Locomotor Dysfunction Associated With the Muscular System in Pigs

Porcine stress syndrome genes, dystrophin genes, exertional stress, other

Abrupt onset of muscle rigidity, tremors or shaking, skin hyperemia, panting. Usually in heavily muscled, exertion-stressed, otherwise healthy pigs. Lactic acidosis; blood lactate highly elevated. Malignant hyperthermia.

Traumatic injury

Pain, bruising, strain, possible nerve damage

Nutritional myopathy

Vitamin E, selenium deficient (usually heart or liver affected). White muscle disease rare.

Splayleg (spraddle leg)

Neonates. Can recover if nursing care is provided.

Acute hypocalcemia

Tetanic seizures, ataxia. Abrupt vitamin D deficiency, usually with exertional stress.

Bacterial myositis (gangrenous, pyogenic)

Clostridia and opportunists with gangrenous myositis, cellulitis.

Pyogenic bacteria with localized lesions of myositis; wound infections, sepsis.

Iatrogenic: injection sites in ham or neck

Poor injection technique or location; dull needles, contaminated products, inadequate hygiene. Adjuvants, iron, and various injectables can be irritating.

Toxins

Ionophore concurrent with tiamulin administration. Gossypol. Chemical toxins.

Focal hemorrhages

Poor euthanasia techniques (stunning) at slaughter. Possibly African swine fever or classical swine fever.

Myalgia

Parasites (Taenia, Trichina) are relatively rare. Exertional stresses.

Multifocal hemorrhage

Improper stunning. Viral infection (African or classical swine fever).