Tag archives: Veterinarian

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 ...

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 ...

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 ...

The Veterinarian's Corner: Incorrectly Recorded Canine Parentage and the Effect on Genetic Health

The Veterinarian's Corner: Incorrectly Recorded Canine Parentage and the Effect on Genetic Health

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 ...

Keep Breed-Specific Thinking from Delaying Your Diagnosis

Keep Breed-Specific Thinking from Delaying Your Diagnosis

Discovery of disease-associated, canine genetic mutations has greatly increased over the past two decades. As a result, identification of these mutations through genetic testing has quickly become a useful tool for dog kennels and veterinary practices by allowing for the identification of asymptomatic disease carriers, diagnosis of affected dogs, and prevention of inherited diseases through informed breeding practices. However, because mutation discovery is often funded by specific breed clubs with interest in a breed-related disease concern, study investigators may not perform extensive, species-wide population studies for a newly discovered mutation. Therefore, in many cases, additional breeds inheriting the same mutation (and developing the same disease) may remain unknown for quite some time after the initial discovery.

As any modern veterinarian can attest, for better or worse, animal lovers have more veterinary medical information at their fingertips than ever before. Occasionally, at Paw Print Genetics, we are contacted by breeders or owners whose veterinarian had opted not to pursue a diagnosis that the client suspected because of the veterinarian’s historical understanding of a disease’s breed-specific distribution rather than the current knowledge. For veterinarians building a differential diagnosis list, keeping the mind open to a particular inherited disease manifesting in an unexpected ...

New Test for Australian Shepherds and Related Breeds - Intestinal Cobalamin Malabsorption

New Test for Australian Shepherds and Related Breeds - Intestinal Cobalamin Malabsorption

Intestinal cobalamin malabsorption, also known as Amnionless Deficiency, Cobalamin Deficiency, Imerslund-Grasbeck Syndrome (IGS), and Vitamin B12 Deficiency, is an inherited disease found in the Australian Shepherd and related breeds (Miniature Australian Shepherd, Toy Australian Shepherd, Miniature American Shepherd). The disease is inherited in a recessive fashion and as such, dogs that inherit two copies of the mutation are at risk for the disease. The disease is caused by the inability 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 require treatment with cobalamin supplementation throughout their life.

Because of the severity of this condition and the fact that it is treatable, this test has been added to the breed-specific panels for Australian Shepherds and related breeds ...

Breeding Carriers of Canine Recessive Diseases- Why It Should be Considered

Breeding Carriers of Canine Recessive Diseases- Why It Should be Considered

The breeding of dogs identified as genetic carriers of recessive disease is a hotly debated topic in the canine breeding world with many breeders firmly entrenched in their own personal approach to the issue. With increasing regularity, dog breeders and their clients are bringing genetic questions (including those about breeding carriers) to their veterinarians under the assumption that most veterinarians would be up to speed on the current information and genetic testing available. Unfortunately, at Paw Print Genetics we occasionally speak to breeders whose veterinarians have given them advice about breeding carriers that may not be in the best interest of the kennel or the breed. Given the large number of variables and differences between the way kennels are operated and the recessive disease risks of individual breeds, there is not necessarily a breeding approach that would be appropriate in 100% of cases. However, understanding some guiding principles and the potential ramifications of doing so, can help a veterinarian advise their dog breeding clients in a way that will help them meet their goals without increasing the incidence of recessive diseases in a kennel or in the breed.

What is a “Carrier” of a Recessive disease?

As a quick refresher ...

Canine Genetics In Practice- A Veterinarian’s Role in Preventing Adult-onset Inherited Disease

Canine Genetics In Practice- A Veterinarian’s Role in Preventing Adult-onset Inherited Disease

Veterinarians examine, treat, and diagnose dogs with inherited diseases daily. Though treatments to fix some inherited disorders such as cryptorchidism and umbilical hernias are relatively safe and effective, rarely are the inherited disorders seen in practice remedied with a simple, relatively low-cost solution. In fact, in many cases of inherited disease, treatment options are extremely limited or non-existent. Therefore, an option to prevent these diseases before they occur would be preferable in most circumstances. Genetic disease testing made possible by the discovery of the causal mutations has become the best medicine to combat many inherited conditions.

Genetic testing of dams and sires has become commonplace in many dog breeds as breeders have recognized the power of identifying those dogs at risk of producing puppies with inherited diseases. Unfortunately, however, some breeders have been slow to adopt the routine use of genetic testing as they continue to rely on traditional selective breeding techniques. Limited by the inability to identify unaffected carriers of disease, selective breeding has historically proven relatively ineffective in the pursuit of large reductions in disease incidence.

Adult and late-onset inherited diseases pose an extra challenge in selective breeding because dogs become sexually mature before signs of the disease ...