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.

Health Information Articles


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 matings are the most appropriate for reducing the incidence of disease and disorders in the offspring.

This document by the Orthopedic Foundation for Animals, Inc. explains the importance of using health testing in breeding programs. 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.

CAER Eye Exam

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.

Download Companion Animal Eye Registry PDF

Hip Dysplasia

The dog’s hips are X-rayed and evaluated by the board certified radiologists at Orthopaedic 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.

Download Canine Hip Dysplasia PDF


Progressive Retinal Atrophy (PRA) is a genetic eye disease that affects Tollers. Recent discoveries have given Toller breeders a DNA test to help to control this affliction. Learn more about it and the steps being taken by breeders to stop this heartbreaking disease below.

Unlike PRCD tests offered for other breeds, this marker test is specific for Tollers and results in a greatly reduced chance (0.05 percent or less) of false positive results. The test eliminates the guess work from a breeding program with respect to PRCD – the only form of PRA seen in Tollers which results in blindness. Breeders will no longer have to remove affected and carrier stock from their breeding programs. As long as these dogs are bred to clear dogs, they will not produce any affected dogs.

To order a Toller Progressive Red Cone Degeneration (PRCD) blood test: Detailed instructions are available from OptiGen’s website that explain how to ship a sample, request a test and information about the Toller PRCD test.

OptiGen Laboratory

The dog is rated Clear or Carrier with the OptiGen PRA and CEA/CH gene marker tests unless the PARENTS are DNA tested and this offspring is deemed Cleared By Parentage (CBP).

The owner agrees never to breed carrier or affected dogs that may produce Progressive Retinal Atrophy or Collie Eye Anomaly/Choroidal Hypoplasia.

These results can be included on OFA’s public database through submission of this document.

Download Optigen DNA Testing for PRA & CEA PDF


OFA Thyroid Panel test levels are within Normal limits as tested by IDEXX Laboratories, Michigan State University (MSU), OFA, or University of Guelph.  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.

[Hemolife can be used as an alternative lab but their results are not recognized by OFA at this time.]

Download Thyroid Testing PDF


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

Download Cardiac Clearances PDF

DNA Tests

The dog has been tested through the Orthopaedic Foundation for Animals to determine DNA status for:

  1. Cleft Palate 1 (CP1) unless the parents are DNA tested and this offspring is deemed Cleared By Parentage (CBP);
  2. Cleft Lip/Palate/Syndactyly (CLPS) unless the parents are DNA tested and this offspring is deemed Cleared By Parentage (CBP);
  3. Degenerative Myelopathy (DM) unless the parents are DNA tested and this offspring is deemed Cleared By Parentage (CBP);
  4. Degenerative Encephalopathy (DEN) unless the parents are DNA tested and this offspring is deemed Cleared By Parentage (CBP).

Futher DNA testing is conducted through the UC Davis Veterinary Genetics Laboratory:

  1. Juvenile Addison’s Disease (JADD) unless the parents are DNA tested and this offspring is deemed Cleared By Parentage (CBP);
  2. Chondrodysdrophy (CDDY) and Hansen’s type I Intervertebral Disc Disease (IVDD) risk; new for 2017 – information available at the link.
Download DNA Tests PDF

Multi-Drug Resistance (MDR1) Gene

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.

Download Multi-Drug Resistance Gene PDF

Ongoing Studies in Liver Shunt Research

“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

Public Databases

Public Databases for more information about Tollers and tracking health information, including:

Download Public Databases for General Information PDF

Testing Packages and DNA Labs

Orthopedic Foundation for Animals offers:

  • a Nova Scotia Duck Tolling Retriever panel which offers JADD, CP1, CLPS, and/or BUFF DNA panels at a multiple test discount.  (DM is currently not offered as part of the group DNA discount.)
  • a discount for HIP Dysplasia and ELBOW Dysplasia evaluation when submitted together
  • a Mixed Soft-tissue Database Discounted Individual Rate of $7.50 per application when three or more soft tissue applications are submitted together on a single dog (example: Cardiac, Thyroid, Patella, and Eye applications). This discount does NOT apply to any applications requiring radiographic evaluations.


This is a list of OFA approved  DNA Labs.

