In 2023 and 2024, there were three cases of salmonellosis in cattle in Town A in the Sorachi District in Hokkaido. On the farms where the outbreak occurred, the invasion of wild animals was one of the livestock hygiene problems. Therefore, we suspected the involvement of wild animals in the outbreak and spread of salmonellosis and conducted a survey of Salmonella Typhimurium isolated from livestock and wild animals. Molecular epidemiological analyses of wild animals and livestock strains showed that they were closely related, and these exhibited multidrug resistance similar to recent isolates. In order to prevent the occurrence and spread of livestock infectious diseases, including salmonellosis on farms, it is necessary to thoroughly prevent the invasion of wild animals.

The goal of this study was to investigate influenza A virus (IAV) antibodies in domestic pigs and captured wild boars in Ehime Prefecture, Japan. The serological survey was conducted using a commercial IAV antibody enzyme-linked immunosorbent assay (ELISA) kit approved for swine influenza in 2022 in Japan. The seropositive rates of farms with domestic pigs that were breeding and fattening were 66.7% (12/18) and 38.9% (7/18), respectively. The seropositive rate of individual domestic pigs that were breeding and fattening were 28.3% (51/180) and 13.9% (25/180), respectively. These results suggested that IAV was widespread in pig farms in Ehime Prefecture. In contrast, the seropositive rate of wild boar was 1.6% (3/185). This result suggested that wild boar did not play a major role in the circulation of IAV among pigs in Ehime Prefecture. Continued surveillance is needed to monitor the distribution of IAV in pig farms.

Follicular cysts and granulosa cell tumors are common diseases in dairy cattle with ovarian enlargement. Two cases of dairy heifers with the common characteristics of granulosa cell tumors, such as no heat, developed udders, unilateral ovarian enlargement on rectal examination and honeycomb-like structures in the ovary on ultrasonography, as well as an elevated concentration of anti-Müllerian hormone in their plasma, were treated by ovariectomies. The histopathological diagnoses of the removed ovaries was a granulosa cell tumor in one and a follicular cyst in the other. The results suggest that high levels of anti-Müllerian hormone in the plasma do not adequately confirm granulosa cell tumors.

In Japan, Hepatozoon canis is reported to be primarily distributed in western Japan. The present study describes the first confirmed Hepatozoon canis infection in a dog from Chiba Prefecture, located in the Kanto region of eastern Japan. The case involved a female stray dog of unknown age and breed rescued in March 2024. Histopathological examination incidentally revealed meronts of Hepatozoon in the inguinal lymph node, which had been removed during the surgical excision of a mammary tumor. Additionally, Hepatozoon gamonts were identified within neutrophils on peripheral blood smears. Molecular identification using polymerase chain reaction targeting the 18S rRNA gene, followed by sequence analysis, confirmed the organism as H. canis. Clinically, the dog exhibited no significant abnormalities in preoperative blood tests or radiographic examination, nor any clinical signs commonly associated with hepatozoonosis, such as fever or anemia. Nonetheless, the detection of H. canis infection in a previously unaffected geographical area underscores the potential expansion of this parasite's distribution within Japan. Veterinarians should, therefore, consider canine hepatozoonosis as a differential diagnosis in dogs presenting with unexplained fever or anemia, even in regions outside traditionally endemic areas. Further epidemiological studies, including surveillance of tick vectors and wild reservoirs, are warranted to elucidate the transmission dynamics and prevent the spread of this infection.

Eight broiler chickens with feather folliculoma, 46 to 50 days of age, were subjected to pathological investigation. The lesions were single or multiple and observed as discrete, hard and ellipsoidal pale yellowish nodules or protuberant masses measuring 2 to 16 cm in the greatest dimension in the various cutaneous areas including the dorsal waist and the lateral thigh. On the cut surface, the lesions consisted of many spaces filled with a caseous pale yellowish material. Histologically, the lesions were multilocular structures confined to the dermis. The structures consisted of variably sized and shaped cysts lined by stratified squamous epithelia with hyperkeratosis and hyperplastic basal and prickle cells, and they were filled with feather remnants including barbs and barbules as well as laminated keratin. Based on the findings which indicated characteristic multilocular cysts with differentiation from basal cells to feather epithelia, the present cases were diagnosed as feather folliculoma. This is the first report of feather folliculoma in broiler chickens.