Client Education & Newsletters

Information for mare owners following a positive ultrasound scan for pregnancy

Equine Atypical Myopathy (EAM).

Over the past few weeks a number of cases of this disease have been found in Cornwall. If you have concerns that your horse maybe suffering from this condition please contact the surgery.

Summary

Disease affecting grazing horses at pasture, which affects the horse’s muscle causing them to break down
Exact cause unproven as yet, suggestions include Clostridial (bacterial) toxin in the ground, or mycotoxins found on fallen leaves, which are then ingested
Similar to equine dysautonomia (grass sickness) but affects muscles rather than digestive system
Associated with wet, windy weather as found in Autumn hence prevalence of the disease at this time
Outbreaks are generally preceded by a change in weather, such as a frost or heavy rain
Affects individuals or groups of horses at pasture but is NOT CONTAGIOUS
Affects mainly young horses in ANY PHYSICAL condition that are AT PASTURE, usually POOR GRAZING and receiving no supplementary feed
89% of affected animals will die or require euthanasia

Clinical signs

Sudden onset muscle weakness/stiffness in horse at pasture, unrelated to exercise
Signs can be variable, ranging from dullness and inappetance , to collapse
Signs can be confused with colic in recumbent horses, especially as the bladder tends to be very full due to an inability to urinate
Myoglobinuria which is the production of very dark urine

Diagnosis

BLOOD TEST-detect levels of the muscle enzymes AST, CK, LDH

Treatment

89% of horses will die or require euthanasia so intensive treatment should be initiated asap
Intravenous fluid therapy to support kidney function, anti-inflammatories and nursing

Prevention

Provide adequate grazing with supplementary feed if required
Rake up all the leaves on the pasture, or if this is not possible move to clean pasture or stable
Feed Selenevite E (Equine Products) supplement
If any of the clinical signs are noted call a vet straight away-the earlier intensive treatment is initiated, the greater the chance of survival
If an animal has been positively diagnosed then other animals on the same pasture should be moved into stables or another paddock, and should be blood sampled