Please be aware that not every lab listed has the patent for specific DNA tests and therefore may not be OFA approved to have their results listed on OFA’s public database.

However, following is a brief summary of popular labs that are currently approved to perform the DNA tests relevant to our breed at this time.  This OFA form must accompany all results obtained from these facilities in order to be posted on OFA’s site.

Download Public Databases for General Information PDF

Health News & News Archive

October 2017: Health Testing updates

Jamie Klein, Chair of the Health and Genetics Committee has updated the articles and information regarding health issues and testing for breeding Tollers. For more information about any of these tests or documents, contact Jamie here

2017: Chondrodystrophy (CDDY and IVDD Risk)

From the UC Davis Veterinary Genetics Laboratory website:

Chondrodysdrophy (CDDY) is a trait that defines many dog breeds and is characterized by reduction of long bone length (shorter legs) as a consequence of early changes in the structure of growth plates. CDDY can also impact health of animals through an abnormal process that causes premature degeneration of the intervertebral discs.

The Chondrodysdrophy (CDDY) mutation was recently discovered by researchers in the Bannasch Laboratory at the University of California, Davis (Brown et al. 2017) as a second FGF4-retrogene insertion in dog chromosome 12.  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). The intervertebral disc, which sits between vertebrae, is composed of an outer fibrous basket (annulus fibrosus) made of 70% collagen and an inner gel-like layer called the nucleus pulposus. These structures allow for flexibility of the vertebral column. In Chondrodystrophic breeds, premature calcification of the nucleus pulposus at early age (from birth to 1 year of age) results in degeneration of all discs in young dogs. These abnormal discs are predisposed to herniation into the spinal canal where the inflammation, and hemorrhage can cause severe pain and neurological dysfunction (myelopathy) termed IVDD. IVDD has high mortality rate and high cost of surgical and medical veterinary care.

CDDY is inherited as a semi-dominant trait for height, meaning that dogs with 2 copies of the mutation are smaller than dogs with only 1 copy. With respect to IVDD, the inheritance follows a dominant mode, meaning that 1 copy of the FGF4-12 mutation is sufficient to predispose dogs to IVDD. Dogs that have both FGF4-12 and FGF4-18 show a more drastic reduction of leg length.  One area of current investigation is how CDDY and CDPA might work in concert to increase the risk of IVDD.

The Veterinary Genetics Laboratory offers the CDDY test for Nova Scotia Duck Tolling Retrievers (NSDTR or Tollers). Testing for this mutation can help breeders determine if CDDY is present among breeding stock and to identify dogs at risk for IVDD. Breeders can benefit from the test result to implement breeding strategies to reduce incidence of CDDY.

April 24, 2014: Requesting Blood Samples for Liver Shunt Research

The following is a request from a member of the NSDTRC-USA:

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 blood work 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

May 2012: OFA Now Offers DNA Testing for JADD and CP1

Scientists from the Bannasch Laboratory at the University of California, Davis have developed a DNA test available through the OFA to identify carriers of Juvenile Addison’s Disease (JADD) in the Nova Scotia Duck Tolling Retriever. They have also discovered the genetic cause of ONE FORM of cleft palate (CP1) in the Nova Scotia Duck Tolling Retriever.

Select this link to read the letter to the NSDTR Club of Canada from the Orthopedic Foundation for Animals (OFA) announcing that they now offer DNA testing for two important diseases, Cleft palate (CP1) and Juvenile Addison’s Disease (JADD) for the Nova Scotia Duck Tolling Retriever.

More information on tests and ordering can be found at these links on the OFA website:

February 2002:PRA Testing

On February 1, 2002, OptiGen Laboratory, LLC, a canine genetic testing laboratory began accepting and processing blood tests to determine – with 99% accuracy – if your Toller is clear, a carrier of, or affected with Progressive Retinal Atrophy (PRA).

This exciting new test, available world wide, is made available through the research of Dr. Gus Aguirre and colleagues of the James A. Baker Institute for Animal Health at Cornell University.

