Nine-year seroepidemiological study of severe fever with thrombocytopenia syndrome virus infection in feral horses in Cape Toi, Japan.

Severe fever with thrombocytopenia syndrome (SFTS) is a fatal zoonosis caused by ticks in East Asia. As SFTS virus (SFTSV) is maintained between wildlife and ticks, seroepidemiological studies in wildlife are important to understand the behavior of SFTSV in the environment. Miyazaki Prefecture, Japan, is an SFTS-endemic area, and approximately 100 feral horses, called Misaki horses (Equus caballus), inhabit Cape Toi in Miyazaki Prefecture. While these animals are managed in a wild-like manner, their ages are ascertainable due to individual identification. In the present study, we conducted a seroepidemiological survey of SFTSV in Misaki horses between 2015 and 2023. This study aimed to understand SFTSV infection in horses and its transmission to wildlife. A total of 707 samples from 180 feral horses were used to determine the seroprevalence of SFTSV using enzyme-linked immunosorbent assay (ELISA). Neutralization testing was performed on 118 samples. In addition, SFTS viral RNA was detected in ticks from Cape Toi and feral horses. The overall seroprevalence between 2015 and 2023 was 78.5% (555/707). The lowest seroprevalence was 55% (44/80) in 2016 and the highest was 92% (76/83) in 2018. Seroprevalence was significantly affected by age, with 11% (8/71) in those less than one year of age and 96.7% (435/450) in those four years of age and older (p < 0.0001). The concordance between ELISA and neutralization test results was 88.9% (105/118). SFTS viral RNA was not detected in ticks (n = 516) or feral horses. This study demonstrated that horses can be infected with SFTSV and that age is a significant factor in seroprevalence in wildlife. This study provides insights into SFTSV infection not only in horses but also in wildlife in SFTS-endemic areas.

Bursa atrophy at 28 days old caused by variant infectious bursal disease virus has a negative economic impact on broiler farms in Japan.

Infectious bursal disease (IBD), caused by IBD virus (IBDV), is highly contagious, immunosuppressive and causes a negative economic impact on poultry industry. IBDV-vaccinated broiler farms at south Kyushu, Japan had a bursa-to-bodyweight ratio (BB ratio) reduction at 28 days (d) old, followed by high mortality 30 d later. We analysed the influence of the IBDV on atrophy of the bursa of fabricius (BF) and the subsequent mortality after 30 d. Ten broilers were sampled at each timepoint from the farm with high mortality at 21, 25, 28 and 35 d. A second flock from the same farm was sampled at 14, 21, 25, 28, 35 and 42 d. IBDV was detected in BF samples at 25, 28 and 35 d and at 21, 25, 28 and 35 d in the first and second flocks, respectively, using immunohistochemical staining and RT-PCR. IBDV isolates from both flocks were closely related to the China KM523643 strain. Histopathology and TUNEL assay indicated apoptosis, severe lymphoid depletion, vacuoles within follicles, lymphoid follicle atrophy and fibrosis in the BF. We observed 75% of the polyserositis and 10% of the airsacculitis at 30 D in dead broilers. The antigenic variant IBDV infection was appeared to be the main influencing factor on BF atrophy and BB ratio reduction in the broilers. High mortality in the broilers after 30 d could be due to secondary infection. The disease caused by IBDV had a negative economic impact in the farm. RESEARCH HIGHLIGHTS New variant IBDV caused bursa atrophy and reduced BB ratio in 28-day-old broilers. After vIBDV had infected broilers, at 21 days old they became immunosuppressed. High mortality at 30 days old in broilers was due to secondary infection. New vIBDV has a negative economic impact on broiler farms in Japan.

A persistent epidemic of porcine epidemic diarrhoea virus infection by serological survey of commercial pig farms in northern Vietnam.

BACKGROUND: Porcine epidemic diarrhoea (PED) is a highly contagious infectious disease with negative economic impacts on the swine industry. PED outbreaks were reported from 2009 to 2015, but sporadic infection has been observed until now in Vietnam. However, the seroprevalence of PEDV infection has not yet been reported for commercial pig farms in Vietnam. The aim of this study was to assess the seroprevalence of PEDV infection in Vietnamese pig farms to reveal the endemic status of PEDV in northern Vietnam. RESULTS: A serological survey of PEDV infection was carried out using indirect ELISA in commercial pig farms in Hai Duong, Hung Yen and Thai Binh provinces in northern Vietnam in 2019. Twenty sera were randomly collected from each of 10 commercial pig farms, from each province; none of the farms had vaccinated for PEDV. Serological evidence of natural PEDV infection, expressed as a high antibody titre, was observed in the pig farms in all 3 provinces. The OD values were significantly higher (p < 0.001) for pig sera from Thai Binh than from Hai Duong and Hung Yen. No significant differences (p > 0.05) were detected for seropositivity to PEDV based on locality, age, pig breed and farm size. CONCLUSIONS: This study indicates serological evidence of natural PEDV infection with high antibody titre in commercial pig farms. PEDV infection was widespread among the pig population in these 3 provinces and that good management and strict biosecurity are needed at these pig farms.

