Category archives: Ask The Vet

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 ...

Does Paw Print Genetics do Ichthyosis Testing?

Does Paw Print Genetics do Ichthyosis Testing?

The Golden Retriever’s easy going, gentle demeanor combined with their robustness of body, eagerness to please, and significant intelligence have consistently kept them near the top of the most popular American dogs for many years.  As a result, Paw Print Genetics frequently comes in contact with golden retriever owners and breeders looking for specific genetic tests to help make sure their dogs are going to be healthy, and in addition, that their favorite breeding sire or dam is not a carrier for a recessive disease that may be inherited by their offspring.

One of the genetic diseases most commonly tested for in Golden Retrievers is the skin disease, ichthyosis.  Ichthyosis is an autosomal recessive disease occurring due to mutations in the PNPLA1 gene and can be seen as early as the first few weeks of life in affected animals (to be affected, dogs must carry two copies of the mutated gene, one from each parent).  The prefix of the word, “ichthy-”, comes from the Greek word, “ikhthus”, meaning fish.  This is in reference to the fish-like dermal scales that characterize this disease.  Most commonly, dogs present with mild to severe generalized skin scaling of ...

Ask the Vet: “I’m confused about the different types of PRAs."

Ask the Vet: “I’m confused about the different types of PRAs."

As most canine breeders can tell you, some of the diseases most commonly tested for in pure bred dogs are the eye diseases falling under the general term, Progressive Retinal Atrophies (PRA).  However, because the various types of PRA can present very similarly, many people are unaware that PRA is not just one disease, but is a general category of disease known to be caused by a number of different genetic mutations in several different genes.  The prevalence of each type of PRA varies by breed and some forms have only been identified in a single breed.  In addition to confusion regarding the variety of disorders grouped under the PRA label, there is often confusion regarding the method used to name the individual types of PRA seen.  A good place to start in understanding the common names of these diseases would be to look at the general types of the disease and how they manifest.  In order to understand the various types however, we must first learn a little about how the eye works.

The retina is a light-sensitive layer of sensory tissue that lines the inner surface of the eye.  Light that shines ...

My Dog’s Mouth Has Been Bleeding? What Could Be Wrong?

My Dog’s Mouth Has Been Bleeding?  What Could Be Wrong?

In my years as an undergraduate college student, struggling to make ends meet, I lived next door to a woman with an old, Labrador mix named Bubba.  By initial impression, he seemed to be a very normal, happy and well-socialized dog.  However, one day, during my daily greeting from Bubba, I noticed some blood around his mouth.  At the time, I was a biology major trying to wade through prerequisites for admission to veterinary school and I hadn’t yet been exposed to the world of clinical veterinary medicine.  So, when I saw the blood around Bubba’s mouth, I didn’t pay much attention.  I had seen blood in my own dog’s mouth on occasion after chewing on a toy or a bone and it never amounted to much.  So, my uninformed mind had little to worry itself about.  I later learned from Bubba’s owner that he had bled like this since he was young.  However, the owner had never taken Bubba to a veterinarian for a diagnosis and to this day I still don’t know what was wrong with him.  Though the memory of Bubba had ...

Do you have a test to screen for hip dysplasia?

Do you have a test to screen for hip dysplasia?

Since I started my work with Paw Print GeneticsTM and began discussions with many in the canine community, I have been asked more about hip dysplasia (HD) than any other disease.  Perhaps it is due to the significant decrease in quality of life it can create for affected dogs or perhaps it is because historically, it has been one of the most extensively studied canine diseases.  Regardless of the reason, it is clear to me that dog owners and breeders are concerned about the disease and would love to see it eradicated.  Unfortunately, we may be years off from fully understanding all of the contributing causes and thus, preventing this often debilitating disease.

In the most basic sense, HD is simply a condition of loose hip joints, but it is the secondary consequences of these loose joints that cause the clinical condition we recognize in dogs.  In affected dogs, laxity in the hip joint leads to abnormal alignment between the head of the femur and the pelvic socket (acetabulum) that serves as the gliding surface for the head of the femur during movement.  This improper alignment leads to abnormal wear and tear of the ...

My dog appears to be going blind. Is it genetic?

My dog appears to be going blind.  Is it genetic?

Just like people, blindness or an otherwise significant reduction in vision is a relatively common occurrence in our canine friends. Whether your puppy loses his sight in bright light or your old faithful companion’s eyes are looking a little "cloudy", the profound impact it can have on the life of both pet and owner, makes preventing or treating eye disease a major concern for veterinarians.

Though there are hundreds of possible biological processes responsible for blindness, these processes can be grouped into two major categories: Non-genetic (acquired disease) and genetically inherited disease caused by mutations in a dog’s DNA (the genetic material found in all cells). Though mutations in DNA are present at birth, disease can present in a variable timeframe from puppy to older dog, depending on the specific mutation present.

Though not all eye diseases have an inflammatory component to them, some of the most commonly acquired, non-genetic eye diseases involve chronic inflammation of the eye’s internal and external structures. External chronic eye inflammation gradually damages the structure of the cornea and can eventually lead to difficulty seeing. Most of the cases involve physiological abnormalities (i.e. eyelashes rubbing on the eye) or trauma resulting ...