"All dogs used for breeding are screened for genetic conditions”.
Labrador Retriever Health Testing Checklist & Results
CERTIFICATIONS AND CLEARANCES
Responsible breeders routinely reference health certifications such as hips, elbows, eyes, and cardiac Responsievaluations, often stating that their dogs have completed all required clearances. These results can be independently confirmed through the Orthopedic Foundation for Animals (OFA) database at OFA.org by searching the dog’s registered name or registration number.
Certain medical conditions are inherited genetically, while others are influenced by multiple factors [multifactorial, including genetics and environment]. Orthopedic conditions, for example, fall into the multifactorial category. Although no breeding program can eliminate all risk, selecting breeding dogs that have undergone comprehensive health screening significantly improves the likelihood of producing sound, healthy offspring.
Inherited genetic conditions follow more predictable patterns. Dogs tested for genetic disorders are classified into one of three categories:
1. “Clear” means the dog possesses no copies of the mutant gene for a disease; it will never have the condition or pass it on to its offspring. Puppies may be designated as “clear by parentage” for specific inherited conditions—such as EIC, CNM, PRA-prcd, RD/OSD, and DM—when both parents have tested clear for the same disorder
2. “Carrier” means the dog possesses one copy of the mutant gene and one copy of the normal gene; the dog does not have and will not develop the disease; it should be bred only to dogs clear of the same disease to prevent producing dogs affected by the disease; if bred to another carrier 25% of the puppies will be expected to be affected by the disease, 50% of the puppies will be carriers; if bred to an affected dog, 50% of the puppies will be expected to be affected by the diseases and 50% carriers. Where carriers are involved, puppies can be individually tested to determine their genetic status.
3. “Affected” means the dog possesses two copies of the mutant gene; it will have the disease/ be affected by the disease in its lifetime. Affected dogs should only be bred to clear dogs to ensure they produce no affected dogs, but all puppies produced in such a mating would be carriers of the disease. If bred to a carrier or affected dog of the same disease, affected puppies will be produced. At Swancor Labradors, dogs diagnosed as affected by any inherited disease are not included in the breeding program. This policy reflects our commitment to ethical breeding practices and the long-term health and wellbeing of every puppy we produce.
ORTHOPEDIC & CLINICAL TESTING
01. Hip Dysplasia – OFA Hips
☐ HIP DYSPLASIA – OFA HIPS
Explanation: A developmental abnormality of the hip joint that can lead to arthritis, pain, and reduced mobility.
Testing method: X-rays reviewed by OFA board-certified radiologists
Testing age: 24 months or older
Retesting: Not required once final OFA certification is issued
Results: ☐ Excellent ☐ Good ☐ Fair ☐ Borderline ☐ Mild ☐ Moderate ☐ Severe
Certifications and Clearances Breeders often describe their dogs as “hip, elbow, eye, and heart certified” or as having “all of their clearances,” and these statements can usually be verified on the website of the Orthopedic Foundation for Animals: OFA.org. Records can be accessed by searching using the dog’s full registered name, exact spelling, or registration number.
Affected dogs are never included in the Swancor Labrador breeding program.
ORTHOPEDIC & CLINICAL TESTING
02. Elbow Dysplasia – OFA Elbows
☐ ELBOW DYSPLASIA – OFA ELBOWS
Explanation: Developmental elbow joint disease that may cause lameness and degenerative arthritis.
Testing method: X-rays reviewed by OFA board-certified radiologists
Testing age: 24 months or older
Retesting: Not required once final OFA certification is issued
Results: ☐ Normal ☐ Grade I ☐ Grade II ☐ Grade III
Elbow dysplasia is largely hereditary and is thought to involve multiple genes. As with hip dysplasia, Labradors cannot be considered “normal” or “good by parentage” for elbows. Many dogs with elbow dysplasia show little to no outward signs, yet they may still transmit more severe forms of the condition to their offspring, making formal screening essential.
Final elbow certification can only be obtained once a dog reaches 24 months of age. Radiographs of the elbows are submitted to the Orthopedic Foundation for Animals (OFA) for evaluation. Dogs that pass the OFA assessment receive a rating of Normal, while all other findings are classified as dysplastic.
Labradors diagnosed with elbow dysplasia should not be used for breeding. Nevertheless, many affected dogs enjoy good quality lives as companions. Management of clinical cases varies according to severity and may include weight management, nutritional supplementation, medication, or surgical intervention.
Swancor Kennels does not breed dogs diagnosed with hereditary heart disease.
ORTHOPEDIC & CLINICAL TESTING
04.Heart Disease – OFA Cardiac
☐ HEART DISEASE – OFA CARDIAC
Explanation: Screens for congenital and inherited heart conditions that may affect quality of life and longevity.
