Tonsils--place of botulinum toxin production: results of routine laboratory diagnosis in farm animals.

Since a case of a veterinarian was reported, who was likely to be infected/intoxicated by Clostridium botulinum during the handling of a diseased animal, tonsils in animals were tested for botulinum neurotoxin and bacterial forms of neurotoxic Clostridium botulinum during routine botulism laboratory examinations including standard samples (intestinal tract and liver) from 48 cattle, 11 horses, and 14 goats. Ten out of 60 samples from tonsils contained free botulinum toxin, and 12 out of 59 were positive for live toxin producing bacteria. In 32 out of 162 intestinal samples toxin was detected. Toxin producing bacteria were found in 37 samples. Eight of 56 liver samples contained free toxin, and 15 out of 43 toxigenic bacteria. Samples from 10 slaughter pigs were all negative, whereas from slaughter cattle tonsils had a high incidence of toxin (7 of 10) or toxigenic bacteria (2 of 8). The results are discussed in the context of effects on animal health and botulism as zoonosis.