Social defeat stress exacerbates atopic dermatitis through downregulation of DNA methyltransferase 1 and upregulation of C-C motif chemokine receptor 7 in skin dendritic cells.

DNA methylation is an epigenetic modification that regulates gene transcription. DNA methyltransferase 1 (DNMT1) plays an important role in DNA methylation. However, the involvement of DNMT1 and DNA methylation in the pathogenesis of atopic dermatitis (AD) remains unclear. In this study, microarray analysis revealed that peripheral blood mononuclear cells of AD patients with low DNMT1 expression (DNMT1-low) highly expressed dendritic cell (DC) activation-related genes. Also, DNMT1-low AD patients exhibited a higher itch score compared to AD patients with high DNMT1 expression (DNMT1-high). By using an AD-like mouse model induced by the application of Dermatophagoides farinae body ointment, we found that Dnmt1 expression was decreased, while the expression of C-C chemokine receptor type 7 (Ccr7) was upregulated in mouse skin DCs. Furthermore, mice exposed to social defeat stress exhibited Dnmt1 downregulation and Ccr7 upregulation in skin DCs. Additionally, dermatitis and itch-related scratching behavior were exacerbated in AD mice exposed to stress. The relationship between low DNMT1 and itch induction was found in both human AD patients and AD mice. In mouse bone marrow-derived DCs, Ccr7 expression was inhibited by 5-aza-2-deoxycytidine, a methylation inhibitor. Furthermore, in mouse skin DCs, methylation of CpG sites in Ccr7 was modified by either AD induction or social defeat stress. Collectively, these findings suggest that social defeat stress exacerbates AD pathology through Dnmt1 downregulation and Ccr7 upregulation in mouse skin DCs. The data also suggest a role of DNMT1 downregulation in the exacerbation of AD pathology.

Severe Degenerative Changes in Cryptorchid Testes in Japanese Black Cattle.

This is a histopathologic and endocrinologic study of 6 calves diagnosed with cryptorchidism. Cases 1-3 were diagnosed as resembling testicular regression syndrome. In cases 1 and 2, the extracted tissue was a small, firm, gray-white mass, and there was lack of obvious testicular tissue in case 3. Histopathologically, the excised tissue in cases 1-3 was a fibrotic testicular remnant with inflammation, mineralization, hemosiderin-laden macrophages or lipofuscin-laden macrophages, and lack of germ cells and interstitial endocrine cells. These findings were compared with cases 4-6, which were diagnosed as testicular hypoplasia due to cryptorchidism. These cases had small but otherwise grossly unremarkable intra-abdominal testicular tissue and histologically had a few germ cells and sustentacular cells with arrested spermatogenesis and an increase in interstitial endocrine cells. Cases 1-3 had more severe degenerative changes compared with cases 4-6. In case 2, the average diameter of the seminiferous tubules was much smaller than in cases 4-6, and there were few tubule cross sections. Anti-Müllerian hormone (214 pg/ml) was detected in the plasma of case 2. Based on the macroscopic and histopathologic findings as well as endocrinologic profiles, the testicular degeneration in cases 1-3 was considered similar to that of testicular regression syndrome. In this condition, it is thought that a normally developing intra-abdominal testis undergoes degeneration due to heat or a vascular disorder such as torsion.

Development of indirect enzyme-linked immunosorbent assay for detection of porcine epidemic diarrhea virus specific antibodies (IgG) in serum of naturally infected pigs.

