Blog Archives for the year 2015

The art of medicine today is nearly unrecognizable from its state in 1776 when the original thirteen colonies of the United States declared their independence from Great Britain. Without knowledge of bacteria or viruses, physicians and veterinarians of the day had few worries about sterility or the fact that they could play a role in the spread of deadly diseases between their patients. Bolstered by anecdotal evidence, dangerous treatments to purge various ailments from the body such as bloodletting and enemas (then called clysters) were commonly practiced in both people and animals in opposition to our modern understanding of their risks and lack of efficacy.

The Birth of Modern Genetics

The 19^th century saw great advances in science including progression of the scientific method by which scientists could more objectively test their observations and develop an explanation for them. These methods also allowed for the modification of previous theories as new information was uncovered through experimentation. It was also the 19th century in which the foundation for the modern era of genetics was laid by an Augustinian friar named Gregor Mendel. Far ahead of his time, Mendel’s study of trait inheritance in the common pea plant went relatively unnoticed ...

Despite its 19^th century reputation as a ferocious and fearless competitor in the cruel sport of dog fighting, the modern, well-bred Staffordshire bull terrier (SBT) is an affectionate, friendly, and loyal companion. At only 24 to 38 pounds, the SBT’s impressive, muscular frame is now a relic from a distant time when dogs slept in the backyard instead of the bedroom and often proved their worth through the use of their agility, strength, tenacity, and teeth. Through nearly a century of careful selective breeding for temperament, the SBT has become as suitable for the family as they once were for the fighting ring. As with other purebred dogs, along the path of breed improvement, the SBT has developed some inherited diseases that have caused problems for SBT owners and breeders alike. One of the most concerning inherited diseases in the SBT is the neurometabolic disorder commonly referred to by the acronym L-2-HGA; short for L-2 hydroxyglutaric aciduria.

What is L-2-HGA?

Dogs affected with L-2-HGA lack functional copies of a protein important in eliminating L-2 hydroxyglutaric acid (a normal product of metabolism) from the body. As a result, L-2 hydroxyglutaric acid accumulates in the urine, blood, and cerebrospinal fluid. Though ...

Though the cruel bull-baiting practices for which the ancestors of bulldogs were used have long passed, the enthusiasm for the modern bulldog as a friendly companion animal is as fervent and robust as ever. Ranked the 4^th most registered dog in the AKC, it’s no secret to most that the bulldog has established itself as one of America’s favorite canines. Through selective breeding practices, the previously fierce and aggressive bulldog of old has given way to a gentle, even tempered, yet strong willed breed with copious amounts of character; in both temperament and physical attributes. Unfortunately, like other purebred dogs, during the course of breed development, some inherited genetic diseases have come to light that can make life difficult for bulldogs and those that love them. Luckily, through the use of genetic testing technologies and selective breeding, some of these inherited diseases can be completely eliminated (or greatly reduced in frequency) from blood lines. One example of an inherited disease that can now be prevented in the bulldog is an inherited form of urinary stones known as hyperuricosuria (HUU), caused by a genetic mutation in the SLC2A9 gene.

Clinical Signs of HUU

Dogs affected with HUU lack a protein which ...

If there is anything that I have learned in Paw Print Genetics’ quest to prevent canine inherited diseases, it is that degenerative myelopathy (DM) is one of the most misunderstood diseases in the dog breeding community. This late-onset, progressive neurological disease is notorious for cutting affected dog’s lives short and preventing them from living out their golden years. Unfortunately, sometimes there are misunderstandings in regard to what causes DM, what DM genetic test results mean, and whether or not DM occurs in certain breeds or bloodlines. I will attempt to address the confusing aspects of DM in order to empower people to eliminate this devastating disease from their blood lines.

How Do DM Affected Dogs Present? How is it Inherited?

Dogs affected with DM typically begin showing signs of painless, hind limb weakness and loss of balance around 7 to 10 years of age. These dogs often have difficulty rising after lying down, will drag their hind feet while walking, and abnormally cross their legs while standing. As the disease progresses, affected dogs’ front limbs also become progressively weaker until the dog becomes unable to walk. Affected dogs also may develop urinary and fecal incontinence as the disease progresses. Most ...

Previously known as the Jack Russell terrier, the Parson Russell terrier’s nearly 200 year long history began in the 1800’s when Parson John Russell of England obtained a terrier named Scout with the purpose of training him for European red fox hunting. Russell eventually developed a particularly adept line of terriers meant to run alongside hunters on horseback and dispatch foxes.

The name, Jack Russell Terrier was previously used to encompass dogs which are now recognized as three separate breeds in the U.S, the Jack Russell terrier, the Parson Russell terrier, and the Russell terrier. Despite their close genetic relationship and very similar appearance, leg length and body shape can be used to help differentiate the three breeds. Parson Russell terriers possess the longest legs and a square-shaped body while the other two breeds display shorter legs and a rectangular body shape. The Russell terrier is the shortest of the three varieties. Parson Russell terriers and Russell terriers are both recognized by the AKC, however the Jack Russell Terrier remains unrecognized by the organization and is bred primarily for its ability to hunt rather than for its conformational merits. Despite these physical differences, the three breeds share many genetic similarities ...

