Monoclonal proliferation of B-cells with two integration sites of bovine leukemia virus proviral DNA in cattle with enzootic bovine leukosis

The present study analyzed B-cell clonality and bovine leukemia virus (BLV) provirus integration sites in cattle with enzootic bovine leukosis (EBL) having BLV proviral copy numbers less or greater than the number of bovine nucleated cells. EBL cattle with BLV copy numbers less than the number of bovine nucleated cells showed monoclonal and biclonal proliferation of B-cells with one BLV provirus integration site. On the other hand, EBL cattle with BLV copy numbers greater than the number of bovine nucleated cells showed monoclonal proliferation of B-cells with two BLV provirus integration sites. These results suggest that superinfection of BLV can occur in EBL cattle.

Diffuse large B-cell lymphoma with DNA copy number changes in a Japanese black calf

A 2-month-old Japanese Black calf exhibited mandibular and superficial cervical lymph node swelling. Fine needle aspiration cytology of the superficial cervical lymph node revealed large lymphoblast-like cells with mitoses. Hematological examination revealed remarkable lymphocytosis with atypical lymphocytes. Increased activities of serum total lactate dehydrogenase and thymidine kinase were detected. At necropsy, generalized swelling of lymph nodes was observed. Histopathological analysis revealed diffuse proliferation of medium-sized round centroblastic neoplastic cells that were positive for CD20, CD79α, PAX5, and BLA-36, and negative for CD3, CD5, CD10, and CD34. The calf was diagnosed with centroblastic diffuse large B-cell lymphoma (DLBCL) based on these findings. Analysis of DNA copy number variation revealed an increased copy number for the GIMAP family relative to that in healthy cattle. Moreover, decreases in copy numbers of GBP-1, MIR3141, OR5P1E, and PTPRG relative to those in healthy cattle were also observed. Because DNA copy number variation represent a major contribution to the somatic mutation landscapes in human tumors, these findings suggest that DNA copy number changes might have contributed to the onset of DLBCL in the present case.

BoLA-DRB3*15:01 allele is associated with susceptibility to early enzootic bovine leukosis onset in Holstein-Friesian and Japanese Black cattle

Enzootic bovine leukosis (EBL) is typically observed in cattle older than 3 years, but some cases of onset in cattle younger than 3 years have been reported in Japan. BoLA-DRB3 polymorphisms are associated with susceptibility to EBL onset. However, little is known about the relationship between the polymorphisms and EBL onset in young cattle. In the present study, we performed BoLA-DRB3 genotyping in 59 EBL cattle younger than 3 years (25 Holstein-Friesian and 34 Japanese Black) and compared the results with those of 69 EBL cattle older than 3 years (38 Holstein-Friesian and 31 Japanese Black). The BoLA-DRB3*15:01 allele was detected at a frequency of 37.3 % (48.0 % and 29.4 % in Holstein-Friesian and Japanese Black, respectively) and was identified as an early EBL onset susceptibility allele. Nine EBL cattle younger than 3 years (5 Holstein-Friesian and 4 Japanese Black), but only 1 EBL cattle older than 3 years (1 Holstein-Friesian), had a BoLA-DRB3*15:01/*15:01 homozygous genotype. The frequency of the BoLA-DRB3*15:01 allele occurring with a different allele (BoLA-DRB3*015:01/other) in cattle younger than 3 years was 44.1 % (56.0 % Holstein-Friesian and 35.3 % Japanese Black) and significantly higher than that in cattle older than 3 years (28.9 % Holstein-Friesian and 9.7 % Japanese Black) (P = 0.0013). These results suggest that BoLA-DRB3*15:01/*15:01 and BoLA-DRB3*15:01/other genotypes are early EBL onset susceptibility genotypes. The present findings may contribute to cattle breeding selection.

Phylogenetic analysis based on whole genome sequence of bovine leukemia virus in cattle under 3 years old with enzootic bovine leukosis

Enzootic bovine leukosis (EBL) is one of bovine neoplasms caused by bovine leukemia virus (BLV). Although EBL is typically observed in cattle over 3 years old, several cases of EBL onset in cattle under 3 years old have been reported in Japan. The mechanism for EBL onset in young cattle remains unclear. Although genetic variation of BLV is limited, the variations could affect viral properties relating to BLV pathogenesis. The purpose of this study was to clarify relationship between early onset of EBL and BLV groups. Moreover, we also aimed to characterize BLV that cause early onset of EBL. Whole genome sequences of BLV in 72 EBL cattle under 3 years old and 50 EBL cattle over 3 years old were identified. Phylogenetic analysis showed that BLV was divided into 4 groups (A, B-1, B-2 and Other). The BLV from EBL cattle under 3 years old were mainly classified as group A and B-1, while those from EBL cattle over 3 years old were mainly included in group B-2. Common sequence of group A and B-1 was compared with those of group B-2. Specific sequences in LTRs, gag-pro-pol, env and tax gene regions were identified in these groups. Amino acid substitutions of Pro and Tax protein were predicted in those nucleotide sequences. Those genetic variations might contribute to the early onset of EBL.

Time course changes in peripheral B-cell clonality in a Japanese Black bull with enzootic bovine leukosis

A 38-month-old Japanese Black bull presenting with anorexia was given supportive treatment without improvement. Findings including bovine leukemia virus positivity and monoclonal B-cell proliferation strongly suggested the onset of enzootic bovine leukosis (EBL). Pathological findings confirmed the diagnosis of EBL. B-cell clonality were analyzed over time using pre-onset preserved genomic DNA at ages 6 months, 16 months, and 30 months. In the B-cell clonality analysis, two minor peaks at 140 and 220 bp were observed before onset, but another large peak at 175 bp appeared at the time of EBL diagnosis. Although the reason for the proliferation of an independent clone is unknown, detection of clonality abnormalities may lead to the detection of cattle at high risk of developing EBL.

