Botulism Synonyms Equine grass tetany Limber neck Shaker

Botulism Synonyms: • Equine grass tetany/ Limber neck / Shaker foal syndrome. Etiology: • Clostridium botulinum is a spore (oval, sub terminal endospores) forming, gram positive organism and produces neurotoxins during their vegetative growth. • It has 7 antigenitically distinct types from A to G. • Farm animals are affected with toxin type B, C and D. Source of infection • Preformed toxin (Forage botulism) • Contaminated feeds with toxin containing carrions(Carrion associated botulism) • Toxin production in wounds (Wound botulism) • Alimentary tract (Toxico infectious botulism) Transmission • Ingestion of contaminated material or birds or blow flies are possible. • Spread of infection through injury.

Host affected: • Cattle and sheep are susceptible for type C and D while horses are susceptible for type B toxin. • Pigs, dogs and cats found to be resistant. • Human is also susceptible for bolutinum toxins. Pathogenesis: • Organism→Botulism toxins (neurotoxin) → absorbed by the intestinal tract or the wound → traverse through the blood stream → peripheral cholinergic nerve terminals → neuromuscular junction→interfere the release of Ach→ leading to flaccid paralysis→Death due to respiratory paralysis. Clinical findings: • Early muscle tremor, • progressive symmetrical weakness, • motor paralysis leading to recumbency. • Mydriasis • ptosis • walking (Limber neck).

• weak tongue retraction • sensation and consciousness retained until death • In sheep, in early stage there is excitability, stiffness while walking and incoordination. The head may be held on one side or bobbed up and down while Diagnosis: • Demonstration of toxin in serum or feed. • Demonstration of organisms in feed, intestinal contents or wounds Treatment: • With type-specific antiserum and supportive treatment as fluid therapy and enteral feeding. Control: • Avoidance of exposure by feed management and Vaccination. Zoonotic implications: • Botulinum toxin is identified as a possible agent for bioterrorism. • The meat and milk from cattle that have botulism should not be used for human consumption.