IgA Antibodies Against Gliadin and Tissue Transglutaminase in Dogs With Chronic Enteritis and Intestinal T-Cell Lymphoma.

Molecular clonality analysis of T-cell receptor (TCR) genes for diagnosing T-cell lymphoma is widely used in veterinary medicine. However, differentiating chronic enteritis (CE) from intestinal lymphoma is challenging because of the incompatibility between histopathologic and clonality analysis results. On the basis of findings that canine intestinal T-cell lymphoma and celiac disease share some common features, we conducted serologic examinations in combination with histopathologic and T-cell receptor clonality analyses in 48 dogs diagnosed with either CE or intestinal lymphoma. Immunoglobulin A (IgA) and immunoglobulin G (IgG) antibodies against gliadin and tissue transglutaminase (tTG) were quantitatively measured using ELISA. The conditions were classified according to the histopathologic diagnosis, clonality analysis, and combined histopathologic/clonality analysis. Histopathologic analysis showed that dogs with intestinal lymphoma were likely to have high levels of serum IgA antibodies against gliadin and tTG, and serum IgG antibodies against tTG. No correlation between the diagnosed groups and control group was observed in the results of the clonality analysis and histopathologic/clonality analysis. It is interesting that dogs with intestinal lymphoma had a higher serum IgA titer against gliadin and tTG than did dogs with CE. These results suggest an association between repetitive inflammatory stimulation by gliadin peptides and subsequent intestinal lymphoma in dogs.

Variations in Histiocytic Differentiation of Cell Lines From Canine Cerebral and Articular Histiocytic Sarcomas.

Two newly established canine histiocytic sarcoma (HS) cell lines, designated as PWC-HS01 and FCR-HS02, were obtained from brain and articular tumors, respectively. These 2 HS cell lines had phagocytic ability and modal chromosome aberrations. Although morphologic features of both HS cells were similar, immunocytochemical examinations revealed that the PWC-HS01 cell line expressed both dendritic cell (ie, S100, CD208, CD1, and CD4) and macrophage (ie, CD68, CD163, and CD204) markers. In contrast, the FCR-HS02 cell line was immunonegative for CD204 and CD68 but consistently positive for the dendritic cell markers. Moreover, reverse transcription polymerase chain reaction analyses confirmed histiocytic differentiation of both HS cell lines. These results suggest that HS from the central nervous system may have a tendency to be more undifferentiated compared with cases from other organs. In addition, the 2 newly established HS cell lines were also tumorigenic and metastatic in immunodeficient mice, supporting that these cell lines can be used as new tumor models for investigating canine histiocytic diseases.

Deposition, Clearance, and Reinduction of Amyloid A Amyloid in Interleukin 1 Receptor Antagonist Knockout Mice.

Amyloid A (AA) amyloidosis is characterized by the extracellular deposition of AA amyloid and results in the irreversible dysfunction of parenchymal organs. In experimental models, AA amyloid deposits are cleared following a decrease in circulating serum amyloid A (SAA) concentrations. Additional inflammatory stimuli during this recovery process may induce more severe amyloid redeposition. In the present study, we confirmed the deposition, clearance, and reinduction of AA amyloid deposits in interleukin 1 receptor antagonist knockout mice (IL-1raKO) and studied the SAA levels and amyloid-enhancing factor activity based on the time-dependent changes of amyloid deposition. Histopathologically, following initial (day 0) injection of amyloid-enhancing factor in combination with an inflammatory stimulus (silver nitrate [AgNO3]), amyloid deposition peaked by day 20, and its deposition gradually decreased after day 35. SAA concentrations in serum were precipitously elevated on day 1 but returned to normal levels by day 10, whereas the SAA dimer was detected in serum after day 45. An additional AgNO3 injection was administered to mice with amyloidosis on day 5, 10, 35, or 50, and all mice developed large amyloid deposits. Amyloid deposition was most severe in mice treated with AgNO3 on day 35. The inoculation of sera from mice with AA amyloidosis, combined with AgNO3, induced AA amyloidosis. Serum samples collected on days 35 and 50, which contained high concentrations of the SAA dimer, induced amyloidosis in a high proportion (83%) of mice. Therefore, increased SAA and/or its dimer in serum during the recovery process may markedly exacerbate the development of AA amyloidosis.

