Breed Submission AVA-ANKC Aust. Canine Eye Scheme
15 March 2010
[Please distribute this report in its entirety to the specialist clubs catering for Welsh Springer Spaniels in all Australian States]
Breed Submissions under the AVA-ANKC Australian Canine Eye Scheme (ACES):
July 2006 – June 2009.
Dear Sir / Madam
As the members of specialist clubs catering for the Welsh Springer Spaniel breed across Australia will be aware, the AVA-ANKC Australian Canine Eye Scheme has been in operation for almost four years.
Qualified specialist ACES Panellists (appointed by the AVA Board) have conducted detailed eye examinations on adult dogs using standardised procedures as prescribed under ACES Rules, in addition to offering breeders a Litter Screening service for pups less than 12 weeks old.
Provided all submission details were in order and the dog’s identity was confirmed by microchip or tattoo, the results of these examinations have been issued to the owner / agent on the day, with a copy retained by the ACES Panellist and a copy also lodged with the AVA office in Canberra, where statistical results have been maintained in a form able to be reported to ANKC and the respective breed clubs.
ACES submissions have continued to grow at a steady rate since the Scheme was launched in July 2006, with full results summaries for more than 70 breeds posted to the AVA website (Community) and the ANKC website (Health & Welfare), covering each of the reporting periods 2006-07, 2007-08 and 2008-09. The official ACES Results table (produced at the end of June each year then ratified at the AGM of the ACVSc Ophthalmology Chapter in July) lists the breeds in order of numbers of adults submitted (expressed as a percentage of ANKC annual registrations) and provides a summary of the Schedule 1 and Schedule 2 conditions reported, other eye defects noted by the Panellists repeatedly and a summary of Litter findings.
Those eye conditions reported under Schedule 1 or Schedule 2 obviously differ from breed to breed and are maintained as a current listing in an Appendix to the ACES Guide to Owners, available as a download from the AVA website (Community). The ACES Guide to Owners provides comprehensive information about how to use the Scheme, including a full list of all serving ACES Panellists with contact addresses and phone numbers, State by State.
The fact that only two scheduled eye conditions are listed for your breed suggests that (based on the BVA-KC Eye Scheme’s experience in the United Kingdom, on which our ACES classifications have been based) historically the breed has been relatively free of congenital eye diseases, which is very encouraging. The number of ACES adult submissions in the 2007 and 2008 years were too small to mean anything really, but in the Welsh Springer Spaniel breed for the year ending June 2009, 31 adult exams were carried out Australia-wide, which was a creditable 41.9% of ANKC annual registrations for the 2007 calendar year – a better-than-average sample! Across the board for all breeds, ACES adult submission rates need to average more than 10% of annual registrations if they are to give us a reliable indication of the potentially vision-threatening conditions being reported in any particular breed, year by year.
A breakdown of significant eye defects reported in the Welsh Springer Spaniel:
Of the total of 31 adults presented in the June 2009 year, 8 revealed evidence of filtration angle changes and were recorded as ‘goniodysgenesis affected’. Seventeen achieved a ‘no lesions’ report but not all of these would have included a gonioscopic exam of the filtration angle, requested by owners as an optional test in addition to the standard ACES examination. While not yet formally entered, I can tell you that up until February this year a further 11 adult exams have been carried out, six of which showed ‘no lesions’. Repeat conditions noted by ACES Panellists included distichiasis and persistent pupillary membranes.
ACES does not report in detail on adnexal variations (i.e. to do with the lids and surrounding features), but in this breed where head and skull shape contribute to the desired expression, it is important to keep eye health to the forefront of a breeder’s priorities. As in all Sporting Gundogs, moderation is the key – the eyes should be neither prominent nor too deeply set, with both upper and lower eyelids fitting neatly so that the corneas are well lubricated by an evenly distributed tear film, that is then collected efficiently by the lacrimal channels (drainage system) to pass down through the tear ducts to the nasal cavity.
Distichiasis (abnormal or misplaced lashes) has been reported as a repeat defect but only in about six adults – not your biggest concern by any means, but something to be aware of nevertheless. While it is hard to predict a definite mode of inheritance and no-one is suggesting that dogs with one or two fine lashes should never be bred, it would still makes sense to try to keep track of dogs sold as pets and perhaps ask puppy purchasers to report back if at any time in the future, the eyes become irritated and watery. Hopefully, the breeder of any bitch with a history of producing distichiasis-affected puppies would then take the precaution of putting her only to a sire with a solid record for producing normal eyes.
ACES Panellists are aware of the concern amongst breeders over some lines being more predisposed to malformation of the aqueous outflow pathway and the possibility that this may lead to greater risks of vision loss due to obstructive glaucoma. As in all situations where similar concerns have been raised overseas, examining panellists have offered angle gonioscopy as a specialised ophthalmic diagnostic test, in an attempt to provide the owner with an indication of the degree of anatomic variation observed in the 360 deg. circumference of the filtration angle of both eyes. That is the purpose of the gonioscopy test – it is simply a measure of the structural changes observed, in an attempt to try to equate this with the subsequent risk of a sudden spontaneous obstruction to the normal passage of aqueous fluid through the front part of the eye. Why? Because any obstruction to fluid outflow soon leads to an acute rise in intraocular pressure (IOP) and that causes irreversible damage to the millions of vulnerable cells in the retina that transmit vision signals to the brain. Left undiagnosed, this will advance to visual blindness.