“The test is as close to perfect as a test can be without actually being a true gene test,” said Dr. Aguirre, Alfred H. Caspary Professor of Ophthalmology. Technically referred to as the Toller PRDC (Progressive Rod Cone Degeneration) test, the new procedure is a gene marker test that can predict with 99 percent accuracy a Pattern A (clear), Pattern B (carrier) or Pattern C (affected) Toller.

2001: Toller Health Coalition

In 2001 the Executive of the NSDTR Club of Canada formed the Toller Health Coalition (THC). The Executive of the NSDTR Club (USA) has wholeheartedly supported this endeavour. The mandate of the THC is as follows: “The mission of the Toller Health Coalition is to be leaders in the collection, research and dissemination of information, ideas, and knowledge of all issues related to Toller health. Our goal is to give members of the Toller community the resources and wisdom they need that will lead to ongoing and sustained health in their own breeding program and particularly in the breed as a whole.”

The Toller Health Coalition developed and sent out a Health Survey, the results of which are published on the companion website: Tollerhealth. Along with the Toller Health Survey, several other health concerns are discussed and explained.

Hip/Eye/Heart Open Registry

The NSDTR Club of Canada’s Hip/Eye/Heart Registry was in existence for over 20 years! Our early members were true pioneers with the inception of this project. Registries of any kind were few and far between and even fewer were in an open format.

On November 29, 1980 a meeting of the Club was held in conjunction with the Ottawa Kennel Club Show.  Present at this meeting were Executive members Alison Strang, Secretary/Editor; Linda Barnes, Treasurer; and members, Jim Barnes, Terry McGlashan, Brenda and Ken Stephens, and Ray and Trudy Stephens. The proposals made at that meeting were put to the membership by mail, and all proposals received approval in 1981, including: “Proposal 1: The club should establish a record of Tollers that have been x-rayed clear for hip dysplasia and certified either by OVC or OFA and examined clear for PRA and cataracts at regular intervals by qualified veterinarians.”

In the 1981 Summer Toller Talk, the first Registry list was published with seven dogs listed in the hip/eye section and six in the hip section. The importance of having proper paperwork to back up the listing was emphasized: “Barb (the Registrar at the time) stresses that dogs cannot be included in these listings unless photostat copies of certifications are received by her. Please let us keep this important file up-to-date.” The emphasis on accurate recording (backed up by copies of veterinary reports) has been maintained throughout the history of the Registry and is still paramount today.

By the early 1990’s it became apparent that only listing phenotypically normal dogs wasn’t providing breeders with a full picture, so in 1995 came the addition of known PRA Carriers and PRA Affected dogs. Also during the 1990’s came the addition of listings for Failed Hips and/or Eyes other than PRA and Date of ERG and Slitlamp. By 1995 there were 322 dogs in the Registry with four PRA Affected and four Carriers entered.

By 1998, now administered by Sue Kish, the Registry was flourishing. It exploded in size during Sue’s tenure as Registrar because of her determination to include all Tollers and because of Toller enthusiasts’ willingness to be open with their information. Individual owners/breeders were contacted personally and encouraged to submit copies of veterinary reports on all the Tollers that they had owned. In early 1999, there were 646 individual dogs in the database, with 55 dogs listed as PRA carriers, 35 affected with PRA and 10 with failed hips. It was during this time that it became evident that there may be a history of pulmonic stenosis in the Toller population and the Registry was expanded further by adding heart results, thus making the Hip/Eye/Heart registry that we have today!

The Registry has had a host of dedicated volunteers administering it, Barb Charais got it off the ground and stayed for two years,  Sheila Paul held the position for 10 years from 1983 – 1993.  In 1993 Lynn Vail took over and maintained the registry for three years until 1996 when Sue Kish came on board.  Cheryl Tomayer held the position from 1999 until she handed it over to Jamie Klein who is the current chair of the Health Committee.

Publishing the Hip/Eye/Heart Registry online allowed for the timely release of updated information and reflected the pioneering spirit of our early members.

However, times have changed and with the incredible improvements in genetic testing, there is no longer a need for the Club to maintain a list of clearances because of the public access to health clearance databases available today.

Currently, all tests and health clearances can be officially documented on the dog’s OFA page and/or on K9Data. The appropriate forms from OFA must accompany the submission of all test results to OFA.

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