Data obtained from 68 farrow-to-finish swine farms were used to evaluate reproductive performance and determine which factors are important in improving performance. The number of pigs weaned per mated female per year (PWMFY), pigs weaned per litter (PWL) and pigs born alive per litter (PBA) increased between 2010 and 2012 among farms with high reproductive performance in 2012 (HP farms). No change was detected in these parameters at farms with normal to low reproductive performance in 2012 (NP and LP farms, respectively). A significant correlation between PBA and preweaning mortality risk (PRWM) was observed in all farm groups classified by reproductive performance, indicating that a high number of the piglets born on these farms were being lost during the suckling stage. Therefore, increasing the PWMFY on HP farms would require increasing the PWL by increasing the PBA and decreasing the PRWM, because there is limited room for improvement in the number of litters per mated female per year (LMFY). However, increasing the PWMFY can be accomplished by improving both the PWL and LMFY among LP farms.

View full abstract

We surveyed the ovulation rates of mares that were treated with human chorionic gonadotropin (hCG) 6-24 hours before mating. The timing of mating was determined according to the pattern of uterine edema (Grade 0-5), and follicular diameter determined through an ultrasound examination. All mares had at least a 35 mm follicle and uterine edema of Grade 1 or more. Of the mares that were treated with hCG, 95.7%(137/147) ovulated within 48 hours after injection. As the follicle diameter and uterine edema grade increased, ovulation rates increased. Of the mares with a follicle diameter greater than 45 mm and a uterine edema of Grade 4, 100% (34/34) ovulated within 48 hours. Detection of the pattern of uterine edema and the follicular diameter through an ultrasound examination, combined with the rectal palpation of the follicles and the use of ovulation-inducing agents (such as hCG), helped veterinarians determine the optimal time for breeding a normal mare.

View full abstract

The occurrence of bovine mycoplasmal mastitis was observed for the first time at a dairy farm in Chiba Prefecture, Japan. Successive cases of refractory mastitis, which was not cured by antibiotics, occurred between May and June of 2012. Mycoplasma bovis was identified in mastitic milk of the diseased cows. Cows with mycoplasma mastitis manifested respiratory symptoms (4/5), udder edema (4/5), and multiple infected quarters (5/5). Bacteriological analysis of milk cultured on 5% sheep blood agar plates was negative for bacterial isolation (4/4). Mycoplasma survey of all milking cows revealed a prevalence rate of 12% (6/50). Six mycoplasma-positive cows were separated from other milking cows and treated with effective antibiotic therapy, and two of them were culled. Mycoplasmas were not seen in bulk milk monitoring after December 2011. A heifer suspected of subclinical infection with M. bovis is believed to have introduced and spread the infection to other cows after delivery. Therefore, in the areas where numerous cows are introduced from other areas, it is important to regularly conduct mycoplasma investigations of bulk milk.

View full abstract

For establishment of cytological diagnostic criteria of inflammatory colorectal polyp (ICRP) in miniature dachshunds (M. dax), cytological specimens of 16 cases of ICRP of M. dax (ICRP group) and 53 cases of a non-ICRP group including normal mucosa, inflammatory diseases and neoplastic diseases were analyzed. In 12 cases of the ICRP group (75.0%), significantly more multinucleated giant cells (MGCs) were detected than those in the non-ICRP group (only one case, 1.9%). Sensitivity, specificity, positive predictive value and negative predictive value of cytological detection of MGCs in cytological specimens to diagnose ICRP were 75.0%, 98.2%, 92.3% and 93.2%, respectively. In conclusion,detection of MGCs in colorectal cytology of M. dax is useful for cytological diagnosis of ICRP.

View full abstract

Lymphoid neoplasms, which were found in 59 cattle infected with bovine leukosis virus (BLV), were examined through histology and immunohistochemistry. Fifty-six cases were found to have CD20- and CD79a-positive pleomorphic B-cell lymphoma, characterized by cytological pleomorphism and atypia. Tissue sections suitable for CD5 immunostaining were obtained from 54 cases, all of which were found to be positive for this marker. In one case of a pregnant cow, the fetus had pleomorphic lymphoma lesions in the subcutis. This was interpreted as resulting from a metastasis of the maternal lymphoma. The remaining three cases, which were diagnosed as precursor B-lymphoblastic leukemia, lymphoplasmacytoid lymphoma and γδT-cell lymphoma, were distinct from the pleomorphic lymphoma in cytology and immunophenotype. Because such histological types are chiefly observed in BLV-negative cattle, these cases were presumably not associated with BLV. The present study indicates that bovine lymphoid neoplasms are classifiable into histologically and immunohistochemically discrete disease entities.

View full abstract

The prevalence of anti-Brucella canis antibodies among dogs in Tokyo was investigated between 2007 and 2013 using a microplate agglutination test and questionnaire survey for dog owners. According to the results, 44 out of 527 dogs (8.3%) were found to be positive for the antibodies. This prevalence was higher than the national average (3.0%), but showed a tendency to decline each year. No significant differences were seen in the prevalence based on sex, breed, locality, age or body weight (P ≥ 0.05). Questionnaires collected from dog owners suggested that B. canis infection may occur directly through contact with infected dogs or indirectly through a contaminated outdoor environment rather than through copulation with infected dogs.

View full abstract