Endoscopic Cytology for the Diagnosis of Chronic Enteritis and Intestinal Lymphoma in Dogs.

Although cytology is a rapid diagnostic procedure in dogs, the cytologic criteria of endoscopic biopsies for chronic enteritis and intestinal lymphoma are not well defined. An immediate diagnosis using cytology would benefit patients by enabling prompt initiation of therapy. The objective of this study was to investigate the correlation between the results of endoscopic cytology and histopathology. In this study, 167 dogs with clinical signs of chronic gastrointestinal disease were included. On the basis of histopathology, the following diagnoses were determined: lymphocytic-plasmacytic enteritis in 93 dogs; eosinophilic enteritis in 5 dogs; small cell intestinal lymphoma in 45 dogs; and large cell intestinal lymphoma in 24 dogs. Two clinical pathologists retrospectively evaluated the endoscopic cytology of squash-smear preparations. The cytologic diagnoses of inflammation, small cell lymphoma, and large cell lymphoma were based on the severity of lymphocyte infiltration, the size of infiltrated lymphocytes, and eosinophil/mast cell infiltration. The clinical severity score was significantly increased along with the degree of lymphocyte infiltration evaluated by cytology. The cytologic diagnosis was in complete agreement with the histopathologic diagnosis in 136 of 167 (81.4%) cases. For the differentiation between enteritis and lymphoma, endoscopic cytology had a sensitivity of 98.6%, a specificity of 73.5%, a positive predictive value of 72.3%, and a negative predictive value of 98.6%. The log-rank test and Cox regression analysis showed that the results of cytology predicted the prognosis. These results suggest that endoscopic cytology is a useful technique to aid diagnosis of intestinal inflammation and lymphoma in dogs.

Pathology of the Aging Brain in Domestic and Laboratory Animals, and Animal Models of Human Neurodegenerative Diseases.

According to the WHO, the proportion of people over 60 years is increasing and expected to reach 22% of total world's population in 2050. In parallel, recent animal demographic studies have shown that the life expectancy of pet dogs and cats is increasing. Brain aging is associated not only with molecular and morphological changes but also leads to different degrees of behavioral and cognitive dysfunction. Common age-related brain lesions in humans include brain atrophy, neuronal loss, amyloid plaques, cerebrovascular amyloid angiopathy, vascular mineralization, neurofibrillary tangles, meningeal osseous metaplasia, and accumulation of lipofuscin. In aging humans, the most common neurodegenerative disorder is Alzheimer's disease (AD), which progressively impairs cognition, behavior, and quality of life. Pathologic changes comparable to the lesions of AD are described in several other animal species, although their clinical significance and effect on cognitive function are poorly documented. This review describes the commonly reported age-associated neurologic lesions in domestic and laboratory animals and the relationship of these lesions to cognitive dysfunction. Also described are the comparative interspecies similarities and differences to AD and other human neurodegenerative diseases including Parkinson's disease and progressive supranuclear palsy, and the spontaneous and transgenic animal models of these diseases.

Pathologic Features of Colorectal Inflammatory Polyps in Miniature Dachshunds.

