Genetics

Each dog breed comes with its own particular set of frequently-diagnosed inheritable diseases. Most often, these diseases come into play when you breed a dog that genetically carries the disease to another dog that carries the same gene(s), although some diseases require a contribution from only one parent.

Thanks to the efforts of many veterinarian universities, DNA markers for many of the diseases affecting the poodle breed have been identified, allowing breeders to eliminate them in the pups they produce. Many other diseases, like hip dysplasia, are believed to have several genes that contribute to their onsets. Efforts continue to establish DNA markers for hip dysplasia and many other genetic diseases, and we will continue to stay abreast of progress made in that regard.

Testing and ancestral analyses are the two most important things breeders can do to eliminate these diseases in dogs; however, we are not mother nature and many of the diseases have not had DNA markers established for them nor are we always able to locate enough information on ancestors to know definitively what they may or may have carried. That said, the best we can do is to test and pair our dogs against other dogs that we believe will positively offset them (considering all things: health, conformation, temperament, etc.).

Inbreeding (or line breeding as many breeders call it) perpetuates the problems found in dogs as a dog used over and over again in the same line may carry a disease unknown to the breeder, and the negative gene(s) is then doubled, tripled, quadrupled, etc. in its offspring. Ongoing research consistently proves that inbreeding impairs our dogs' immune systems, making them increasingly vulnerable to infection, allergies, and other immune-mediated problems, even cancer. Because of all of the unknowns involved, we subscribe to Dr. John Armstrongs' (Canine Diversity Project) breeding recommendations, in addition to conducting diligent research into the health of the dogs used in our lines.

We test our dogs for the Standard Poodle's most common inheritable diseases. A brief description of these diseases follows:

Degenerative Myelopathy (DM): Degenerative Myelopathy is a progressive disease of the spinal cord in older dogs.  The disease has an insidious onset, typically between 8 and 14 years of age.  It begins with a loss of coordination in the hind limbs.  The affected dog will wobble when walking, knuckle over, or drag its feet.  This can first occur in one hind limb and then affect the other.  As the disease progresses, the limbs become weak, the dog begins to buckle, and he eventually has difficulty standing.  The weakness gets progressively worse until the dog is unable to walk. A DNA marker is available for this disease, allowing us to eliminate it totally in our pups.

Eye Diseases: Eye diseases can cause a series of ailments, including eye pain, discharge, cloudy or filmy eyes, glaucoma, etc.

Hip Dysplasia: In a dysplastic hip, the head of the femur fits loosely into a poorly developed, shallow acetabulum. Joint instability occurs as muscle development lags behind the rate of skeletal growth. As the stress of weight-bearing exceeds the strength limits of the supporting connective tissue and muscle, the joint becomes loose and unstable. This allows for free play of the femoral head in the acetabulum, which promotes abnormal wear and tear. While it is considered to be genetic, being overweight supports the genetic potential for hip dysplasia and other skeletal diseases. Inappropriate exercise during the period of rapid bone growth (generally up to 18-24 months of age) can also bring on the symptoms of hip dysplasia. Young dogs should be discouraged from jumping up and down from heights and from standing up on their back legs. For the most part, we have chosen to use PennHIP for hip testing. You can read about their hip tests at: PennHIP Radiographic Evaulation At A Glance.

Hypothyroidism (Thyroid): Thyroid deficiency can cause a host of problems in dogs, including hair loss, absence of heat cycles and abortions in breeding females, weight gain, intolerance to cold, a slow heart rate, lethargy, and a variety of nonspecific symptoms.

Neonatal Encephalopathy: This results in fatal developmental brain disease and has been found in an extensive family of Standard Poodles. The disease is inherited as an autosomal recessive trait, and most affected puppies die shortly after birth. With intensive nursing care, affected pups can be kept alive for a few weeks; however, none have survived past their fifth week. A DNA marker is available for this disease, allowing us to eliminate it totally in our pups.

von Willebrands (vWD): This is the most common inherited bleeding disorder in dogs. vWD is inherited as an autosomal dominant gene with variable expression. That is, the severity of the bleeding is related to the degree to which the gene is expressed. The bleeding is caused by a deficiency of a plasma protein called the von Willebrand factor, which is critical for normal platelet function in the early stages of clotting. In most cases, the bleeding in vWD is mild or inapparent, and lessens with age. Severe problems include prolonged nose bleeds, bleeding beneath the skin and into the muscles, and blood in the stool and urine. A DNA marker is available for this disease, allowing us to eliminate it totally in our pups.

