average size and location of radiographically enlarged sternal LNs for dogs and cats. The diseases represented demonstrate the wide spectrum of potential causes of sternal lymphadenopathy.

Introduction: Canine visceral leishmaniasis (CVL) is a zoonotic disease with different clinical manifestations. Parasitism often occurs in bone marrow, but changes have been observed in peripheral blood and serum biochemical parameters. The aim of this study was to evaluate the hematological and biochemical parameters in dogs naturally infected by Leishmania chagasi., Methods: Eighty-five adult dogs of both sexes and various weights and ages from the Zoonosis Control Center of Fortaleza (CCZ) were used, selected by immunofluorescence assay (IFA) and considered positive with IFA titers greater than 1:40 and by visualizing amastigotes of Leishmania chagasi in smears obtained by bone marrow aspiration. The dogs (n = 85) were grouped according to clinical signs: negative (CN = 7), subclinical (CS = 10), and clinical (CC = 68). Blood samples were collected for determination of hematological and biochemical serum values. The experimental protocol was approved by the CEUA/UECE., Results: The most frequent clinical signs were cachexia (77.9%), keratitis (61.8%), and lymphadenopathy (55.9%), and 86.8% of the animals showed more than one clinical sign characteristic of CVL. In CC were observed reductions in red blood cells (63%), hematocrit (72%), and hemoglobin (62%), as well as leukocytosis (33%), neutropenia (28%), thrombocytopenia (50%), uremia (45%), hyperproteinemia (53%, p<0.05), hypergammaglobulinemia (62%, p<0.01), and hypoalbuminemia (58%)., Conclusions: Animals with the clinical form of the disease demonstrate hematological and biochemical changes consistent with anemia, uremia, hyperproteinemia, and hyperglobulinemia, which present themselves as strong clinical markers of visceral leishmaniasis associated with the signs previously reported.

The present case report describes isolation of the fungus Oxyporus corticola from multiple lymphocutaneous tissues of a Beagle dog. Until recently, this fungus had not been reported in the human or veterinary medical literature as a cause of animal disease. A single previous report also involved infection in a German Shepherd Dog, a breed with reported increased susceptibility to disseminated fungal infection and dysfunctional immune response. Isolates were non-sporulating and required molecular identification methods for prompt differentiation from other fungal pathogens. Risk factors for infection with O. corticola are unknown.

Trypanosoma cruzi connatal transmission was studied in male and female mongrel dogs. Both dogs were experimentally infected, after which on the 20(th) day, lymphoadenomegaly and fever were found. Four months postinfection, they mated. At this time, Chagas disease was confirmed by two different diagnostic tests. The electrocardiogram and echocardiogram taken at the eight postinoculation month showed data consistent with ischemia, local conduction abnormalities and hypertrophy, as well as a diminished ejection fraction and left ventricular dilation, respectively. Four puppies were born and after weaning had weakness, progressive weight loss, and chronic diarrhea. Necropsy of all four showed digestive alterations and cardiac dilation. Serology in the offspring was positive for Chagas disease. The histopathological study demonstrated a cardiac chronic inflammatory process, although no parasites were found. Clinical data and serological determinations are consistent with death from advanced Chagas disease.

A domestic ferret (Mustela putorius furo) was presented with lymphadenopathy and acute bilateral blindness. Cytologic evaluation and biopsy of an affected lymph node revealed pyogranulomatous lymphadenitis with intralesional yeast consistent with Cryptococcus sp. Subsequent studies demonstrated Cryptococcus gattii serotype B VGI/AFLP4 as the causative agent. The ferret was treated with fluconazole and prednisone. After one month of therapy, an improvement of the clinical symptoms was detected although blindness persisted. Seven months after presentation, the disease progressed to a severe neurologic condition, and it was euthanized. Postmortem exam revealed disseminated cryptococcosis with prominent neurologic involvement. Nasal swabs of other ferrets and humans from the same household revealed that two ferrets and two humans to be asymptomatic carriers of the same strain of cryptococcus as the necropsied ferret. These findings stress the importance of veterinary diagnostic work with pets and epidemiological investigations for disease prevention in them and in their owners.