The histopathologic characteristics of colorectal inflammatory polyps that formed in Miniature Dachshunds were compared with those of other colorectal proliferative lesions, including adenomas and adenocarcinomas. Fifty-three colorectal polypoid lesions were histopathologically classified into inflammatory polyps (26 cases), adenoma (18 cases), and adenocarcinoma (9 cases). All 26 dogs that were diagnosed with inflammatory polyps were Miniature Dachshunds, indicating that colorectal inflammatory polyps exhibit a marked predilection for this breed. The inflammatory polyps had complex histopathologic features and were classified into 3 stages based on their epithelial composition. In early stage (stage 1), the polyps tended to exhibit a thickened mucosa containing hyperplastic goblet cells, dilated crypts filled with a large amount of mucus, and mild lymphocyte and macrophage infiltration. In later stages (stages 2 and 3), more severe neutrophil infiltration, interstitial mucus accumulation, granulation tissue, and occasional osteoid tissue were seen. Also, a few small foci of dysplastic epithelial cells were detected. The hyperplastic goblet cells, which were a major component of the epithelium of the inflammatory polyps, were positive for cytokeratin 20 (CK20), while the dysplastic epithelial cells found in inflammatory polyps (stage 3) and the tumor cells of the adenomas and adenocarcinomas were negative for CK20. These CK20-negative epithelial cells exhibited cytoplasmic and nuclear immunoreactivity for beta-catenin. In addition, the epithelial cells in the inflammatory polyps demonstrated significantly higher cyclooxygenase 2 and fibroblast growth factor 2 expression than did those of the adenomas and adenocarcinomas, suggesting that the arachidonate cascade is involved in the development of colorectal inflammatory polyps in miniature dachshunds.

Expression of Autophagy-Related Proteins in the Spinal Cord of Pembroke Welsh Corgi Dogs With Canine Degenerative Myelopathy.

Canine degenerative myelopathy (DM) is a progressive neurodegenerative disease frequently found in Pembroke Welsh Corgi (PWC) dogs, and it has clinical and pathologic similarities to human amyotrophic lateral sclerosis. Autophagy is a major intracellular protein degradation system. Abnormalities of autophagy--resulting in cell death through mechanisms called type II programmed cell death--have recently been reported to occur in various neurodegenerative diseases, including amyotrophic lateral sclerosis. Thus, the distribution and expression levels of proteins involved in autophagy were examined in the spinal cords of 8 PWC dogs suffering from DM with superoxide dismutase mutation, 5 non-DM PWC dogs, and 6 Beagle dogs without neurologic signs. There was no significant difference in the ratio of neurons with microtubule-associated protein light chain 3 (LC3)-positive somata relative to those that were LC3 negative among the 3 groups, whereas the number of LC3-positive neurites was significantly increased in DM dogs. Punctate LC3 immunoreactivity did not colocalize with a lysosome marker, LAMP2 (lysosome-associated membrane protein 2). NBR1 (neighbor of BRCA gene 1) was localized mostly in reactive astrocytes, whereas there were p62 (p62/A170/SQSTM1)-positive foci in the neuropil of the spinal cord of DM dogs. Western blotting revealed in DM dogs the decreased expression of Beclin1 and Atg16 L, which are molecules involved in formation of the isolation membrane. These findings suggest that altered autophagosome degradation may result in LC3 and p62 accumulation in the DM spinal cord, whereas the early stage of membrane formation is likely to be downregulated.

Experimental transmission of AA amyloidosis by injecting the AA amyloid protein into interleukin-1 receptor antagonist knockout (IL-1raKO) mice.

The incidence of AA amyloidosis is high in humans with rheumatoid arthritis and several animal species, including cats and cattle with prolonged inflammation. AA amyloidosis can be experimentally induced in mice using severe inflammatory stimuli and a coinjection of AA amyloid; however, difficulties have been associated with transmitting AA amyloidosis to a different animal species, and this has been attributed to the "species barrier." The interleukin-1 receptor antagonist knockout (IL-1raKO) mouse, a rodent model of human rheumatoid arthritis, has been used in the transmission of AA amyloid. When IL-1raKO and BALB/c mice were intraperitoneally injected with mouse AA amyloid together with a subcutaneous pretreatment of 2% AgNO3, all mice from both strains that were injected with crude or purified murine AA amyloid developed AA amyloidosis. However, the amyloid index, which was determined by the intensity of AA amyloid deposition, was significantly higher in IL-1raKO mice than in BALB/c mice. When IL-1raKO and BALB/c mice were injected with crude or purified bovine AA amyloid together with the pretreatment, 83% (5/6 cases) and 38% (3/8 cases) of IL-1raKO mice and 17% (1/6 cases) and 0% (0/6 cases) of BALB/c mice, respectively, developed AA amyloidosis. Similarly, when IL-1raKO and BALB/c mice were injected with crude or purified feline AA amyloid, 33% (2/6 cases) and 88% (7/8 cases) of IL-1raKO mice and 0% (0/6 cases) and 29% (2/6 cases) of BALB/c mice, respectively, developed AA amyloidosis. These results indicated that IL-1raKO mice are a useful animal model for investigating AA amyloidogenesis.

