“There seems to be an increased risk of cases of Atypical Myopathy during the spring, when the disease has occurred during the previous fall” warns Dr Domonique Votion, of the University of Liege.
In the last few months of 2009, Western Europe experienced the largest ever series of cases of the disease, according to the Atypical Myopathy Alert Group (AMAG).
No less than 371 cases were notified to the AMAG. Of those horses, 265 died, giving a survival rate of just 22%. Most cases were reported in France (124) Germany (92), and Belgium (64).
Thirty-five cases were identified in the UK.
Horses with Atypical Myopathy suffer from severe, generalised weakness. They are often unable to get to their feet, or only do so with difficulty. If they are still able to walk, they do so with a stiff gait - especially of the hindquarters. Muscle tremors and generalised or patchy sweating may be seen.
Affected animals have elevated heart rates. They often have increased respiratory rates, with difficulty on expiration. The rectal temperature is usually below normal. Dark brown colouration of the urine is characteristic.
Despite the severity of the signs, horses often still seem keen to eat and will try to grasp hay that is held close to their mouth.
Often the first sign of disease is stiffness, especially of the hindquarters. However, it is not unusual for severely affected cases to be found dead on the pasture with no previous sign of illness.
For more details about the Atypical Myopathy and the Atypical Myopathy Alert Group see: