SOUTH AFRICAN IRISH SETTER HEALTH REVIEW 2016
DNA TESTING FOR ADVERSE INHERITED CONDITIONS
PROGRESSIVE RETINAL ATROPHY rcd 1 (PRA rcd 1) & CANINE LEUCOCYTE ADHESION DEFICIENCY (CLAD)
Progressive Retinal Atrophy rcd 1 is an early onset blinding condition. As a result of genetic research, The Kennel Club Centre of the Animal Health Trust (UK) developed the first canine DNA test in the 1990’s for PRA rcd 1 in Irish Setters. With the mating of tested CLEAR parentage it can be guaranteed their progeny would not develop nor carry the condition.
Initial research by Upsala University, Sweden led to the development of a DNA test for Canine Leucocyte Adhesion Deficiency (CLAD) a lethal auto-immune condition which gave pups in a litter little chance of survival as they were prone to any opportunistic infection. Like PRA rcd 1 the condition is also the result of a defective simple recessive mutant gene. In 1999 a more robust test was developed by the Animal Health Trust.
Testing Laboratories for both PRA rcd 1 and CLAD are available worldwide and in
South Africa is undertaken by Inqaba Testing Laboratory. Such results are recognized by The Kennel Union of Southern Africa and the UK governing body of dogdom, The Kennel Club. The local SA testing facility uses Whatman Cards which only require a few drops of blood collected from the ear of the dog by the breeder or Veterinarian for testing.
A properly structured scheme was instituted by a group of Irish Setter Breeders in South Africa in 2006 and proved highly successful, thus in the ten years of operation we can report:
351 (three hundred and fifty-one) Irish Setters currently appear on the PRA rcd 1 and CLAD National Registers as either DNA Tested Clear or Inherited Clear by virtue of tested ancestry. In 2010 Irish Setters were the first breed to be issued with The Kennel Union of Southern Africa Health Screening Certificates which is an annexure to the KUSA Registration Certificate and currently reflects the status of the parentage and the pup together with all other health screening results.
NO cases of PRA rcd 1 or CLAD have been reported and NO Carriers or Affected Irish Setters are currently recorded on KUSA Irish Setter Breed Registers or the group’s National Registers. Irish Setters imported into SA from anywhere in the world MUST be proven CLEAR of PRA rcd 1 and CLAD before Breed Registration will be effected by the Kennel Union of Southern Africa.
LATE ONSET PROGRESSIVE RETINAL ATROPHY rcd4 (LOPRA)
In the latter half of 2011 Animal Health Trust announced that a new form of Progressive Retinal Atrophy had been identified, initially in Gordon Setters and later in Irish Setters, which affected dogs showing rod cone degeneration (initially night blindness) beyond mid-life and blindness in later life. To distinguish this from any other form of PRA it is termed Late Onset Progressive Retinal Atrophy rcd 4 (LOPRA rcd 4).
Initially it was estimated that between 30 to 40% of Irish Setters were involved as Carriers in UK alone and this sent shock waves around the world as some very prominent sires were implicated.
From August 1st 2011 The AHT offered a DNA test to Irish Setter breeders and owners which examined the DNA of each dog being tested for the presence or absence of this precise mutation.
Previously the only means of diagnosis was Clinical Eye Examination by a Specialist Veterinary Ophthalmologist of affected dogs which displayed symptoms of blindness in later life (carrying two copies of the defective gene) Carriers (one copy of the defective gene) show no symptoms and would thus be considered clear on clinical examination. It is reasonable to assume that the mutation silently developed over a period of at least ten and probably nearer twenty years, before affected dogs were identified by Clinical Eye Examination in any numbers.
By DNA testing prior to mating any Irish Setters together the breeder acquires the knowledge to avoid breeding any pups that are LOPRA rcd 4 affected and reduce the number of Carriers, who will remain normally sighted. Those breeding clear tested mates together can guarantee Clear progeny.
CLEAR – These dogs have two normal copies of DNA. Clear dogs will not develop LOPRA rcd 4 nor pass defective genes to progeny
CARRIER – These dogs have one copy of the simple recessive mutation gene and one normal copy, they WILL NOT DEVELOP LOPRA rcd 4 but will pass one mutated gene to approximately half their progeny
AFFECTED- These dogs have two copies of the LOPRA rcd 4 gene (one inherited from each parent) and WILL GO BLIND in later life.
Steps were taken at the beginning of 2012 to institute a Scheme for South African breeders and owners. As is the case with CLAD and PRA rcd 1 proposals were made to the Kennel Union of Southern Africa to prohibit the Breed Registration of any imported Irish or Gordon Setter from being placed on the respective breed register unless DNA tested Clear or proven Inherited Clear (by virtue of being the progeny of tested clear ancestry) of LOPRA rcd 4. At that time the LOPRA rcd 4 status of local Setters was unknown, but it was necessary to protect SA’s limited gene pool from being further compromised. The proposals were approved by Provincial Councils and Federal Council and appear under KUSA Sch. 2 Appendix E.
Protocols and Procedures to be followed by owners/breeders participating in the Scheme were also compiled, distributed and are subscribed to on a voluntary basis. These, importantly, indicate that:
Ideally, only DNA tested CLEAR or INHERITED CLEAR parentage should be mated together to produce 100% INHERITED CLEAR PROGENY.
If a CARRIER is used for breeding purposes the following is mandatory:
ONLY CLEAR DOGS TO BE MATED TO CARRIER DOGS producing a litter which would average 50% LOPRA rcd 4 CARRIERS and 50% CLEAR progeny.
If such a mating is undertaken by a breeder it is obligatory to DNA test the ENTIRE LITTER after micro-chipping at SIX WEEKS of age. KUSA to be requested not to Breed Register such a litter until this process is complete.
All pups to be sold with Breeders Restrictions and it should be emphasized that LOPRA rcd 4 CARRIER pups from such a mating WILL NOT go blind.
LOPRA rcd 4 CLEAR Setter pups from such a mating can enter the breeding gene pool with impunity and should only be mated to clear dogs within the breed.
This pattern of CLEAR to CARRIER dogs must only be undertaken in exceptional circumstances and for a limited period NOT EXCEEDING TEN YEARS FROM DATE OF COMMENCEMENT OF THE SCHEME (2013)
Irish Setters DNA tested as AFFECTED should NOT BE BRED UNDER ANY CIRCUMSTANCES not to CLEAR and definitely NOT TO CARRIER dogs. They unfortunately will go blind and encourage the spread of the LOPRA rcd 4.
Those Setters DNA tested as CARRIERS should NOT UNDER ANY CIRCUMSTANCES be bred together (i.e.Carrier sire to Carrier dam) approximately a quarter of the litter will be AFFECTED.
To date the local Inqaba Genetic Testing Laboratory have been unable to offer a DNA test for LOPRA rcd 4 so initial testing was undertaken by the University of Missouri, America from DNA samples collected from Irish Setter owners and breeders prior to the end of 2012. Subsequently the testing laboratory was switched to Animal Heath Trust UK due to the tardiness of the University of Missouri in effecting the testing and providing proof of results. .
The first batch of 27 (twenty-seven) results were received in 2013 from Missouri University and were of great concern as it was revealed that the South African gene pool had been compromised and Carriers were identified albeit that there was only one dog affected – an import from UK which had not been used at stud. The balance tested Clear of LOPRA rcd 4.
The co-ordinators of the Scheme, Mark & Bridget Simpson, advised all those who had participated of the results and, in so far as could be ascertained the direction from which they inherited the mutant LOPRA rcd 4 gene.
All reports and results were subsequently forwarded to the Kennel Union of South Africa for capture on their data base and updated Health Screening Certificates were issued reflecting the status of each dog with regard to LOPRA rcd 4.
With great fortitude breeders accepted the results and have juggled their breeding plans to make the best possible use of LOPRA rcd 4 Clear Irish Setters to add to the pool of Inherited Clear pups. Thus we conclude 2016 with National Registers reflecting:
13.14% Irish Setters DNA tested Clear of LOPRA rcd 4
70.80% Irish Setters Inherited Clear
13.14% Irish Setters DNA tested Carriers
2,92% Irish Setters DNA tested Affected
A total of 137 Irish Setter KUSA Health Screening Certificates indicating the above LOPRA rcd 4 status of each dog have been issued.
Progress has undoubtedly been made since the commencement of the LOPRA scheme and most breeders have elected to breed only DNA tested CLEAR or INHERITED CLEAR partners to produce Inherited CLEAR progeny. DNA LOPRA testing has been thwarted this year by the South African Postal Services “snail mail” as Animal Health Trust post the saliva testing kits to participants. Owners are therefore using courier services to reliably deliver a dog’s saliva swabs to AHT for testing albeit that this adds to the costs.
