Category archives: Ask The Vet

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 ...

In the first part of this examination of risk assessment and genetic testing, I dissected the concept of risk.  Although relative risk is incomplete without the perspective provided by absolute risk, logistical constraints within veterinary research often limit this perspective.  There is still value to these tests. In this next entry, I want to look at specific genetic tests where the result is functionally a risk assessment.  Hopefully, you will better understand how to use the information provided by these tests with the goal of producing better dogs with each generation.    

Genetic testing for dermatomyositis (DMS) is a true risk assessment test. Results from this test place a dog in risk categories of low, medium, high, and unknown.  This type of risk assessment is uncomplicated.  For each possible genotype listed in the report, the percentage of affected dogs in that group has been determined. Based on the genotype, the likelihood of an individual dog developing DMS is classified as low (0% - 5%), moderate (33% – 50%), or high (90% – 100%).  These percentages correlate with the absolute risk for these dogs. With this test result, decisions about breeding a dog can be made ...

Paw Print Genetics offers tests that can be categorized into two types.  Most tests offered directly test for a DNA change (or mutation) that causes a disease. For a small number of diseases, we test for a mutation that increases “the chance” that a dog will develop a disease. These have been termed risk variants. Recently, we have been getting a lot of questions about these risk variants and what a positive result means for your dog.  One example is dermatomyositis (DMS) testing, which generates an associated risk (low, moderate, high, or unknown) for this skin condition.  Chondrodystrophy (CDDY) is another example in which the test is for a mutation that causes abnormal cartilage formation and having the mutation may put a dog is at an increased risk for intervertebral disc disease (IVDD).  If you have a Labrador that carries one or two copies of the ATP7B mutation for copper toxicosis, this mutation puts a dog at a greater risk of developing the disease compared to dogs without the mutation. This risk may be mitigated if the dog also has one or two copies of the ATP7A protective mutation for copper toxicosis, which may reduce the ...

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 ...

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 ...

One thing a veterinarian does when either assisting a dog during whelping, or in the immediate follow up to a cesarean section is examine the puppies.  Included in this examination is an oral exam to check both suckle reflex and for any congenital defect which may compromise the puppy’s quality of life.  In effect, the vet is looking for any sign of a cleft lip/palate (CL/P).  A CL/P is a relatively common congenital defect of the craniofacial region.  The development of the palate includes the soft palate, the rostral (frontal) hard palate, the premaxilla section of the skull and the lips¹.  This defect creates an opening between the oral and nasal cavities.  This opening is concerning because the puppy will have difficulties nursing leading to malnutrition and may inhale milk into the respiratory system which can lead to a sinus infection or pneumonia¹¹.  Some dog breeds more commonly present with cleft defects than others suggesting a genetic component to this condition¹.  Genetics do play a role in the formation of this defect, but they are not the only cause of a cleft lip/palate.  Genetic ...

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 ...

Dermatomyositis (DMS), also known as Juvenile Dermatomyositis or Canine Familial Dermatomyositis is an inflammatory disease of the skin and muscles caused by an over reactive immune system¹. This disease has consistently plagued Shetland Sheepdogs and Collies of all varieties.  What makes this condition truly insidious is that although it mostly affects immature dogs, it can flare up seemingly out of nowhere to create issues in dogs of any age².  Although testing for the genetic mutations that pre-dispose certain dogs for this disease has been around for some time, interpreting the results can be complicated often leaving owners confused about the results of this test.  Misunderstanding genetic results may lead to poor breeding decisions.  Let us look closer at DMS, how the disease presents, the complexity of genetic testing, and how to best utilize the results of this test.   

What is Dermatomyositis?

DMS is an inherited disease that causes dramatic inflammation of the skin, blood vessels and muscles in affected dogs.  Lesions often originate and are limited to the skin of the face with the lips with the area around the eyes particularly affected³.  Although the mechanisms of the ...