Tag archives: dog genetic test

Von Willebrand disease (vWD) is arguably the most well recognized canine blood clotting disorder. A common genetic mutation in the VWF gene (first described in the Doberman pinscher in 2001) has played a significant role in increasing the recognition of vWD as a cause of clotting problems in dogs¹. Genetic testing for this mild to moderate platelet disorder, known as vWD type 1 (vWD1 or vWDI), has played an important role in assisting veterinarians in diagnosis and in assisting breeders in identification of non-symptomatic carriers of the mutation prior to breeding. Since that time, dozens of other breeds have also been found to be affected by the same mutation. Thus, solidifying vWD as a potential concern for many dog lovers. In addition, other genetic mutations in the VWF gene have also been associated with more severe forms of von Willebrand disease (type 2 and type 3) in some breeds.

Despite the important role of testing some breeds for the identified vWD1 mutation, it is also important to keep in mind that hemostasis is an incredibly complex process involving multiple physiologic steps and the interaction of many protein clotting factors, various cell types, and endogenous molecules. In some breeds, other ...

To usher in 2022, Paw Print Genetics (PPG) has added 12 new canine disease and trait tests to expand upon the largest selection of canine genetic tests in the industry. However, because diseases seen in veterinary practice are not seen with equal frequency, here I will highlight five of the new test offerings for diseases that are among the most likely to be encountered in veterinary practice. 

Ataxia (Norwegian Buhund Type)¹- Norwegian Buhund

Ataxia (Norwegian buhund type), also known as cerebellar ataxia, is an early-onset autosomal recessive neurological disease affecting the Norwegian buhund. Dogs inheriting two copies of the associated KCNIP4 gene mutation present between three and five months of age with progressive neurological disease. Initial clinical signs are consistent with cerebellar ataxia, including wide-based stance, hypermetria, head tremors, and truncal sway. As the disease progresses, dogs are eventually unable to stand or walk without falling. Cerebellar degeneration is a common histopathological finding in affected dogs and dramatic reductions in cerebellar KCNIP4 protein have been described. The speed of disease progression is variable, but affected dogs are often euthanized due to quality-of-life concerns.

In one study, 19% out of 146 apparently healthy Norwegian buhunds tested carried one copy ...

By Casey R. Carl, DVM and Blake Ballif, PhD

A topic in veterinary genetic testing currently getting significant attention is the difference between direct and indirect genetic testing for mutations associated with various diseases and traits. Although both types of testing can play a useful role in determining a dog’s genetic health status, the use of indirect genetic testing comes with some additional caveats that need to be considered when selecting the best testing strategy for a particular dog.

Direct Genetic Testing

As the name indicates, direct genetic testing is a general term for any genetic testing technique which looks for the presence of the specific genetic variant (mutation) known to play a causal role in a particular disease or trait. Therefore, regardless of which genotyping technique used, test results obtained from direct testing identify the presence or absence of the specific mutation that has been associated with the disease or trait. Barring differences in quality of laboratory practices and test development, direct testing is therefore the ideal method to detect a specific mutation. Furthermore, identifying the precise causative mutation in a DNA sample from a dog allows one to draw appropriate conclusions about the implications of this mutation in this ...

2021 has been an exciting year for Paw Print Genetics (PPG) and canine genetic health. With the addition of 15 new genetic disease and trait tests in July 2021, PPG has now added more than 50 new canine test offerings this year alone! However, when it comes to specific genetic diseases, variability in the population size of affected breeds and the frequency of the associated mutations, means that some diseases are much more likely to be seen in veterinary hospitals than others.

Here we will highlight four new genetic disease tests offered at PPG for canine diseases common enough to be seen in general veterinary practice. In addition, we will briefly discuss PPG’s new web-based disease and coat color probability calculators which assist breeders and veterinarians in selecting ideal parents for producing healthy puppies in the coat colors and patterns desired.

Progressive Retinal Atrophy (Giant Schnauzer Type)¹- Giant Schnauzer, German Spitz, German Spitz Klein, Keeshond, Miniature Smooth and Longhaired Dachshund, Pomeranian

Progressive retinal atrophy (Giant Schauzer Type), also known as generalized PRA or PRA5, is an autosomal recessive form of PRA affecting the giant schnauzer and several other breeds. Dogs inheriting two copies of the associated NECAP1 gene ...

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 ...

With the current, rapid pace of new genetic discoveries, inherited disease testing is quickly becoming a common part of clinical veterinary diagnostics. Paw Print Genetics is excited to announce the release of six new canine genetic disease tests, including highly anticipated tests for three diseases in retriever breeds; macular corneal dystrophy and congenital myasthenic syndrome in the Labrador retriever and neuronal ceroid lipofuscinosis 5 in the golden retriever.