The sonographic characteristics of intraabdominal abscesses in 11 foals and intraabdominal lymphadenitis in five foals with Rhodococcus equi infections are presented. Intraabdominal abscesses were usually present in the ventral abdomen adjacent to the ventral body wall, well-marginated, and contained a mixed or complex echo pattern. Lymphadenitis appeared as singular or multiple clusters of lymph nodes of mixed echogenicity adjacent to any portion of the gastrointestinal tract or body wall. Sonographic findings were supported by necropsy examinations, but sonographic measurements consistently underestimated the size of abscess., (© 2011 Veterinary Radiology & Ultrasound.)

This is the first report of the isolation of Actinomyces denticolens, an opportunistic pathogen, from a draining submandibular lymph node abscess in a horse in Ontario. Due to the similarity of the clinical signs with strangles, this pathogen should be included in the differential diagnosis of submandibular lymphadenopathy in the horse.

Angiomatoid lesions in a lymph node associated with a thyroid carcinoma of a dog were restricted to the subcapsular and medullary sinuses. Lymphoid atrophy was present, but nodal architecture was not distorted and normal structures were not invaded. Immunohistochemical staining indicated that the vascular spaces formed by spindloid cells were lined by endothelium with a low mitotic index. The spindloid cells were positive for smooth muscle actin, vimentin, and desmin and thus were likely to be fibroblasts, myofibroblasts, smooth muscle cells, and/or pericytes. These features are comparable to vascular transformation of lymph node sinuses in humans (nodal angiomatosis), a nonneoplastic condition often associated with mechanical or functional blockage of efferent lymphatics and veins.

Background: Recognition of different cytologic patterns in lymph nodes (LNs) from dogs with canine monocytic ehrlichiosis (CME) and noninfectious causes of lymphoid reactivity may have diagnostic utility., Objectives: The aims of the present study were to compare cytologic patterns in LNs of dogs with different phases of CME, to investigate the association of cytologic pattern and presence of Ehrlichia spp. morulae, and to compare patterns of lymphoid reactivity between dogs with CME and those with noninfectious causes of lymphoid hyperplasia., Methods: Cytologic preparations of LNs from 35 dogs with nonmyelosuppressive CME (group A), 16 dogs with myelosuppressive CME (group B), 26 dogs with noninfectious diseases (group C), and 15 healthy dogs (group D) were evaluated. Percentages of lymphocyte types, plasma cells, macrophages, neutrophils, and eosinophils were determined. Samples from dogs in groups A and B were evaluated for the presence of morulae., Results: Cytologic abnormalities in LNs were recorded in 54% of dogs in group A, 88% in group B, 39% in group C, and 0% in group D and were more frequent (P=.02) in dogs with myelosuppressive CME than those with nonmyelosuppressive CME. Plasma cell hyperplasia was more frequent in CME than in noninfectious diseases (P=.03). An association between the presence of cytologic abnormalities and morulae in group A dogs was not found., Conclusions: Dogs with myelosuppressive CME have more lymphoid cytologic abnormalities than dogs with nonmyelosuppressive CME. LN plasmacytosis is the major pattern of lymphadenopathy in dogs with CME and is found more frequently in dogs with CME than in dogs with noninfectious causes of lymphadenopathy., (©2011 American Society for Veterinary Clinical Pathology.)