Testing for coat color and a D-locus test for color dilution have recently become available. The coat color test allows breeders to fairly accurately predict the colors of puppies that will be produced with each breeding. As for the D-locus test for fading, it was originally held that if both parents carried the DD allele their pups would not fade. Unfortunately, even in those with DD alleles, it appears that there is another gene working specifically in poodles that causes some to fade (it is believed to be the G locus, but a DNA marker has not yet been isolated for that allele).  Until this marker is identified, the D-locus test can only tell us whether the one "identified" fading gene is present in that dog. The best we can do is to test for this one known cause and hope the other, currently unidentified gene is not present. VetGen and DDC labs are able to test for the one dilute gene and VetGen has authored this table to assist red breeders in removing brown and fading coats in their dogs.

Another possible cause for fading coats is environment. If a dog is over exposed to the sun, the sun can fade the coat. Let me provide you with a visual example of Boom (a DD). The two far left pictures below this paragraph were taken of Boom as a pup. He was born with a beautiful dark apricot color. Then, after a summer of playing outdoors with Richard, his coat faded (see center picture). (We live in Phoenix where the summer sun is intense.) Then, just 3-1/2 months later in the two right pictures below, Boom had regained his dark apricot color. During the time that he was lighter, we were still able to see that the coat color closer to his skin was dark, so weren't panicked. Shaving him down was all it took to have our boy look like a dark apricot again.

            

The following information was authored by VetGen. You can read more about it on their site. I have displayed the chart on our site to help others determine the probability of various coat colors in our planned litters.

Coat Color in Poodles:

DNA research has identified the genotype associated with the brown (b allele) and cream- white-red-apricot (e allele) coloring.

What does this mean to breeders of Poodles?

VetGen has discovered that Poodles who are brown have the 'bb' genotype and Poodles who are cream, white, apricot or red have the 'ee' genotype. The DNA Test for coat color in Poodles will allow breeders to test dogs who are NOT brown, to identify whether the b allele is present, as well as to test those dogs who are NOT cream, white, apricot or red, to identify whether the e allele is present.  The DNA test for band e allows breeders the choice of producing dogs with brown coat color, as well as the opportunity of breeding away from the cream, white, apricot or red coat color.

The ChromaGene™ test will determine which one of the genotypes listed below your Poodle is:

If your dog is black the possible genotypes are: BBEE, BBEe, BbEE, BbEe.
If your dog is brown, the possible genotypes are: bbEE, bbEe.
If your dog is cream, white, apricot or red with a black nose, possible genotypes are: BBee, Bbee.
If your dog is cream, white, apricot or red with a brown nose, your dog's genotype is bbee.

ChromaGene™ testing is valuable for determining if a breeding pair is carrying e, b or both and would therefore be capable of producing the brown or cream-white-red-apricot coat color.

Table of Statistical Outcomes of Mating Pairs:
*Note:   cream represents - cream, white, apricot or red 

Once your dog has been tested and you know its genotype, use this table for breeding strategies and breeding stock selection. The outer ring shows the visible coat color with the small upper right circle showing the nose color (black or Brown). The inner rings show the hidden color genes carried by the dog. Entries in the table show the probabilities of producing various coat color within a litter. For example, if your results show that your dogs genotype is a Type Bbee, your dog is cream, white, apricot or red and has a black nose, the dog is carrying the hidden genes for black and brown.  If you were to mate this dog with a dog of the genotype bbEE, on the average, half of the Litter would would be black and the other half of the litter would be brown.  These probabilities represent expectations averaged over the long run and are subject to the law of probabilities.

Note that any breeding which produces both Brown or Cream, White, Apricot or red, has the potential to produce brown nosed cream, white, apricot or red. If the breeding does not have the potential to produce blacks, only cream, white, apricot, red and brown, all cream, white, apricot and red will have brown noses.