BACKGROUND: Porcine epidemic diarrhea virus (PEDV) infection is a highly contagious infectious disease causing watery diarrhea, vomiting, dehydration and high mortality rate in newborn piglets. PEDV infection can cause high economic losses in pig industry. In Japan, a PEDV outbreak occurred with high mortality from 2013 to 2015. Even though until now, PEDV infection occurs sporadically. For the control and monitoring of PEDV infection, not only symptomatic pigs, but also asymptomatic pigs should be identified. The objective of this study is to develop and optimize novel indirect ELISA as a simple, rapid, sensitive and specific method for the detection of anti-PEDV antibodies and evaluate the efficacy of the assay as a diagnostic method for PED. RESULTS: One hundred sixty-two serum samples, consisting of 81 neutralization test (NT) positive and 81 NT negative sera, were applied to the assay. Indirect ELISA test based on whole virus antigen (NK94P6 strain) derived from Vero cell culture was evaluated by receiver operating characteristic (ROC) analysis with neutralization test (NT) as a reference method, and cut-off value was determined as 0.320 with sensitivity and specificity of 92.6 and 90.1%, respectively. The area under curve (AUC) was 0.949, indicating excellent accuracy of indirect ELISA test. There was significant positive correlation between indirect ELISA and neutralization test (R = 0.815, P < 0.05). Furthermore, the kappa statics showed the excellent agreement between these two tests (kappa value = 0.815). In addition, the sensitivity and specificity of preserved plates with different periods (1 day, 2 weeks, 1, 2, 3, 4, 5 and 6 months) after drying antigen coated plates were 100% and 80-100%, respectively. CONCLUSIONS: The developed indirect ELISA test in our study would be useful as a reliable test for serological survey and disease control of PEDV infection, and our pre-antigen coated ELISA plates can be preserved at 4 °C until at least 6 months.

MicroRNA-766-3p Contributes to Anti-Inflammatory Responses through the Indirect Inhibition of NF-κB Signaling.

MicroRNA (miRNA) is small RNA of 20 to 22 nucleotides in length and is stably present in plasma. Regulating the expression of miRNA taken into cells has been suggested as a general therapeutic approach. We identified the novel anti-inflammatory miRNA hsa-miR-766-3p and investigated its biological function in human rheumatoid arthritis (RA) fibroblast-like synoviocyte MH7A cells. To verify the function of the miRNA present in the plasma of RA patients, we performed a comprehensive analysis of the miRNA expression during abatacept treatment and identified eight miRNAs with significantly altered expression levels. Among these eight miRNAs, miR-766-3p was found to have a clear function. The expression of inflammatory genes in response to inflammatory stimuli was suppressed in MH7A transduced with miR-766-3p. We showed that miR-766-3p indirectly reduced the activation of NF-κB and clarified that this mechanism was partially involved in the reduction of the mineralocorticoid receptor expression. In addition, the inflammatory responses were suppressed in other types of cells. These results indicate the novel function of miR-766-3p, findings that may aid in the development of therapies to suppress inflammation, not only in RA but also in other diseases.

Molecular characterization of US-like and Asian non-S INDEL strains of porcine epidemic diarrhea virus (PEDV) that circulated in Japan during 2013-2016 and PEDVs collected from recurrent outbreaks.

BACKGROUND: Since late 2013, porcine epidemic diarrhea virus (PEDV) has reemerged in Japan and caused severe economic losses to the swine industry. Although PEDV vaccines have been used widely, the disease has swept rapidly across the county, and is commonly observed in PED-vaccinated farms, and has recurred in domestic herds. To better understand PEDVs responsible for the reemerging outbreaks in Japan, full-length spike (S), membrane (M), and nucleocapsid (N) genes of 45 PEDVs collected in Japan during 2013-2016, were sequenced and analyzed. RESULTS: Phylogenetic analysis based on S gene sequences revealed that all the recent field PEDVs were genetically distinct from the classical Japanese strains, and were classified into three genotypes: North American (NA), S INDEL, and Asian non-S INDEL. Our data suggested a possibility that multiple parental PEDV strains were introduced into Japan from abroad at the same time or similar times. The newly identified Japanese strains showed the closest relationship to the US strains. Two sublineages of Japanese strains circulating in Japan were similar to two sublineages identified in the US, suggesting common ancestors for these strains. In comparison with two vaccine strains used in Japan, the field strains had various changes in epitope regions, glycosylation sites, and phosphorylation sites. These substitutions, particularly observed in epitope regions of the S (521, 553, 568, and 570), M (5), and N (123, 252, and 255) proteins, may have affected antigenicity and vaccine efficacy, resulting in an unsuccessful PEDV control. Sequence comparisons between PEDVs collected from primary and secondary outbreaks in three herds revealed that the disease has developed to an endemic stage in which PEDV could persist for nearly two years in the herds or local regions, causing subsequent epidemics. CONCLUSIONS: These results elucidate the genetic characteristics, origin, and molecular epidemiology of PEDVs circulating in Japan, as well as the PEDV strains causing recurrent outbreaks. This study provides a better insight into the PEDVs responsible for recent outbreaks in Japan, and could potentially help to develop measures for controlling and preventing the disease.

