Tollers and Health Issues

Much like any breed, Nova Scotia Duck Tolling Retrievers face health issues. However, this club has a long history of trying to meet these issues head-on and working to eliminate the most severe problems.

Jamie Klein, Chair of the Toller Health Committee, has developed the following series of articles to provide information on a variety of tests and health issues that may affect our breed. Knowing the health status of the dogs in a breeding program and others in its lineage allows breeders and genetic counselors to decide which pairings are the most appropriate for reducing the incidence of disease and disorders in the offspring. By using the data submitted to public registries breeders have access to a wealth of data when  determining which dogs are best for their breeding program.

Following is a list of health tests currently required or recommended for screening Tollers in a current breeding program, including links to the various health registries and organizations as well as a detailed article on each subject.

The dog has a Normal Companion Animal Eye Registry (CAER) Exam performed annually clearing the dog of hereditary eye problems by a board certified ophthalmologist.

The dog`s hips are X-rayed and evaluated by the board certified radiologists at Orthopedic Foundation for Animals  when the Dog is at least 24 months of age and/or by PennHIP.

OFA maintains the database. It is encouraged to make all results open to the public.

The dog’s elbows are X-rayed and evaluated by the board certified radiologist at OFA for elbow dysplasia Radiographs determine the presence of pathology involving the medial coronoid of the ulna (FCP), osteochondritis of the medial humeral condyle in the elbow joint (OCD), and an ununited anconeal process (UAP).

NOTE – OFA offers a discount for HIP Dysplasia and ELBOW Dysplasia evaluation when submitted together 

An OFA Thyroid Panel test is recommended for any dogs in an active breeding program. A list of approved labs for blood testing for thyroid status can be viewed here. The results of testing by these laboratories are accepted by OFA and can be included on its database. Screen annually from puberty; test females during anestrus.

The dog is Certified Normal for Cardiac disease via an OFA Heart certification (to be performed by a Practitioner/Cardiologist/Specialist) after 12 months of age to rule out congenital defects. An Echo Ultrasound Heart Analysis and/or Holter 24-48 monitoring of the heart’s electrical activity would be the
ideal heart evaluation protocol.

A physical exam by the veterinarian or specialist will determine the presence of luxation, whether it’s unilateral or bilateral, and to what degree. This evaluation can be done on any dog over 12
months of age. 

Once all the dog’s adult teeth have erupted, a physical exam can be done to determine the presence or absence of teeth, if there are any retained deciduous teeth, or if there are any supernumary

NOTE – OFA offers a Mixed Soft-Tissue Database Discounted Individual Rate per application when three
or more soft tissue applications are submitted together on a single dog (example: Cardiac, Patella, and
Eye applications) – this discount does NOT apply to any applications requiring radiographic evaluations

There are other phenotypic evaluations available for certification by OFA.

The dog has been DNA tested by approved labs  to determine status for:

  1. Progressive Retinal Atrophy RCD4 (PRA)
    Genetic testing of the PRCD gene in Nova Scotia Duck Tolling Retrievers will reliably determine whether a dog is a genetic carrier of PRA-prcd. PRA-prcd is inherited in an autosomal recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease.
    Orthopedic Foundation for Animals (OFA)
    Paw Print Genetics 
  2. Collie eye anomaly and choroidal hypoplasia CEA/CH
    Collie Eye Anomaly (CEA), also known as choroidal hypoplasia (CH), is an inherited disease affecting several dog breeds including the Nova Scotia duck tolling retriever.
    Paw Print Genetics
  3. Degenerative Myelopathy (DM)
    Degenerative Myelopathy is a debilitating disease that causes gradual paralysis in many dog breeds. It is caused by a degeneration of the spinal cord that onsets typically between 8 and 14 years of age. This DNA test can be tested on any breed, but some breeds show a clear genetic risk for producing the
    Orthopedic Foundation for Animals (OFA)
  4. Degenerative Encephalopathy (DE)
    Dogs with DE show neurologic signs beginning at a young age. These signs become progressively worse with age and most affected dogs have been euthanized due to poor quality of life by 3-5 years of age. Though this is a devastating disease, it does not appear to be common in the breed.
    Researchers at the University of Missouri have found a genetic mutation that is highly associated with
    DE. A DNA test for this mutation will permit the detection of dogs that have inherited two copies of the
    mutation and are at risk for developing the disease
    Orthopedic Foundation for Animals (OFA)
  5. Juvenile Addison’s Disease (JADD)
    The juvenile form of Hypoadrenocorticismcan be expressed in tollers between 8 weeks and 12 months of age when the adrenal glands stop secreting the body’s natural steroid hormones necessary for the regulation of the blood’s electrolytes sodium and potassium. The general clinic signs are lethargy, anorexia, vomiting, and diarrhea, and eye problems. Addison’s disease is diagnosed with the ACTH Stimulation Test performed by the veterinarian.
    UC Davis
  6. Cleft Palate 1 (CP1)
    A cleft palate is a birth defect whereby a hole (cleft) in the roof of the mouth (palate) develops in a puppy during gestation. There are multiple genetic causes of cleft palate within the Nova Scotia Duck Tolling Retriever breed; however, the most common form has been identified as CP1.
    UC Davis
  7. Cleft Lip/Palate/Syndactyly (CLPS)
    Another genetic variant that causes a second form of cleft lip and cleft palate called CLPS has been identified by scientists from the Bannasch Laboratory at the University of California, Davis and the Wade Laboratory from the University of Sydney.
    UC Davis 
  8. Chondrodystrophy and Intervertebral disc disease (CDDY and IVDD)
    CDDY includes a short-legged phenotype and abnormal premature degeneration of intervertebral discs leading to susceptibility to Hansen’s type I intervertebral disc disease (IVDD). Testing for the CDDY variant in Tollers can help breeders determine if CDDY is present among breeding stock and to identify dogs at risk for IVDD.
    UC Davis
    Gen Sol
    Paw Print Genetics
  9. Buff/Dilute Coat Color (D Locus/Blue)
    Buff is a disqualifying feature for the show ring but otherwise appears to cause no health issues in the breed.
    UC Davis
  10. Cerebellar Degeneration and Myositis Complex (CDMC)
    CDMC is a serious condition that can effect the cerebellum region of the brain and lead to a loss of coordination and balance. Affected dogs develop first symptoms at the age between 10 weeks and 6 months.
    UC Davis
  11. CLAM (Cardiac Laminopathy)
    Cardiac Laminopathy is a fatal heritable condition that results in dilated cardiomyopathy and sudden death in young adult Nova Scotia Duck Tolling Retrievers.  Affected dogs are homozygous for the variant and present with sudden death associated with dilated cardiomyopathy (DCM). No treatment is available at this time and the condition is typically lethal in young adult dogs. Affected dogs studied to date experienced sudden death by 1.5 years of age.  This research is not yet published, however the genetic variant causing this disease was recently discovered by Dr. Bannasch at UC Davis in the School of Veterinary Medicine and she has shared this finding with the VGL pre-publication so that we can more rapidly offer genetic testing to toller breeders as soon as discoveries are made.
    UC Davis 2023 Toller CLAM Update