The present study aimed to estimate the cell response and parasite load in the popliteal lymph nodes of dogs with visceral leishmaniasis (VL), comparing these findings with the clinical staging of the disease. From the necropsy, 33 dogs were classified as symptomatic (S), asymptomatic (A), or oligosymptomatic (O). Cytology and histopathology were used to determine any presence of microscopic lesions and immunohistochemistry, for parasite load. Dog hyperimmune serum was used as the primary antibody. The inflammatory infiltrate in lymph nodes consisted of macrophages and plasmocytes. The granulomas invaded the trabecular and sinusoid regions and sometimes compressed the lymphocytes of the cortical region (atrophy) and medullary cord cells. Parasite load intensity was unrelated to the density of the macrophages infiltrating the lymph node. Significant differences in parasite load (P < 0.05) were observed between the three groups of infected dogs. Follicular hyperplasia of the cortical region occurred among A and O, while follicular atrophy predominated among S. The parasite load was the greatest among S, followed by O. It can be concluded that, regardless of clinical condition, the most evident cell response consisted of macrophages and plasmocytes. Lymphoid atrophy was observed among animals with intense granulomatous reaction and high parasite load, such as among the symptomatic dogs (P < 0.05). Likewise, the oligosymptomatic dogs also presented high density of parasites in the lymph nodes. Thus, we can confirm that dogs with clinical manifestations of VL have an immune system that is less effective for controlling infection by Leishmania chagasi, thereby favoring parasite multiplication.

Systemic toxoplasmosis and concurrent infection with porcine circovirus-2 (PCV-2) was diagnosed in a fattening pig. Clinical examination of the herd showed that up to 30% of the pigs of this weight group suffered from severe respiratory signs including sneezing and coughing, with a mortality rate of up to 5%. Gross necropsy examination revealed severe interstitial pneumonia and generalized lymphadenopathy. On microscopical examination there was necrotizing inflammation of the lung, adrenal glands and lymph nodes, associated with lymphoid depletion, cytoplasmic basophilic botryoid inclusion bodies and protozoal microorganisms. Infection with Toxoplasma gondii was confirmed by immunohistochemistry (IHC). Polymerase chain reaction analysis, in-situ hybridization and IHC confirmed systemic PCV-2 infection. These findings, associated with the respiratory signs and lesions in lymphoid tissues, are characteristic for post-weaning multisystemic wasting syndrome (PMWS). In this case, immunosuppression by PCV-2 may have triggered systemic toxoplasmosis, or immune stimulation caused by coinfection with T. gondii may have caused extensive replication of PCV-2., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Although the use of tributyltin in antifouling paints has been banned, this compound is still a serious pollutant of the marine environment. This paper describes a unique study in which European flounder (Platichthys flesus) were chronically (8 months) exposed to bis(tri-n-butyltin)oxide (TBTO) in the water under controlled laboratory conditions. Residue levels in selected tissues (liver, muscle) and general health status indices were measured and the effects on several organs (gills, liver, mesonephros, ovary/testis, spleen, and gastrointestinal tract) were examined histopathologically. Additionally, morphometric analysis of the thymus was performed. The major finding is that exposure of flounder to 5 microg TBTO/l over a period of 8 months, resulting in body burdens comparable to high field levels, induced significant reduction of thymus volume, possibly affecting immunocompetence of the animals. Chronic exposure of European flounder to tributyltin is therefore likely to affect the general health status of this species in heavily polluted aquatic environments.

An outbreak of Yersinia pseudotuberculosis (Yptb) occurred in a closed colony of Egyptian fruit bats (Rousettus aegyptiacus) and resulted in the death of seven bats over a 6-week period. An initial survey of the remaining bats revealed visceral abscessation characteristic of pseudotuberculosis in five of the 12 bats examined (41.7%), inciting depopulation of the colony. At necropsy, 70% of the 115 bats in the colony exhibited gross evidence suggestive of Yptb infection, including mesenteric lymphadenopathy (ML), hepatic abscessation (HA), and/or splenomegaly (SPM). Thirty of these bats (13 females and 17 males of various ages) were chosen at random and their tissues submitted for bacterial culture and histopathologic examination. Twenty-three of these 30 bats had one or more gross lesions considered consistent with Yptb, including ML, HA, and SPM. On histopathology, four of the 30 bats had necrotizing lesions containing Gram-negative bacteria in multiple organs, while 18 others exhibited mild mesenteric lymphadenitis and hepatitis. Four of the 30 bats had positive cultures for Yptb. Bats with gross evidence of mesenteric lymphadenopathy, splenomegaly, or histopathologic presence of demodicosis or bacteria in tissues were more likely (P < 0.05) to have a positive Yersinia culture. Examination of the correlation between population density and mortality rates of the colony revealed that the mortality rate of subadult bats increased dramatically at the time of the outbreak, when the population density was at its highest. It is suspected that stress, primarily from severe overcrowding, predisposed the bat colony to morbidity and mortality from this organism, which likely originated from a rodent reservoir.

