Category archives: Ask The Vet

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 ...

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 ...

The leaves are falling and the pumpkins are reaching their proper jack ‘o lantern size. Soon children everywhere will be dining on a steady diet of Halloween candy while many of us adults relive our youth by taking full advantage of the one day every year we can pretend to be someone (or something) else. Though many dogs also enjoy the excitement that Halloween brings, this time of year can present additional hazards and stressors for our canine friends.

Alcohol and Junk Food

Although Halloween parties in 2020 are likely to be much different than in years past, our opportunistic dogs are still likely to find themselves around more potentially dangerous food and drink than is typical in their daily lives. A cocktail placed at dog height or a single plate of carelessly placed food have been known to ruin more than one celebratory day.

Alcoholic beverages are a particular concern for dogs during holidays and celebrations. Dogs under the influence of alcohol tend to suffer the same consequences as their overindulgent human counterparts including drowsiness, vomiting, lack of coordination, and slow reflexes. Dogs consuming toxic levels of alcohol may experience depression, breathing and heart rate abnormalities, collapse, low ...

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 ...

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.

Shortened Legs and Genetic Link to Intervertebral Disc Disease

Two genetic mutations associated with shorter limb length have been reported in domestic dogs^2,4,5. 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 ...

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 ...

The discovery of various disease-associated genetic mutations has greatly changed the way some inherited canine diseases are categorized and perceived by the veterinary community. Through the use of genetic testing developed to identify these discovered mutations, various diseases which were once assumed to have a single underlying molecular cause (due to similarity between disease states) have been found in some cases to actually be caused by many different mutations, often in different genes. This phenomenon, known as genetic heterogeneity, elucidates the way genes work together in pathways and how a disruption in different genes of a pathway may result in similar or nearly identical disease states despite seemingly disparate underlying molecular etiologies. Understanding that there may be one of many different genetic mutations responsible for a dog’s clinical signs can help plot a better course for veterinarians to obtain an accurate, definitive diagnosis and in some cases, may alter treatment strategies.

Pet Owner vs Breeder

The accuracy and specificity of an inherited disease diagnosis are particularly important in the world of dog breeding where every potential health issue must be considered prior to breeding. Unlike general pet owners who may not need to know the specific underlying molecular mechanisms of ...