Enzootic bovine leukosis in a 21-month-old Japanese Black cow with high susceptibility

A 21-mo-old Japanese Black beef cow had swollen mandibular and superficial cervical lymph nodes. Fine-needle aspiration cytology of the superficial cervical lymph node revealed large lymphoblasts with mitoses present. The bovine leukemia virus (BLV) proviral load was relatively high, and phylogenetic analysis of the whole BLV genome classified the BLV strain as one with high viral replication activity. Genotyping of bovine leukocyte antigen genes indicated that the cow was susceptible to enzootic bovine leukosis (EBL). The bone morphogenetic protein 6 (BMP6) gene promoter region was hypermethylated. Monoclonal proliferation of B cells and monoclonal integration of the BLV provirus in the bovine genome were detected by a clonality test of B cells and an inverse PCR assay, respectively. At autopsy, generalized swelling of lymph nodes and spinal canal invasion by tumor tissue at vertebrae L5-6 were observed. Histologic analysis revealed diffuse proliferation of large round neoplastic cells that were positive for BLA36 and negative for CD3. The cow was definitively diagnosed with EBL based on these findings. Infection with a highly pathogenic strain of BLV, susceptibility of the BoLA-DRB3 alleles, and hypermethylation of the BMP6 gene may have contributed to the development of EBL in our case.

Congenital syringohydromyelia in a crossbred (Holstein-Friesian × Japanese Black) beef calf

A 5-day-old male crossbred beef calf presented with a well-coordinated bilateral hopping gait of the hind limbs. Postmortem CT showed a poorly defined oval-shaped region at the L3–L4 spinal segments, which had high signal intensity on T2 weighted postmortem MRI images. On pathological examination, we identified a large cystic cavity filled with a large amount of cerebrospinal fluid on the cut surface of the spinal region. Histopathological examination revealed that the spinal cord parenchyma was compressed by the cystic structure, and the cystic cavity was lined with a thin layer of discrete ependymal cells, indicating syringohydromyelia. This is the first reported case of a Holstein-Friesian × Japanese Black crossbred calf with solitary syringohydromyelia. Our findings suggest that myelodysplasia with cystic cavities can be suspected by CT, without the need for MRI.

Congenital cutaneous fibropapillomatosis without evidences of papillomavirus infection in a Holstein-Friesian calf

A male Holstein-Friesian calf was born with multiple, cauliflower-like, pale pink cutaneous masses on the head and limbs. On histopathological examination, the cutaneous masses were diagnosed as congenital cutaneous fibropapillomatosis. Those lesions involved focal proliferation of sebaceous gland in the dermis. There were no histological findings to suggest bovine papillomavirus infection, such as the presence of intranuclear inclusion bodies, large keratohyalin granules, and koilocytosis. Furthermore, papillomaviral antigens and DNA were not detected by immunohistochemistry and polymerase chain reaction, respectively. These results suggested that there was no association between these cutaneous lesions and bovine papillomavirus infection, and the lesions were considered as harmartomatous changes.

Abnormal clonalities of B-lymphocytes in bovine leukemia virus-infected cattle with persistent lymphocytosis

Peripheral B-lymphocyte clonality of 274 bovine leukemia virus-infected cattle with lymphocytosis was analyzed using clonality PCR based on sequences of the variable region of the bovine immunoglobulin H chain. None of the cattle showed monoclonal proliferation, while 10, 31, and 233 showed minor-clonal, oligoclonal, and polyclonal proliferation, respectively. A total of 163 cattle were analyzable the following year, and lymphocytosis was maintained in 157, indicating persistent lymphocytosis (PL). B-lymphocyte clonality of the 157 PL cattle was minor-clonal in 6 (3.8%), oligoclonal in 8 (5.1%), and polyclonal in 143 (91.1%). A higher rate of enzootic bovine leukosis (EBL) onset within a year was observed in PL cattle with minor-clonal (50.0% (3/6)) and oligoclonal (25.0% (2/8)) proliferation compared to those with polyclonal (5.6% (8/143)) proliferation. Minor-clonal and oligoclonal proliferation in PL cattle may be a prognosis factor for developing EBL.

Acute myelomonocytic leukemia negative for alpha-naphthyl acetate esterase stain in a Holstein cow

A 4-year, 7-month-old Holstein cow presented with anorexia. Physical examination revealed masses in the interscapular region and vagina. Blast cells were detected in the masses and peripheral blood by fine needle aspiration cytology and hematological examination. By bone marrow aspiration, blast cells constituted up to 24.2% of all nucleated cells, and 22% and 2% of non-erythroid cells stained positive for myeloperoxidase and alpha-naphthyl acetate esterase (ANAE), respectively. Pathological examination revealed the mass lesions consisted of a proliferation of tumor cells, which were positive for monocytic markers (HLA-DR and Iba-1). The cow was diagnosed with acute myelomonocytic leukemia (AMML). Even when tumor cells are ANAE-negative, AMML cannot be completely ruled out and should be considered when diagnosing cattle with leukemia/lymphoma.

Analysis of the bone morphogenetic protein 6 gene promoter region in young beef cattle affected by enzootic bovine leukosis

Enzootic bovine leukosis (EBL) is typically observed in cattle over 3 years old. However, some cases of EBL onset in young beef cattle have been reported in Japan. The mechanism for early EBL onset is unclear. In Japan, beef cattle are given large amounts of concentrated feed with low vitamin A. Bone morphogenetic proteins (BMPs) are regulators of cell proliferation, differentiation, and apoptosis, and thought to represent one of the key players in tumor malignancy. The purpose of this study was to evaluate the differences in BMP-6 methylation status between EBL beef cattle under 3 years old and other cattle. We investigated the methylation status of the BMP-6 promoter region in 32 EBL beef cattle under 3 years old. We also compared the methylation status of EBL dairy cattle to that of healthy cattle. Median methylation rate of the BMP-6 promoter region in EBL beef cattle under 3 years old was 8.9%, which was significantly higher than that of other groups. Hypermethylation of the BMP-6 promoter region might contribute to early onset of EBL in beef cattle under 3 years old, and animal feeding management practices specific to beef cattle may affect the methylation status of the BMP-6 promoter region.

A clinical case of acute myelomonocytic leukemia in a Holstein cow

A 2-year, 3-month-old Holstein cow presented with anorexia and enlarged superficial lymph nodes. Fine needle aspiration cytology of the superficial lymph nodes revealed large blast cells. Hematological examination revealed anemia, neutropenia, and blast cells in peripheral blood. Blast cells were the predominant cell type in bone marrow aspirates. Of the non-erythroid cells, 26%, 58%, and 18% were positive for myeloperoxidase, α-naphthyl acetate esterase, and naphthol AS-D chloroacetate esterase, respectively. Pathological examination revealed the proliferation of neoplastic cells, which were positive for monocytic markers, in the affected lymph nodes. The cow was diagnosed with acute myelomonocytic leukemia based on these findings. This report highlights the importance of performing bone marrow aspiration cytology and cytochemical staining when diagnosing bovine myeloid leukemia.