Breeders have been hard hit by the fluctuating Rand to Pound Sterling exchange rate which currently stands at R18.07 to one Pound Sterling. Thus the AHT £40.00 cost of the LOPRA rcd 4 test per dog amounts to R 723.80. To this must be added courier fees to ensure safe arrival of samples for analysis at AHT. While expensive for South Africans, all remain committed to rid the breed of LOPRA rcd 4. .
Note The full Irish Setter National Registers of DNA Testing are available and will be e-mailed on request. These indicate the PRA rcd 1 – CLAD - LOPRA rcd 4 status of dogs and their progeny under the headings CLEAR – CARRIER – AFFECTED (Tested dogs) and INHERITED CLEAR dogs and progeny.
SPECIALIST VETERINARY OPHTHALMOLOGY
SAVA Clinical Eye Examination
Despite their being DNA tests which genetically identify Progressive Retinal Atrophy rcd 1 (early onset blindness) and LOPRA rcd 4 (late onset blindness) there are NO other genetic tests available for eye diseases in Irish Setters yet The Kennel Club Centre of Animal Health Trust in Newmarket, UK has reported that a third form of PRA maybe present, but the only way of diagnosis currently is by clinical examination by a specialist veterinary ophthalmologist of Setters which have been genetically DNA tested and cleared of PRA rcd 1 and LOPRA rcd 4.
Breeders and owners can also only rely on clinical eye examinations of their Setters for the diagnosis or clearance of such conditions as Entropion which manifests as the edge of one (usually the bottom) eyelid turning inwards to the eyeball which causes damage to the cornea, Posterior Polar Cataracts (particularly in Irish Red & White Setters) and a host of other mild defects which may or may not be inherited such as persistent pupilliary membrane.
Clinical examination with South African Veterinarian Association Certification is undertaken by Drs. Goodhead, Venter and Lo-An Odayar who commute between their Fourways, Johannesburg Animal Hospital (011-4651237) and Cape Animal Eye Hospital , Panorama (021-9036632). Clinics in the major cities of Durban and Port Elizabeth are also held periodically throughout the year.
SAVA Examination certificates can be submitted to KUSA for capture on their data base with the request for an updated KUSA Health Screening Certificate which is an annexure to the dog’s KUSA registration Certificate.
Further information can be obtained from KUSA website under Health Schemes and website www.animaleyehospital.co.za
KUSA/SAVA HIP & ELBOW X-RAY SCHEME for DYSPLASIA
No DNA test is available to determine the degree, if any, of Hip and Elbow Dysplasia in parentage prior to breeding thus no guarantee can be given by any breeder, in any breed, that progeny will be Hip and Elbow Dysplasia free. The best any breeder can do is join the KUSA/SAVA Control Scheme for diagnosis of Dysplasia whereby parentage of progeny are hip and elbow X-rayed and clinically scored by a panel of expert Veterinary Radiologists.
The commitment by the majority of Irish Setter breeders to enter the KUSA/SAVA Scheme has paid dividends. The overall mean average of Irish Setters Hip X-rayed and scored since the mid 1990’s when the scheme was opened to all breeds gives a mean average of B2:C1/C1:B2 but on review of the results in the last five years the average score has improved to B1:B2/B2:B1 interpreted under the FCI criteria as ‘near normal hip joints’ with almost half the number scoring A1’s or A2’s for each hip ‘No signs of hip dysplasia’.
KUSA Table illustrating interpretation between the “Old” South African HD Scoring System and the “New” SA internationally accepted FCI Scoring System
Over the years Countries and Continents developed various methods and symbols to indicate scoring results which need to be interpreted when imported dogs are being used for breeding or form part of a South African dog’s pedigree ancestry and although comparisons cannot be completely accurate the following table of the American Orthopedic Foundation of Animals (www.offa.org) to which has been added the “old” KUSA scoring system for Hip Dysplasia is a useful aid:
The addition of Elbow X-raying for dysplasia and scoring is a relatively new practice and is undertaken at the same time as X-ray of the hips while the dog is under anesthetic. In total twenty-five Irish Setters have been X-rayed, twenty-two in the last five years three had 0:1/1:0 scores which indicate ‘Minimal bone change along anoconeal process of ulna – less than 2mm while the balance achieved 0:0 scores ‘no signs of elbow dysplasia’.
Thus the breed is in good shape regarding Hip and Elbow Dysplasia, but only continued vigilance and commitment to X-ray and join the KUSA/SAVA Scheme will maintain this position.
