Toller Health

Search the breed browser for all health tests held by the NSDTR Club, including hereditary results
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Results of all health tests recorded by the Kennel Club are recorded on the breed browser for individual dogs, in addition if certificates are provided we will also record results from other tests.

The Kennel Club continues to work alongside breed clubs and breed health coordinators, in a collaborative effort to improve the health of pedigree dogs. The Kennel Club is happy to accommodate a club's request to add a new DNA test to its lists and would normally need a formal request from the breed's health coordinator or a majority request from the breed clubs.

These are all known potential health issues in the breed, however none of these issues are unique to Tollers. Providing that breeders take care to health test their breeding stock, and ensure that at least one parent is genetically clear for each of the recessive DNA tests, the incidence of health issues should be minimised.

PRA refers to a group of diseases that cause the retina of the eye to degenerate slowly over time. The result is declining vision and eventual blindness. "prcd" stands for "progressive rod-cone degeneration" which is currently the only type of PRA known in Tollers. The OptiGen prcd-PRA DNA test for Tollers became available in 2002.

There have been a total of 15 Tollers reported with PRA, either via the eye testing scheme or the DNA test, the youngest of these being born in 2007. Providing that breeders ensure that at least one parent is clear of the disease, we should not see any future cases. Use the search facility here to find dogs tested as clear, carrier and affected.

CEA is more technically known as Choroidal Hypoplasia (CH). It is a recessively inherited eye disorder that causes abnormal development of the choroid - an important layer of tissue under the retina of the eye. The OptiGen CEA/CH DNA test for Tollers became available in 2006.

There have been no known cases of CEA reported in the UK Toller population although we are aware of a number of Carriers. Providing that breeders ensure that at least one parent is clear of the disease, we should not see any cases. Use the search facility here to find dogs tested as clear and carrier.

Veterinary neurologists in Europe and America have recently recognised a new neurodegenerative disease in the Nova Scotia Duck Tolling Retriever (NSDTR). The disease is called Degenerative Encephalopathy with Sleep Disorders and Caudate Necrosis or simply Degenerative Encephalopathy (DE) for short. The term encephalopathy comes from the Greek words encephalo- (the brain) and -pathy (disease) and simply refers to a disorder of the brain. In this encephalopathy there 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 behaviour. In DE, this portion of the brain undergoes necrosis or complete destruction of the area. 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.

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, and dogs that have inherited one copy of the mutation and have the potential of producing puppies that will develop the disease. This test was made available in summer 2015.

At least 5 cases of DE have been reported in the UK Toller population to the breed health coordinator. A number of carriers from different lines have already been identified. Providing that breeders ensure that at least one parent is clear of the disease, we should not see any future cases.

Use the search facility here to find dogs tested as clear, carrier and affected.

Prcd-PRA, CEA/CH and DE have all been determined to be autosomal recessive traits.
The table below highlights all the desirable breedings that include at least one Normal/Clear parent. All other breedings are at risk of producing Affected pups with an extremely high probability of developing the disease during their lifetime. However, all dogs can be bred safely. It isn't necessary - or even desirable - to remove dogs from the breeding population. But when choosing pups to retain as potential breeding stock, it is important to select for Normal/Clear dogs and select against Affected dogs.

Expected results for breeding strategies using the DNA tests
Parent 1 Status	Parent 2 Status
Parent 1 Status	Normal/Clear	Carrier	Affected
Normal/Clear	All = Normal/Clear	1/2 = Normal/Clear 1/2 = Carrier	All = Carrier
Carrier	1/2 = Normal/Clear 1/2 = Carrier	1/4 = Normal/Clear 1/2 = Carrier 1/4 = Affected	1/2 = Carrier 1/2 = Affected
Affected	All = Carrier	1/2 = Carrier 1/2 = Affected	All = Affected

The DNA tests can be done reliably at any age, even in young pups, and the result will be the same whenever it is repeated. These tests therefore only need to be carried out once during the dog's life time.

Laboklin is a UK laboratory. Tests can be completed for both prcd-PRA and CEA/CH.

Animal Diagnostics is a UK laboratory. Tests can be completed for both prcd-PRA and CEA/CH.

The Kennel Club will recognise DE results, however owners will need to send a copy of the certificate to the KC in order to have it recorded.

Hip Dysplasia is a term which includes a number of specific developmental and other abnormalities involving the hip joint.

All radiographs submitted to the BVA/KC Hip Dysplasia Scheme are assessed by means of scoring. The hip score is the sum of the points awarded for each of nine radiographic features of both hip joints. The lower the score the less the degree of hip dysplasia present. The minimum (best) score for each hip is zero and the maximum (worst) is 53, giving a range for the total of 0 to 106. Tollers have scored between 0 and 70. The average score of the breed, or the 'breed mean score', is calculated from all the scores recorded for a given breed and is shown alongside its range thereby giving a representation of the overall hip status of the breed. Breeders wishing to reduce the risk of hip dysplasia should choose stock with scores on or below the Breed Mean Score (BMS). 901 Tollers have been scored under the scheme to date giving a current BMS for Tollers as 10.79.