A clinical case of single left ventricle in a Holstein calf

A 15-day-old Holstein calf with lethargy and tachypnea presented to the Veterinary Teaching Hospital at Obihiro University of Agriculture and Veterinary Medicine for evaluation of suspected congenital heart defect. A Levine grade 6 systolic murmur was noted at right apical site auscultation and phonocardiogram also recorded systolic a murmur. Electrocardiography findings include increased R and S waves, R wave split, and negative T waves without arrhythmia. Echocardiography revealed a single ventricle with a trace of the right ventricular wall, atrioventricular valve regurgitation, and turbulent in a single ventricle. Arterial blood analysis showed a marked decrease in oxygen saturation of 78% and oxygen partial pressure of 44 mmHg. Post-mortem examination confirmed the diagnosis of a single left ventricle.

A clinical case of presumed cerebellar medulloblastoma in a Japanese Black calf with increased neuron-specific enolase in cerebrospinal fluid

A 2-day-old Japanese Black male calf that presented with opisthotonos with spastic extension of all four limbs and nystagmus was presented. Evaluation of cranial neurology revealed a horizontal slow nystagmus and absence of menace response in the left eye. Necropsy revealed a mass located between the posterior margin of the cerebrum and anterior margin of the cerebellum, and continuously with the cerebellar lesion. The brainstem was severely compressed by those lesions. Original structures of the cerebellum were mostly replaced by grayish-white and brownish tissues. Those lesions were diagnosed as presumed cerebellar medulloblastoma by histopathological and immunohistochemical examination. As neuron-specific enolase in the cerebrospinal fluid which is a biomarker for neuronal damage was increased compared with healthy calves.

Development and evaluation of a novel loop-mediated isothermal amplification (LAMP) method targeting Theileria parasites infecting Yezo sika deer

The increasing Yezo sika deer (Cervus nippon yesoensis) population is creating a large problem. Yezo sika deer are an important blood meal source, and these deer contribute to the maintenance of tick populations. Theileria spp. infections in Yezo sika deer and T. orientalis infections in cows occur at high frequencies, and the same tick species infests both deer and cows. Therefore, a specific detection method to identify deer Theileria spp. is important. In this study, we establish a novel molecular detection method for identifying Theileria spp. from deer and tick samples using loop-mediated isothermal amplification (LAMP). This method targets a metalloprotease/cell division cycle protein gene homologue. Our LAMP protocol was able to detect deer Theileria and did not show cross reactivity with other closely related protozoan parasites, including T. orientalis. The LAMP method showed sensitivity and specificity equivalent to those of nested PCR performed on the same field samples from deer and ticks. These results demonstrate the applicability of LAMP to field surveys in which the detection of deer Theileria spp. is required. In conclusion, due to its simplicity, specificity, and reliability, we suggest our LAMP protocol as an appropriate method for routine surveys to detect Yezo sika deer and ticks infected with deer Theileria spp. parasites. Additionally, this LAMP method offers great promise as a useful tool to distinguish Yezo sika deer Theileria from related Theileria parasites present in livestock.

Evaluation of Neospora caninum serodiagnostic antigens for bovine neosporosis

Abortion and reproductive failure caused by Neospora caninum infection has a dramatic negative economic impact on the cattle industry. To date, no definitive serodiagnostic tool for assessing N. caninum abortion has been reported. In this study, we evaluated the diagnostic performance of numerous N. caninum antigens in relation to abortion in cattle. Five recombinant proteins with potential as diagnostic antigens (NcGRA6, NcGRA7, NcGRA14, NcCyP, and NcSAG1) were compared by indirect enzyme-linked immunosorbent assay (iELISA) using sera from mice and cattle experimentally infected with N. caninum. The best-performing three antigens (NcSAG1, NcGRA7, and NcGRA6) were evaluated by IgG-iELISAs to assess their utility in diagnosing Neospora abortion using sera from confirmed N. caninum-aborted dams based on immunohistochemical assays (IHC). Additionally, all samples were tested using a commercial N. caninum antibody competitive ELISA (cELISA). The iELISAs against both NcSAG1 and NcGRA7 could efficiently distinguish IHC positive and negative samples compared with iELISAs against NcGRA6 and the cELISA. Furthermore, antibody levels against NcSAG1 and NcGRA7 were significantly higher in aborting cows comparing with infected but non-aborted dams in a herd experiencing a Neospora abortion outbreak. Tracking the dynamics of antibody levels during pregnancy revealed a marked increase in NcSAG1- and NcGRA7-specific antibodies at the last trimester of pregnancy. In contrast, no marked differences in antibody levels against either antigen were noted in neurologically symptomatic calves compared with non-symptomatic infected calves. Our data suggests NcSAG1 and NcGRA7 as indicators for Neospora abortion.

Molecular diagnosis of bovine B-cell lymphoma using polymerase chain reaction for immunoglobulin heavy chain gene

We performed a clonality analysis using polymerase chain reaction (PCR) for immunoglobulin heavy chain (IgH) gene rearrangement, specifically with regard to its utility as a method to diagnose bovine B-cell lymphoma. PCR for IgH gene rearrangement indicated monoclonal proliferation of B-cells in 24 of 35 cattle with B-cell lymphoma. In contrast, PCR for IgH gene rearrangement in lymph nodes and tumor tissues from 65 cattle diagnosed with tumors other than B-cell lymphoma and non-tumors revealed polyclonal population of B-cells. Sensitivity, specificity, positive predictive value, and negative predictive value for PCR for IgH gene rearrangement for bovine B-cell lymphoma were 68.6%, 100%, 100%, and 85.5%, respectively. Clonality analysis using PCR for IgH gene rearrangement may be useful for adjunctive diagnosis of bovine B-cell lymphoma.