NOTE – UC Davis Veterinary Genetics Laboratory offers a Nova Scotia Duck Tolling Retriever – Panel
which offers JADD, CP1, CLPS,DM, CDDY/IVDD, and Dilute DNA panels at a multiple test discount

OFA will issue clearances to untested offspring if the sire and dam have both been DNA tested “CLEAR,”
the test results have been OFA registered, and if all three (sire/dam/offspring) have been DNA identity
profiled and parentage verified. These offspring will be certified Clear by Parentage “CBP” and only the
first generation will be cleared.

“Unfortunately, liver shunts have been present too often in my line as well as with other tollers.  I have been in contact with Bannasch Laboratory to see what we can do to help genetically identify this disease.  We need bloodwork from affected tollers, parents of tollers with shunts, and non-affected siblings.  I would appreciate everyone’s help on this.  If you have a toller that fits one of the categories above, please contact me personally and I will speak with you about what is needed.  Your help can really make the difference in working to conquer this illness!”

Alyson Casper
Cyon Tollers
NSDTRC-USA National Rescue Coordinator
Phone: 954.424.8194

Washington State University performs this test and they have indicated that Tollers are not listed as a breed affected by the mutation because the breed has not encountered a positive result to date.

Orthopedic Foundation for Animals
When completing forms for submission to the OFA public database, it is strongly encouraged to sign on the Authorization to Release Abnormal Results. This will allow the OFA to release the results of
its evaluation of the animal described on this application to the public if the results are abnormal. This will enable other breeders to follow pedigrees and familial lines in order to make educated decisions on their breeding program.

Please be sure to include all registration numbers (CKC AND AKC) in order for the database to link all related dogs accordingly and confirm the spelling of the dog’s name so that they can be looked up correctly. If there are any misspellings or information that needs to be updated, OFA can be contacted quite easily at


K9Data is an open database for pedigree information on Nova Scotia Duck Tolling Retrievers. The database is a licensed work of Amy Burzynski and an amazing tool for the public. The data here is editable by many breeders and can be viewed by anybody. By combining resources, the set of data that is available is larger and new/corrected information can proliferate to more people more quickly. K9Data doesn’t replace the private pedigree database; it supplements it.

It is strongly encouraged to list all tollers and any health clearances, concerns, cause of death, notes of interest for others to access. Be sure to include all registration numbers (CKC, AKC, etc) in order for the database to link all related dogs accordingly. Be sure to spell the dog’s name correctly so that they can be looked up and found very easily. The registry data can be used by breeders in determining which dogs are best for their breeding program. Knowing the status of the dog and the status of the dog’s lineage, breeders and genetic counselors can decide which pairings are the most appropriate for reducing the incidence serious conditions in the offspring.

K9Data is not a registry. Registries are organizations like the AKC, UKC, CKC, KC, etc., which register dogs for a fee and keep extensive pedigree records. This is merely a database. Most of the dogs in this database are probably registered with one or more registries, or they may not be registered at all. Any registered user, not just the owner or breeder of the dog, may enter pedigree information. We do not review the information and we make absolutely no claims as to its accuracy. K9Data is a good place to
start your pedigree research, but if accuracy of information is important, you should independently verify the accuracy of the information you find.

To verify the accuracy of pedigree and other information, here are some useful sources:

  • Registries like the AKC, CKC, UKC, etc. can be used to verify pedigree information for registered dogs.
  • Health clearances may be verified at health registries such as OFA.
  • The breeder(s) and/or owner(s) of the dog may be consulted.

This database consists entirely of information provided by end users. The providers of this site hereby disclaim any liability for the accuracy or meaning of any such information provided in the site. Users hereby agree to use or rely on such information at their own risk.

We provide no warranty, express or implied, as to the accuracy of any such information, and user agrees to hold the site operator or any successor or representative thereof harmless from any claim of liability or damage resulting from use of any information provided for any purpose, personal or commercial.

If, when using this site, you discover information that is incorrect, please contact the appropriate administrator.

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