We investigated the antibody response to the Salmonella O4 antigen using the microplate agglutination test (MAT) and MAT combined with dithiothreitol (DTT) treatment using serum samples sequentially obtained from horses with equine paratyphoid, apparently healthy horses kept in the same stable, horses kept on farms near the farm that raised Salmonella enterica subsp. enterica serovar Abortusequi-infected horses, and horses kept in a non-endemic area of equine paratyphoid. DTT-MAT titers of samples collected from all symptomatic horses were tentatively positive (1:20 or more) and were maintained for a long time although those in MAT were negative (less than 1:320). In DTT-MAT, antibodies of the O4 antigen were detected in 8 of 15 (42.1%) serum samples collected from apparently healthy horses kept in the same stable. The antibody-positive rate of DTT-MAT in horses kept on farms near the farm where S. Abortusequi-infected horses were raised and horses kept in a non-endemic area of equine paratyphoid were 4.5% and 0.1%, respectively. The presence of IgG or IgA antibody against S. Abortusequi LPS in ELISA were confirmed in almost all DTT-MAT-positive sera. DTT-MAT would be useful in the serological diagnosis of equine paratyphoid because of its prolonged ability to detect a specific antibody against the somatic antigen produced by an S. Abortusequi infection.
Although enzootic bovine leukosis (EBL) usually occurs in cattle over 4 years of age, a diagnosis of EBL was able to be established in a 5-month-old crossbred steer. This animal showed marked swelling of the superficial lymph nodes at 134 days old. At 168 days old, swelling of the superficial lymph nodes deteriorated. A blood examination revealed the rapid elevation of the white blood cell count (104,000/μl ) with 89% atypical lymphocytes. In the necropsy, the abdominal lymph nodes were greatly enlarged. Histologically, tumor cells characterized by pleomorphism and atypia showed proliferation or infiltration in lymph nodes and a variety of internal organs. Real-time PCR showed an extremely high number of copies of proviral bovine leukemia virus (BLV) in the peripheral blood and the lymph nodes examined. B cell clonality tests showed biclonality growth of tumor cells. A diagnosis of EBL was made based on these findings. Analysis of bovine leukocyte antigen (BoLA) genes, associated with the susceptibility to BLV, showed BoLA-DRB3＊1101 and ＊1601 ; therefore, multiple factors are thought to have been implicated in the neoplastic transformation in the present case.
This study examines the relationship between the damaged area of the atrioventricular (AV) conduction system, and both the QRS width and ventricular rate in the electrocardiography of 31 subjects. The subjects were dogs diagnosed with severe anatomical lesions in the AV conduction system by postmortem histopathological examination and were selected from 36 dogs with third-degree AV block. The narrow QRS complex group consisted of four cases, and the wide QRS complex group consisted of 27 cases. Among the 31 cases, 26 cases (84%) were in accordance with the QRS width and lower automatic center, which was assumed to have been derived from the damaged area (supposed lower center). Ventricular rates in 15 cases were less than 40/minute, seven cases were 40 to 60/minute, and nine cases were greater than 60/minute. Thirteen out of 31 cases (42%) were in accordance with the ventricular rate and supposed lower center. In conclusion, it was recognized that QRS duration indicated the locations of the severe AV conduction disturbances more favorably than the ventricular rate.