The purpose of the Hip scheme is to reduce the incidence of the disease in dogs used for breeding. The minimum age of the dog at the time of radiography is 12 months; there is no upper age limit. Dogs may not be scored under the scheme more than once.

While breeding from dogs with good hip scores is recommended for reducing the risk of hip dysplasia it does not guarantee this as environmental influences also play a part. Exercise and feeding regimes for the young puppy can also make a difference.

Use the search facility here to find details of dogs that have been hip scored.

It is also possible to have the Annual Eye Test done through the European College of Veterinary Opthalmology http://www.ecvo.org/

Unlike DNA testing, this examination should be done Annually throughout the dog's lifetime by a veterinary ophthalmologist recommended by the BVA/KC. They cover all eye conditions that can possibly affect dogs. Please Note: Unaffected for GPRA on this certificate means that the dog is clinically clear of prcd-PRA at the time of testing only.

Distichiasis
Distichiasis is the abnormal growth of an eyelash or several extra eyelashes. This congenital disease affects the meibomian glands along the eyelid. In some dogs, the position of the eyelash has no effect on the dog and it is likely to go unnoticed. However, if the eyelash makes direct contact with the surface of the eye, the eye may suffer from microscopic scratches and irritation. Over time, these scratches can become infected and may predispose your dog into developing a corneal ulcer.

Distichiasis is also commonly associated with tearing of the eye, squinting or a painful eye, visible scratches or white spots on the surface of the eye as well as eyelid spasms. Dogs who are showing signs of distichiasis are usually taken to their veterinarian when an eye infection is suspected. Although these dogs respond well to treatment, the infections may recur and the offending eyelash may remain hidden under the eyelid. An ophthalmic examination is often needed to reveal the eyelash, although this examination may require sedation.

The permanent treatment of distichiasis requires the removal of the offending eyelash or eyelashes. Plucking the eyelash will only result in regrowth, so other methods should be considered. Cryosurgery, or the freezing of the lid margin, can be used to prevent hair regrowth as can other surgical procedures. The surgical procedure your veterinarian proposes will be determined by the number of eyelashes and the state of the lids themselves. In some severe cases, your veterinarian may refer you to a veterinary opthalamologist for treatment.

Distichiasis is recorded on the Eye Test Certificate but is not reported to the Kennel Club by the BVA. It is reported by the ECVO.

The recommendation is not to mate together two Tollers that have/had distichiasis.

Use the search facility here to find details of dogs that have been eye tested.

Canine degenerative myelopathy (also known as chronic degenerative radiculomyelopathy) is a progressive disease of the spinal cord in older dogs. The disease has an insidious onset typically between 7 and 14 years of age. It begins with a loss of coordination (ataxia) in the hind limbs.

DM is an autosomal recessive trait, with the same mode of inheritance as prcd-PRA, CEA/CH and DE.

There have been no known cases of DM reported in the UK Toller population although we are aware of a number of Carriers. Providing that breeders ensure that at least one parent is clear of the disease, we should not see any cases.

The Kennel Club will recognise DM results from OFA, however owners will need to send a copy of the certificate to the KC in order to have it recorded.

BVA/KC scoring scheme for elbow dysplasia (ED) was launched in 1998. Dysplasia means abnormal development, and the degree of elbow dysplasia present is indicated by a grade assigned to each elbow on a scale of 0 to 3 (0 being the best and 3 being the most severe). Only the highest grade of the two elbows is taken as the elbow grade for that dog. The minimum age for elbow grading is one year, and each dog is only ever graded once under the scheme.

Graded radiographs have shown that the majority of dogs with grade 1 elbows display obvious signs of unilateral and bilateral arthritis, therefore the current breeding advice from the BVA is as follows:

'It is strongly recommended that breeders wishing to reduce the risk of elbow dysplasia should select their breeding stock (both dogs and bitches) only from animals with an overall grade of 0. Dogs with elbow grades of 2 or 3 have marked osteoarthritis likely to be due to ED, with or without a visible primary lesion. Dogs with elbow grades of 1 show mild or early osteoarthritis which is also likely to be due to ED.'

Most Tollers who have been elbow scored have received a score of 0, however 9 dogs have received a score of 1, and 2 dogs have received a score of 2.

Use the search facility here to find details of dogs that have been elbow scored.

Heart testing can be carried out by a certified Cardiologist, if the Cardiologist is on the official Heart Testing panel then a Heart Testing certificate can be issued.
Heart disease is not considered a problem in the breed but a number of breeders choose to have this test done on their breeding stock.

Use the search facility here to find details of dogs that have been officially heart tested.

Addison's disease (hypoadrenocorticism) occurs when the adrenal glands stop secreting the natural steroid hormones (glucocorticoid) and hormones (mineralicorticoids) necessary for the regulation of sodium and potassium levels in the blood. Addison's disease can occur in any breed of dog and it has an average age of onset of 4 years. Addison's disease is diagnosed by a veterinary surgeon using a blood test called an ACTH stimulation test. The clinical signs of Addison's disease can include lethargy, inappetance, vomiting and diarrhoea.

