Cone degeneration (German Shorthaired Pointer type) is an inherited eye disease affecting dogs. Affected dogs develop day-blindness (blindness in bright light) and Photophobia (light sensitivity) between 8 to 12 weeks after birth due to degeneration of cells in the eye called cone photoreceptors which are responsible for vision in bright light. Affected dogs have normal vision in low light and structures of the inner eye appear normal on a veterinary eye exam. Normal cone cell function can be seen on Electroretinogram (ERG) before six weeks of age, but becomes abnormal between 6 to 12 weeks of age and is completely absent in affected adult dogs signifying complete loss of Cone Cells. The cells responsible for vision in low light called Rod photoreceptors are not affected and thus, affected dogs will still be able to see normally in low light throughout life.
Degenerative myelopathy caused by Mutation of the SOD1 gene is an inherited neurologic disorder of dogs. This mutation is found in many breeds of dog, though it is not clear whether all dogs carrying two copies of the mutation will develop the disease. The variable presentation between breeds suggests that there are environmental or other genetic factors responsible for modifying disease expression. The average age of onset for dogs with degenerative myelopathy is approximately nine years of age. The disease affects the White Matter tissue of the spinal cord and is considered the canine equivalent to amyotrophic lateral sclerosis (Lou Gehrig’s disease) found in humans. Affected dogs usually present in adulthood with gradual muscle Atrophy and loss of coordination typically beginning in the hind limbs due to degeneration of the nerves. The condition is not typically painful for the dog, but will progress until the dog is no longer able to walk. The gait of dogs affected with degenerative myelopathy can be difficult to distinguish from the gait of dogs with hip dysplasia, arthritis of other joints of the hind limbs, or intervertebral disc disease. Late in the progression of disease, dogs may lose fecal and urinary continence and the forelimbs may be affected. Affected dogs may fully lose the ability to walk 6 months to 2 years after the onset of symptoms. Affected medium to large breed dogs can be difficult to manage and owners often elect euthanasia when their dog can no longer support weight in the hind limbs. Affected small breed dogs often progress more slowly than affected large breed dogs and owners may postpone euthanasia until the dog is paraplegic.
Von Willebrand disease type II (VWDII) is an inherited bleeding disorder affecting
dogs. Dogs affected with VWDII have decreased levels and abnormal function of von
Willebrand coagulation factor (vWf), which is an essential protein needed for normal
blood clotting. Affected dogs generally have moderate to severe signs of a bleeding
disorder. Affected dogs may bruise easily, have frequent nosebleeds, bleed from the
mouth when juvenile teeth are lost and experience prolonged bleeding after surgery or
trauma. The bleeding may be severe enough to cause death. Due to variable severity of
the disorder, affected dogs may not be identified until a surgery is performed or trauma
occurs at which time excessive bleeding is noted. Veterinarians performing surgery on
known affected dogs should have ready access to blood banked for transfusions. Dogs
can have a normal lifespan with this condition although they are susceptible to life-
threatening bleeding with an accidental injury or any surgical procedure.\