Quantification of plasma cell-free DNA levels in dogs with various tumors

Circulating cell-free DNA (cfDNA) is extracellular DNA released into the bloodstream by apoptotic or necrotic tumor cells, with cfDNA determination proposed as a noninvasive, sensitive marker for the diagnosis of human cancer. We evaluated cfDNA quantification as a diagnostic and prognostic tool in dogs with various tumors. We quantified plasma cfDNA concentration by absolute real-time PCR of long interspersed nuclear elements in 50 dogs with malignant tumors, 13 dogs with benign tumors or nodules, and 11 healthy controls. Six patients with malignant tumors were followed-up, and plasma cfDNA was quantified throughout disease progression. We found that plasma cfDNA concentrations were significantly elevated in dogs with malignant tumors compared with dogs with benign nodules or healthy controls. The DNA integrity index (the ratio between long and short cfDNA fragments) was significantly lower in dogs with malignant tumors compared to healthy controls. Significantly higher cfDNA levels and a lower DNA integrity index were observed in dogs with lymphoma or leukemia, hemangiosarcoma, and distant metastasis; cfDNA levels correlated well with clinical stage and tended to increase during or before periods of disease progression, suggesting potential efficacy of cfDNA for the detection of distant metastasis and to monitor the clinical stage of neoplasia.

Disseminated thymic B-cell lymphoma in a Holstein heifer

A 19-mo-old Holstein heifer was inactive and dyspneic. Physical examination revealed wheezing, exophthalmos, a cervical mass, and lymphadenopathy. Cytology of the cervical mass and lymph nodes showed predominantly large atypical lymphocytes. Lactate dehydrogenase and thymidine kinase activities were elevated. Although nested PCR for bovine leukemia virus (BLV) using blood was positive, quantitative PCR showed a low number of provirus copies. Autopsy revealed enlargement of most lymph nodes examined, as well as white masses of various sizes in muscles of the left hindlimb and thoracic and abdominal organs. Histopathology revealed severe infiltration with neoplastic lymphocytes in these organs. The cervical mass was immune-positive for B-cell markers. The final diagnosis was thymic B-cell lymphoma with BLV infection.

Molecular Detection of Anaplasma phagocytophilum from Larvae of Haemaphysalis longicornis in Ibaraki, Japan

We collected 1,084 ticks by flagging vegetation in Tsukuba and Moriya (Ibaraki, Japan), where several cases of canine granulocytic anaplasmosis were reported. The DNA of the collected ticks was molecularly examined for infection with the family Anaplasmataceae. Twenty-six positive samples of Anaplasmataceae-specific PCR of partial 16S rRNA gene were subjected to semi-nested PCR, covering the divergent regions, the gene, and sequence analysis. Anaplasma phagocytophilum was detected in 3 pools of Haemaphysalis longicornis larvae and A. bovis from a H. flava male. Sequences of both amplicons had high homologies to those from dogs in our previous studies in Ibaraki. These results suggest that Haemaphysalis ticks are candidate vectors of A. phagocytophilum and A. bovis in Ibaraki, Japan.

Subclinical Infections of Anaplasma phagocytophilum and Anaplasma bovis in Dogs from Ibaraki, Japan

We evaluated the prevalence of Anaplasma infection in 332 dogs from Ibaraki, Japan, using serological and molecular methods. An immunofluorescence antibody assay against Anaplasma phagocytophilum indicated that 7 of the 328 serum samples tested (2.1%) were positive for A. phagocytophilum. Screening by polymerase chain reaction (PCR) analysis demonstrated that 8 of the 331 peripheral blood samples tested (2.4%) were positive for Anaplasmataceae. Phylogenetic analysis of the partial 16S rRNA sequence of the PCR amplicons revealed that 6 sequences were most similar to the 16S rRNA sequence of a Wolbachia sp., and the remaining 2 to A. bovis. Further analysis by A. phagocytophilum-specific nested PCR demonstrated that 1 dog infected with A. bovis was also positive for A. phagocytophilum. This is the first study to report the dual infection of a dog in Japan with A. bovis and A. phagocytophilum.

First detection of Mycoplasma wenyonii in France: Identification, evaluation of the clinical impact and development of a new specific detection assay

Mycoplasma wenyonii, a hemoplasma infecting cattle, was never detected in France. In 2014, evocative inclusions were observed in erythrocytes from cattle presenting milk drops, anemia, and edema in Brittany (France). A survey was then initiated to investigate the epidemiological situation and correlate mycoplasma detection with clinical signs. For this purpose, a new PCR assay targeting polC gene was designed. Comparative results with published PCR assays place this new one as more specific, allowing a one-step diagnosis without further sequencing. A total of 181 cows were included in this study and 4.97% (n = 9) were positive, resulting in the first molecular identification of M. wenyonii in France. All positive animals presented anemia, edema and milk drop. When selecting animals presenting evocative clinical signs, the prevalence of M. wenyonii in Brittany was estimated to 25.6%. Further studies are needed to evaluate the importance of the infection, the implication of arthropods and the existence of asymptomatic carriers.

Three-legged radiographic view for evaluating cranioventral lung region in standing calves with bovine respiratory disease

This study proposed a novel radiographic positioning in order to image the cranioventral lung region using a portable X-ray unit and digital radiography system. In the novel position, calves were restrained in a chute and a unilateral forelimb was pulled cranially with the contralateral forelimb tied to the chute; the forelimbs were then spread cranio-caudally as in a scissor position (Three-legged view: TL view). In a preliminary study, we applied the TL view for imaging of 14 clinically healthy calves. In a clinical study, accuracy in detecting cranioventral lung lesions was compared between the standard standing view and the TL view for 19 calves, which were culled from herd; the results of postmortem examination were used as gold standard. Seven evaluators independently interpreted the images. The median (range) number of trials and the time for obtaining optimal position were 2 (1–7) and 263 sec (105–488), respectively in 14 healthy calves. Calves thicker than approximately 40 cm were not considered candidates for TL view in this setting because of difficulty in restraint and the low output of the portable X-ray unit. The TL view improved the detection of consolidation in the cranioventral lung region, compared with the standard view. The TL view was considered an optional view when the cranioventral lung region was an area of interest, because this view was relatively easy to perform and required a small number of personnel, even for large calves.