JAK inhibitor has the amelioration effect in lupus-prone mice: the involvement of IFN signature gene downregulation.

BACKGROUND: We previously reported that JAK-STAT-pathway mediated regulation of IFN-regulatory factor genes could play an important role in SLE pathogenesis. Here, we evaluated the efficacy of the JAK inhibitor tofacitinib (TOFA) for controlling IFN signalling via the JAK-STAT pathway and as a therapeutic for SLE. RESULTS: We treated NZB/NZW F1 mice with TOFA and assessed alterations in their disease, pathological, and immunological conditions. Gene-expression results obtained from CD4+ T cells (SLE mice) and CD3+ T cells (human SLE patients) were measured by DNA microarray and qRT-PCR. TOFA treatment resulted in reduced levels of anti-dsDNA antibodies, decreased proteinuria, and amelioration of nephritis as compared with those observed in control animals. Moreover, we observed the rebalance in the populations of naïve CD4+ T cells and effector/memory cells in TOFA-treated mice; however, treatment with a combination of TOFA and dexamethasone (DEXA) elicited a stronger inhibitory effect toward the effector/memory cells than did TOFA or DEXA monotherapy. We also detected decreased expression of several IFN-signature genes Ifit3 and Isg15 in CD4+ from SLE-prone mice following TOFA and DEXA treatment, and IFIT3 in CD3+ T cells from human patients following immunosuppressant therapy including steroid, respectively. CONCLUSION: Modulation of type I IFN signalling via JAK-STAT inhibition may exert a beneficial effect in SLE patients, and our results suggest that TOFA could be utilised for the development of new SLE-specific therapeutic strategies.

Experimental induction of chicken amyloid A amyloidosis in white layer chickens by inoculation with inactivated vaccines.

We investigated the amyloidogenic potential of inactivated vaccines and the localized production of serum amyloid A (SAA) at the injection site in white layer chickens. Hens in the treated group were injected intramuscularly three times with high doses of inactivated oil-emulsion Salmonella Enteritidis vaccine and multivalent viral and bacterial inactivated oil-emulsion vaccines at two-week intervals. Chickens in the control group did not receive any inoculum. In the treated group, emaciation and granulomas were present, while several chickens died between 4 and 6 weeks after the first injection. Hepatomegaly was seen at necropsy, and the liver parenchyma showed inconsistent discolouration with patchy green to yellowish-brown areas, or sometimes red-brown areas with haemorrhage. Amyloid deposition in the liver, spleen, duodenum, and at injection sites was demonstrated using haematoxylin and eosin staining, Congo red, and immunohistochemistry. The incidence of chicken amyloid A (AA) amyloidosis was 47% (28 of 60) in the treated group. In addition, RT-PCR was used to identify chicken SAA mRNA expression in the liver and at the injection sites. Furthermore, SAA mRNA was detected by in situ hybridization in fibroblasts at the injection sites, and also in hepatocytes. We believe that this is the first report of the experimental induction of systemic AA amyloidosis in white layer chickens following repeated inoculation with inactivated vaccines without the administration of amyloid fibrils or other amyloid-enhancing factors.

Intestinal perforation due to hemorrhagic Cytomegalovirus enteritis in a patient with severe uncontrolled lupus nephritis: a case and review of the literature.

A 31-year-old woman with systemic lupus erythematosus and lupus nephritis was treated with prednisone and immunosuppressants. After her lupus nephritis symptoms worsened, both high-dose steroid and cyclophosphamide pulse therapy were administered. The patient developed an intestinal perforation, and laparoscopic Hartmann's surgery was performed on the sigmoid colon. Serum Cytomegalovirus (CMV) antigen C7HRP was detected, and the patient was diagnosed with CMV colitis and underwent a colon resection. Severe hematochezia continued despite ganciclovir administration, and the patient underwent laparoscopic total colectomy and partial ileostomy. CMV enteritis should be considered in patients treated with prednisone and immunosuppressants and those who have abdominal pain and hematochezia. Immunocompromised patients with intestinal perforation due to CMV enteritis have a poor prognosis. We report a case with along with the results of a literature review.

