An outbreak of equine botulism type D in Israel

Abstract

Summary An outbreak of type D botulism involved 12 horses in an equine farm in Israel. Clinical signs included progressive weakness and decreased tongue and tail tonus. Ten of the horses died. Supportive care was provided, without antitoxin administration, since it was not available. In two samples of the gastrointestinal content, the presence of Clostridium botulinum type D toxin producing bacteria was demonstrated by the mouse bioassay test. Botulism represents a severe concern, due to high mortality rate and public health problem. Since clinical signs are insufficient to make a definitive diagnosis, laboratory confirmation is required. Prevention of exposure, immunisation and early aggressive treatment may decrease mortality.

Botulism: Knowledge and preparation improve outcome for horses

“…Botulism is a devastating disease that occurs worldwide, as demonstrated in a report which describes an outbreak that resulted in the death of 10/12 affected horses (Shnaiderman‐Torban et al . ). Although disease is only sporadically reported, Clostridium botulinum spores are ubiquitous in the environment, found in soil and particularly concentrated in decaying vegetation or animal carcasses.…”

“…Neither of these products would have been effective in treating the affected horses described by Shnaiderman‐Torban et al . () because these horses ingested type D toxin. Therefore, veterinarians must be aware of the prevalent C. botulinum types in their practice areas and choose prevention and treatment strategies accordingly.…”

“…In the outbreak described by Shnaiderman‐Torban et al . (), rotten silage was almost certainly the source of botulinum toxin, although specific confirmatory testing was not performed. Had the rotten silage been detected prior to feeding it to the horses, the entire outbreak might have been avoided.…”

“…Shnaiderman‐Torban et al . () expressed concern that lactating mares with botulism might have toxin in their milk that could affect nursing foals. This has been extensively examined in people with botulism, with no evidence for transmission in milk (Lawrence and Lawrence ).…”

“…As demonstrated in the type D outbreak in Israel (Shnaiderman‐Torban et al . ), very mildly affected horses can survive without antitoxin administration. Likewise, severely affected horses might succumb despite receiving antitoxin.…”