Equine grass sickness in italy: a case series study

Area of Science:

• Veterinary Neurology
• Equine Medicine
• Pathogenesis Research

Background:

• Equine grass sickness (EGS) is a rare but severe neurological disease affecting horses, primarily those on pasture.
• Clinical signs are linked to autonomic nervous system (ANS) and enteric nervous system (ENS) lesions, presenting acutely, subacutely, or chronically.
• The etiology of EGS remains speculative, with various hypotheses proposed.

Observation:

• This study details four cases of EGS in Central Italy, including one subacute and three chronic forms.
• All affected horses had a poor prognosis and were euthanized.
• Diagnosis was histologically confirmed via ANS/ENS examination, with two cases diagnosed in vivo via laparoscopy and enteric biopsy.

Findings:

• EGS may be underdiagnosed in Italy, with an underestimated incidence.
• Clinical signs include dullness, anorexia, dysphagia, drooling, tachycardia, ptosis, sweating, and muscle fasciculations.
• Horses in the study were from the same pasture, suggesting pasture-linked and management-linked factors in EGS.

Implications:

• Increased awareness of EGS is crucial for differential diagnosis in horses with abdominal pain, gastric reflux, or muscle fasciculations.
• The findings support age (2-7 years) as a risk factor for EGS.
• Environmental factors like recent cool, dry weather and prior suspected cases in the herd may also contribute to EGS outbreaks.