Evaluation of costimulatory molecules in dogs with B cell high grade lymphoma

B cell high grade lymphoma is the most common hematopoietic malignancy in dogs. Although the immune checkpoint molecules, programmed death-1 (PD-1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), and immune checkpoint inhibitors have been evaluated for the treatment of various human lymphoid malignancies, the expression of those molecules and their relationship with prognosis remain unknown in canine lymphoma. The objective of this study was to evaluate the expression of costimulatory molecules on peripheral blood lymphocytes and tumor infiltrating lymphocytes, in addition to associated ligand expression in the lymph nodes of patients with B cell multicentric high grade lymphoma. Eighteen patients diagnosed with B cell high grade lymphoma and nine healthy control dogs were enrolled. Flow cytometric analysis revealed that the expression of PD-1 on CD4+ peripheral and tumor infiltrating lymphocytes and CTLA-4 on CD4+ peripheral lymphocytes was significantly higher in the lymphoma group than in the control group. The expression level of CD80 mRNA was significantly lower in the lymphoma group than in the control group. In contrast, there were no significant differences in PD-L1, PD-L2, and CD86 expression between the groups. Dogs with CTLA-4 levels below the cutoff values, which were determined based on receiver operating characteristic curves, on peripheral CD4+, CD8+, and tumor infiltrating CD4+ lymphocytes had significantly longer survival than dogs with values above the cutoff. Although it is uncertain whether the expression of immune checkpoint molecules affect the biological behavior of canine lymphoma, one possible explanation is that PD-1 and CTLA-4 might be associated with the suppression of antitumor immunity in dogs with B cell high grade lymphoma, particularly through CD4+ T cells.

Histopathological study of encephalomalacia in neonatal calves and application of neuronal and axonal degeneration marker

Five calves that had shown neurological symptoms within 9 days after birth were histopathologically diagnosed as encephalomalacia. Two calves showed bilateral laminar cerebrocortical necrosis and neuronal necrosis in the corpus striatum and hippocampus. Since the distributional pattern of the lesions was consistent with that of global ischemia in other species, the lesions were probably hypoxic/ischemic encephalopathy consistent with the history of dystocia and perinatal asphyxia. One calf also showed bilateral laminar cerebrocortical necrosis. However, the lesions were chronic ones, because the calf had survived for long time and necropsied at postnatal day 118. Additionally, the lesions did not involve the corpus striatum and hippocampus. The other two calves showed multifocal necrosis with vascular lesions characterized by fibrin thrombi, perivascular edema and perivascular hyaline droplets in the cerebral cortex, corpus striatum, thalamus, brain stem and cerebellum. Considering the age of onsets and histopathological appearance, it was possible that latter three calves were also hypoxic/ischemic encephalopathy, however, exact cause of them was not revealed. In all calves, degenerated/necrotic neurons showed positive reactions for Fluoro-Jade C and degenerated axons showed immunoreactivity for Alzheimer precursor protein A4. Therefore, these markers were applicable to examination of brain injury in neonatal calves.

First Molecular Detection and Phylogenetic Analysis of Anaplasma phagocytophilum from a Clinical Case of Canine Granulocytic Anaplasmosis in Japan

Anaplasma phagocytophilum DNA was detected from a dog with canine granulocytic anaplasmosis (CGA) in Japan. Phylogenetic analysis of the DNA using 16S rRNA, gltA, and groEL sequences revealed that the strain was nearly identical to A. phagocytophilum detected from Apodemus agrarius (black-striped field mouse) in China and Korea. To our knowledge, this is the first report of molecular detection and phylogenetic analysis of A. phagocytophilum from a clinical case of CGA in Japan.

A clinical case of neosporosis in a 4-week-old holstein friesian calf which developed hindlimb paresis postnatally

A 4-week-old female Holstein Friesian calf presented with hindlimb paresis. Neurologic examination of spinal reflexes revealed depressed or absent reflexes of the hindlimbs. Menace responses on both sides disappeared on examination of cranial nerves. The calf was finally diagnosed with Neospora caninum infection by pathological findings including nonsuppurative inflammation associated with cysts in the cerebrum and spinal cord. High levels of antibody against recombinant surface antigen 1 of N. caninum (NcSAG1) were detected by ELISA from both serum and cerebrospinal fluid (CSF) samples. This result suggests that detection of antibodies against N. caninum by NcSAG1-ELISA in serum and CSF could be useful for the clinical diagnosis of neosporosis in calves with acquired neurological signs.

Fluoroscopic observation of the development of displaced abomasum in dairy cows

To clarify the mechanisms underlying the development of displaced abomasum (DA), we repositioned DA in 12 cows by rolling and observed the course of redisplacement using X-ray fluoroscopy. Displacement of the abomasum was observed to follow three patterns: displacement to the left side of the abdominal cavity through the gap formed at the reticulum, atrium of the rumen and ventral sac of the rumen (n=7); displacement to the left side after cranial movement along the diaphragm (n=3); displacement to the right side after cranial movement along the diaphragm (n=2). These differences were considered to be associated with the rumen volume. To the best of our knowledge, this is the first study reporting the visual observation of the course of DA in dairy cows.

Polysplenia syndrome with duodenal and pancreatic dysplasia in a Holstein calf: a case report

Background

Laterality disorders of the abdominal organs include situs inversus totalis that mirrors the arrangements of all internal organs and heterotaxy syndrome (situs ambiguus) in which the thoracic or abdominal organs are abnormally arranged. Heterotaxy is often accompanied by multiple congenital malformations, and it generally comprises asplenia and polysplenia syndromes. To our knowledge, polysplenia syndrome has been reported in only three cattle, and computerized tomographic (CT) images of these animals were not obtained.

Case presentation

A six-month-old Holstein heifer had ruminal tympani and right abdominal distension. CT imaging showed that the rumen occupied the right side of the abdominal cavity, the omasum and abomasum occupied the left ventral side and the liver was positioned on the left. The colon and cecum were located at the left dorsum of the cavity, and the left kidney was located more cranially than the right. Postmortem findings revealed two spleens attached to the rumen. Significantly, the duodenum was too short to be divided into segments, except the cranial and descending parts, or flexures, except the cranial flexure, and the pancreas, which lacked a left lobe, was covered with mesojejunum. The liver comprised a relatively large right lobe and a small left lobe without quadrate and caudate lobes. The caudal vena cava that connected to the left azygous vein passed irregularly through the aortic hiatus of the diaphragm, and the common hepatic vein without the caudal vena cava passed through the caval foramen. Although the lungs and heart were morphologically normal, the right atrium received three major systemic veins. Polysplenia syndrome was diagnosed based on the CT and postmortem findings.

