| Abstract: | Forty‐four faecal samples from piglets (2–3 animals per group) experimentally infected with Isospora suis were examined 4, 5, 7, 10, and 11 days after infection either with a modified flotation technique followed by McMaster counting (MM), MM combined with autofluorescence microscopy of faecal smears (MM‐A), or nested‐polymerase chain reaction (PCR). PCR was the most sensitive method, detecting I. suis in 70% of the samples (MM 25%, MM‐A 52%). More positive samples were detected in the untreated and the diclazuril‐treated 15 mg/kg bodyweight (BW) once or twice, respectively] groups (10 samples per group; MM 30–40%, MM‐A 50–70%, PCR 60–90%), than in the toltrazuril‐treated (20 mg/kg BW) group (14 samples; MM 0%, MM‐A 21%, PCR 57%). Parasites could be detected in the untreated group on all days with PCR and MM‐A, while MM detected oocysts only from day 5. Autofluorescence should be used as a routine diagnostic aid for the detection of oocysts in faecal samples, while PCR, being the most sensitive technique, can be employed when large numbers of samples are examined, and in experimental setups. |
