Feline Muscle Disorders


This is a neuromuscular disorder that is caused by a disruption of signal transmission between nerves and muscles. Myasthenia Gravis is most commonly congenital (present at birth) and becomes apparent between 6-8 weeks of age. It can also be an acquired disorder that appears later in life (either between 1-4 or 9-13 years of age) and is caused by having the appropriate genetic background as well as environmental, infectious, or hormonal influences.


  • Progressive weakness, fatigue, or cramping
  • May sleep with eyes open
  • Vocal changes
  • Excessive drooling or difficulty swallowing
  • Difficulty breathing
  • Abnormal resting position of the neck
  • Regurgitation with esophageal involvement
  • Decreased or absent gag reflex


Your veterinarian will need to conduct a chemical blood profile, urinalysis, and thyroid test. They might also suggest diagnostic imaging which will include a chest x-ray to look for enlarged esophagus and aspiration pneumonia, and an ultrasound guided exploration of the chest to look for a mass.


Antibiotic therapy, intravenous fluid therapy, and oxygen therapy are common. Nutritional maintenance with a feeding tube may be necessary if the cat is unable to eat or drink without significant regurgitation. If a tumor or mass is found during exploration, surgery will be required.


Although it is not a true muscle disease, Steatitis – or yellow fat disease – is a condition in which inflammation of fatty tissue occurs. It is thought that an excess of unsaturated fatty acids in food combined with a vitamin E deficiency causes this condition. Most known cases have involved animals whose diet consists of fish or fish byproducts.


  • Weight gain/obesity
  • Full hair coat or dry skin
  • Lethargic and loss of agility
  • Tender back or abdomen
  • Lumpy deposits of fat under the skin
  • Fever


The cat’s diet must be changed to exclude the source of excess fat. In addition, supplementing the diet with vitamin E is recommended.


This is a muscle weakness disorder that affects the entire body. This is typically caused by a potassium deficiency.

(Normal Skeletal Muscle)

(Polymyositis in Skeletal Muscle)


  • Generalized weakness
  • Bending forward of the neck
  • Stiffened posture
  • Persistent loss of appetite
  • Muscle pain


The condition is treatable with dietary potassium supplements. The outlook for recovery is excellent if the condition is diagnosed and treated quickly.

This material is provided for educational purposes only and is not intended to diagnose or treat any disease or condition. All specific treatment decisions must be made by you and your local, attending veterinarian.

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