Conclusion

We defined the positions of the abdominal organs and morphological abnormalities in various organs of a calf with polysplenia syndrome based on CT and postmortem findings. These findings will improve understanding of the malpositioning and malformations that can occur in the organs of cattle with polysplenia syndrome.

Electronic supplementary material

The online version of this article (10.1186/s12917-017-1213-2) contains supplementary material, which is available to authorized users.

Multiple infections of Anaplasma platys variants in Philippine dogs

Aim:

Anaplasma platys, the causative agent of infectious canine cyclic thrombocytopenia, is a tick-borne pathogen that also has been implicated as potentially zoonotic. To provide molecular evidence on the multiple infections of A. platys variants in Philippine dogs.

Materials and Methods:

DNA fragments of A. platys from infected dogs in the Philippines were molecularly characterized. For screening, 25 dogs suspected to have canine anaplasmosis were tested using a 16S rRNA-based nested polymerase chain reaction (PCR). Infection was confirmed by sequencing of positive amplicons. Second round PCR targeting a longer 16S rRNA fragment was subsequently performed on the first round PCR amplicons of the positive samples. Further characterization using the heat-shock operon (groEL) gene was also performed on the A. platys-positive samples.

Results:

10 16S rRNA sequences were obtained and found 99.6-100% identical to each other and 99.6-99.7% identical to the closest registered A. platys sequences. On the other hand, 36 groEL clone sequences were obtained and found to be 85.1-99.8% identical with each other and 85.0-88.9% identical to the closest previously registered A. platys sequences. Four dogs were found coinfected with 2-3 groEL variant sequences. Phylogenetic analyses suggest that the detected A. platys in the Philippines may represent unique variants.

Conclusion:

A. platys variants were detected in Philippine dogs. Coinfection of different A. platys variants in dogs was also demonstrated. The present study may indicate the potential genetic diversity of A. platys in the country.

Anaplasma species of veterinary importance in Japan

Anaplasma species of the family Anaplasmataceae, order Rickettsiales are tick-borne organisms that can cause disease in animals and humans. In Japan, all recognized species of Anaplasma (except for Anaplasma ovis) and a potentially novel Anaplasma sp. closely related to Anaplasma phagocytophilum have been reported. Most of these detected tick-borne pathogens are believed to be lowly pathogenic in animals in Japan although the zoonotic A. phagocytophilum has recently been reported to cause clinical signs in a dog and in humans. This review documents the studies and reports about Anaplasma spp. in Japan.

Periventricular leukomalacia in a neonatal calf

A 10-day-old, Japanese Black, female calf had shown astasia since just after birth. Focal symmetrical periventricular malacic lesions of the cerebrum and suppurative arthritis of the left hip joint were observed in macroscopic examination. Histologically, the cerebral lesions were confirmed as periventricular leukomalacia (PVL). The location and histological features of the lesions were similar to PVL in humans, caused by neonatal ischemia/hypovolemia. This is the first report of PVL in a neonatal calf.

Serological survey of Borrelia infection of dogs in Sapporo, Japan, where Borrelia garinii infection was previously detected

A serological survey of Borrelia infection of dogs was performed in Sapporo, Japan, where Borrelia garinii infection in dogs was detected in 2011. A total of 314 serum samples were collected from dogs that visited three animal hospitals in Sapporo from 2012 to 2014. The two-step evaluation method, involving screening ELISA followed by Western blot analysis, was used to detect antibodies against Borrelia species. A total of 34 samples were positive by ELISA. Among those 34 samples, 32 were positive for Borrelia spp. by Western blot. These findings suggest that the 32 dogs (10.2%) generated antibodies against Borrelia burgdorferi sensu lato, such as B. garinii or B. afzelii. Antibody positivity was 7.6% and 13.3% for dogs living in urban and rural areas, respectively. Dogs with a history of tick infestation showed a positive rate of 16.7%, which was higher, although not significantly, than the 6.7% among dogs without a history.

Molecular detection and characterization of Babesia bovis, Babesia bigemina, Theileria species and Anaplasma marginale isolated from cattle in Kenya

Background

Infections with Babesia bovis, Babesia bigemina, Theileria species and Anaplasma marginale are endemic in Kenya yet there is a lack of adequate information on their genotypes. This study established the genetic diversities of the above tick-borne hemoparasites infecting cattle in Kenya.

Methods

Nested PCR and sequencing were used to determine the prevalence and genetic diversity of the above parasites in 192 cattle blood samples collected from Ngong and Machakos farms. B. bovis spherical body protein 4, B. bigemina rhoptry-associated protein 1a, A. marginale major surface protein 5, Theileria spp. 18S rRNA, T. parva p104 and T. orientalis major piroplasm surface protein were used as the marker genes.

Results

B. bovis, B. bigemina, T. parva, T. velifera, T. taurotragi, T. mutans and A. marginale were prevalent in both farms, whereas T. ovis, Theileria sp. (buffalo) and T. orientalis were found only in Ngong farm. Co-infections were observed in more than 50 % of positive samples in both farms. Babesia parasites and A. marginale sequences were highly conserved while T. parva and T. orientalis were polymorphic. Cattle-derived T. parva was detected in Machakos farm. However, cattle and buffalo–derived Theileria were detected in Ngong farm suggesting interactions between cattle and wild buffaloes. Generally, the pathogens detected in Kenya were genetically related to the other African isolates but different from the isolates in other continents.

Conclusions

The current findings reaffirm the endemicity and co-infection of cattle with tick-borne hemoparasites, and the role of wildlife in pathogens transmission and population genetics in Kenya.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-015-1106-9) contains supplementary material, which is available to authorized users.

Detection of the nonsense mutation of OPA3 gene in Holstein Friesian cattle with dilated cardiomyopathy in Japan

Bovine dilated cardiomyopathy (DCM) is an autosomal recessive genetic disorder causing congestive heart failure and subsequent death. Recently, a nonsense mutation c.343C>T in the bovine optic atrophy 3 (OPA3) gene had been reported to cause the DCM in Holstein cattle in Switzerland. However, the mutation has not been confirmed in bovine DCM outside Switzerland. Nine Holstein Friesian cows that were macroscopically and histologically diagnosed with or suspected of DCM and 12 control cows kept in Japan were tested for the mutation. The mutation surrounding OPA3 DNA fragment was amplified by PCR and subjected to direct sequences. The homogeneous c.343C>T mutation was proved to occur in all the affected cows and not in the control cows. The present study is the first report of the mutation in the DCM affected cows outside Switzerland.