Testing method: Board-certified veterinary cardiologist (auscultation ± echocardiogram)
Testing age: 12 months or older
Retesting: Not required if cleared by cardiologist
Results: ☐ Normal ☐ Abnormal ☐Echocardiogram Performed
Heart Disease – OFA Cardiac
A small proportion of Labradors may develop an inherited cardiac condition known as subvalvular aortic stenosis. Although the incidence in the breed is low, the condition can be serious. For this reason, all dogs considered for breeding should undergo a cardiac examination after 12 months of age by a board-certified veterinary cardiologist.
During the examination, the cardiologist performs auscultation using a stethoscope to detect any heart murmurs. If a murmur is identified, further diagnostic testing may be advised. Cardiac evaluations result in either a passing or non-passing determination, with non-passing results classified by murmur severity ranging from Grade 1 through Grade 6. Dogs with normal cardiac findings may receive OFA cardiac certification.
Swancor Kennels does not breed dogs diagnosed with hereditary heart disease.
ORTHOPEDIC & CLINICAL TESTING
05. OFA (CERF) Eye Examinations
☐ CAER EYE EXAMINATION (ANNUAL)
Explanation: Detects inherited and late-onset eye diseases that may not be apparent in young dogs.
Testing method: Board-certified veterinary ophthalmologist (CAER certification)
Testing age: First exam by 12 months
Retesting: Required annually for the lifetime of breeding dogs
Results: ☐ Normal ☐ Breeder Option ☐ Affected
According to the American College of Veterinary Ophthalmologists (ACVO), the following are the ten most common inherited eye diseases monitored in dogs:
- Keratoconjunctivitis sicca (KCS)
- Cataracts
- Lens luxation or subluxation
- Glaucoma
- Persistent hyperplastic primary vitreous (PHPV)
- Retinal detachment
- Retinal dysplasia (geographic or detached forms)
- Optic nerve coloboma
- Optic nerve hypoplasia
- Progressive Retinal Atrophy (PRA)
OFA eye certifications, formerly known as CERF examinations, are screening evaluations conducted by board-certified veterinary ophthalmologists. These examinations are designed to detect ocular changes that may indicate the presence of one or more inherited eye disorders. The assessment is performed after pharmacologic dilation of the pupils and includes indirect ophthalmoscopy and slit-lamp biomicroscopy.
Following the examination, the ophthalmologist completes the OFA Companion Animal Eye Registry (CAER) form, noting any specific abnormalities identified. The form is produced in three copies: one retained by the veterinarian, one provided to the owner, and one submitted to the OFA Clinical Database. Eye certifications are valid for 12 months from the date of examination, and annual re-evaluation is recommended.
Swancor Kennels does not breed Labradors affected by any hereditary eye disease.
DNA-BASED GENETIC TESTING (One-time tests – any age)
01.Exercise-Induced Collapse (EIC)
☐ EXERCISE-INDUCED COLLAPSE (EIC)
Explanation: Causes muscle weakness or collapse following intense exercise or excitement.
Testing method: DNA test
Retesting: Not required
Results: ☐ Clear ☐ Carrier ☐ Affected
Exercise-Induced Collapse (EIC) is a hereditary neuromuscular condition found in Labrador Retrievers. It is characterized by exercise intolerance in dogs that otherwise appear healthy. Affected dogs are typically identified before two years of age and usually perform normally during mild to moderate activity. However, following approximately 5 to 20 minutes of intense exercise, signs begin to appear.
During an episode, dogs may develop a wobbly, uncoordinated gait, most commonly involving the hind limbs. Despite the physical symptoms, affected dogs remain conscious, mentally alert, and do not experience pain. In some cases, the condition can worsen, leading to generalized weakness with decreased muscle tone (flaccid paralysis), disorientation, loss of consciousness, seizures, and, in rare instances, death. Episodes generally last between 5 and 10 minutes, with most dogs making a full recovery within 15 to 30 minutes.
Genetic testing classifies dogs as EIC Clear, Carrier, or Affected. Dogs that are Clear or Carrier will not show clinical signs, while Affected dogs will exhibit symptoms. To prevent the production of affected puppies, appropriate breeding combinations include breeding clear dogs to clear, carrier, or affected dogs; carriers only to clear dogs; and affected dogs only to clear dogs. The presence of an EIC Carrier status in a dog’s health clearances does not indicate that its puppies will develop the condition.
Swancor Kennels follows breeding practices designed to produce genetically sound Labradors.
DNA-BASED GENETIC TESTING (ONE-TIME TESTS – ANY AGE)
02. Dilute
☐ DILUTE (COLOR DILUTION GENE)
Explanation: Identifies coat color dilution genes, sometimes associated with skin and coat conditions.
