Author archives: Rob Westra

Interpreting Risk-Based Genetic Tests Part Two: Examples of Genetic Testing that offer Risk Assessments.

Interpreting Risk-Based Genetic Tests Part Two: Examples of Genetic Testing that offer Risk Assessments.

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 ...

Interpreting Risk-Based Genetic Tests: What is Risk?

Interpreting Risk-Based Genetic Tests: What is Risk?

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 ...

The Biology of Cleft Palate Defects

The Biology of Cleft Palate Defects

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 ...

Testing for Dermatomyositis Risk

Testing for Dermatomyositis Risk

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 ...

The Genetics of Hairlessness

The Genetics of Hairlessness
A hairless Chinese Crested next to a Powder puff

Aficionados of the hairless breeds are motivated to perpetuate and conserve these very historical and special dogs. The Xoloitzcuintles (“show-low-itz-QUEENT-ly.” or just Xolo “SHOW-low”) and the Chinese Crested dog are the more common hairless dogs but are no means the only hairless breeds. Some controversy surrounds the hairless breeds due to the nature of the hairless gene variant and its inheritance from one generation to the next. Looking at some basic genetics and how they apply to the inheritance of the mutation responsible for hairlessness will benefit the breeder trying to determine the best pairing for these unique dogs.


All genes are inherited from the parents. Half of the genetic material, or alleles, come from the mother, the other set of alleles come from the father. Two alleles, one from the dam and one from the sire, make up the genotype. The genotype will then determine the phenotype, or what trait or condition we observe in the dog. Further, we define genes as either being dominant or recessive. A dominant gene requires only one allele, passed from one parent, to express its phenotype. Whereas, a recessive gene requires two alleles, one passed from each parent, for its phenotype to ...

Pembroke Welsh Corgi Early Onset Risk Modifier

Pembroke Welsh Corgi  Early Onset Risk Modifier

Degenerative myelopathy (DM) is a chronic, progressive neurologic condition that typically develops in the latter third of a dog’s life. DM starts in the central portion of the spinal cord then gradually progresses to involve all spinal cord segments. 1 Although DM is unique to the dog, it is a natural-occurring model of human amyotrophic lateral sclerosis (ALS) also known as Lou Gehrig’s Disease.3,4 In dogs, the common form of DM results from a DNA change (mutation) in the SOD1 gene. This is a recessive condition, meaning that dogs with two copies of the mutation are at risk for developing DM. For most affected dogs this condition develops late in life, however a change in the DNA at a different gene than the SOD1 gene has been identified in some dogs that modifies the risk for DM in the Pembroke Welsh corgi. In dogs that have two copies of the at-risk DM mutation and have one or two copies of a mutation found in the SP110 gene, will reduce the age of onset for DM.   

Typical DM presents with dysfunctional and abnormal movements of the pelvic limbs around 8 years of age or later. Dogs may ...

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 ...

Does Your Dog Suffer from Noise Anxiety?

Does Your Dog Suffer from Noise Anxiety?

Summertime is usually a very positive time for our pets.  The weather is pleasant, walks are more frequent, and general outside playtime is more regular.  Unfortunately, this is also the time of thunderstorms and increase fireworks use, especially around July 4th.  The loud noises associated with these events can cause fear and anxiety in some pets.  A new behavioral study out of the University of Helsinki suggests that sensitivity to noise, especially fireworks, is the most common form of anxiety in pet dogs.  In this study, 72.5% of all dogs showed some type of anxiety, whereas, 32% displayed a form of noise sensitivity1.

People who own pets with noise sensitivity usually recognize the classic display of anxiety behaviors such as trembling, panting, drooling, pacing, vocalizing, hiding, and trying to escape.  Often, dogs are confused about the source of the noise and therefore try to escape to the outside, or just the opposite, scratch at the door to come inside.  Because some rooms are better at dampening sound, these dogs may run to the basement or hide under or behind furniture. There are some displays of anxiety that owners may not pick ...

New information regarding pet transmission of COVID-19

New information regarding pet transmission of COVID-19

Researchers at the Harbin Veterinary Research Institute in China have pre-released a study that indicates the virus SARS-CoV-2, responsible for the COVID-19 disease, can infect and replicate efficiently in cats.  They have also found that cats can transmit the virus to other cats via respiratory droplets.  There is still little evidence to suggest that cats can be a source of viral transmission to humans.  This study also found that dogs appear to have low susceptibility to the virus. 

Accordingly, the American Veterinary Medical Association (AVMA) makes these recommendations when it comes to COVID-19 and your pets.

- If you are not ill with COVID-19, you can interact with your pet as you normally would, including walking, feeding, and playing. You should continue to practice good hygiene during those interactions (e.g., wash hands before and after interacting with your pet; ensure your pet is kept well-groomed; regularly clean your pet’s food and water bowls, bedding material, and toys).

- Out of an abundance of caution, it is recommended that those ill with COVID-19 limit contact with animals until more information is known about the virus. Have another member of your household take care of walking, feeding, and playing ...

COVID 19 and Your Pets

COVID 19 and Your Pets

With the COVID -19 Pandemic creating many challenges today, we thought we would provide information to help you understand the condition and reduce any risk to you or your furry family members.

A novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified as the cause of an outbreak of respiratory illness first detected in Wuhan, China in 2019. The illness caused by this virus has been named coronavirus disease 2019 (COVID-19).

The Agriculture, Fisheries and Conservation Department of Hong Kong reported on March 4th, 2020 a pet dog had repeatedly tested weak positive for SARS-CoV-2.  This is consistent with a low level of infection.  The transmission was most likely human to animal, as the dog lived with a human that tested positive for the virus.  The pet was quarantined for 14 days and never developed clinical signs. Sadly, the pet passed away shortly after its quarantine from unrelated causes. 

Although this case is concerning, we don’t really know if SARS-CoV-2 can infect dogs, cats and other animals.  The World Health Organization stated there is no evidence at present that dogs and cats can be infected with the SARS-CoV-2 virus, or develop ...