A case of hydronephrosis due to intrarenal ureteral obstruction in a Japanese Black calf.

A 23-day-old Japanese Black female calf presented with distension of the lower abdomen. Abdominal ultrasonography revealed a cystic structure with fluid accumulation and moderate echoluminance in the right abdominal cavity. Ultrasonography and contrast-enhanced computed tomography revealed congenital hydronephrosis due to narrowing of the intrarenal ureter, and right kidney resection was performed. Blood urea nitrogen and serum creatinine levels, which were within reference values preoperatively, peaked on the third postoperative day and gradually decreased afterward until reaching preoperative values on the tenth day. In bovine hydronephrosis, nephrectomy may provide a favorable prognosis if one kidney is intact. Moreover, this case suggests that blood tests immediately after surgery are not suitable for evaluating residual kidneys.

Hepatocellular carcinoma with lung metastasis showing hemochromatosis in an Egyptian fruit bat (Rousettus aegyptiacus).

After an Egyptian fruit bat (Rousettus aegyptiacus) in a zoo became emaciated and died, a necropsy revealed multiple nodules on the liver and lung surfaces. Microscopy revealed that the liver nodules consisted of neoplastic hepatocytes and showed metastasis in the lung lobes. Most of the neoplastic cells in the liver and lung showed positive labeling for HepPar-1, cytokeratin 19, glypican-3, and Ki-67. Hepatocellular degeneration and necrosis were diffuse in the liver parenchyma. Berlin blue staining revealed large amounts of iron in normal and neoplastic cells. Based on these pieces of evidence, this case was diagnosed as hepatocellular carcinoma with hemochromatosis. This is believed to be the first report of hepatocellular carcinoma in an Egyptian fruit bat that has been immunophenotypically examined in detail by pathological examination.

Expression patterns of aquaporins 1, 3, 5 in canine mammary gland carcinomas.

Aquaporins (AQPs) are water channel proteins, and the expression of AQPs in carcinoma cells has received much attention over the last 15 years. In the veterinary field, however, little is known about the expression of AQPs. In the present study using immunohistochemistry, we examined the expression of AQP1, AQP3, and AQP5 in canine mammary gland carcinomas. The 27 samples comprised 10 grade I, 12 grade II, and 5 grade III samples (See Materials and Methods section for grade classification method). AQP1 was expressed in only 2 of the grade III carcinomas, and the expression was limited to spindle-shaped cells in the solid structure and on the outside of the solid mass. AQP3-positive cells were observed in 20 of 22 grade I and II samples. On the other hand, among grade III carcinomas, AQP3 was expressed only in spindle-shaped cells in 1 sample. AQP5 was expressed in all grade I and II carcinomas but not in the grade III tumors. In addition, enhanced expression of basolateral AQP3 and apical AQP5 was observed in lobular hyperplastic cells. These results suggest that the expression patterns of AQP3 and AQP5 can be of help for judging the grading of canine mammary tumors and that AQP1 is likely to be involved in metastasis. Moreover, AQP3 and AQP5 might be relevant to lactation in female dogs.

Aquaporin 3 is expressed in the basaloid cells of canine sebaceous glands.

The role of aquaporin proteins (AQPs) in tumor biology has attracted attention over the past 20 years. However, the expression profiles of AQPs in canine sebaceous gland tumors remain obscure. This study was performed to clarify the expression of AQP1, 3, 5, the most studied AQPs in tumor biology, in sebaceous adenoma and sebaceous epithelioma. Among these AQPs, only AQP3 was expressed in normal tissue and both tumor types and located to only undifferentiated sebocytes (basaloid cells). A cellular proliferation marker, Ki-67, was detected only in the area including basaloid cells in both tumor types. These findings suggest that AQP3 is useful for clarifying the origin of sebaceous gland tumors, and that AQP3 may be related to sebaceous gland development.

Nectin4 is an epithelial cell receptor for canine distemper virus and involved in neurovirulence.

Canine distemper virus (CDV) uses signaling lymphocyte activation molecule (SLAM), expressed on immune cells, as a receptor. However, epithelial and neural cells are also affected by CDV in vivo. Wild-type CDV strains showed efficient replication with syncytia in Vero cells expressing dog nectin4, and the infection was blocked by an anti-nectin4 antibody. In dogs with distemper, CDV antigen was preferentially detected in nectin4-positive neurons and epithelial cells, suggesting that nectin4 is an epithelial cell receptor for CDV and also involved in its neurovirulence.

