Congenital abnormalities of the musculoskeletal system may result in deformities in the dogs. Viral infections contracted by the mother during pregnancy as well as certain plant toxins ingested by her may be the cause of these disorders in the puppies. Some genetic abnormalities may be inherited by the pups. They are usually neurologic disorders that involve the muscles too.
A few of the congenital disease conditions affecting the muscles and the bones of dogs are the following:
Muscular Dystrophy (Myopathy)
Several disease conditions that involve progressive deterioration of muscles may affect dogs. Some of them are inherited disorders and are similar to certain muscular dystrophies found in people. For example, a disorder much like the Duchenne disease in humans is often observed in the American Golden Retrievers and the Irish Terriers of Europe. The main symptoms are weakening of the muscles which results in a typical stiff gait and difficulty in swallowing food in addition to the wasting away of muscles. Absence of a protein necessary for the normal working of the muscle membranes is the cause of this condition. In some cases, this disease may be accompanied by a disorder of the heart muscles too.
Labrador Retrievers in Australia, Europe and North America may be affected by another type of muscular dystrophy that starts very early in life with 6 month old pups developing muscle wastage. The characteristic stiff gait and reluctance to exercise are the usual symptoms. A type of muscular dystrophy affecting European Bouviers interferes with their swallowing ability.
This is a glycogen storage disease resulting from the faulty processing of glycogen, which is a form of carbohydrate. It is usually synthesized by the body mainly in the liver as well as the muscles and stored there. There are several types of glycogenosis that affect both humans and other animals including dogs. Horses and cats are affected too. Dogs affected by this progressive disease become increasingly weaker until they can no longer get up. Lapland dogs are especially prone to Type II glycogenosis.
As the name indicates, this skeletal disorder affects the hip joints. It is an abnormality in which the long bone in the upper part of the hind limb called femur is not fitting correctly into the hip socket. This is a common occurrence in dogs, often resulting in arthritis later in life. Some larger breeds have higher risk of inheriting this disorder.
This skeletal disorder which causes deformities in the head, body or legs of the dogs is an inherited condition. In Basset Hounds, Alaskan Malamutes and Dachshunds, it affects their heads and trunks. In some other breeds such as Scottish Terriers and Poodles which are greatly affected by this disorder, not only their heads and trunks but their limbs may also be affected. Dyschondroplasia causes a reduction in red blood cells in Malamutes, making them anemic. The structural features resulting from this disorder are considered typical characteristics of Pekingese, Dachshunds and Basset Hounds.
This is a skeletal disorder that generally affects dogs of the larger breeds. The growth of the bones is the most affected at a time when the dogs are growing up very fast. This results in great stress to the immature skeletal system during this early stage of bone development, and causes the joint cartilage to get separated from the head of the bones. The separated cartilage remains loose in the joint, causing inflammation. The disintegration of the cartilage results in the formation of debris in the joint cavity which disrupts further growth of the bones. Shoulder joints are the most affected; the elbows and the ankles also may be involved, but to a lesser extent.
This rare condition found in dogs may be a genetic abnormality. It has been found to be a cause of stillbirth, as the affected puppies are usually born from ten days to up to a month preterm. The typical characteristics are shortened lower jaws and brittle bones. The molar teeth may be impacted. Instead of bone marrow, the long bones and the skull are filled with a spongy bone tissue. The skull may become thickened, and the brain may get compressed as a result.
Loose joints and extremely fragile bones are characteristic symptoms of this abnormality. Slender long bones of the both forelimbs and hind limbs make the dog prone to frequent fractures. The calluses that are formed at the site of breakages may alert the veterinarian to the probability of Osteogenesis imperfecta in the dog. Blue tinged whites of eyes are another telltale sign of this condition.