HEALTH & GENETICS
|
At Bellbright Australian Shepherds, we test all our dogs through Paw Print Genetics, Embark, and the Orthopedic Foundation for Animals (OFA).
Testing is usually performed when the dogs reach two years of age. Each breeding pair will be tested prior to having puppies. This helps ensure the best possibility of a long and healthy life for your puppies. It also helps to better the breed, which is the goal of many reputable breeders. |
|
The following health clearances are performed through Orthopedic Foundation for Animals (OFA):
Hip Dysplasia: According to the Orthopedic Foundation for Animals (OFA): "Hip Dysplasia typically develops because of an abnormally developed hip joint, but can also be caused by cartilage damage from a traumatic fracture. With cartilage damage or a hip joint that isn’t formed properly, over time the existing cartilage will lose its thickness and elasticity. This breakdown of the cartilage will eventually result in pain with any joint movement. No one can predict when or even if a dysplastic dog will start showing clinical signs of lameness due to pain. Severity of the disease can be affected by environmental factors, such as caloric intake or level of exercise. There are a number of dysplastic dogs with severe arthritis that run, jump, and play as if nothing is wrong and some dogs with barely any arthritic x-ray evidence that are severely lame." Elbow Dysplasia: According to the OFA: "Elbow dysplasia is a general term used to identify an inherited polygenic disease in the elbow. Clinical signs involve lameness which may remain subtle for long periods of time. No one can predict at what age lameness will occur in a dog due to a large number of genetic and environmental factors such as degree of severity of changes, rate of weight gain, amount of exercise, etc.. Subtle changes in gait may be characterized by excessive inward deviation of the paw which raises the outside of the paw so that it receives less weight and distributes more mechanical weight on the outside (lateral) aspect of the elbow joint away from the lesions located on the inside of the joint. Range of motion in the elbow is also decreased." EYE CERTS (CAER): iris coloboma According to the OFA: "The purpose of the OFA Companion Animal Eye Registry (CAER) is to provide breeders with information regarding canine eye diseases so that they may make informed breeding decisions in an effort to produce healthier dogs. OFA Eye Certification examinations are screening exams performed by board certified veterinary ophthalmologists. The exams can take place either in the veterinary office or at a special clinic held in conjunction with another event (such as a dog show). The exam is performed 30 to 40 minutes after pupil-dilating drops are placed in the eyes. The Eye Certification exam consists of indirect ophthalmoscopy and slit lamp biomicroscopy. It is not a comprehensive ocular health examination, but rather an eye screening exam." |
|
|
|
The Full Australian Shepherd Panel from Paw Print Genetics or Embark currently consists of the following 10 disease tests:
1. COLLIE EYE ANOMALY (CEA or CH) According to Paw Print Genetics, Collie Eye Anomaly (CEA), also known as choroidal hypoplasia (CH), is an inherited disease affecting several dog breeds including the Australian shepherd. The choroid is the layer of tissue in the eye responsible for supplying blood and nutrients to the Retina. In dogs affected with CEA, the choroid does not develop properly and is therefore thinner than normal. The severity of the condition can vary from dog to dog. In mild cases, affected dogs may only show signs of collie eye anomaly on eye exam between about 5 and 12 weeks of age, just prior to normal, age-related pigmentation of the retina which often masks the characteristic, disease-related changes. After this time period, mildly affected dogs may be impossible to distinguish from normal dogs on eye exam (a phenomenon often referred to as “going normal”) and may not display obvious vision deficits. In more severely affected dogs, clinical signs include malformations of the eye and/or optic nerve (colobomas), retinal detachment, intraocular bleeding, and subsequent blindness. Both mild and severe forms of CEA are associated with the same NHEJ1 gene Mutation. Therefore, predicting the potential severity of the disease in an affected puppy is difficult as mildly affected parents may produce offspring that are severely affected. Though the frequency of the gene mutation in the overall Australian shepherd population is unknown, in one study of 223 Australian Shepherd dogs from Australia, 4% were found to be affected with collie eye anomaly." 2. CONE DEGENERATION According to Paw Print Genetics, Cone Degeneration 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 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. The frequency of the causal mutation in the general Australian shepherd population is unknown." 3. DEGENERATIVE MYELOPATHY According to Paw Print Genetics, 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, including the Australian shepherd. While it is not clear for some of the other breeds, Australian shepherds are known to develop degenerative myelopathy associated with this mutation. 