Macular Corneal Dystrophy

With an estimated mutation carrier rate of 3.3% in a 2015 study of the UK Labrador retrievers, macular corneal dystrophy (MCD) is an inherited eye disease that that is likely to be encountered at some point in a small animal veterinarian’s career¹.

Inherited in a recessive manner, Labradors with two copies of the associated CHST6 gene mutation typically present in middle age with MCD-associated vision loss. Affected dogs display decreased activity of an enzyme known as corneal glucosamine N-acetyl-6-sulfotransferase (C-GlcNAc6ST), which results in decreased sulfation of the corneal glycosaminoglycan, keratin sulfate (KS). Decreased sulfation of KS reduces its solubility, thus preventing its full metabolism and allowing for deposition into the extracellular space of the corneal stroma and Desmet’s membrane, and intracellularly in keratinocytes and corneal epithelial cells ...

Shortened legs are a major defining feature for some of today’s most popular domestic dog breeds. Although dogs with extreme shortening of the limbs likely come to mind when pondering this trait (such as dachshunds or basset hounds), many other breeds also display a more subtle or moderate limb shortening (e.g. West Highland white terrier, Nova Scotia duck tolling retriever, beagle). Unfortunately, in some breeds, dogs with shortened legs have also been found to be at an increased risk for early-onset intervertebral disc disease (IVDD). However, over the past several years, genetic discoveries and development of genetic testing have made it possible to better understand the short-legged appearance of some dog breeds and the genetic underpinnings which make some of these dogs more likely to develop IVDD.

Intervertebral Discs and the Spinal Cord

In order to understand IVDD, we must first understand the role, location, and structure of the intervertebral discs (IVDs) and their anatomical relationship to the spinal cord. IVDs play a crucial role as cartilaginous ‘shock absorbers’ for the spine and allow for spinal flexibility. IVDs are often compared to a ‘jelly doughnut’ sitting between the vertebrae as they are composed of an outer ring of tough fibrous ...

The impact of canine genetic testing on veterinary medicine continues to grow as dog owners become increasingly interested in the genetic factors underlying their dogs’ health and how knowledge of these factors may improve the lives of their furry companions. Genetic screening tools which test for large numbers of deleterious genetic mutations, such as the Canine HealthCheck (CHC) developed by Paw Print Genetics (PPG), are particularly useful when performed on a young dog to identify specific inherited health concerns; especially in cases where the lineage of the dog is unknown.

Early Screening, Faster Diagnosis

Among the tests performed on the CHC are disease tests which may prove invaluable in decreasing client costs associated with diagnosis, increasing speed of diagnosis, or improving medical outcomes. For example, many tests included on the CHC, such as the test for the neurological disease, degenerative myelopathy (DM) are adult-onset conditions which may not be observed in a dog until it has reached late adulthood. DM is a progressive disease caused by a genetic mutation in the canine SOD1 gene which can only be definitively diagnosed after death through histologic examination of the spinal cord because antemortem diagnostic methods fail to yield pathognomonic results. In addition ...

Over the past two decades, usage of genetic testing technologies has revolutionized the world of dog breeding. Once limited to selective breeding practices based upon the characteristics or disease states that could be physically observed in a dog, genetic testing has allowed dog breeders to uncover the inherited genetic variants (mutations) that are not being expressed in an individual but may be expressed in their offspring. By comparing the disease-associated mutations inherited by a dog to those of a prospective mate, informed breeding decisions can be made to avoid producing puppies with these diseases. However, despite the immense value of genetic disease testing in the production of healthy puppies, incorrect assumptions about the parentage of a litter can have disastrous consequences for the health of a kennel, even when parental genetic disease testing results are 100% accurate.

Clear by Parentage/Hereditary Clear

In ideal situations, potential dams and sires are tested for breed-specific, disease-associated genetic mutations prior to being bred. If both parents are found to be free of these mutations (often referred to as being “clear”), it can be assumed for practical purposes that the offspring are also clear of the same mutations. With this understanding, it is common ...

Every veterinarian leaves veterinary school with a mental laundry list of animal diseases and their textbook presentations. While this knowledge serves the young graduate well in most circumstances, with clinical experience and mentorship comes the ability for veterinarians to expand their mental notes about the various ways some diseases can present in the real world. For some inherited canine diseases, genetic testing has allowed the practitioner to correlate a broader set of clinical signs for dogs affected by identical underlying genetic mutations. This variability in disease phenotype, known as variable expressivity, is a result of the combined effect of all genetic and environmental factors influencing each individual and can add significant challenge to some diagnoses. However, supplementing a disease workup with genetic test results can prove invaluable in diagnosing inherited diseases that have the frustrating attribute of rarely presenting the same way twice.

Collie Eye Anomaly

Now known to occur in well over a dozen breeds, the recessively inherited collie eye anomaly or CEA (also known as choroidal hypoplasia) is a relatively common eye disease of dogs and a good example of a disorder which can have diagnostic challenges due to its phenotypic variability. CEA is caused by a deletion ...