On entering this Scheme there is agreement by owners that the results of scoring are forwarded by Onderstepoort’s Prof Kirberger, who heads the panel of scrutineers, to the Kennel Union of Southern Africa for capture on their data base and subsequent update of KUSA Health Screening Certificates which are conveyed to the owner
INBREEDING COEFFICIENTS (COI)
At the commencement of 2014 a new dimension to the breeding of healthy Irish Setters in South Africa was introduced thanks to the generosity of Miss Michelle Webster and her
Hooley Pedigree data base at www.hooley-irish-setters.co.uk to which she has added over1,250 KUSA registered South African Irish Setter pedigrees. As a result in addition to other relevant information each dog’s Coefficient of Inbreeding is expressed as a percentage by the Wright’s Coefficient Programme which is the same system used by the Kennel Club (London) for their Breed Mate Selection site.
This is particularly helpful to SA breeders who, of necessity, work with a relatively small genetic pool compared to those in UK and Europe. While most breeders understand that a mating between half siblings, or cousins represents inbreeding many do not understand which is the closest relationship.
Simply described “inbreeding” is that which results in progeny where the sire and the dam have common ancestry. The parameter used to express this common heritage, is called the INBREEDING COEFFICIENT and was first used by Sewell Wright in 1922. Designated ‘F’ by Wright, but more commonly known as COI by breeders, it ranges from 0 to 100%, the lower the percentage the less inbreeding. Obviously the greater number of common ancestors in the pedigrees of the parentage the higher the percentage of inbreeding.
To be as accurate as possible in calculating the COI of progeny currently bred the maximum number of ancestral generation are captured and to this end the earliest SA pedigree submitted for inclusion on Hooley’s data base dates back to an exported UK dog born in 1932 and imported into SA. Many more SA Irish Setter pedigrees of dogs imported or bred in the post world war II period have followed, up to and including those bred and KUSA registered in the course of this year. As a result breeders are now able to gain insight into the degree of inbreeding of prospective parentage by typing the name of
a South African dog into Hooley Pedigree search engine. As SA Irish Setters also have strong links to UK bred dogs it is also possible to access their ancestry and that of many other Setters around the world. 7.
The Kennel Union of Southern Africa have been approached to include the Coefficient of Inbreeding of SA Irish Setters on their data base and on the breed’s Health Screening Certificates, but as usual the wheels of KUSA turn slowly and we await the application of this information on these certificates.
No fee is applicable for this service.
KUSA ADVANCED REGISTRATION CERTIFICATE (ARC) FOR IRISH SETTERS
From the above it can be seen, that while South Africans face enormous challenges to effect health screening tests for their dogs, the majority remain committed to ensuring the future wellbeing and protection of the breed in South Africa.
Motivated by this quest a referendum was held during 2013 amongst all Irish Setter KUSA breeders and stud dog owners who were KUSA members to amend and update the existing version of the KUSA Advanced Registration Certificate for Irish Setters. At the KUSA Federal Council Meeting In December 2013 the New Advanced Registration was approved and became applicable at the beginning of 2014. This indicates the following:
1. Positively identified by tattoo, microchip or DNA;
2.Over twenty four (24) month of age;
3.A Kennel Union Breed Champion;
4.The registered name of the dog contains an affix (Kennel Name);
5.Hip X-rayed and scored under KUSA/SAVA scheme at or after 12 months of age for dysplasia and scored no worse than C2:C2
6.Elbows X-rayed and scored under KUSA/SAVA scheme for dysplasia at or after 12 months of age and scored no worse than 0:1/1:0;
7.Genetically clear (normal) of Canine Leucocyte Adhesion Deficiency (CLAD) either by DNA testing or by virtue of being the progeny of DNA tested parentage (inherited clear);
8.Genetically clear (normal) of Progressive Retinal Atrophy rcd 1 (early onset
PRA rcd 1) and Late Onset Progressive Atrophy rcd 4 (LOPRA rcd 4) either by DNA testing or by virtue of being the progeny of DNA tested parentage (inherited clear);
9.The holder of a valid SAVA Clinical Eye Examination Certificate (issued in the year of application for an ARC) stating ‘unaffected’ by any obvious eye disease or other disorder
In closing we wish to thank all owners and breeders for their co-operation during 2016 and the staff of KUSA, particularly Pascale Midgley (General Manager) and Cynthia Ross, who ensure the recording of data on KUSA systems and the issue of Health Screening Certificates so that all Irish Setter Health Screening Schemes run smoothly.
Irish Setter Health Screening Co-ordinators South Africa.