Though there are mysteries in regards to the early origins of the French bulldog, it is probable that this spunky breed is a 19^th century product of breeding early English bulldogs and miniature bulldogs with other small breeds. As these smaller, English bred bulldogs became popular, many were either exported to France from England or accompanied their English owners to France in search of employment. At some point in the mid to late 1800’s, the small bulldogs were given the name “Bouledogue Français” and were recognized as their own unique breed. Early French bulldogs with either “rose ears” (ears folded at the tip) or pricked “bat ears” were common. However, with the spread of the breed to the United States, American dog fanciers created the first French bulldog breed standard describing the “bat ear” trait seen in modern Frenchies as the “correct” ear type.  In the process of establishing their modern appearance and perfecting the breed, like other purebred dogs, French bulldogs have developed some inherited diseases that concern Frenchie aficionados today. One such disease is a disorder known as hereditary cataracts (HC).

A cataract, in general, is the clouding of the lens of the eye. This cloudiness interferes ...

Despite being one of the most recognizable dog breeds in existence due to their unique physical attributes, the early history of the Chinese crested is a bit mysterious due to a lack of adequate written records. Though early hairless dogs have been documented in Africa, Central and South America, and Asia, the relationship between these dogs is not well understood. Evidence to suggest that they may be related is found in the fact that at least 3 hairless breeds originating from different continents (Mexican hairless, Peruvian hairless, and Chinese crested) are all known to inherit the same FOXI3 gene mutation responsible for their hairlessness. It is most likely that a common ancestor to the hairless breeds developed a spontaneous FOXI3 mutation that was later passed to the individual breeds as they were developed. It is theorized that early hairless dogs travelling on shipping routes with their human companions played a role in the spread of the trait to numerous locations in the world.

In addition to genetic mutations responsible for particular physical traits, like other purebred dogs, Chinese cresteds are known to inherit some genetic mutations responsible for causing inherited disease. Inherited diseases of the eyes are of particular concern ...

If you are anything like me, planning for Mother’s Day can be like planning for a future litter of puppies. Caught up in the whirlwind of life, work, fun, kids and family, sometimes the important planning that goes into celebrating our mom or getting our prospective canine mothers prepped for their 9-week puppy rearing adventure, slips to the bottom of the “to do” list.

Luckily, most human moms are easy to please if we simply make a small effort to show that we care. An eleventh hour bouquet of flowers or a last minute lunch date is often enough to let mom know that she really matters, despite our procrastination. Unfortunately for the canine mothers in our life, procrastination in regards to planning a new dam’s first litter, can mean the difference between a healthy group of puppies and a sickly one. In addition to setting aside the time for veterinary health clearances of the heart, eyes, hips, and elbows, genetic testing of a new potential dam (or sire, for that matter) is of utmost importance to puppy health and the reputation of your breeding program. Unfortunately, accidentally putting off genetic testing until your dam is fully ready to breed ...

From their roots as a well-rounded Swiss farm dog, the modern Bernese mountain dog (BMD) is well known for its friendly and affectionate demeanor. This intelligent and adaptable breed has gained the love of many Americans since its introduction to the United States in 1926. In 2014 the BMD moved to 31^st place in the AKC registration statistics and appears to be growing in popularity as the breed has moved up 8 places in the rankings since 2009.

Like many purebred dogs, the Bernese mountain dog is known to inherit some health issues that are of major concern to breeders. Unfortunately, genetic discoveries for some of the most concerning inherited issues for BMD breeders, such as a type of cancer known as histiocytic sarcoma, have remained elusive. However, some inherited diseases of Bernese mountain dogs can be avoided through the use of genetic testing technologies and selective breeding practices.

Degenerative Myelopathy

The late-onset neurological disease, degenerative myelopathy (DM) is one such disease that can be prevented through genetic testing. In 2009, a mutation in the canine SOD1 gene was described as a major cause of DM. Since then, the mutation has been reported in over 100 dog breeds including ...

 In this second blog of a two part blog series (read part one here) about inherited diseases of the wonderful old English sheepdog (OES), we will examine two inherited diseases reported in multiple dog breeds in addition to the OES.

Degenerative Myelopathy

Historically a disease associated with the German shepherd dog, degenerative myelopathy (DM) has now been identified in over 100 dog breeds. A canine disease similar to amyotrophic lateral sclerosis (“Lou Gehrig’s Disease”) which affects people, DM is a late-onset neurological disease caused by a mutation in the SOD1 gene. Affected dogs initially present around 7 to 10 years of age with weakness in the hind limbs and difficulty rising after lying down. As affected dogs gradually lose the ability to fully control their hind limbs, it is common for them to begin dragging their hind feet while walking and may occasionally lose their balance and fall over. In some circumstances, affected dogs will also suffer from urinary and/or fecal incontinence. Once initial signs of disease present, progression of the neurological dysfunction to the front limbs tends to be rapid with most dogs losing the ability to walk within 6 months to two years.

Diseases with a late ...