Surgical management of a dermoid cyst with mandibular gland tissue in a Japanese Black calf.

A 131-day-old male Japanese Black calf presented with a swollen right cheek from birth. Imaging examination revealed a cyst under the right buccal area and debris-containing fluid inside the cyst, and puncture aspiration revealed a mildly cloudy fluid containing hair and tissue fragments. Histological examination of the excised cyst revealed stratified squamous epithelium with skin appendages in the cyst wall, which was diagnosed as a dermoid cyst. In addition, some submandibular gland tissue was found within the cyst wall. After removal of the cyst, there was swelling in the same area, which resolved with steroid administration. Surgical treatment of buccal dermoid cysts should be performed with caution to avoid damage to adjacent salivary gland tissue.

Generation of a Porcine Cell Line Stably Expressing Pig TMPRSS2 for Efficient Isolation of Swine Influenza Virus.

Pigs are important animals for meat production but can carry several zoonotic diseases, including the Japanese encephalitis virus, Nipah virus, and influenza viruses. Several Orthomyxoviridae and Coronavirinae respiratory viruses require cleavage of envelope proteins to acquire viral infectivity and consequently, need a host protease or the addition of exogenous trypsin for efficient propagation. Host TMPRSS2 is a key protease responsible for viral cleavage. Stable expression of human TMPRSS2 in African green monkey-derived Vero cells can enhance the porcine epidemic diarrhea virus. However, considering the narrow host tropism of viruses, a porcine cell line expressing pig TMPRSS2 could be optimal for replicating pig-derived viruses. Herein, we generated and evaluated a pig-derived PK-15 cell line stably expressing pig TMPRSS2. This cell line markedly (>1000-fold) and specifically enhanced the growth of influenza viruses. Furthermore, we demonstrated the usefulness of a PK-15 cell line lacking the Stat2 gene with a stable expression of pig TMPRSS2 for efficient virus isolation from clinical samples in the presence of type I interferons. Therefore, PK-15 cells expressing pig TMPRSS2 could be a valuable and promising tool for virus isolation, vaccine production, and virological studies of TMPRSS2-dependent viruses.

Antimicrobial resistance in Salmonella serovars isolated from meat shops at the markets in North Vietnam.

A total of 97 out of 245 carcass, sewage effluent, and table surface samples in meat shops at the retail markets in North Vietnam showed Salmonella positive. Eleven Salmonella serovars, including Infantis, Anatum, Rissen, Reading, London, Typhimurium, Enteritidis, Agona, Newport, Emek, and Derby, were identified. The Salmonella isolates were tested for antimicrobial susceptibility and further investigated for antimicrobial resistance genes. Resistance to kanamycin, gentamicin, neomycin, nalidixic acid, chloramphenicol, trimethoprim, streptomycin, tetracycline, ampicillin, and sulphonamides was found in 28.9-56.7%. The isolates were neither resistant to ceftazidime nor norfloxacin. Sixty-four (66.0%) out of 97 isolates were resistant to at least one of 14 antimicrobials, and 55 (85.9%) out of the 64 isolates showed multidrug resistance. Thirteen resistance genes (bla(TEM), bla(OXA-1), aadA1, sul1, tetA, tetB, tetG, cmlA1, floR, dfrA1, dfrA12, aac(3)-IV, and aphA1-1AB) were detected in the resistant isolates. This study indicates that Salmonella isolated from meat shops were resistant to multiple antimicrobials, and the resistance genes were widespread among the serovars isolated.

Adenomyomatous uterine polyp in a Miniature Pinscher: histologic, immunohistochemical, and clinical aspects.

A 14-y-old Miniature Pinscher bitch was admitted to a veterinary clinic because of inappetence and a distended abdomen; ultrasound examination revealed a fluid-filled uterus with a single 1-cm hyperechoic nodule in its lumen. Ovariohysterectomy was performed. Grossly, the uterine horns were distended irregularly and asymmetrically, and the uterine lumen contained 200-300 mL of brown watery fluid. A single white polypoid 0.9-cm diameter nodule was present at the site of the distended uterine horn and arose from the endometrium with a narrow stalk. Histologically, the polyp consisted of dense, smooth muscle fascicles admixed with glandular components; its surface was covered by simple cuboidal epithelium with areas of squamous metaplasia. The myomatous cells expressed the myogenic markers smooth muscle actin and desmin. We interpreted the mass as an adenomyomatous uterine polyp, which is a rare variant of an endometrial polyp.