What is Botulism? 

Botulism is a progressive, flaccid paralysis resulting from ingestion of a bacterial toxin (from Clostridium botulinum) which can be rapidly fatal if not aggressively treated from the first clincal signs. 

Clinical Signs: Clinical Signs of Botulism include the following: 

• Severe muscle weakness 
• Flaccid paralysis with normal mentation 
• Inability to swallow 
• Poor tail, tongue and eyelid tone
• Hypoventilation, respiratory arrest 
• Paresis/inability to stand for extended periods 
• Limb paralysis 
• Progression to muscular weakness and recumbency 
• Drooling 
• Muscle trembling 
• Unexplained mydriasis with sluggish pupillary light reflexes
• Tachycardia 
• Colic and decreased gastrointestinal motility 
• Sudden unexplained death
• inability to rise after lying down 

Diagnosis: Botulism should be the primary concern for horses suffering from flaccid paralysis without any signs of precipitating conditions. Diagnosis is by elimination of other causes of neurological disease-causing weakness and recumbency such as EPM, EHM, arboviral encephalitis, rabies, metabolic derangements, myopathies and other toxins.  

Treatment:  Treatment with antiserum can be used if administered early in the disease.

Prevention: Vaccination is effective and may be used in environments known for the disease.