A highly sensitive assay for hyaluronidase (HAase) activity was examined in this study. Canine urine HAase (canine u-HAase) can be used as a therapeutic agent for canine intervertebral disc herniation (IVDH). The sensitivity of fluorescinamin-labeled hyaluronan (FAHA) was 30 times higher than the conventional method. The FAHA method can measure 1.0 IU/ml or less. Canine u-HAase was assumed to be an end-type glycosidase based on the variation pattern seen on its chromatographs, and its molecular weight was determined to be 39,000 by HPLC-GPC. At pH 3.6 or higher, canine u-HAase activity decreased with increasing substrate solution pH and disappeared at pH 5.0 and higher. Canine u-HAase degraded hyaluronan most quickly, followed by chondroitin sulfates A, D, and C sodium. Significant proteoglycans emigration from canine nucleus pulposus powder was observed by canine u-HAase. Thus, the properties of canine u-HAase resemble those of human Hyal-1 in enzyme type, and it is presumed to be a low-molecular enzyme derived from canine Hyal-1. Since canine u-HAase showed a high chemonucleolytic effect on canine nucleus pulposus in vitro, canine u-HAase is expected to be largely applied in chemonucleolytic therapy for dogs in the future.

Microchips are a useful means for individual identification, and they are hoped to become popular for reuniting separated companion animals (dogs and cats) with their owners. However, pet owners’ views and thoughts regarding microchip mounting is not clear. This study aimed to reveal the predictors of behavioral intentions toward microchip mounting using questionnaires based on the Theory of Planned Behavior (TPB). The results revealed 306 valid responses [47.4% of owners (dog owners 51.7%, cat owners 42.1%, both owners 6.2%) and 52.6% of non-owners], in which 35 owners (28.4% of dogs and 8.8% of cats) had already mounted a microchip to their own pet. Pet owners scored significantly higher on subjective norms than non-owners on the TPB items. It was found that TPB explained the differences in attitudes between respondents and their use of microchips and their behavioral intentions for microchip adoption. Finally, this study also suggested that veterinarians would be the key to further dissemination of microchips.

A 9-year-old male Chihuahua was referred to our hospital for lymphocytosis. There was a marked increase in small to middle-sized lymphocytes in the peripheral blood smear and cytology of the spleen. Clonal analysis of lymphocytes using peripheral blood showed clonal expansion of B cells. Bone marrow examination confirmed an increase in small lymphocytes that accounted for more than 50% of all nucleated bone marrow cells. Chronic lymphocytic leukemia was suspected based on the above results; however, histopathological evaluation of the spleen revealed marginal zone lymphoma.

Atypical mycobacteria （AM） are widely distributed in the environment and cause spontaneous diseases in humans, pigs, birds, and pets such as dogs and cats. However, no cases have been reported in the chinchilla, which is completely housed indoors in Japan. In a general household with five chinchillas, three developed respiratory disorders due to pneumonia. None of them showed any improvement after treatment with antibiotics such as antibacterial and antifungal drugs, and died 14, 44, and 186 days after the first treatment, respectively. Necropsy was performed on two chinchillas. Gross examination revealed caseous nodules in the lungs and digestive organs, and histopathological examination revealed granulomatous inflammation and many acid-fast bacteria in the inflamed macrophages and epithelioid cells. The remaining two chinchillas live without symptoms. It was found that even completely housed animals have a risk of developing lethal AM disease, presenting as a serious respiratory disease, and that the susceptibility of chinchilla to AM varies.

The palatability of a chewable formulation, ‘Bravecto’ (MSD Animal Health K.K., Tokyo, Japan) containing fluralaner as an active ingredient was evaluated in 100 dogs. Of the dogs, 90 voluntarily consumed the drug within 25 seconds, with a median of 6 seconds, after the formulation was presented directly under each dog’s nose. Results show that the chewable formulation can be regarded as having high palatability for dogs and that it can be administered easily to many dogs.