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 Australian shepherd, can be difficult to manage and owners often elect euthanasia when their dog can no longer support weight in the hind limbs. The overall frequency of this disease in the breed and approximate age of disease onset is unreported for the Australian shepherd. However, in one study of 113 Australian shepherds tested, 17.7% were carriers of the mutation and 31.9% were at-risk/affected." 4. HEREDITARY CATARACTS According to Paw Print Genetics, Hereditary cataracts (Australian shepherd type) is an inherited eye disease affecting Australian shepherds. Cataracts are opacities in the lens of the eye caused by structural changes in lens proteins. A normal lens allows light to pass through it to the Retina in the back of the eye. Light cannot pass through the parts of the lens affected by cataracts and vision becomes blurry. Dogs with hereditary cataracts (Australian shepherd type) most commonly present between 2 to 7 years of age with small cataracts that are visible on a veterinary eye exam. Dogs that carry a single copy of the Mutation have an increased risk over the general (normal) population of developing cataracts. In dogs that inherit one copy of the mutation, cataracts develop slowly, sometimes leading to complete blindness. However, it has been speculated that dogs carrying two copies of the mutation are more likely to develop a more rapidly progressing and severe Cataract. Of note, not all forms of cataracts are inherited and environmental factors such as UV damage can also play a role in the severity of disease. This specific mutation in the HSF4 gene shows Incomplete Penetrance, meaning that not all dogs inheriting two copies of the mutation develop clinical disease. This suggests that other unknown genetic or environmental factors may play a role in modifying disease development and progression. Though the overall frequency in the Australian shepherd population is unknown, in one study of 392 Australian shepherds with and without cataracts from North America and Europe, 25.5% were carriers of the mutation and 3.8% had two copies of the mutation. In this same study, Australian shepherds with this mutation had an approximately 17-fold increased risk of developing cataracts." 5. HYPERURICOSURIA (HUU) According to Paw Print Genetics, Hyperuricosuria is an inherited condition affecting Australian Shepherds. The SLC2A9 gene codes for a protein that allows the kidneys to transport uric acid from the urine. Dogs with mutations in both copies of the SLC2A9 gene are predisposed to have elevated levels of uric acid in the urine, hence the name hyperuricosuria. Uric acid can form crystals and/or stones (uroliths) in the urinary tract. Dogs with hyperuricosuria most commonly present with symptoms of recurrent urinary tract inflammation, which include frequent urination, blood in the urine, and straining to urinate. They may also have loss of appetite, lethargy, weakness, vomiting and pain. Urinary stones in the bladder can cause urinary tract infections or more seriously, blockage of the Urethra. Both male and female dogs can be affected, but obstruction of urine flow is more common in males due to differences in anatomy. Although an x-ray can be used to exclude other types of stones, urate stones cannot typically be seen using x-rays and must be evaluated by ultrasound. Not all dogs with mutations in both copies of the SLC2A9 gene will have symptoms of disease, though they will have increased uric acid excretion in the urine. Though the exact frequency in the overall Australian Shepherd population is unknown, based on 142 Australian Shepherds tested, 3.46 % of Australian Shepherds in the United States are estimated to be carriers of the mutation and 0.03% are estimated to be at-risk for hyperuricosuria." 6. Intestinal cobalamin malabsorption (IGS) According to Paw Print Genetics, Intestinal cobalamin malabsorption (Australian shepherd type) is an inherited disease affecting Australian shepherds. Affected dogs are unable to make adequate amounts of a protein that plays a role in absorption of certain nutrients from the intestinal tract and kidneys, including the B vitamin, cobalamin. Affected dogs have increased levels of methylmalonic acid in their urine (a sign of cobalamin deficiency) after weaning, but symptoms of disease may not be recognized by owners for months or years. Symptoms of disease include anorexia, lethargy, poor weight gain, poor muscle mass, and in rare circumstances, a severe neurological dysfunction called hepatic encephalopathy that can lead to altered mental state, seizures, coma and death. Affected dogs have an increase in certain proteins in their urine, and have decreased synthesis of blood cells resulting in Anemia and decreased numbers of neutrophils. Affected dogs require cobalamin supplementation for life that results in disease remission for most animals within a few weeks. Though not associated with clinical disease, affected dogs will continue to pass increased amounts of certain proteins in the urine even with cobalamin supplementation. 