Date Received: 23-05-2026 / Date Accepted: 02-07-2026 / Date Published: 30-09-2026
This study was conducted to evaluate the composition, morphological characteristics, and association between intestinal protozoan infection intensity and digestive disorders in cultured frogs. A total of 219 frog samples collected from 19 farms showing reduced feeding, abdominal distension, and digestive disorders were examined for clinical signs, while intestinal samples were analysed using fresh wet mounts combined with Lugol’s iodine staining to determine the composition, prevalence, and infection intensity of protozoa. Protozoa were preliminarily identified based on morphology, motility patterns, ciliary distribution, and cytoplasmic characteristics. Protozoa were detected in 198/219 examined samples (90.4%), with three major groups identified as Balantidium spp., Nyctotherus spp., and Cepedea spp. Protozoan infection intensity varied considerably among surveyed farms, ranging from 21 to 664 protozoa per microscopic field. Common clinical signs observed in infected frogs included reduced feeding, abdominal distension, intestinal gas accumulation, and intestinal haemorrhage. Correlation analysis showed that total protozoan burden was positively associated with cumulative mortality and clinical severity in frogs (p < 0.001). The results suggest that excessive proliferation of intestinal protozoa may be closely associated with digestive disorders in cultured frogs under intensive farming conditions.
