Category archives: The Veterinarian's Corner

The Veterinarian’s Corner- New Canine Genetic Disease Tests to Aid in Clinical Diagnosis

The Veterinarian’s Corner- New Canine Genetic Disease Tests to Aid in Clinical Diagnosis

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 ...

Direct vs Indirect Genetic Testing

Direct vs Indirect Genetic Testing

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 ...

The Veterinarian's Corner- 2021: A Banner Year for Canine Genetic Health

The Veterinarian's Corner- 2021: A Banner Year for Canine Genetic Health

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 ...

Genetic Consultations for Veterinarians - A Free Service of Paw Print Genetics

Genetic Consultations for Veterinarians - A Free Service of Paw Print Genetics

With the rapid expansion of feline and canine genetic disease testing popularity over the past several years, today it is more common than ever for veterinarians to be asked to interpret genetic test results for their clients and offer recommendations based upon the results. However, the team at Paw Print Genetics (PPG) realizes that genetic counseling has not been a traditional part of veterinary education. For this reason, PPG offers no-cost genetic consultations for veterinarians and veterinary staff to assist their clients with genetic questions. Here we will discuss some of the many factors to be considered when assisting the veterinary team with interpreting genetic test results, assessing disease risk, and making breeding recommendations for the 300+ genetic tests offered at PPG.

Disease Inheritance

Understanding exactly how a specific disease is inherited by offspring can alter your assessment of disease risk and recommendations for breeding. The most common inheritance types discussed in animal genetics are autosomal recessive, autosomal dominant, and X-linked recessive inheritance. However, less common inheritance patterns may also be seen for some animal diseases. Disease risk in animals inheriting one copy of a disease-associated mutation varies based upon the specific mode of inheritance. For example, dogs carrying one ...

The Veterinarian’s Corner: New Canine Genetic Disease Tests at Paw Print Genetics

The Veterinarian’s Corner: New Canine Genetic Disease Tests at Paw Print Genetics

As of January 2021, Paw Print Genetics (PPG) is proud to offer 44 new inherited disease tests for the canine health and breeding community. While these new tests are associated with diseases identified in dozens of breeds, the population size of each breed and the relative frequency of these mutations in those populations mean that some of these diseases are much more likely to be seen in clinical veterinary practice than others. Here we will highlight five diseases from the recent PPG test additions that are among those most likely to be diagnosed in the veterinary hospital setting.

Cerebellar Degeneration- Old English Sheepdog and Gordon Setter1

A genetic mutation in the canine RAB24 gene is associated with a juvenile-onset, autosomal recessive form of cerebellar degeneration (CD) in two seemingly disparate breeds, the Old English Sheepdog (OES) and Gordon Setter (GS). Also referred to as hereditary ataxia or cerebellar abiotrophy (CA), CD presents between 6 months and 4 years of age with progressive neurological dysfunction due to degeneration of cerebellar neurons, especially Purkinje neurons. Coordinated movement becomes progressively more difficult as the disease progresses and can include intention tremors, ataxia, and a stiff, high-stepping gait (hypermetria). Affected dogs are often ...

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 ...

Tissue Management Prior to Genetic Testing

Tissue Management Prior to Genetic Testing

Nothing brightens the schedule like seeing an 11:20am slot given to Mrs. Doe who is bringing in a three-day old litter for assessment, tails and dewclaws.  The whole clinic reminds you all morning that puppies are coming in.  Then the magic hour arrives and in comes Mrs. Doe with a laundry basket covered in a towel that is making a surprising level of grunts and squeals.  Wow! Thirteen little fuzzballs in varied states of activity from litter-surfing to dreamless slumber that makes you a little jealous.  You go through the exam; each one is fully formed with no gross congenital defects.  While prepping your tools for dewclaw removal and tail docking, Mrs. Doe asks that you save the remnants so she can have the litter tested with Paw Print Genetics for known disease-causing mutations in this breed.  Hmmm, what does this entail?

Typically, we recommend to clients who choose to submit cheek swabs to wait until they begin weening the pups off mom. This allows them to separate the puppies from their mother to reduce possible contamination by the mother’s milk that may remain in the puppies’ mouths.  Given that testing takes ...

Feline Genetic Health Screening with the CatScan- Benefits for Veterinary Practice

Feline Genetic Health Screening with the CatScan- Benefits for Veterinary Practice

The popularity of genetic health testing in domestic animals is rapidly increasing for a variety of different applications. Although genetic testing of dogs has been more widely recognized by the public than similar testing in cats, advancements in genetic testing are also becoming increasingly popular among those that have a special feline in their life. In order to address the genetic health concerns of our cat-loving friends and their wonderful felines, the team at Paw Print Genetics has developed the CatScan, a powerful genetic screening tool for inherited diseases and traits. Aside from its important use by feline breeders to make informed breeding decisions and to prevent the production of kittens with certain inherited diseases, the CatScan also has powerful applications in clinical veterinary medicine especially in cases where testing is performed early in a cat’s life or when the cat’s pedigree is unknown.  

Early Screening for Greatest Impact

From a technical perspective, the CatScan can be performed using cheek swabs from kittens of any age as long as it is possible to prevent contamination of their DNA sample with DNA from other cats or mother’s milk. However, testing kittens early (around the beginning of weaning) is a common ...

Paw Print Genetics Adds New Canine Genetic Disease Tests to Ever-Expanding Offerings

Paw Print Genetics Adds New Canine Genetic Disease Tests to Ever-Expanding Offerings

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 ...

For The Veterinarian: The Genetics of Shortened Limbs and the Association with Canine Intervertebral Disc Disease (IVDD)

For The Veterinarian: The Genetics of Shortened Limbs and the Association with Canine Intervertebral Disc Disease (IVDD)

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.

Shortened Legs and Genetic Link to Intervertebral Disc Disease

Two genetic mutations associated with shorter limb length have been reported in domestic dogs2,4,5. Both mutations consist of a duplicated section of the canine FGF4 gene (called an FGF4-retrogene) which has been inserted into two aberrant locations of the genome; one copy has been inserted into a region on chromosome 12 (CFA12 FGF4 insertion) and the other copy has ...