Author archives: Casey Carl

Who To Test? - Canine Autosomal Recessive Genetic Diseases

Who To Test? - Canine Autosomal Recessive Genetic Diseases

Genetics play an enormous role in the health of dogs walking through the doors of any veterinary hospital. However, the treatment of an animal with an inherited disease rather than proactive testing of the genetic mutations responsible for disease has been the traditional role of the veterinarian. With an increase in the availability of canine genetic disease testing and great improvements in the ease and convenience of ordering genetic testing through Paw Print Genetics, more and more dog breeders and their clients are having genetic testing performed preemptively and learning the benefits of these powerful technologies. As a veterinarian, understanding the basics of genetic testing and how genetic test results can be used to prevent and diagnose disease will keep you current and prepared for your clients as these technologies inevitably become a more significant part of clinical veterinary practice.

One of the more challenging but important aspects of canine genetic testing is deciding what recommendations to make when a dog or one of its relatives are found to be at risk for (or affected with) an inherited disease. Appropriate testing recommendations for the relatives of affected dogs may be crucial for prevention of additional affected puppies and identification of ...

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 ...

If a cavalier King Charles spaniel falls in the woods and no one’s around, is it episodic falling syndrome?

If a cavalier King Charles spaniel falls in the woods and no one’s around, is it episodic falling syndrome?

There aren’t many things sweeter in life than a cavalier King Charles spaniel (CKCS). From their friendly, outgoing demeanor to their adorable, pouty eyes, they have definitely become one of my favorite breeds over the years. It appears that others understand my enthusiasm for the breed as well. In the fifteen years from 2002 to 2017, CKCS have moved up from 40th place to 19th place on the AKC’s registration statistics and are one of the most popular breeds in the United Kingdom. Unfortunately, like other popular dog breeds, cavaliers have their share of inherited diseases that can potentially reduce their quality and quantity of life. At Paw Print Genetics, we strive to control these diseases for our canine companions.

One interesting yet, debilitating disease unique to the CKCS is an inherited neurological condition first reported in 19831, known as episodic falling syndrome (EFS). Affected dogs begin showing signs of spastic muscle contractions of the limbs and trunk between 14 weeks and 4 years of age particularly during exertion, excitement, or frustration. As an episode starts, affected dogs most commonly develop rigid hind limb extension, a convex bending of the spine (“roach backed”), and hold their head near the floor ...

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 ...

Nature Versus Nurture- The Case of the All-Male Litter

Nature Versus Nurture- The Case of the All-Male Litter

The often-debated biological argument of “nature versus nurture” is at the center of the challenging considerations dog breeders must make in their effort to produce the healthiest, happiest, and most beautiful dogs they can. Breeders routinely contact the veterinarians or geneticists at Paw Print Genetics (PPG) looking for genetic testing to identify dogs that may be at risk of producing puppies with certain diseases. Given the emotional, temporal, and monetary damages associated with being forced to remove a dog from a breeding program, it is important for breeders to understand whether the disease in question appears to be inherited or whether there might be a more likely environmental explanation for what they see in their blood line. However, when no genetic testing is available for a particular condition, the answer to the question of nature versus nurture may not be quite as straight forward as it may seem at first glance. Keeping your mind open to environmental factors associated with disease might prevent your clients from having to remove their prized breeding dog from their gene pool.

An All-Male Litter?

As a veterinarian, one of the great joys of helping improve the genetic health of dog kennels are the many ...

Canine Genetics in Practice- Congenital and Early-onset Inherited Diseases

Canine Genetics in Practice- Congenital and Early-onset Inherited Diseases

Some of the most emotionally challenging canine cases seen in the veterinary hospital are those involving serious illnesses of newborns or young puppies. Owners’ joyous expectations of a long, healthy relationship with their new puppy makes a disease which decreases that puppy’s quality of life or results in early euthanasia, all the more heartbreaking. Though infectious diseases like parvovirus are often of particular concern in young pups, some puppies ending up on the exam room table show signs of one of a wide array of inherited diseases caused by a known genetic mutation. Unfortunately, limitations in available therapies for many inherited diseases often lead to frustrating and emotional outcomes for all the parties involved; veterinarians and veterinary staff included. Thereby, making prevention of inherited disease through the use genetic testing, an essential part of healthy dog breeding.