Testing method: DNA test
Retesting: Not required
Results: ☐ Clear ☐ Carrier ☐ Dilute
The dilute gene is a hereditary factor that influences coat color. Under the American Kennel Club (AKC) breed standard, dogs that carry or express the dilute gene are not recognized as purebred Labrador Retrievers. Genetic testing categorizes dogs as Clear, Carrier, or Affected.
Carrier dogs display standard Labrador coat colors but have the potential to produce affected offspring if bred to another carrier or an affected dog. Affected dogs express coat color and pigmentation that fall outside the AKC breed standard.
Swancor Kennels does not breed Labradors exhibiting so-called rare colors, including silver, charcoal, or champagne...
DNA-BASED GENETIC TESTING (ONE-TIME TESTS – ANY AGE)
03. Retinal Dysplasia / Oculoskeletal Dysplasia (RD/OSD)
☐ SKELETAL DYSPLASIA 2 (SD2)
Explanation: A form of inherited dwarfism affecting normal bone growth.
Testing method: DNA test
Retesting: Not required
Results: ☐ Clear ☐ Carrier ☐ Affected
Retinal Dysplasia / Oculoskeletal Dysplasia (RD/OSD) is an inherited collagen disorder seen in Labrador Retrievers. The condition can result in visual impairment, dwarfism, and other physical abnormalities, with signs sometimes evident in affected puppies as early as 4 to 6 weeks of age. Dwarfism is marked by shortened front limbs that progressively curve as the dog matures. In young puppies, the skull may also appear more dome-shaped when compared to littermates.
Veterinary ophthalmic examinations can reveal a variety of eye abnormalities, most commonly retinal detachment and cataracts.
Genetic testing classifies dogs as RD/OSD Clear, Carrier, or Affected. Clear dogs will not develop the condition. Carrier dogs may, though not consistently, show mild retinal folds during a CERF eye examination but do not display other clinical signs of RD/OSD. Affected dogs will exhibit symptoms associated with the disorder.
Swancor Kennels does not breed Labradors that are affected by RD/OSD.
DNA-BASED GENETIC TESTING (ONE-TIME TESTS – ANY AGE)
04. Centronuclear Myopathy (CNM)
☐ CENTRONUCLEAR MYOPATHY (CNM)
Explanation: Inherited muscle disorder resulting in weakness and abnormal gait, often from a young age.
Testing method: DNA test
Retesting: Not required
Results: ☐ Clear ☐ Carrier ☐ Affected
Centronuclear Myopathy (CNM) is a hereditary, progressive muscle disorder found in Labrador Retrievers. The severity of the condition varies, but affected dogs commonly begin showing signs between 6 weeks and 7 months of age. Early symptoms often include reduced exercise tolerance, an uncoordinated or abnormal gait, and difficulty eating. As the condition advances, dogs may develop generalized muscle wasting, lowered muscle tone, and a characteristic downward flexion of the head and neck. Episodes of collapse may occur more frequently, particularly when the dog is exposed to cold temperatures.
Disease progression generally stabilizes by approximately one year of age. Although affected dogs typically have a normal life expectancy, they often experience ongoing medical issues related to the underlying muscle disorder.
Genetic testing classifies dogs as CNM Clear, Carrier, or Affected. Dogs that are Clear or Carrier will not develop clinical signs, whereas Affected dogs will exhibit symptoms of the disease.
Alleles: N = Normal, CNM = Centronuclear myopathy
Breeds appropriate for testing: Labrador Retriever
Explanation of Results:
- Dogs with N/N genotype will not have centronuclear myopathy and cannot transmit this CNM variant to their offspring.
- Dogs with N/CNM genotype will not be affected by centronuclear myopathy, but are carriers. They will transmit this CNM variant to 50% of their offspring. Matings between two carriers are predicted to produce 25% centronuclear myopathy-affected puppies.
- Dogs with CNM/CNM genotype will have centronuclear myopathy.
Swancor Kennels does not breed Labradors that are affected by CNM.
DNA-BASED GENETIC TESTING (ONE-TIME TESTS – ANY AGE)
05. Hereditary Nasal Parakeratosis (HNPK)
☐ HEREDITARY NASAL PARAKERATOSIS (HNPK)
Explanation: Causes chronic dryness, cracking, and thickening of the nasal tissue.
Testing method: DNA test
Retesting: Not required
Results: ☐ Clear ☐ Carrier ☐ Affected
Hereditary Nasal Parakeratosis (HNPK) is a genetic condition in Labrador Retrievers that results in abnormal overproduction of keratin affecting the nasal tissue. Clinical signs typically begin between 6 and 12 months of age. Affected dogs develop dry, coarse, gray to brown crusting on the tip of the nose, and in some cases, painful fissures may form. Lesions may also extend into the haired portion of the nose.