Lymphadenomegaly is the enlargement of the lymph node/nodes, due to various nonneoplastic or neoplastic processes, observed mainly in dogs, rarely in other animal species. The first step of a diagnostic procedure in cases of lymph nodes enlargement, apart from physical examination and morphological blood analysis, should be a cytological examination of an enlarged lymph node/nodes. The aim of the present study was to determine the character and the cause of the lymph node/nodes enlargement in dogs and to evaluate the usefulness of fine-needle cytology in a diagnosis of lymphadenomegaly. The study was performed on dogs submitted to consultation in the Small Animal Clinic of Department of Clinical Sciences, Warsaw University of Life Sciences, due to generalized or local lymphadenomegaly, and in which fine-needle biopsy was made. A signalement, general state of dog, the presence and duration of clinical signs, the character (generalized vs. localized) and intensity (mild, moderate or severe) of lympadenomegaly were recorded during physical examination. The average age of dogs examined was 8 years, 64 were males and 36 were females of various breeds; however the majority of them were greater than 25 kg in weight. The cytological diagnosis including most often lymphoma and reactive hyperplasia, more seldom metastatic neoplasm and lymphadenitis were recognized, some of the samples were considered nondiagnostic/nondefined. On the basis of the present results it can be concluded that cytological examination of good quality samples allows to obtain final diagnosis in over 90% of lymphadenomegaly. Higher incidence of canine lymphomas in males is suggested.

Hilar lymphadenopathy is a common radiographic finding in coccidioides infections. Serologic studies are used most often for the diagnosis of coccidioidomycosis in endemic areas, with IgG titers > 1:8 considered positive for infection and lower IgG titers of < 1:8 considered indicative of exposure and not necessarily related to organism presence. The objective of this study was to determine the relationship of hilar lymphadenopathy to coccidioidomycosis titers for dogs in an endemic area. A positive association between these parameters would allow treatment to be initiated before obtaining titer results. Thoracic radiographs of 131 dogs from an endemic area were reviewed for evidence of hilar lymphadenopathy. These results were compared with serology results. There was a significant association between hilar lymphadenopathy and a positive serology result (P < 0.001). With hilar lymphadenopathy as a predictor of a positive titer result, sensitivity was 28.0%, specificity was 91.5%, the positive predictive value was 43.8%; and the negative predictive value was 84.4%. There was no association between the titer result and gender, age, or weight. The radiographic finding of hilar lymphadenopathy appears to be a useful indicator of coccidioidomycosis infection in an endemic population of dogs supporting the treatment of patients for coccidioidomycosis when hilar lymphadenopathy is present and before obtaining serology results.

Objective: To evaluate pulsed-wave Doppler spectral parameters as a method for distinguishing between neoplastic and inflammatory peripheral lymphadenopathy in dogs., Sample Population: 40 superficial lymph nodes from 33 dogs with peripheral lymphadenopathy., Procedures: 3 Doppler spectral tracings were recorded from each node. Spectral Doppler analysis including assessment of the resistive index, peak systolic velocity-to-end diastolic velocity (S:D) ratio, diastolic notch velocity-to-peak systolic velocity (N:S) ratio, and end diastolic velocity-to-diastolic notch velocity ratio was performed for each tracing. Several calculation methods were used to determine the Doppler indices for each lymph node. After the ultrasonographic examination, fine needle aspirates or excisional biopsy specimens of the examined lymph nodes were obtained, and lymphadenopathy was classified as either inflammatory or neoplastic (lymphomatous or metastatic) via cytologic or histologic examination. Results of Doppler analysis were compared with cytologic or histopathologic findings., Results: The Doppler index with the highest diagnostic accuracy was the S:D ratio calculated from the first recorded tracing; a cutoff value of 3.22 yielded sensitivity of 91%, specificity of 100%, and negative predictive value of 89% for detection of neoplasia. Overall diagnostic accuracy was 95%. At a sensitivity of 100%, the most accurate index was the N:S ratio calculated from the first recorded tracing; a cutoff value of 0.45 yielded specificity of 67%, positive predictive value of 81%, and overall diagnostic accuracy of 86.5%., Conclusions and Clinical Relevance: Results suggested that noninvasive Doppler spectral analysis may be useful in the diagnosis of neoplastic versus inflammatory peripheral lymphadenopathy in dogs.

