Tag archives: 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 ...

The discovery of various disease-associated genetic mutations has greatly changed the way some inherited canine diseases are categorized and perceived by the veterinary community. Through the use of genetic testing developed to identify these discovered mutations, various diseases which were once assumed to have a single underlying molecular cause (due to similarity between disease states) have been found in some cases to actually be caused by many different mutations, often in different genes. This phenomenon, known as genetic heterogeneity, elucidates the way genes work together in pathways and how a disruption in different genes of a pathway may result in similar or nearly identical disease states despite seemingly disparate underlying molecular etiologies. Understanding that there may be one of many different genetic mutations responsible for a dog’s clinical signs can help plot a better course for veterinarians to obtain an accurate, definitive diagnosis and in some cases, may alter treatment strategies.

Pet Owner vs Breeder

The accuracy and specificity of an inherited disease diagnosis are particularly important in the world of dog breeding where every potential health issue must be considered prior to breeding. Unlike general pet owners who may not need to know the specific underlying molecular mechanisms of ...

Paw Print Genetics is excited to announce that it has launched 12 new, very sought-after disease tests.  These tests compliment the breed-specific assays that PPG already offers, and cements our dedication to providing the largest menu of genetic tests for dogs. The following tests can be ordered as individual tests or may be part of one of our breed-specific panels that should be considered for any breeding dog.

Degenerative Myelopathy in the Bernese Mountain Dog

The Bernese Mountain Dog (BMD) has been identified as breed that can inherited degenerative myelopathy (DM). In this particular breed, two different mutations in the SOD1 gene have been identified. Degenerative myelopathy SOD1B is caused by a mutation of the SOD1 gene currently identified only in the Bernese mountain dog that is a different mutation from the common SOD1 mutation causing DM in a large number of breeds.  Bernese mountain dogs are known to develop a more slowly progressive form of degenerative myelopathy associated with the SOD1B mutation.  Both types of DM affect 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 around 8-9 ...

Despite being one of the most recognizable dog breeds in existence due to their unique physical attributes, the early history of the Chinese crested is a bit mysterious due to a lack of adequate written records. Though early hairless dogs have been documented in Africa, Central and South America, and Asia, the relationship between these dogs is not well understood. Evidence to suggest that they may be related is found in the fact that at least 3 hairless breeds originating from different continents (Mexican hairless, Peruvian hairless, and Chinese crested) are all known to inherit the same FOXI3 gene mutation responsible for their hairlessness. It is most likely that a common ancestor to the hairless breeds developed a spontaneous FOXI3 mutation that was later passed to the individual breeds as they were developed. It is theorized that early hairless dogs travelling on shipping routes with their human companions played a role in the spread of the trait to numerous locations in the world.

In addition to genetic mutations responsible for particular physical traits, like other purebred dogs, Chinese cresteds are known to inherit some genetic mutations responsible for causing inherited disease. Inherited diseases of the eyes are of particular concern ...

In this fourth and final blog in a series about preventable inherited diseases in the Labrador retriever (see previous blogs here; part one, part two, and part three), we will examine a potentially life-threating urinary disease and a cause of blindness in dozens of dog breeds including the Labrador.

Cystinuria

Urinary tract obstruction is one of the most urgent and potentially life-threatening conditions in dogs. One common cause of urinary obstructions in dogs is the presence of bladder stones which leave the bladder during urination and become lodged in the urethra. The inability to urinate results in a toxic buildup of certain electrolytes and waste products in the body including potassium, which tends to be the most concerning in regards to health effects. Excess potassium in the body prevents the heart from beating normally, ultimately resulting in death due to cardiac arrest. Though it is not the only cause of bladder stones in Labradors, a genetic mutation in the SLC3A1 gene is reported to cause an early-onset disease known as cystinuria, which can result in bladder stone formation.

While normal kidneys reabsorb a variety of nutrients and electrolytes from the urine, dogs affected with cystinuria lack the ability to produce ...

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 ...

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 16^th and 18^th 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 19^th 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 ...

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 ...

Basenjis are an ancient, charming and unique breed originating in Africa. According to the Basenji Club of America, dogs resembling basenjis have been found in African cave paintings and Egyptian art dating back to between 1000 and 6000 BC. In the late 1800’s, the German botanist and ethnologist, Georg Schweinfurth described a domesticated dog closely resembling the Basenji belonging to native people of central Africa that he had encountered on his trips to the region. Shortly after this description was published, dogs resembling Basenjis were exported from Africa and displayed in Great Britain and Berlin as “Lagos Bush Dogs” and “African Bush Dogs” respectively. Despite their unique and desirable characteristics (such as their yodel-like vocalization known as a baroo), basenjis are similar to other dog breeds in the sense that they are known to inherit a handful of genetic diseases that can cause significant issues in breeding programs. Luckily for the basenji, genetic tests are now available through Paw Print Genetics to help breeders prevent future generations of dogs from being born with some of these preventable illnesses. The two inherited disease tests recommended by the Basenji Club of America and of great importance for basenji breeders have been the ...

When we bring a new puppy into the home, we often envision years of companionship and adventures. Hiking, swimming, hunting and running are just a few activities our healthy canine companions can join us on – and there’s something to be said for the bonding that takes place when we’re just lounging around the house, too.

For healthy dogs, the financial investment of daily care and routine veterinarian visits is well worth the cost of keeping them a healthy, happy and active member of the family. Unhealthy dogs due to poor breeding practices, however, exact a premium on our pocketbooks, tax our emotions and take a toll on our daily lives – not to mention the quality of life the puppy is condemned to live.

While many unforeseen diseases and health issues can affect a dog throughout its lifetime, there are nearly 200 disease-causing genetic mutations known to science. These mutations can be identified in dogs prior to breeding, which allows breeders to produce healthier puppies. As a new-puppy buyer, make sure you’re purchasing from a breeder that has screened for genetic disorders common to your breed of choice.

Seven of the most common, and potentially deadly, diseases include:

Degenerative ...