As reported above, out of a total of 42 adult dogs which brings us right up to date, 14 reported significant degrees of goniodysgenesis (i.e. narrowing of the outflow pathway around the circumference of the drainage angle in both eyes, or malformation of the meshwork with a reduced number of ‘flow holes’).
The reported incidence of degrees of goniodysgenesis amongst Welsh Springer Spaniels in Australia has caused uncertainty amongst owners as to whether or not this is a significant problem that breeders should be trying to avoid. Conscientious breeders in Australia have a very good record for taking positive action against potentially threatening health issues, and it is for that reason that I have been keen to deliver the above information as hard figures (available for the first time through an independently qualified survey), so that together we can now start to sort out what this actually means.
I am sure I reflect the views of all ACES Panellists in re-stating what we do and don’t know about glaucoma in the dog. It is a serious problem when it arises as a clinical disease for whatever reason, and because of frequent delays in confirming a diagnosis and commencing treatment, ophthalmologists expect to reverse the IOP rise in only half of the cases presented, with only half of these likely to retain vision one year later.
Of course, not all cases of glaucoma arise spontaneously, especially in older dogs – there are a number of other diseases or changes within the eye (e.g. slow-growing intraocular tumours) that will result in a gradual pressure rise and vision loss, even when the outflow pathway structures remain relatively normal. This should explain some of those cases reported from overseas where glaucoma has arisen in dogs in an older age group – having previously been assessed as ‘within normal limits’ on a gonioscopy exam.
Clearly, we need more data over a longer period of time before we can draw precise conclusions on the true ‘cause and effect’ relationship between the sort of abnormal variations we are able to pick up on a gonioscopy exam and the likelihood that this animal is therefore at a 50% or greater risk of developing glaucoma in one or other eye. All we can say is that any malformation that leads to a reduced outflow of aqueous and thereby compromises normal IOP regulation in the canine eye may predispose this particular eye to increased risk – but again that may depend on other age-related factors or concurrent events.
Recommendations:
Based on these results and bearing in mind the possibility of an unrepresentative sample over the three years that figures have been generated, I expect the ACES Panel would support a general recommendation that the Breed Clubs seek to encourage the participation of more Welsh Springer Spaniel owners especially if they have any plans to breed a litter, with the reminder that at least one mature age exam should be carried out between 18 - 24 months and preferably with gonioscopy requested. Secondly, all potential breeding stock (juveniles as well as adults) should be monitored for evidence of developmental anomalies inside the growing eye – in addition to the cataracts and goniodysgenesis that most breeders are already looking for. Thirdly, breeders everywhere should be encouraged to select against poorly fitting lids and distichiasis (abnormal lashes) in an effort to reduce these insidious problems over time.
Fortunately, once carried out in the fully grown animal at around 18 months of age, the gonioscopy test should not need to be repeated as the presence or absence of abnormal filtration angle structures is not expected to change significantly over time. Until we can ascertain the true risk relationships, it would seem prudent for the owners of any male Welsh Springer offered at public stud to be able to produce an eye specialist’s report on his gonioscopy status, so that any breeder (novice or experienced) planning a mating can match this information against the gonioscopy findings for the bitch before making their own decision, if necessary under the guidance of a qualified veterinary eye specialist or ACES Panellist.
Suggested frequency for repeat testing by an ACES Panellist:
It is probably not necessary to test every adult animal for emerging eye conditions every year, especially in this breed where most conditions are likely to have shown up by four or five years of age. The first adult exam should be carried out no later than 18-24 months of age then repeated at least every second year through to eight years. Any active breeding-age animal (dog or bitch) from which a litter is planned in the near future needs to be able to produce a current ACES Certificate, i.e. updated within the last 12 months.
Advice on Litter Screening:
There were no Welsh Springer Spaniel litters presented for pre-sale screening to the end of June 2009, which is not really surprising as apart from juvenile distichiasis, none of the more serious recognised defects are likely to be showing up at that young age. However that does not mean that Litter Screening at 8-10 weeks would not be worthwhile, for the reassurance it would give to new puppy owners, alone. Of course, the result recorded at this early age cannot be used as a permanent certificate – it is essential to re-test adolescent males and females retained for breeding, then through their active breeding lives.
Concluding remarks:
On behalf of all ACES Panellists, I congratulate those owners who have made a commitment to regular eye testing, especially in this breed where Club members do try to maintain fully verifiable standards amongst their selected breeding stock. Your numbers are still small of course, but the breed has great potential for much wider popularity and it would be good if we could encourage the highest possible participation in the uptake of organised eye testing as a routine procedure, important to the monitoring of canine health.
Yours faithfully
Dr Bruce Robertson
Chief Panellist, AVA-ANKC Australian Canine Eye Scheme.
Please Note: This report should be distributed to Club members and any interested non-members. It may be posted to On-line Newsletters or Discussion groups, but only in its entirety, please.