Detection of monoclonal integration of bovine leukemia virus proviral DNA as a malignant marker in two enzootic bovine leukosis cases with difficult clinical diagnosis

Monoclonal integration of bovine leukemia virus (BLV) proviral DNA into bovine genomes was detected in peripheral blood from two clinical cases of enzootic bovine leukosis (EBL) without enlargement of superficial lymph nodes. A BLV-specific probe hybridized with 1 to 3 EcoRI and HindIII fragments in these 2 atypical EBL cattle by Southern blotting and hybridization, as well as in 3 typical EBL cattle. The probe also hybridized to a large number of EcoRI and HindIII fragments in 5 cattle with persistent leukosis. These results suggest that the detection of monoclonal integration of BLV provirus into the host genome may serve as a marker of monoclonal proliferation and malignancy in difficult to diagnose EBL cattle.

Glomus tumor of the liver in a cow

An 11-year-old Holstein-Friesian cow exhibited anorexia and jaundice. A large mass was found in the liver during necropsy. Macroscopically, the mass was composed of dark red multilobular tissue and a centrally located abscess, which was connected to the hepatic duct. Histologically, the mass consisted of proliferation of small neoplastic cells and was demarcated from the hepatic parenchyma by a thick region of granulation tissue. The neoplastic cells were predominantly arranged in solid sheets, but they also formed blood-filled cancellous structures, and proliferating foci were seen around blood vessels. Periodic acid-Schiff reaction demonstrated that a fine basement membrane-like structure surrounded the neoplastic cells. Immunohistochemically, the neoplastic cells were positive for vimentin and alpha smooth muscle actin and negative for cytokeratin, factor VIII-related antigen, chromogranin and desmin. Based on its histopathological features, the hepatic neoplasm was diagnosed as a primary glomus tumor. This is the first report about a primary glomus tumor of the liver in a cow.

Evaluation of S100B in cerebrospinal fluid as a potential biomarker for neurological diseases in calves

S100B in cerebrospinal fluid (CSF-S100B) was measured in calves with 20 neurologic and 21 non-neurologic diseases to clarify its utility as a biomarker for neurologic diseases. The median CSF-S100B value in the neurologic disease group (43.0 ng/ml) was significantly higher than that in the non-neurologic disease group (10.2 ng/ml). As CSF-S100B levels in calves with neurologic diseases widely differed, the utility of CSF-S100B as a diagnostic marker for neurologic diseases in cattle remains inconclusive.

Molecular characterization of Cryptosporidium parvum from two different Japanese prefectures, Okinawa and Hokkaido

Infectious diarrhea is the most frequent cause of morbidity and mortality in neonatal calves. Cryptosporidium parvum is one of the main pathogens associated with calf diarrhea. Although diarrhea is a symptom of infection with various pathogens, investigations to detect the types of pathogens have never been performed in Japan. This study investigated the prevalence of four major diarrhea-causing pathogens in calves: C. parvum, rotavirus, coronavirus, and enterotoxigenic Escherichia coli (E. coli K99). Commercial immunochromatography testing of all four pathogens and molecular analysis of C. parvum with diarrhea in calves from southernmost Okinawa and northernmost Hokkaido, Japan, were conducted. The frequencies of C. parvum, rotavirus, coronavirus, and E. coli (K99) in Okinawa were 50%, 28%, 2.3%, and 4.7%, respectively. Watery fecal stools were significantly correlated with C. parvum (p < 0.05). In oocyst calculations for C. parvum, no significant difference was observed between the single-infection cases and the mixed-infection cases with rotavirus. Interestingly, molecular analyses targeting small subunit ribosomal RNA as well as glycoprotein 60 (GP60) genes revealed that the C. parvum nucleotide sequences from the two prefectures were identical, indicating that C. parvum with a uniform characteristic is distributed throughout Japan. GP60 subtyping analysis identified C. parvum from Okinawa and Hokkaido as belonging to the IIaA15G2R1 subtype, a known zoonotic subtype. Hence, control of cryptosporidiosis is important not only for pre-weaned calves, but also for human health.

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ICT strips were used for calf diarrhea to detect four major enteric pathogens.

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C. parvum showed the highest frequency in the southernmost Okinawa prefecture, Japan.

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C. parvum from the northernmost Hokkaido prefecture was used for a comparative study.

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C. parvum from the two prefectures had a uniform character in SSUrRNA and GP60 genes.

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GP60 subtyping revealed that IIaA15G2R1, a known zoonotic subtype, was predominant.

Optic pathway degeneration in Japanese black cattle

Degeneration of the optic pathway has been reported in various animal species including cattle. We experienced a case of bilateral optic tract degeneration characterized by severe gliosis in a Japanese black cattle without any obvious visual defects. To evaluate the significance, pathological nature and pathogenesis of the lesions, we examined the optic pathway in 60 cattle (41 Japanese black, 13 Holstein and 6 crossbreed) with or without ocular abnormalities. None of these animals had optic canal stenosis. Degenerative changes with severe gliosis in the optic pathway, which includes the optic nerve, optic chiasm and optic tract, were only observed in 8 Japanese black cattle with or without ocular abnormalities. Furthermore, strong immunoreactivity of glial fibrillary acidic protein was observed in the retinal stratum opticum and ganglion cell layer in all 5 cattle in which the optic pathway lesions could be examined. As etiological research, we also examined whether the concentrations of vitamin A and vitamin B12 or bovine viral diarrhea virus (BVDV) infection was associated with optic pathway degeneration. However, our results suggested that the observed optic pathway degeneration was probably not caused by these factors. These facts indicate the presence of optic pathway degeneration characterized by severe gliosis that has never been reported in cattle without bilateral compressive lesions in the optic pathway or bilateral severe retinal atrophy.

