Neuromuscular pathologies present with varying clinical signs.
The most common signs are alterations in muscle size (atrophy or hypertrophy), muscle weakness and altered gait.
Clinical signs can be localised, multifocal or generalized.
Unilateral atrophy is easier to observe by comparing muscles on either side of the body.
In cases of generalized atrophy, we should remember what normal musculature is for that particular breed.
For example, the musculature in a dairy cow is less prominent than that of an animal destined for meat, and mild generalized atrophy in a draft horse will be much more difficult to detect than in a racing horse.
Weakness may be evident when an animal cannot get up or when it refuses to exercise. Careful attention should be given to gait analysis. In an animal with generalized weakness, due to muscular or peripheral nerve dysfunction, the step will be shortened or seem problematic and all four legs will be carefully positioned under the body to ensure greater stability when stationary.
If the plasma membrane of the muscle fibres is damaged or in necrosis, some of the enzymes contained in it will be found in the blood.
The serum levels of some of these components are indicators of myofibral damage.
One of the most commonly used parameters is creatine kinase (CK).
Aspartate aminotransferase (AST) and lactate dehydrogenase levels can also be checked but they are not specific indicators of muscle damage as they are present in other tissues.
It is important to remember that. . .
… myopathies or neuropathies causing atrophy, weakness, spasm, stiffness or myotonia rarely lead to significant increases in serum enzymes.
CT and MRI are valid diagnostic tools for assessing and localising neuromuscular pathologies.
1. Introduction to the study of Veterinary Myopathology
2. Structure and characteristics of normal skeletal muscle
2. Structure and characteristics of normal skeletal muscle
3. Diagnosis of neuromuscular pathology
5. Specific alterations to muscle fibres
6. Congenital and hereditary muscle disorders in farm animals
8. Bacterial and Parasitic Myopathies
9. Nutritional and toxic myopathies
10. Polysaccharide storage myopathy