Tag archives: neurologic disease

The Genetics of Shortened Limbs and the Association with Canine Intervertebral Disc Disease (IVDD)

The Genetics of Shortened Limbs and the Association with Canine Intervertebral Disc Disease (IVDD)

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 ...

Preventable Inherited Diseases of the Old English Sheepdog- Part Two

Preventable Inherited Diseases of the Old English Sheepdog- Part Two

 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 ...

Degenerative Myelopathy and Centronuclear Myopathy in the Labrador Retriever

Degenerative Myelopathy and Centronuclear Myopathy in the Labrador Retriever

It’s not hard to love a Labrador retriever. Their outgoing, family friendly personality, great rapport with children, receptiveness to training, and their ability to hunt both waterfowl and upland game have made them a highly desirable and well-loved breed. This popularity is reflected by their place at the top of the American Kennel Club’s registration statistics for the past 24 consecutive years.

When adopting or purchasing a new canine family member or hunting companion, we would all like to know that our enormous investments in love, time, and money will see a sizable return. For a family dog, we’d like to know that they will be healthy and live as long as possible. For a hunting or working dog, in addition to a long life, we’d also like to know they will be able to have a long, healthy career performing the specific task for which we’ve prepared them. Though we could never eliminate or predict all disease risks for our dogs, genetic testing technologies have made elimination and prediction of some inherited diseases easier than ever before.

This blog is the first of a four part blog series examining preventable inherited diseases of America’s favorite dog, the Labrador retriever. What ...

Polyneuropathy: A Preventable Inherited Disease of the Greyhound

Polyneuropathy: A Preventable Inherited Disease of the Greyhound

From their ancient Egyptian roots depicted in carvings of their predecessors, the speed and agility of the greyhound has long fascinated humans who found great potential in the breed as hunting companions, and much later, as fantastic family dogs. Like other members of the large grouping of dog breeds known as sighthounds, it was obvious to their ancient human handlers that the greyhound’s exceptional athletic skill, lean muscular body, and keen vision could be invaluable for hunting both large and small game. While it is no longer as common for greyhounds to be used for hunting, their docile temperament outside of the hunt contributed to an easy transition to the more domestic lifestyle most greyhounds now live. Though able to run 40 miles per hour when properly conditioned, with regular exercise the greyhound is just as content taking it easy with their human family members. Despite their majestic appearance and impressive athletic attributes, like other purebred dogs, greyhounds are known to inherit some genetic diseases that may keep this talented runner at the starting block. One such disease, known as greyhound polyneuropathy (GP), is caused by a mutation in the NDRG1 gene.

GP is a severe, progressive neurological disease similar ...

My bird dog isn't hunting like he used to. What's wrong Doc?

My bird dog isn't hunting like he used to.  What's wrong Doc?

The season of the bird dog is upon us! Whether it's ducks, pheasants, geese or quail, your four-legged, bird-tracking machine needs to be well-trained and in optimal physical health if you want to improve your chances of collecting a limit. You handled the training through hours and hours of sacrifice, treats, frustration and love… and last year it showed. However, this year you are noticing that something is a little off with ol’ Chopper, and you can’t quite place what it is.

He seems unmotivated and won’t trail like he did last year. He acts like he’s excited for the hunt, but something is holding him back. Is it a health issue? Do you need to take him to the veterinarian? Given the immense financial, time and emotional commitments of purchasing and training a great hunting dog, wouldn’t it be nice to know that you’ve increased the chances of your hunting companion tracking birds with you late into their adult life? 

There are many different diseases or conditions that could take a bird dog off his game. Some of the most common ailments such as osteoarthritis, intervertebral disc disease, traumatic injuries and eye problems are called “acquired” diseases and ...

I perform genetic testing for CNM on my Labradors, but what is CNM?

I perform genetic testing for CNM on my Labradors, but what is CNM?

The popularity of the Labrador retriever doesn’t seem to wane.  It has been the number one dog breed registered by the American Kennel Club from 2002 to 2012 (the last time registration statistics were calculated) and is currently the most popular breed in the world.  Their cheerful dispositions, great prey drive, and high intelligence, has made them a common sight in American households.  Unfortunately, like many dog breeds, certain inherited diseases have become an issue as the popularity of the breed has increased.  One such disease, centronuclear myopathy (commonly referred to as “CNM” by Labrador breeders), has become a concern for the breed.  It is currently recommended (though considered optional) by the Labrador Retriever Club to perform genetic testing for CNM on all Labradors.  Despite that many Labrador breeders are currently testing for the disorder, from conversations, I have discovered that many breeders still have a significant number of questions in regards to what the disease actually is and what causes the symptoms seen in CNM.

CNM is a hereditary muscle disease of dogs caused by a genetic mutation in the PTPLA gene.  This disease was first described in dogs (Labrador retriever) in ...

How prevalent is Neuronal Ceroid Lipofuscinosis in the dog?

How prevalent is Neuronal Ceroid Lipofuscinosis in the dog?

Neuronal Ceroid Lipofuscinosis (NCL) is a group of inherited mammalian diseases characterized by abnormal accumulations of a metabolic byproduct known as lipofuscin in nerve cells and various organs of the body.  The accumulation of lipofuscin eventually leads to progressive nerve cell dysfunction and severe neurological symptoms including behavioral changes, balance issues, muscle atrophy, uncoordinated movement, blindness, head tremors and seizures.  Other organ systems can also be affected to various degrees depending on the severity of lipofuscin build up.  Most dogs will die due the disease or are euthanized when neurologic problems progress to the point of preventing normal daily activities.  While most types of NCL begin to cause clinical signs around 1 to 2 years of age in dogs, the age of onset and speed of progression vary significantly upon the type of NCL.  Variable presentation and progression among NCL types is expected given that multiple genes can cause this clinical condition.

Unfortunately, details about disease incidence and prevalence within a breed are often difficult to obtain including NCL.  Without going into an in-depth discussion about statistics, among other conditions, in order to estimate incidence and prevalence of disease for an entire population, individuals ...