Читать книгу Animal Behavior for Shelter Veterinarians and Staff - Группа авторов - Страница 118

Most degenerative conditions of the neurologic system are heritable and will appear within the first few weeks to months of life. They include such conditions as cerebellar abiotrophy and lysosomal storage diseases.

Cerebellar abiotrophy can be minimal to rapidly progressive and varies to some degree by the breed affected. The condition has been reported in many breeds, including the Kerry blue terrier, rough‐coated collie, beagle, Samoyed, Irish setter, Gordon setter, Airedale, Finnish harrier, Bernese mountain dog, Labrador and golden retriever, cocker spaniel, cairn terrier, and Great Dane. Most puppies will be normal at birth. At two to nine weeks of age, they begin to show signs of cerebellar damage, including ataxia, intention tremors, swaying, hypermetria, a head tilt, and a broad‐based stance. At the extreme, pups may demonstrate opisthotonos with extensor rigidity of the forelimbs and flexed hindlimbs, the typical decerebellate posture. While the age of onset is prior to four months in most cases, some animals may not show signs of disease until two to two‐and‐a‐half years of age. In some cases where the disease progression is minimal or very slow, some animals can learn to compensate for their disabilities. Cerebellar abiotrophy can develop in the cat but has been less well documented. A single case report has described adult‐onset cerebellar cortical abiotrophy with retinal degeneration in a domestic shorthaired cat (Joseph 2011). If observed and examined carefully, the clinical signs associated with cerebellar degeneration should be readily differentiated from primary behavioral problems.

Lysosomal storage diseases are relatively rare genetic defects that are characterized by progressive neuronal degeneration. They are most likely to occur in purebred animals with a history of inbreeding in the affected line. Animals born with lysosomal storage diseases are normal at birth, with clinical signs usually developing during the first year of life. Neuronal ceroid lipofuscinosis is one of the storage diseases that can appear in adult animals. Case reports of dachshunds with this condition have reported dogs developing the signs at three, five, and seven years of age (Cummings and de LaHunta 1977; Vandevelde and Fatzer 1980). Early signs may include ataxia, disorientation, weakness, and behavioral changes, but, with time, affected individuals will suffer vision loss, progressive motor and cognitive decline, and seizures.