Clinical and Pathologic Study of Feline Merkel Cell Carcinoma With Immunohistochemical Characterization of Normal and Neoplastic Merkel Cells.

The authors herein describe the morphologic and immunohistochemical features of normal Merkel cells as well as the clinicopathologic findings of Merkel cell carcinoma in cats. Merkel cells were characterized as vacuolated clear cells and were individually located in the epidermal basal layer of all regions examined. Clusters of Merkel cells were often observed adjacent to the sinus hair of the face and carpus. Immunohistochemically, Merkel cells were positive for cytokeratin (CK) 20, CK18, p63, neuron-specific enolase, synaptophysin, and protein gene product 9.5. Merkel cell carcinoma was detected as a solitary cutaneous mass in 3 aged cats (13 to 16 years old). On cytology, large lymphocyte-like cells were observed in all cases. Histologic examinations of surgically resected tumors revealed nests of round cells separated by various amounts of a fibrous stroma. Tumor cells were commonly immunopositive for CK20, CK18, p63, neuron-specific enolase, and synaptophysin, representing the characteristics of normal Merkel cells.

Prognostic value of increased intraepithelial lymphocytes and lymphocytic clonality in dogs with chronic enteropathy or small-cell lymphoma.

The clinical significance of severe infiltration of small intraepithelial lymphocytes (IEL) and the results of polymerase chain reaction for antigen receptor rearrangement (PARR) in dogs with chronic enteropathy (CE) and small-cell lymphoma (SCL) are controversial. This cohort study aimed to evaluate the prognostic significance of the IEL and PARR results in dogs with CE or SCL. Although definitive diagnostic histopathological criteria for SCL in dogs have yet to be established, dogs with the histopathological findings of severe IEL infiltration were diagnosed with SCL in this study. One hundred and nineteen dogs were recruited, with 23 dogs classified as having SCL and 96 dogs as having CE. The positive rate of PARR was 59.6 % (71/119) in the duodenum and 57.7 % (64/111) in the ileum. Subsequently, three dogs with SCL and four dogs with CE developed large-cell lymphoma (LCL). The median overall survival (OS) of dogs with SCL was 700 days (range, 6-1410 days), and that of dogs with CE was not reached. In the log-rank test, shorter OS was observed in cases with histopathological SCL (P = 0.035), clonal TCRγ rearrangement in the duodenum (P = 0.012), and clonal IgH rearrangement in the ileum (P < 0.0001). The Cox proportional hazards model adjusted for sex and age showed that histopathological SCL (hazard ratio [HR] 1.74; 95 % confidence interval [CI], 0.83-3.65), duodenal clonal TCRγ rearrangement (HR, 1.80; 95 % CI, 0.86-3.75), and ileal clonal IgH rearrangement (HR, 2.28; 95 % CI, 0.92-5.70) could shorten overall survival, although their 95 % CIs included 1.0. These results indicate that severe IEL infiltration could be a useful histopathological feature for diagnosing SCL, and clonality-positive results could be a negative prognostic factor in dogs with CE. Furthermore, the development of LCL should be carefully monitored in dogs with CE and SCL..

Beta amyloid deposition and neurofibrillary tangles spontaneously occur in the brains of captive cheetahs (Acinonyx jubatus).

