The neuronal ceroid-lipofuscinoses (NCLs) are a class of inherited neurological disorders that have been diagnosed in American Bulldogs and some other breeds. NCL is almost always inherited as an autosomal recessive trait. A DNA test is commercially available to identify whether a dog carries the genetic mutation that can be passed on to its progeny. This test is included in many commercially available DNA breed identification tests, as well, including the Embark. Wisdom does not currently test for the AB variant, NCL10.
Age of onset of clinical signs: 0.9 to 3 years
Age of death or euthanasia: 3.5 to 5.5 years
Abnormalities often observed by the owner:
Mental changes: Physical symptoms may appear to worsen during times of stress. Affected dogs do not indicate they are in any pain as coordination decreases.
Changes in gait and posture: Initially, uncoordinated movement in the rear is noted. As the disease progresses, affected dogs develop a wide-based stance starting in rear, and eventually involving all four legs. Affected dogs may exhibit muscle twitching, especially when sleeping. The dogs remain well-muscled through the course of the disease.
Visual abnormalities: None reported
Seizures/convulsions: None reported
Other changes: None reported
Ichthyosis is a skin disorder that can be found in the American Bulldog. The pup in the picture above was produced at Eagle's Wing Kennels before any commercial genetic testing for Ichthyosis was available. Signs that a pup is affected by the disorder are apparent within the first couple of weeks following birth. The skin appears "dirty" and won't wash clean, and the fur takes on a wrinkled appearance. Beware the breeder who doesn't know what Ichthyosis is or tries to pass off a skin condition in a young pup that looks like this as "normal." The University of Pennsylvania isolated the gene with help of biopsies from the 2 affected puppies in this litter, and developed a test that is commercially available from U of P, as well as included in many DNA profiles offered commercially, including the Embark and Wisdom. While not a life threatening disease, it can be uncomfortable for the dog and a nuisance for the owner due to excessive scaling, itching and dander production.
Hyperuricosuria (HUU) means elevated levels of uric acid in the urine. This trait predisposes dogs to form stones in their bladders or sometimes kidneys. These stones often must be removed surgically and can be difficult to treat. HUU is inherited as a simple autosomal recessive defect. HUU can occur in any breed but is most commonly found in the Dalmatian, Bulldog and Black Russian Terrier. Genetic testing is available to determine if a dog carries the genetic trait to pass on HUU. Dogs that carry two copies of the mutation will be affected and susceptible to develop bladder/kidney stones. HUU is not the sole cause of urate bladder stones in dogs. Other factors such as liver disease and diet also may contribute. A dog that is HUU affected may never suffer from bladder/kidney stones, but it is more susceptible to present with same. The Wisdom DNA panel tests for HUU, along with many other diseases (including NCL, Ich, DM and NM discussed on this page).
Allergies have become more common in dogs over the years. There are many schools of thought as to the cause, from commercial diets (dog used to eat meat and table scraps before Purina developed kibble) to over vaccinating (allergies are a response of an overactive immune system, which can be impacted by multiple, unnecessary vaccinations), genetics, and our general environment. Weaker immune systems subject the dog to the possibility of having allergies or the inability to deal with environmental/biological assaults from parasites and disease. Allergies can range from mild to severe and may or may not respond to treatment. Treatment for allergies also may be relatively inexpensive to thousands of dollars over a dog's lifetime.
All large breed dogs are susceptible to hip dysplasia and/or elbow dysplasia. That is why is is important for a breeder to recognize and test for structural faults that are sometimes not noticeable from outward appearances. Dysplasia, also referred to as osteoarthritis, is painful. A dog with incorrectly developed hips and/or elbows may develop OA at an early age. Surgical intervention is available, but is expensive and not always effective. Breeding dogs with hips that have passed OFA or PennHip evaluation helps breeders ensure that they are passing along the best genetics to the offspring of their dogs. Pups from parents with good hips/elbows are far less likely to have hip/elbow disorders. Diet and exercise also play a role in maintaining a dog's bone and joint health. Keeping a dog at a healthy weight with a proper diet, and growing puppies "slowly" helps keep joints in good shape for many years.
While both of these are more rare, they are genetic disorders than can be tested for through the Embark or Wisdom Panel.
Nemaline Myelopathy's clinical symptoms in the affected dog include generalized muscle weakness, exercise intolerance, and tremors which usually start around 2 months of age. The owners often report that their dog since an early age is constantly shaking and is reluctant to exercise. The affected dog has a generalized atrophy, and the myopathy is relatively non-progressive. Muscle examination reveals an atrophy of the cervical and dorsal thoracic limb muscles as well as hypertrophy of the triceps muscles. Serum creatine kinase activities were mildly elevated. Compared to the healthy muscle, affected Americal Bulldogs showed a marked variability in myofiber size and present generalized atrophy. In most of muscles a rod-like inclusion bodies could be found, which are not present in a healthy muscle.
Degenerative Myelopathy is an inherited neurologic disorder caused by a mutation of the SOD1 gene known to be carried by American bulldogs. This mutation is found in many breeds of dog, though it is not clear for American bulldogs 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, such as the American bulldog, can be difficult to manage and owners often elect euthanasia when their dog can no longer support weight in the hind limbs.