Case Study of Bacterial Diseases in Frogs
Yu-Ting Liu

Abstract
In February 2025, the Aquatic Animal Laboratory received bacterial samples isolated from the internal organs and wound sites of tadpoles submitted by frog farming operator. The primary clinical signs reported were abdominal distension and tail ulceration. Bacterial culture and identification confirmed the presence of Aeromonas hydrophila, Chryseobacterium gleum, Acinetobacter junii, Shewanella putrefaciens. Further investigation was conducted for farm management practices, including water sources, equipment, personnel movement, and feed organism quality. The feed was found to be of poor quality and contaminated with various environmental bacteria. Farmers were advised to improve feed quality, implement strict hygiene and disinfection measures, and administer appropriate medication. Following these interventions, the clinical symptoms of the affected tadpoles shown significant improvement.

Analysis of surveillance data for Major Pathogens in Fourfinger threadfin
I-Wen Chen

Abstract
From 2023 to 2024, a technical service team was established to assist Taiwan's Fourfinger threadfin industry. This team comprised experts from the Veterinary Research Institute and the Fisheries Research Institute. The primary objectives of the team were to conduct disease assessments, investigate the epidemic situation of bacterial pathogens in Taiwan, and provide professional advice for safe medication to farmers. For the last two years, the number of cases submitted for inspection has been pretty steady, with a slight decrease from 71 in 2023 to 69 in 2024. Back in 2023, there were 71 cases submitted for inspection. The pathogens include Streptococcus iniae, Edwardsiella piscicida, Photobacterium damselae subsp. damselae and Vibrio spp. In 2024, 69 cases were submitted for inspection, the predominant pathogens are Streptococcus iniae, especially in the Fangliao region, where S. iniae accounted for 40% of the cases. The reasons behind these variations remain unclear, highlight the need for more researches. The study with the Fisheries Research Institute has shown that the bacteria present in the early stages of fish development are mainly affected by water management, rather than feed organisms. However, enriching feed organisms with probiotics can introduce probiotics into the intestines of Fourfinger threadfin fry, reducing the risk of bacterial disease outbreaks.