Peer-reviewed veterinary case report
Muscle spasms associated with ear tick (Otobius megnini) infestations in five horses.
- Journal:
- Journal of the American Veterinary Medical Association
- Year:
- 1995
- Authors:
- Madigan, J E et al.
- Affiliation:
- Department of Medicine and Epidemiology · United States
- Species:
- horse
Plain-English summary
Five horses were found to have severe muscle cramping that wasn't related to exercise, along with other symptoms like sweating, pawing, and tremors. These signs were sometimes mistaken for colic, which is a type of abdominal pain. Tests showed that their electrolyte levels were normal, but some muscle enzymes were higher than usual, indicating muscle stress. A muscle biopsy showed only a few damaged muscle fibers, and one horse's nerve activity suggested increased muscle use. Once the ear ticks were treated, the horses stopped showing these symptoms.
Abstract
Severe muscle cramping not associated with exercise was observed in 5 horses. Focal muscle groups in various regions underwent intermittent visible contraction. Intermittent prolapse of the third eyelid, sweating, pawing, muscle tremors, and muscle fasciculations also were observed. Clinical signs often were misconstrued as signs of colic. Percussion of muscle induced contraction of muscle groups. Concentrations of serum electrolytes and the acid-base balance were within reference limits, but activities of creatine kinase and aspartate transaminase were moderately high. Muscle biopsy revealed no abnormalities except for a few necrotic muscle fibers undergoing phagocytosis. Electromyography of 1 horse was suggestive of increased motor unit activity. All horses had Otobius megnini (ear tick) infestations and had recurrence of signs until treatment was initiated for ear ticks.
Find similar cases for your pet
PetCaseFinder finds other peer-reviewed reports of pets with the same symptoms, plus a plain-English summary of what was tried across them.
Search related cases →Original publication: https://pubmed.ncbi.nlm.nih.gov/7601699/