7. MULTI DRUG RESISTANCE 1 (MDR1) According to Paw Print Genetics, Multidrug Resistance 1, also called MDR1, is an inherited condition affecting several breeds of dogs, especially herding dogs such as the Australian Shepherd. The Mutation in the ABCB1 gene associated with MDR1 causes dysfunction of P-glycoprotein, which is responsible for removing certain drugs and toxins from the body. Clinical signs are most commonly associated with distribution of the drug in the central nervous system. If an at-risk dog is treated with one of several common drugs (see below*), they are at risk of developing neurologic symptoms that could range from tremors, excess salivation, anorexia and blindness to coma and even death. Because of the defective ability to metabolize specific drugs, these drugs can be lethal even at low doses. The MDR1 mutation does not cause adverse effects in dogs unless the dog is exposed to these drugs. Therefore, veterinarians should be notified when a dog is at risk for multidrug resistance 1 prior to administration of any medications. Though the exact frequency in the overall Australian Shepherd population is unknown, in North America 37% out of 1,421 Australian Shepherds were carriers and 10% were at-risk. In Europe, 48% out of 907 Australian Shepherds were carriers and 11% were at-risk. Worldwide, the percentage of carriers ranges from 25% to 44% and the percentage of Australian Shepherds at-risk for MDR1 ranges from 10% to 25%. *Drugs known to cause neurological signs related to the MDR1 mutation: Acepromazine, butorphanol, doxorubicin, emodepside, erythromycin, ivermectin, loperamide, milbemycin, moxidectin, rifampin, selamectin, vinblastine and vincristine In addition to this list, there are many other drugs known to be removed from the central nervous system via the P-glycoprotein mechanism in humans. However, reports of neurological dysfunction related to drugs other than those listed here are scarce in dogs. Please consult your veterinarian when giving drugs to known multidrug resistance carriers, affected dogs, or untested dogs of breeds commonly affected with this condition." 8. MULTIFOCAL RETINOPATHY 1 According to Paw Print Genetics, Multifocal Retinopathy 1 is an inherited disorder of the Retina affecting Australian Shepherds. Affected dogs typically present between 11 and 16 weeks of age with multiple discrete circular areas of retinal detachment with underlying fluid accumulation that are visible on an eye exam performed by a veterinarian. These blister-like lesions are typically found in both eyes and can appear gray, tan, orange or pink and vary in number, size and location. Progression of retinal changes is usually slow and new lesions are not noted after 6 to 12 months of age. Occasionally as affected dogs age, lesions appear to heal and are no longer visible on an eye exam. Generally the dog’s vision is not affected although vision loss has been described in some cases of multifocal retinopathy 1. The Mutation of the BEST1 gene associated with multifocal retinopathy 1 has been identified in Australian Shepherds, although its overall frequency in this breed is unknown." 9. NEURONAL CEROID LIPOFUSCINOSIS 6 According to Paw Print Genetics, Neuronal Ceroid Lipofuscinosis 6 (NCL6) is a lysosomal storage disease affecting Australian Shepherds. Affected dogs lack a specific Enzyme necessary for normal metabolism. As a result, there is an abnormal accumulation of waste compounds primarily in the cells of the nervous system, leading to a range of nervous system disorders. Affected dogs present around 1.5 years of age with progressive neurologic disease. Symptoms include loss of vision, behavioral change, anxiety, lack of muscle coordination and abnormal gait. Affected dogs are often humanely euthanized by 2 years of age due to progression of the disease. Though the exact frequency in the overall Australian Shepherd population is unknown, of the 637 Australian Shepherds tested none were carriers and only one was affected. Another Australian Shepherd with neuronal ceroid lipofuscinosis did not have this mutation and it is likely that more than one mutation is associated with this disease in this breed." 10. PROGRESSIVE RETINAL ATROPHY, PROGRESSIVE CONE-ROD DEGENERATION According to Paw Print Genetics, Progressive retinal Atrophy, progressive Rod-cone degeneration (PRA-prcd) is a late onset, inherited eye disease affecting Australian Shepherds. PRA-prcd occurs as a result of degeneration of both rod and cone type Photoreceptor Cells of the Retina, which are important for vision in dim and bright light, respectively. Evidence of retinal disease in affected dogs can first be seen on an Electroretinogram around 1.5 years of age for most breeds, but most affected dogs will not show signs of vision loss until 3 to 5 years of age or later. The rod type cells are affected first and affected dogs will initially have vision deficits in dim light (night blindness) and loss of peripheral vision. Over time affected dogs continue to lose night vision and begin to show visual deficits in bright light. Other signs of progressive retinal atrophy involve changes in reflectivity and appearance of a structure behind the retina called the Tapetum that can be observed on a veterinary eye exam. Although there is individual and breed variation in the age of onset and the rate of disease progression, the disease eventually progresses to complete blindness in most dogs. Other inherited disorders of the eye can appear similar to PRA-prcd. Genetic testing may help clarify if a dog is affected with PRA-prcd or another inherited condition of the eye. The Mutation of the PRCD gene associated with progressive retinal Atrophy, progressive Rod-cone degeneration has been identified in Australian Shepherds, although its overall frequency in this breed is unknown. |
MORE INFORMATION ON GENETICS TESTING
|
Each genetic test from Paw Print Genetics can have 1 of 3 results.
|
