A dog's muscular system is one of its largest body structures. The tissues that make up the muscular system facilitate movement, including voluntary functions such as walking and chewing, as well as involuntary movements such as breathing and heart function.
-
Function
-
A dog's muscular system serves many functions. The primary function of a dog's muscular system is to move different parts of the body. Muscles also stabilize joints to keep them functioning under pressure.
Types
-
The two main types of muscles are voluntary and involuntary. Voluntary muscles are controlled by thought, whereas involuntary muscles are controlled by the central nervous system.
These muscles are composed of three types of tissues.
Smooth muscles are internal, involuntary muscles that surround arteries, the bladder, and intestines.
Cardiac muscles are involuntary muscles located in the heart.
Skeletal muscles are voluntary and typically attach to the skeletal system. Skeletal muscles in the dog are involved in walking, chewing, and tail wagging.
Structure
-
Muscles are composed of many cells held together by connective tissue. Each muscle fiber gets nerve impulses from the central nervous system, which is converted into mechanical energy by the muscle, causing muscle contraction and movement.
Diseases of the Muscular System
-
Dogs are susceptible to three main types of muscular diseases. Congenital diseases are those in which a muscle fails. Those disorders are usually inherited and are more common in purebred dogs. Examples of congenital diseases include muscular dystrophy, muscle fiber deficiency, familial reflex myclonus, and congenital myotonia.
Another class of muscular disorder is inflammatory disorders. Inflammatory diseases cause inflammation in one or more muscles.vExamples of inflammatory disorders include polymyositis, eosinophilic myositis, and myositis caused by infection.
Neoplasia, or tumors, rarely occur in dogs. Secondary tumors from nearby bone or organs sometimes invade muscle tissue and inhibit muscle function.
Evaluating Muscle Function
-
There are four common ways to evaluate muscle function in dogs.
Serum muscle enzyme tests measure the amount of muscle enzyme that are released into the bloodstream when muscles are damaged.
Electromyography, or EMG, is a test that evaluates the electrical properties of skeletal muscles.
A muscle biopsy is the removal of muscle tissue for examination under a microscope. Examination of the muscle tissue can detect inflammation or infection and determine whether a tumor is malignant or benign.
X-Rays, or radiography, are sometimes used when diagnosing muscle problems. Although the x-rays do not reveal much about the muscles themselves, they can detect problems in surrounding skeletal structures.
-