Dogs with HNPK are susceptible to superficial bacterial infections of the nasal tissue, and progressive loss of pigmentation is common over time. Aside from the nasal changes, affected dogs are generally healthy. The severity of symptoms can fluctuate throughout the dog’s life. While the condition is manageable, ongoing topical treatment is required to control recurring crust formation.
Genetic testing categorizes dogs as Clear, Carrier, or Affected. Clear and Carrier dogs do not develop clinical signs, whereas Affected dogs will exhibit symptoms associated with the condition.
Swancor Kennels does not include HNPK-affected Labradors in its breeding program.
DNA-BASED GENETIC TESTING (ONE-TIME TESTS – ANY AGE)
06. Degenerative Myelopathy (DM)
☐ DEGENERATIVE MYELOPATHY (DM)
Explanation: Progressive neurological disease causing hind-end weakness and paralysis in older dogs.
Testing method: DNA test
Retesting: Not required
Results: ☐ Clear ☐ Carrier ☐ At-Risk
Degenerative Myelopathy (DM) is a hereditary neurological condition associated with a genetic mutation known to occur in Labrador Retrievers. This mutation is present across multiple dog breeds, and in Labradors it remains uncertain whether all dogs carrying two copies of the mutation will ultimately develop clinical disease.
Differences in how the condition appears among breeds suggest that environmental influences or additional genetic factors may affect disease expression. The typical age of onset for degenerative myelopathy is around nine years. The disorder involves progressive degeneration of the spinal cord and is often compared to amyotrophic lateral sclerosis (ALS, or Lou Gehrig’s disease) in humans. Affected dogs generally show gradual loss of coordination and muscle wasting, most often starting in the hind limbs. While the condition is usually not painful, it is progressive and eventually leads to an inability to walk.
Genetic testing classifies dogs as Clear, Carrier, or At Risk. Dogs identified as At Risk are likely to develop symptoms during their lifetime, although the degree of severity can vary. It should be noted that the available genetic tests were not developed specifically for Labrador Retrievers, and questions regarding test reliability in this breed have been raised.
Swancor Kennels breeds only Labradors with a Clear DM status.
DNA-BASED GENETIC TESTING (ONE-TIME TESTS – ANY AGE)
07. Copper Toxicosis
☐ COPPER TOXICOSIS
Explanation: Leads to excessive copper accumulation in the liver, potentially causing liver disease.
Testing method: DNA test
Retesting: Not required
Results: ☐ Clear ☐ Carrier ☐ At-Risk
Copper toxicosis is a metabolic condition that disrupts normal copper balance within the body and may lead to chronic liver disease as well as neurological complications. In Labrador Retrievers, genetic testing is used to detect variants associated with an increased risk of developing copper toxicosis or, conversely, copper deficiency.
Swancor Kennels does not include "At Risk" affected Labradors in its breeding program.
DNA-BASED GENETIC TESTING (ONE-TIME TESTS – ANY AGE)
08. Stargardt Disease
☐ STARGARDT DISEASE
Explanation: Inherited retinal disorder causing early-onset vision impairment.
Testing method: DNA test
Retesting: Not required
Results: ☐ Clear ☐ Carrier ☐ Affected
Stargardt disease is a degenerative ocular condition characterized by the gradual deterioration of photoreceptor cells responsible for light perception. Dogs affected by this disorder experience progressive vision loss as they age, although some level of vision is typically retained throughout their lifetime.
Swancor Kennels does not breed Labradors affected by any hereditary eye disease.
DNA-BASED GENETIC TESTING (ONE-TIME TESTS – ANY AGE)
09. PROGRESSIVE RETINAL ATROPHY (PRA-prcd)
☐ PROGRESSIVE RETINAL ATROPHY (PRA-prcd)
Explanation: Degenerative eye disease causing gradual vision loss and eventual blindness.
Testing method: DNA test
Retesting: Not required
Results: ☐ Clear ☐ Carrier ☐ Affected
Progressive Retinal Atrophy, specifically the progressive rod–cone degeneration form (PRA-prcd), is a late-onset inherited eye disease affecting Labrador Retrievers. The condition results from degeneration of the retina’s photoreceptor cells, beginning with the rod cells. Affected dogs typically first experience reduced vision in low-light conditions and loss of peripheral vision. As the disease progresses, night blindness worsens and visual impairment becomes evident even in bright light.
Dogs with PRA-prcd may not show clinical signs until later in life and may have been bred before the disease is identified. A standard OFA/CERF eye examination alone is insufficient to diagnose PRA-prcd and cannot identify carriers. For this reason, genetic testing is essential. Dogs are classified through DNA testing as Clear, Carrier, or Affected. Clear and carrier dogs will not develop clinical signs, while affected dogs will experience vision loss.
Swancor Kennels does not breed Labradors affected by any hereditary eye disease.