Alzheimer disease is a dementing disorder characterized pathologically by Aß deposition, neurofibrillary tangles, and neuronal loss. Although aged animals of many species spontaneously develop Aß deposits, only 2 species (chimpanzee and wolverine) have been reported to develop Aß deposits and neurofibrillary tangles in the same individual. Here, the authors demonstrate the spontaneous occurrence of Aß deposits and neurofibrillary tangles in captive cheetahs (Acinonyx jubatus). Among 22 cheetahs examined in this study, Aß deposits were observed in 13. Immunostaining (AT8) revealed abnormal intracellular tau immunoreactivity in 10 of the cheetahs with Aß deposits, and they were mainly distributed in the parahippocampal cortex and CA1 in a fashion similar to that in human patients with Alzheimer disease. Ultrastructurally, bundles of straight filaments filled the neuronal somata and axons, consistent with tangles. Interestingly, 2 of the cheetahs with the most severe abnormal tau immunoreactivity showed clinical cognitive dysfunction. The authors conclude that cheetahs spontaneously develop age-related neurodegenerative disease with pathologic changes similar to Alzheimer disease.

Spontaneous intranasal tumours in degus (Octodon degus): 20 cases (2007-2020).

OBJECTIVE: The objective of this retrospective study was to describe the clinical and histopathological findings associated with intranasal tumours in degus. MATERIALS AND METHODS: Medical records of degus diagnosed with intranasal neoplasms on histopathological examination between the years 2007 and 2020 at one hospital were included in the study. RESULTS MEDICAL RECORDS OF DEGUS: Twenty degus (10 males and 10 females) were eligible for inclusion. Initial clinical signs included sneezing, abnormal nasal sounds, and nasal discharge, followed by anorexia and frequent nose rubbing. On radiography, 15 out of 20 animals showed space-occupying lesions in the nasal cavity. CT was performed in 16 animals and revealed various degrees of changes, including abnormal radiopacity within the nasal cavity and damaged nasal septum. Rhinostomy and excisional biopsy was performed in all 20 animals. Six out of 20 patients died during the perioperative period. Six and seven degus survived for 3 months and 1 year, respectively. One animal was lost to follow-up. In 16 cases the histological diagnosis was consistent with fibromas, while in 4 cases with osteomas. CLINICAL SIGNIFICANCE: Intranasal neoplasms in degus are mostly benign mesenchymal tumours with various degrees of bone formation, which is unique to this animal species. This occurrence should be considered as an important differential diagnosis for upper respiratory tract disease in degus.

Clinical and pathologic features of neuronal ceroid-lipofuscinosis in a ferret (Mustela putorius furo).

Clinical and pathologic features of neuronal ceroid-lipofuscinosis in a 4-month-old ferret are reported. Clinical signs including neurological symptoms appeared at 3 months of age and progressed rapidly. By magnetic resonance imaging, severe cerebral atrophy was recognized. Histopathologically, there was severe neuronal loss and diffuse astrogliosis with macrophage accumulations; lesions were found predominantly in the cerebral cortex. Intracytoplasmic pigments were observed in surviving neurons and macrophages throughout the brain. The pigments were intensely positive for periodic acid-Schiff, Luxol fast blue, and Sudan black B and exhibited a green autofluorescence. Electron microscopic examination revealed the accumulation of electron-dense granular material within lysosomes of neurons and macrophages. Immunohistochemically, a large number of saposin-positive granules accumulated in the neuronal cells, astrocytes, and macrophages of the lesions, but significant immunoreactivity for subunit c of mitochondrial adenosine triphosphate synthase was not observed. Based on these findings, the animal was diagnosed as affected by neuronal ceroid-lipofuscinosis.

Spontaneous oral tumours in 18 rabbits (2005-2015).

This retrospective study of a series of 18 cases aimed to describe the clinical and pathological findings of oral tumours in rabbits, as there have been few reports detailing spontaneous oral tumours in this species. A total of 13 different tumour types were diagnosed: squamous cell carcinoma (three), ameloblastoma (two), fibrosarcoma (two), osteosarcoma (two), cementoma (one), complex odontoma (one), giant cell epulis (one), sarcoma (one), chondrosarcoma (one), trichoepithelioma (one), papilloma (one), malignant melanoma (one) and basal cell carcinoma (one). Odontogenic tumours were relatively common in this study as compared to the oral tumours typically identified in dogs and cats. The most common clinical sign in this study was feeding abnormalities. Surgical excision and radiation therapy were found to be effective in rabbits.