Comparison of bacterial endotoxin lipopolysaccharide concentrations in the blood, ovarian follicular fluid and uterine fluid: a clinical case of bovine metritis

We investigated the concentration of the bacterial endotoxin lipopolysaccharide (LPS) in the blood, ovarian follicular fluid and uterine fluid of a clinical case of bovine metritis. A 2-year-old lactating Holstein cow exhibited continuous fever >39.5°C for more than 2 weeks after normal calving. The cow produced a fetid, watery, red-brown uterine discharge from the vagina and was diagnosed with metritis. The LPS concentrations in plasma and uterine fluid were 0.94 and 6.34 endotoxin units (EU)/ml, respectively. One of seven follicles showed an extremely high level of LPS (12.40 EU/ml) compared to the other follicles (0.62-0.97 EU/ml). These results might suggest the presence of high concentration of LPS in follicles in cows with postpartum metritis.

Molecular survey of Babesia gibsoni using Haemaphysalis longicornis collected from dogs and cats in Japan

A nationwide survey of Babesia gibsoni using Haemaphysalis longicornis collected from dogs and cats in Japan was conducted using molecular methods. A total of 1,341 H. longicornis, including 305 females, 14 males, 332 nymphs and 690 larvae (153 pools) from 44 prefectures, were examined by B. gibsoni-targeted PCR. Partial sequence analysis revealed that 12 of 13 positive samples sequenced, including samples from Tottori, Hiroshima, Yamaguchi, Tokushima, Ehime and Oita prefectures (all in western Japan), were identical to B. gibsoni, and 1 sample from Kyoto Prefecture was most closely related to a Babesia species recently detected from feral raccoons in Hokkaido. H. longicornis is a candidate for transmission vector tick of the new Babesia species.

High genetic diversity of Anaplasma marginale detected from Philippine cattle

A total of 658 cattle in 6 provinces in the Philippines were screened for Anaplasma marginale infection by using a diagnostic heat-shock operon (groEL) gene-PCR assay. The screening-positive samples were further tested using the major surface antigen protein 1a (Msp1a) gene-PCR assay. Screening PCR results showed 130 cattle (19.8%) were positive for the A. marginale infection. Subsequent amplification using the Msp1a gene only showed 93 samples (14.1%) to be positive. In addition, 37 tandem-repeat structures, including 20 novel structures, and 41 distinct genotypes were identified. Interestingly, multiple infections of 4 different genotypes were also observed in A. marginale-infected cattle. The present study demonstrated the prevalence and characterization of diverse genotypes of A. marginale in the Philippine cattle.

Higher sika deer density is associated with higher local abundance of Haemaphysalis longicornis nymphs and adults but not larvae in central Japan

Haemaphysalis longicornis (Acari: Ixodidae) is one of the most common and important arthropod disease vectors in Japan, carrying Japanese spotted fever and bovine theileriosis. The recent expansion of sika deer (Cervus nippon, Artiodactyla: Cervidae) populations, the most common wild host of H. longicornis, has also caused concern about increasing the risk of vector-borne diseases in Japan. We used generalized linear mixed model analysis to determine the relative contribution of deer density and other biological and abiotic factors on the abundance of H. longicornis ticks questing at each developmental stage. A total of 6223 H. longicornis adults, nymphs, and larvae were collected from 70 sites in three regions of central Japan. The abundance of questing adult and nymphal ticks was associated with deer density and other biotic and abiotic factors. However, the abundance of questing larvae showed no association with deer density but did show an association with other biotic and abiotic factors. These findings show that a high density of deer along with other biotic and abiotic factors is associated with increased risk of vector-borne diseases through amplified local abundance of questing nymphal and adult H. longicornis. Further, questing larvae abundance is likely regulated by environmental conditions and is likely correlated with survival potential or the distribution of other host species.

Prevalence and molecular analyses of hemotrophic Mycoplasma spp. (hemoplasmas) detected in sika deer (Cervus nippon yesoensis) in Japan

Hemotropic mycoplasmas (hemoplasmas) are cell-wall deficient, epierythrocytic bacteria that cause infectious anemia in several mammalian species. The prevalence of hemoplasma species was examined by screening and species-specific PCR using blood samples collected from 51 sika deer in Hokkaido, Japan. Molecular analyses were performed for the 16S rRNA, 23S rRNA and RNase P RNA (rnpB) gene sequences. A total of 23/51 (45%) deer DNA samples were positive for hemoplasmas in the screening PCR. Using species-specific PCR, 12 and 17 samples were positive for ‘Candidatus Mycoplasma haemocervae’ and ‘Candidatus M. erythrocervae’, respectively. Sequencing and phylogenetic trees of those three genes indicate that the ‘Candidatus M. haemocervae’ and ‘Candidatus M. erythrocervae’ detected in Japanese deer are potentially different species from the cervine hemoplasma found in deer from America and Brazil.

The phylogenetic position of Anaplasma bovis and inferences on the phylogeny of the genus Anaplasma

The present study aimed to determine the complete citrate synthase (gltA) and heat-shock protein (groEL) gene sequences of Anaplasma bovis and to infer phylogenetic relationships within the genus Anaplasma. Multiple alignments from single and concatenated sequences of the 16S rRNA, gltA and groEL genes of the genus Anaplasma were subjected to phylogenetic analyses. Percent identities of A. bovis nucleotide sequences were found highest with A. phagocytophilum in gltA (65.4%) and groEL (79.8%). Single gene phylogenetic tree results assumed similar phylogenetic positions within the genus Anaplasma, except for A. bovis. However, consensus and concatenated sequence phylogenetic trees showed similar results, revealing 2 subgroups within the genus.

Zygomycotic mediastinal lymphadenitis in beef cattle with ruminal tympany

A 9-month-old steer was autopsied due to recurrent ruminal tympany. A macroscopic examination found an enlarged caudal mediastinal lymph node, and a section of the lymph node revealed necrosis with marked calcification, similar to tuberculous lymphadenitis. Histopathologically, the lesion consisted of multiple coagulative necrotic foci and fibrosis with macrophage, lymphocyte, eosinophil and multinucleated giant cell infiltration. Non-uniform width hyphae were detected in the necrotic area and within the cytoplasm of the multinucleated giant cells, and they were found to be anti-Rhizopus arrhizus antibody positive in an immunohistochemical examination. Therefore, the steer was diagnosed with necrotic caudal mediastinal lymphadenitis due to zygomycetes infection, and inhibition of eructation by the enlarged lymph node was the likely cause of the ruminal tympany.