In the NSDTR, a genetic form of this disease, called JADD, occurs in much younger animals. The average age of puppies affected with JADD is 5 months; however, puppies as young as 8 weeks and as old as 12 months of age have been identified.

All dogs who develop the juvenile form have two identical copies of a specific region within their genome. Scientists at Bannasch Laboratory at the University of California, Davis have identified numerous markers within this region and compiled these markers into a haplotype based test in order to identify dogs that carry JADD. They believe that in addition to the markers that distinguish affected puppies from unaffected ones, the actual mutation responsible for JADD is included in this haplotype test.

Since the exact gene resonsible for JADD has not yet been found, this test can only give results as 'Probable Clear', 'Probable Carrier' and 'Probable Affected'.

At least 2 cases of JADD have been reported in the UK Toller population, although the results are not officially recorded. A number of carriers from different lines have already been identified. Providing that breeders ensure that at least one parent is clear of the disease, we should not see any future cases. The test for JADD has been available since 2012.

Use the search facility here to find dogs tested as probable clear, probable carrier and probable affected.

The Kennel Club will accept results from the JADD test as of January 2020 but will not record hereditary clear dogs. More information can be found here.

This is a neurological condition. It may cause symptoms in puppies as young as 10 weeks, such as generalised ataxia (stumbling or lack of coordination), hypermetria (abnormal walking with front legs extending higher than normal), generalised weakness, exercise intolerance, episodic collapse, stiff gait and bunny hop movement.

There have been no known cases of CDMC reported in the UK Toller population although we are aware of a number of Carriers. Providing that breeders ensure that at least one parent is clear of the disease, we should not see any cases.

Use the search facility here to find dogs tested as clear and carrier for CDMC.

This is a serious heart condition. Affected dogs present with dilated cardiomyopathy at a young age and typically experience sudden death within the first year of age. There have been no known cases of CLAM reported in the UK Toller population. Providing that breeders ensure that at least one parent is clear of the disease, we should not see any cases.

Use the search facility here to find dogs tested as clear and carrier for CLAM.

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. Cleft Lip is a split in the lip and can occur on one or both sides of the mouth. Syndactyly is fusion of the middle two digits of the feet. There are multiple genetic causes of cleft palate within the breed; however, the most common form has been identified as CP1.

The club is aware of 1 case of CP1 and no cases of CLPS in the UK Toller population. Carriers of both have been reported.

Some breeders consider that cleft palate is a "breeder" problem as the affected puppy is normally put down soon after birth.

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.
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 mutation is sufficient to predispose dogs to IVDD.

This is a new test made available in October 2017, initial estimate is that 70% of the worldwide Toller population has at least one copy of the CDDY mutation.
The club is currently collecting results and from 524 UK dogs with reported results, 67.75% are free of the mutation.

Buff is a recessively inherited coat colour variant that occurs in the breed. Buff is an undesirable feature for the show ring but otherwise appears to cause no health issues in the breed. Puppies are born a lighter shade of red that can appear silver in colour. As they age they can sometimes darken to a more red colour but they are lighter than they would be without the effect of the buff mutation.

While not a health issue in itself, the test is currently offered by UC Davis. The correct colour test to order is Dilute (Blue).

It is also possible to test for other colours on loci A, B, D, E and K, see Wikipedia for further explanations.

The Kennel Club opened up the BAER (Brainstem Auditory Evoked Response) Scheme to all breeds in December 2015.

Deafness is not common in the breed, although there is some incidence of deafness in older Tollers. The club has been officially notified of 3 Tollers who were born deaf, two of which were tested under the BAER Scheme. We are aware there are others that have not been officially notified to the club.

The club accepts that there are auto immune mediated problems within the UK Toller population and is doing all it can to identify the genetic and environmental factors. The current state of knowledge is that there are family tendencies with a probable environmental trigger, but we would stress that research is ongoing at present. Breeders should be willing to discuss this with any prospective purchasers.

Auto immune diseases affect dogs of many breeds including crossbreeds and are not limited to Tollers. The most recent estimate is that approximately 5% of the Toller population may be affected.

Current advice from the club is not to breed from dogs who have been affected by one of these diseases, and not to repeat a mating which has produced it. Where a dog or bitch has produced multiple cases of auto immune, or has more than one sibling affected by one of these diseases, serious consideration needs to be given to the risk before making any breeding plans.

Epilepsy is a brain disorder that causes the dog to have sudden, uncontrolled, recurring physical attacks, with or without loss of consciousness. This may sometimes occur for unknown reasons (idiopathic) or due to genetic abnormalities. However, idiopathic epilepsy is often characterised by structural brain lesions and is more likely seen in male dogs. If left untreated, the seizures may become more severe and frequent.

Epilepsy is thankfully rare in Tollers, but affected dogs should not be bred from.

TOLLER HEALTH

Health tests required by the Assured Breeder Scheme

Health tests recommended by the Assured Breeder Scheme

Other health tests available

Other health issues