Spontaneous intranasal tumours in rabbits: 7 cases (2007-2019).

OBJECTIVES: Neoplasms that arise in the nasal cavity are reported infrequently in rabbits. This case series aims to review and determine the clinical behaviour of neoplasms in the nasal cavity in rabbits. MATERIALS AND METHODS: A retrospective study was conducted on seven pet rabbits diagnosed with intranasal tumours to describe the clinical and histopathological findings and prognoses after surgery and/or radiotherapy. RESULTS: The most common clinical signs were nasal snoring when breathing, nasal discharge, and subsequent dyspnoea and anorexia. Six different histopathological types of tumours were diagnosed: intranasal adenocarcinoma, squamous cell carcinoma, osteosarcoma, carcinoid tumour, osteoma, and lymphoma. Skull radiography only revealed the abnormalities in three of seven cases but on CT, the intranasal masses were more clearly identified in all cases. All cases received tumour resection through rhinostomy and four cases received radiotherapy after surgery. In the six cases with a known outcome, the survival time after surgery was more than 13 months. CLINICAL SIGNIFICANCE: This case series provides an insight of the behavior of intranasal neoplasms in rabbits. Surgical treatment and radiotherapy could improve their clinical sings.

Histological and Immunohistochemical Features of Normal Histiocytes and Langerhans Cells, and Histiocytic Sarcomas in Four-Toed Hedgehogs (Atelerix albiventris).

Histiocytic sarcoma (HS) is a haematopoietic tumour of histiocyte origin that has been sporadically reported in four-toed hedgehogs (Atelerix albiventris). The present study aimed to investigate clinical, gross, histopathological and immunohistochemical features of HS in eight hedgehogs. Histological and immunohistochemical features of normal histiocytes and Langerhans cells (LCs) of hedgehogs were also investigated. HLA-DR-, Iba-1- and E-cadherin-positive LCs were observed in the epidermis, while Iba-1- and CD204-positive histiocytes were detected in the lymph nodes and spleen of normal hedgehogs. Localized HS (six cases) developed in the skin and spleen, while disseminated HS (two cases) occurred in the intestine. Tumour cells of disseminated HS were also distributed within the mesenteric lymph nodes, liver, kidney, spleen, lung and adrenal glands. Tumour cells of both localized and disseminated HS were composed of histiocytic cells, spindle to pleomorphic cells, multinucleated giant cells and erythrophagocytic cells. Most tumour cells were immunopositive for Iba-1, CD204 and lysozyme. A small number of tumour cells were positive for E-cadherin and CD208, and the tumour cells in one case were positive for HLA-DR. These results suggest that the tumour cells have variable features of histiocyte origin, including dendritic cells, LCs and macrophages. The behaviour of HS in the hedgehog was very aggressive, and 50% of cases died within 90 days of resection. The present study also highlighted the tendency for local tumour recurrence in localized cutaneous HS cases, suggesting a requirement for a long-term follow-up after excision.

Evaluation of epithelial and mesenchymal cell markers in canine urinary bladder transitional cell carcinoma.

Canine transitional cell carcinoma (cTCC) is the most common malignant tumour in the urinary bladder: it is highly invasive and exhibits metastatic characteristics. Inflammation is also strongly related to cTCC. Epithelial tumours often exhibit a mesenchymal cell phenotype during tumour invasion and metastasis owing to epithelial-mesenchymal transition (EMT), which is often induced in chronic inflammation. The aim of this retrospective study was to investigate the expression of epithelial and mesenchymal cell markers in tumour cells and to evaluate its relationship with prognosis of cTCC. In this study, 29 dogs with cTCC who underwent surgical treatment were enrolled. Clinical parameters were reviewed using medical records. Tissue expression of epithelial and mesenchymal markers was evaluated by immunohistochemical analysis. The association between the expression of mesenchymal cell markers and clinical parameters, including prognosis, was statistically examined. In five normal bladder tissues used as controls, no expression of mesenchymal markers was observed, except for one tissue that expressed fibronectin. Conversely, epithelial tumour cells expressed vimentin and fibronectin in 23/29 and 19/28 cTCC tissues, respectively. Regarding clinical parameters, vimentin score in Miniature Dachshunds was significantly higher than those in other dog breeds (P < 0.001). Multivariate survival analyses revealed that age>12 years was related to shorter progression-free survival (P = 0.02). Higher vimentin score, lower fibronectin score, and advanced clinical T stage were significantly correlated with shorter median survival time (P < 0.05). The results of this study indicate that vimentin expression was associated with cTCC progression. Further studies are needed to examine the incidence and relevance of EMT in cTCC.

