Tag archives: retinal disease

Picking the Right Genetic Test for Canine Progressive Retinal Atrophy

Picking the Right Genetic Test for Canine Progressive Retinal Atrophy

Canine progressive retinal atrophy (PRA) is a group of inherited eye diseases which are among the most common causes of inherited blindness in domestic dogs. Extensive study and characterization of the various PRAs have led to the discovery of well over a dozen different genetic mutations in many different genes which can now be identified to help prevent, predict, or diagnose PRA in many breeds. However, complicated PRA naming schemes and the breed-specific nature of the PRA tests can make it challenging for dog breeders or veterinarians to select the correct test for the dog in front of them.  

Multiple Genes, Similar Clinical Findings

The known underlying mutations associated with the various forms of PRA are found in a wide variety of different genes. Thus, highlighting the complexity of the biological pathways involved in the development and ongoing maintenance of the eyes. PRAs are marked by the abnormal development and/or the gradual degeneration of rod and cone photoreceptor cells of the retina. Each type of PRA may display variation in the age of onset, speed of disease progression, and the relative rates at which each of the two photoreceptor types are destroyed. However, when it comes to clinical ...

Prevention Is Smart Breeding- Progressive Retinal Atrophy and the American Eskimo Dog

Prevention Is Smart Breeding- Progressive Retinal Atrophy and the American Eskimo Dog

Despite its name, the roots of the American Eskimo dog can be traced back to Germany where it was known as a white colored, miniature to medium sized variety of the German spitz. This well rounded farm dog came to the United States with German immigrants in the early 20th century and adopted the name American spitz in the World War I era when war related anti-German sentiment and American patriotism were widespread. The breed was first recognized as the American Eskimo dog (AED) by the United Kennel Club in 1919 and was accepted by the American Kennel Club for registration in 1995. Known for its alert demeanor, the AED makes an excellent watchdog that alarms its family of potential danger through warning barks. The AEDs intelligence, fast learning, and desire to please have made it a competitor in the agility ring and obedience trials. Though not universally recognized as three separate varieties, the modern AED is often split into three size groups (toy, miniature, and standard).

Despite its many talents, beautiful physical characteristics, and intelligence, like other pure breeds, the AED has developed some inherited disease concerns over the course of its development that have caused significant issues ...

Preventing Inherited Congenital Stationary Night Blindness in the Briard

Preventing Inherited Congenital Stationary Night Blindness in the Briard

With depictions in artwork from as early as the 8th century, the ancient Briard is a French dog breed that has been employed in diverse roles throughout its history, but is most commonly recognized as a herding breed or as a guard dog for flocks of sheep. Though documentation of its early history is sparse, the first breed standard for the Briard was written in the late 19th century and the breed was accepted for registration by the AKC in 1922 after being brought to North America from Europe (including Briards imported by Thomas Jefferson). Praised for their intelligence and memory, the Briard is a naturally protective dog that can benefit from early and extensive socialization in order to establish proper boundaries and temperament toward strangers. They are often regarded as extremely loyal and bonded to their owners and appreciate significant time with their human “pack”. Though the breed is regarded as relatively healthy, as with most purebred dogs, the Briard has developed some inherited disease concerns during its path to the modern state of the breed. One of the best known Briard inherited disease concerns, unique to the breed, is a disease known as congenital stationary night ...

Preventing Inherited Progressive Retinal Atrophy in Poodles

Preventing Inherited Progressive Retinal Atrophy in Poodles

Despite their characterization in popular culture as a gorgeous, yet delicate dog breed with more beauty than brawn, the ancestors of today’s poodles (especially standard poodles) were revered for their ability to work. Still well known for their exceptional intelligence, the standard poodle (the oldest poodle variety), was commonly used as a gun dog and water retriever to assist European hunters. Portrayed in drawings and paintings from as early as the 15th century, the standard poodle was eventually bred to smaller breeds in order to create poodles of smaller size. The resulting smaller dogs, which reportedly disliked water, were used for truffle hunting and formed the ancestry of today’s toy and miniature poodle breeds. Though no longer commonly thought of as gun dogs, interest in using standard poodles as hunting dogs has reemerged with some standard poodles experiencing success in AKC and CKC hunting trials since the mid to late 1990’s. Toy and miniature poodles are most commonly recognized today as family-friendly companion dogs. During their path of development, like other purebred dogs, all three commonly recognized varieties of poodles have developed some inherited diseases that can make life challenging. One particular disease of poodles known as progressive retinal ...

Skeletal Dysplasia 2 and Retinal Dysplasia/Oculoskeletal Dysplasia 1 in the Labrador retriever

Skeletal Dysplasia 2 and Retinal Dysplasia/Oculoskeletal Dysplasia 1 in the Labrador retriever

In this second part of a four part blog series examining preventable inherited diseases of the Labrador retriever (see part one here) we will be examining two diseases known to cause dwarfism in the breed.

Skeletal Dysplasia 2

Skeletal dysplasia 2 (SD2) is an inherited disease of collagen resulting in disproportionate dwarfism in the Labrador. Disproportionate dwarfism is marked by abnormal size discrepancies between the limb length of affected individuals and the size of their torso. In the case of SD2, the limbs of affected dogs tend to be shorter than normal despite an average sized torso. International breed standards of the Labrador list shoulder heights of 56-57 cm in males and 54-56 cm in females. In the publication describing the COL11A2 gene mutation associated with SD2, the authors found that most of the affected males had shoulder heights of less than 55 cm and most affected females showed heights of less than 50 cm. However, there is some overlap of shoulder heights between those of normal dogs from blood lines of smaller size and affected dogs from larger sized blood lines. Though the front limbs tend to be more severely affected (and sometimes slightly bowed) with SD2, the long ...