A nine-year-old, domestic shorthair cat was diagnosed with hyperthyroidism and treated with methimazole, which resulted in lethargy, inappetence and marked generalised lymphadenomegaly within two weeks of initiation of therapy. Cytology, histopathology and immunohistochemistry were suggestive of atypical lymphoid hyperplasia. Cessation of treatment resulted in resolution of all clinical signs and physical abnormalities within two days. Subsequent treatment with radioactive iodine cured this cat of its hyperthyroidism. The lymphadenomegaly did not return at any stage and the cat is currently asymptomatic. Although methimazole administration for feline hyperthyroidism has been associated with many side effects, lymphadenomegaly has, to the authors' knowledge, not been previously reported.

A glandular choristoma found in the mesenteric lymph node of a goat would appear to represent the first reported case of non-neoplastic glandular inclusions in domestic animals. The origin of this type of lesion may be difficult to determine, but in the present case cytokeratin expression patterns suggested that the inclusions had an intestinal origin.

Rare cases of thymic granulomatous lesions were found in pigs. The lesions consisted of epithelioid cells, multinucleated giant cells, and lymphocytes. Such lesions also were observed in the mesenteric lymph nodes, spleen, kidney, and stomach. The cytoplasm of the majority of giant cells and some epithlioid cells was periodic acid-Schiff (PAS) positive. All cells were positive for vimentin, lysozyme, and desmin. Ultrastructurally, the giant cells were rich in organella and attached to adjacent epithelioid cells by membrane interdigitation. The cells included numerous coated vesicles and granules. No etiologic pathogen, including porcine circovirus type 2, was detected in the lesions. This is the rare case of idiopathic thymic granulomatous lesion in pigs.

Objective: To compare results of computed tomography (CT) and radiography with histopathologic findings in tracheobronchial lymph nodes (TBLNs) in dogs with primary lung tumors., Design: Retrospective case series., Animals: 14 client-owned dogs., Procedures: Criteria for inclusion were diagnosis of primary lung tumor, use of thoracic radiography and CT, and histologic confirmation of TBLN status. Medical records were reviewed for signalment; history; and physical examination, clinicopathologic, radiographic, CT, surgical, and histopathologic findings., Results: Tracheobronchial lymphadenopathy was not identified via radiography in any dogs. Tracheobronchial lymphadenopathy was diagnosed in 5 dogs via CT. Six dogs had histologic confirmation of metastasis to TBLNs. Radiographic diagnosis yielded 6 false-negative and no false-positive results for tracheobronchial lymphadenopathy. Computed tomography yielded 1 false-negative and no false-positive results. Sensitivity of CT for correctly assessing TBLN status was 83%, and specificity was 100%. Positive predictive value was 100%, and negative predictive value was 89%. Dogs with lymphadenopathy via CT, histologic confirmation of TBLN metastasis, or primary tumors with a histologic grade > 1 had significantly shorter survival times than their counterparts., Conclusions and Clinical Relevance: Results of CT evaluation of TBLN status were in agreement with histopathologic findings and more accurate than use of thoracic radiography for evaluating TBLNs in dogs with primary lung tumors. Computed tomography imaging should be considered as part of the staging process to more accurately assess the TBLNs in dogs with primary lung tumors.