An Outbreak of Fatal Bordetella bronchiseptica Bronchopneumonia in Puppies.

Twenty-two newborn puppies that did not receive colostrum exhibited acute respiratory signs and died at a breeding facility. Pathological examinations were performed on four of the puppies. At necropsy examination, the lungs were firm and mottled dark red, consistent with acute bronchopneumonia. Histopathologically, there was marked infiltration of neutrophils and macrophages into the bronchi and alveoli, and gram-negative coccobacilli were attached diffusely to the cilia of bronchial mucosa. Immunohistochemistry for Bordetella bronchiseptica antigen revealed positive labelling of the bacterial agents. On electron microscopy, a large number of coccobacilli were observed attaching to the cilia of bronchial epithelial cells. Real-time polymerase chain reaction amplified a B. bronchiseptica gene from the affected lung tissue. Based on these findings, the four puppies were diagnosed with fatal B. bronchiseptica bronchopneumonia.

Duodenal expression of antimicrobial peptides in dogs with idiopathic inflammatory bowel disease and intestinal lymphoma.

Although antimicrobial peptides (AMPs) play an integral role in the regulation of intestinal microbiota and homeostasis, their expression in canine gastrointestinal diseases, including idiopathic inflammatory bowel disease (IBD) and intestinal lymphoma, remains unknown. The objective of this study was to investigate the intestinal expression of AMPs in dogs with IBD or intestinal lymphoma. IBD was diagnosed in 44 dogs, small cell intestinal lymphoma in 25 dogs, and large cell intestinal lymphoma in 19 dogs. Twenty healthy beagles were used as normal controls. Duodenal mRNA expression of six representative AMPs - lactoferrin, lysozyme, cathelicidin, secretory leukocyte peptidase inhibitor (SLPI), bactericidal/permeability increasing protein (BPI), and canine beta defensin (CBD103) - was quantified by real-time reverse transcription polymerase chain reaction. The relative expression of BPI, lactoferrin, and SLPI was significantly higher in dogs with IBD and intestinal lymphomas than in healthy controls. Interestingly, the expression patterns of AMPs differed between dogs with IBD and those with intestinal lymphomas, especially small cell lymphoma. Increased expression of BPI differentiated IBD from dogs with small cell intestinal lymphoma, with a sensitivity of 93.2%, a specificity of 100%, and an area under the curve of 0.955. These results suggest that the expression patterns of AMP aid in the diagnosis of canine IBD and intestinal lymphoma, although it remains uncertain whether the altered AMP expression is the cause or effect of mucosal inflammation.

Expression of Stem Cell Factor in Feline Mast Cell Tumour.

Stem cell factor (SCF) is a ligand of the molecule Kit, which is expressed in mast cells and is important for mast cell proliferation, migration and survival. Mast cell tumours (MCTs) are associated with mutations of c-kit, a proto-oncogene encoding the Kit protein. In this study, we examined SCF expression in 23 samples of feline MCTs. SCF expression was detected in 10 cutaneous MCTs and a case of splenic mastocytosis. In the cutaneous MCTs, SCF-positive tumour cells were located at the margins. Kit was expressed in eight of the 10 cutaneous cases of SCF-expressing MCTs. In these cases, Kit-positive cells were located near to SCF-positive cells, and SCF/Kit double-positive tumour cells were found. Ki67-positive tumour cells were not found near to SCF-positive cells. These results suggest that SCF autocrine/paracrine mechanisms are involved in the expansion of cutaneous MCTs, but not in tumour proliferation.