Retinal Dysplasia/Oculoskeletal Dysplasia 1 (RD/OSD1): A Preventable Inherited Disease of the Labrador Retriever

Retinal Dysplasia/Oculoskeletal Dysplasia 1 (RD/OSD1): A Preventable Inherited Disease of the Labrador Retriever

Thanks to our loyal and dedicated clients, Paw Print Genetics continues to increase test offerings in 2015! To start our year off right, we released DNA profiling and parentage testing, seven long-awaited canine coat color tests, and four tests for other specific traits of the hair coat and tail. In addition, Paw Print Genetics continues to expand upon the largest canine inherited disease testing menu in North America by releasing 10 new inherited disease tests. One newly added test that will make many Labrador retriever owners happy is the test for an inherited disease known as retinal dysplasia or the more apt term, oculoskeletal dysplasia (often written as retinal dysplasia/oculoskeletal dysplasia 1 or abbreviated, RD/OSD 1). In March of 2014, RD/OSD 1 became a little more personal for Paw Print Genetics when we had the honor of meeting Frank, an adorable, blind RD/OSD 1 affected Labrador retriever living at the Double J Dog ranch in Hauser Lake, Idaho. We are excited to launch a test that allows breeders of sweet dogs like Frank to produce puppies free of this severe and challenging disorder!

RD/OSD 1 is a genetic disease of collagen caused by a mutation ...

Testing for Progressive Retinal Atrophy, GR1 and GR2 Now Available for the Golden Retriever

Testing for Progressive Retinal Atrophy, GR1 and GR2 Now Available for the Golden Retriever

After many inquiries by our wonderful clients, Paw Print Genetics is excited to announce that we have begun testing for two genetic mutations reported to cause progressive retinal atrophy in the golden retriever. Known specifically as progressive retinal atrophy, GR1 and GR2 (PRA-GR1 and PRA-GR2), these two diseases were found to be caused by genetic mutations in the SLC4A3 and TTC8 genes, respectively. In addition to the golden retriever, the TTC8 mutation that causes PRA-GR2 has also been identified in a clinically affected Labrador retriever.

Progressive retinal atrophy (PRA) is not a single disease, but rather a group of inherited diseases each caused by different genetic mutations in different genes. The various forms of PRA affect over 100 different dog breeds. Though there are variations in the progression of disease, most varieties of PRA (regardless of genetic cause) result in blindness due to an inherited degeneration of the retina; more specifically, the degeneration of retinal cells known as rods and cones, which play an important role in vision.

In PRA-GR1 and PRA-GR2, signs of night blindness and loss of peripheral vision are seen first with progression to complete blindness occurring over time. In addition, they are both considered late onset ...

Progressive Retinal Atrophy (PRA1): A Preventable Inherited Disease of the Papillon and Phalène

Progressive Retinal Atrophy (PRA1): A Preventable Inherited Disease of the Papillon and Phalène

With their picturesque appeal, predecessors of the modern day papillon (known as continental toy or Titian spaniels) were popular subjects for European painters between the 16th and 18th centuries. The popularity of these small spaniels with European aristocrats and royalty of the Renaissance period, led to their appearance in many paintings from the era. The iconic, longhaired “butterfly-like” ears, for which papillons are named, are obvious in these paintings though many of the portrayed dogs were of the drop-eared variety of the breed that today is known as the phalène. According to an article on the Papillon Club of America website, in the late 19th century erect ears became a more desirable trait with papillon fanciers and eventually the erect-eared variety obtained their current position as the more popular form of the breed. In addition to their beautiful physical attributes, in their modern form, well-socialized papillons are described as happy, playful and affectionate family members. Papillons are also often described as frequent barkers, making them great guard dogs. Despite their adorable personalities and good temperament, like other purebred dogs, the papillon is known to inherit some genetic diseases that could prevent this regal breed from reaching the ...

Progressive Retinal Atrophy: An Inherited Disease of the English Springer Spaniel

Progressive Retinal Atrophy: An Inherited Disease of the English Springer Spaniel

The intelligent, prey-driven English springer spaniel (ESS) has forged its path as a popular, hardworking companion for bird hunters while maintaining a loyal and affectionate personality suitable to family life. Until the early 1900’s, springer spaniels were produced in the same litters as cocker spaniels; springers were chosen from the largest puppies of the litter and were trained for flushing or “springing” game while the smaller littermates were labeled cocker spaniels and were trained for hunting the elusive woodcock. Since then, springer spaniels have been further split into the generally leaner, shorter haired field (hunting) variety and the denser boned, densely haired show (“bench”) line. Unfortunately, like other purebred dogs, English springer spaniels are known to inherit genetic diseases that can keep some individuals from reaching the great potentials for which the breed is capable. One such inherited condition is an eye disease known as progressive retinal atrophy, cone-rod dystrophy 4 (PRA-crd4) caused by a mutation in the RPGRIP1 gene.

Progressive retinal atrophy (PRA) is not a single disease, but rather a group of inherited diseases each caused by different genetic mutations in different genes. The various forms of PRA affect over 100 different dog breeds. Though there are variations ...