Historically, methods to prevent inherited diseases have been limited to selective breeding practices. However, an inability to identify asymptomatic carriers of recessively inherited diseases or dogs in the preclinical phase of late-onset inherited diseases, have traditionally made great reductions in disease incidence difficult to obtain through selective breeding alone. Genetic testing is now playing an important role in identifying these dogs such that ...

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 ...

The Labrador Retriever Copper Toxicosis Test- Interpretation, Breeding Strategy, and Monitoring

The Labrador Retriever Copper Toxicosis Test- Interpretation, Breeding Strategy, and Monitoring

The liver disease, copper toxicosis (CT) has become a hot topic among Labrador retriever breeders and dog owners with the arrival of a new genetic test which identifies two recently described mutations found in Labradors associated with opposite effects on the amount of dietary copper stored in the liver. As with all new canine genetic tests, questions and concerns may arise from breeders about how to interpret their dog’s test results, how to use this information to maintain the health of their dog, and how to use the information for their breeding program.

What is liver copper toxicosis?

Copper toxicosis is an inherited metabolic disease affecting Labrador retrievers and other breeds, which can result in chronic liver failure. Dogs with copper toxicosis have a decreased ability to excrete dietary copper from the body resulting in excessive copper storage in tissues and organs, including the liver, which can result in liver damage, subsequent cirrhosis and the inability of the liver to function properly. Though the age of onset and speed of disease progression are variable, most affected dogs will present in middle age with non-specific signs of liver dysfunction including weight loss, lethargy, weakness, vomiting, diarrhea, and abdominal pain. In late ...

Improving Client Experience and Clinical Outcomes with Canine Genetic Disease Testing

Improving Client Experience and Clinical Outcomes with Canine Genetic Disease Testing

The expanding role of the dog over recent decades as an anthropomorphized member of the modern American family has led to an increase in dog owners’ expectations of their veterinarians. With social media, where the old adages about the number of people a dissatisfied client will tell about their experience can be easily multiplied by a factor of hundreds, the pressure to meet client expectations is more intense than ever.

Far more actionable than the commonly used genetic testing for canine breed identification, canine genetic disease testing is an accurate and reliable tool to help veterinarians meet their clients’ expectations in new ways. Genetic testing for a variety of inherited diseases has become commonplace in the dog breeding community to help breeders produce puppies free of particular maladies. However, as we know, not every dog seen in practice is the product of two purebred parents which have been genetically tested and vetted to make sure they are a good genetic match. Having a solution to easily perform canine genetic disease testing for any dog in a clinical setting, no matter the breed, adds a level of sophistication and progressiveness to your practice which can also supplement and improve your overall ...

What’s the Deal with von Willebrand Disease II? - An Important Update for the Boykin Spaniel

What’s the Deal with von Willebrand Disease II? - An Important Update for the Boykin Spaniel

The clotting disorder known as von Willebrand disease (vWD) is a relatively common and potentially lethal disease of dogs. Three general types of vWD (types I, II, and III) have been described based upon the specific genetic cause and level of deficiency in a protein known as von Willebrand factor (vWF), which plays an important role in blood coagulation. Dogs deficient in vWF protein are at risk of potentially life-threatening bleeding episodes when undergoing surgical procedures or as a result of traumatic injury. Therefore, when a relatively high frequency of Boykin spaniels was identified in the Paw Print Genetics (PPG) laboratory to carry a mutation in the VWF gene previously associated with vWDII in German shorthaired and wirehaired pointers (Kramer and colleagues), Boykin spaniel lovers and our team at Paw Print Genetics (PPG) were understandably concerned.

Concern turned to confusion as Boykins expected to be at risk for vWDII (based upon their genetic testing results) failed to show any signs of a clinical clotting disorder. In addition, results of additional blood tests looking at the product produced by the gene on several “at-risk” dogs showed no deficiency in vWF protein and no increase in blood clotting times. At that time ...