Breed Health Information
We are very fortunate to have a number of genetic tests available for the breed, due to the dedication and commitment of many breeders on improving the health of the breed.
Here is a list and brief description of each genetic test, as well as other tests Tollers should complete before breeding is considered.
PRA (Progressive Retinal Atrophy)/ PRCD (Progressive Rod Cone Degeneration)
PRCD affects the photoreceptor cells in the eye involved in both night and day vision. The cells of the retina involved in low light vision, known as rods, are affected first, resulting in night blindness. Subsequently, the bright light photoreceptors known as cones, which are important for color vision, are also affected, resulting in daytime visual deficit. The age of onset and rate of progression vary among breeds, but retinal changes can be identified by screening performed by a veterinary ophthalmologist from adolescence to early adulthood. Most PRCD-affected dogs have noticeable visual impairment by 4 years of age, typically progressing to complete blindness.
CLPS, Cleft Lip/Palate and Syndactyly
Affected puppies can vary from only a cleft palate (hole in the roof of the mouth) to cleft palate and cleft lip (split in the lip that can occur on one or both sides of the mouth). In both cases puppies may also have syndactyly (fusion of the middle two digits of the feet).
CP1, Cleft Palate
A cleft palate is a birth defect whereby a hole (cleft) in the roof of the mouth (palate) develops in a puppy during gestation. Puppies born with cleft palate can experience difficulty nursing, which will greatly increase their risk of developing aspiration pneumonia, a serious life-threatening condition.
JADD Addison’s Disease
JADD Addison’s disease occurs when the adrenal glands stop secreting necessary natural steroid hormones. In the Nova Scotia Duck Tolling Retriever, a genetic form of Addison's disease can occur in puppies.
Degenerative Encephalopathy (DE)
DE is degeneration of a region of the brain called the caudate nucleus. The caudate nucleus is a part of the brain that is important in controlling movement and some aspects of behavior. In DE, this portion of the brain undergoes necrosis or complete destruction. One of the manifestations of caudate necrosis is a very unusual change where the dogs vigorously act out their dreams, and are difficult to awaken. Hence the name Degenerative Encephalopathy with Sleep Disorders and Caudate Necrosis.
DM, Degenerative Myelopathy
Degenerative myelopathy (DM) is an inherited neurologic disorder of dogs characterized by gradual muscle wasting and loss of coordination typically beginning in the hind limbs.
Chondrodystrophy, a trait that is characterized by a short-legged phenotype, also impacts the health of dogs by increasing susceptibility to intervertebral disc disease
Cerebella Degenerative-Myositis Complex (CDMC)
CDMC is a heritable disorder that causes neurological signs that manifest as early as 10 weeks of age in affected Nova Scotia Duck Tolling Retrievers.
Cardiac Laminopathy (CLAM)
CLAM is a fatal heritable condition that results in dilated cardiomyopathy and sudden death in young adult Nova Scotia Duck Tolling Retrievers. Affected dogs present with dilated cardiomyopathy at a young age and typically experience sudden death within the first year of age.
Collie Eye Anomaly (CEA)
The choroid is the layer of tissue in the eye responsible for supplying blood and nutrients to the Retina. In dogs affected with CEA, the choroid does not develop properly and is therefore thinner than normal. The severity can vary from dog to dog, with mild symptoms to symptoms leading to subsequent blindness.
BUFF Coat Color
A DNA test for dilute coat color in tollers. Buff is a disqualifying feature in the show ring, but otherwise causes no health issues in the breed.
Hip dysplasia typically develops because of an abnormally developed hip joint. Screenings are performed by a veterinarian with x-rays sent for grading and certification with OFA or PennHIP. Breeders will commonly only breed dogs with ratings of Excellent, Good, or Fair (OFA Scale).
Elbow dysplasia is a general term used to identify an inherited polygenic disease in the elbow. Three specific etiologies make up this disease and they can occur independently or in conjunction with one another. These etiologies include: Pathology involving the medial coronoid of the ulna (FCP), Osteochondritis of the medial humeral condyle in the elbow joint (OCD), and Ununited anconeal process (UAP). Screenings are performed by a veterinarian with x-rays sent for grading and certification with OFA. Breeders will typically only breed dogs with a rating of Normal.
Basic Cardiac Database Certificate: Auscultation is performed by a licensed veterinarian to determine that the dog’s heart is phenotypically normal prior to use in a breeding program.
Advanced Cardiac Database Certificate: An echocardiographic examination is performed by a Board Certified Veterinary Cardiologist to determine if the dogs heart is phenotypically normal prior to use in a breeding program.
Hypothyroidism is the most common endocrine disorder of canines. A blood test is performed to check that Free T4 (FT4) is within normal range, Canine Thyroid Simulating Hormone (cTSH) is within normal range, and that Thyroglobulin Autoantibodies (TgAA) is negative. Knowing the status of the dogs can help breeders make more informed decisions to reduce incidence of autoimmune thyroiditis in the offspring.
The patella, or kneecap, is part of the stifle joint (knee). In patellar luxation, the kneecap luxates, or pops out of place, either in a medial or lateral position. A dog is examined by a veterinarian and results are graded Normal and then Grade 1-4.