Legacy AHT Vizsla Health Day

Please see also our Glaucoma page

a wonderful programme for the day – click flyer below to read more

Animal Health Trust
Vizsla Day
Talks & DNA Collection Day
6thNovember 2015

The Animal Health Trust continues its ground breaking research for many breeds that are affected with the multitude of different inheritable illnesses. Friday saw the Vizsla day –firstly to continue to collect DNA for the Glaucoma research and secondly to give us an overview of the research being done and further insight into some of the Vizsla diseases.

Dr Cathryn Mellersh- Head of Canine Genetics-
A leader in the Canine Genetics field gave us brief outline of the AHT work, and that its core being is to prevent illness & injury in companion animals. i.e. – cats, dogs & horses an occasional rabbit!! and a few exotic animals.
As a Charity their sole funding is from donations and their fund raising events. The Kennel Club is also one of their main sponsors for the research they do along with some other large names in the Canine world and the many breed clubs whose breeds they are trying to help.

Myositis- Dr Oliver Forman- (Postdoctoral Geneticist)

VIEW

He gave us description of Myositis and the signs & symptoms which many of us who have looked at the Health page on the Vizsla Club web site will be familiar with.
The geneticists have received to date 478 samples with 46 VIP confirmed. A variant has been found in the gene structure but this is just the first step.

Average age for onset is 3yrs. However can be 18mths- 8yrs.
There is currently enough funding for 144 samples to go forward for Genotyping..
The geneticists will check these against samples from healthy dogs and search for mutations that cause or increase the risk of the disease.

All the 2.4billion letters that make up the dog genome have been identified; so we could understand the enormity of the numbers involved, Oliver likened it to putting them on the pages of a book which would take up 2.4million pages.

Ataxia-
Is loss of balance/ head tremor- the head tremor is worse when the dog tries to focus on an object.
Onset can be from 2-3mths of age. It is progressive and there is no known treatment. Rare in the Vizsla. There have been two reported in the UK, but more worldwide.
The area affected is the Cerebellum which is located at the base of the brain – the name means “little brain”. It is responsible for motor control (it activates & coordinates muscle control) it does not initiate movement but contributes to the coordination.
Again they are looking for variants but the change could be just one letter in the 2.4billion.
There will be a report to the breed club in the near future. Because technology is advancing rapidly tests are being developed more quickly than ever before.
We were reminded that for all health problems- transparency and honesty are the key words for us.
Epilepsy- Dr Fabio Stabile- Neurology Clinician.

Epilepsy is –Abnormal firing of neurones in the brain. There becomes an imbalance in neuronal excitement and inhibition and this causes the seizure.
Seizures are a clinical sign not a disease in its own right.

Generalised Seizures- As the name implies – affects many areas of the brain. The dogs can collapse, urinate, defecate & foam at the mouth.

Focal Seizures- Are where specific areas of the brain are affected. It may show with a head twitch or a single limb maybe affected.

Complex Focal Seizures- The dog may hallucinate for example, may think a fly is pestering them catch it and can be seen to eat the imaginary fly –very real to the dog.

Isolated Seizures- As the name implies –only occasionally happen.

Cluster Seizures- Need to be 1 or 2 within 24hrs, if 3-4 a day it becomes an emergency situation.

Status Epilepticus- seizures last longer than 5mins and one fit rolls into another, again this is an emergency situation.

Dogs & bitches are equally affected. Average age onset 3yrs.

Causes:-
Reactive- Due to ingestion of toxins, liver disease, diabetes etc.

Structural-
Could be a tumour, other brain abnormalities or inflammation of the brain such as Encephalitis.

Idiopathic Epilepsy –
Can only be given this name when all other causes have been eliminated. It is the most common chronic canine disorder.
0.6%- reported epilepsy in UK in Vizslas
0.62%- Prevalence in all breeds in the UK
Onset can be from 6mths to 6yrs.

The underlying cause dictates the treatment. New thinking is if one seizure every 6mths then medication should be started. Investigations should start early and not wait as possible outcome may be better if medication required – but far from guaranteed.
Canine Glaucoma & the AHT‘s Research- James Oliver- Head of Ophthalmology

Every year 1,500 dogs all breeds develop this painful disease.
Some of the most commonly affected breeds are Flat Coat Retrievers, Welsh Springer Spaniels, Golden Retrievers and Leonberger’s.
The Vizsla is at present on the “B” list which is an “At Risk list/ known in the breed”

Due to the poor fluid drainage pathway within the eye, pressure builds up and causes pain as it is a closed structure when this happens pressure is put onto the Retina and Optic nerve leading to eventual loss of sight apart from extreme pain.

There are two types-

1) Secondary Glaucoma-
This can be due to bleeding within the eye due to trauma, inflammatory process, tumours, and luxation of the lens of the eye.

2) Primary Glaucoma-

a) Open Angle- Initially responds to eye drops but will eventually progress to blindness. Is less common and fewer breeds worldwide affected. The drainage angle when examined can look normal. The breed most affected in the UK is the Petit Basset Griffon Vendeen.

b) Closed Angle- Many more breeds affected, on examination the drainage angle in the eye is abnormal.

Both types, painful, blinding, treatment is expensive and difficult to treat.
Most dogs require removal of the eye to prevent further pain.

One breed that has benefited from the research is the Basset Fauve de Bretagne. In October 2014 the scientists had found the gene responsible and by January 2015 they had developed a test for it.

40 breeds worldwide affected with Primary Closed Glaucoma. In the UK 15 breeds which relates to 1,500 dogs –which eventually leads to loss of one or both of their eyes to the disease.

Onset can be very sudden. The dogs behaviour may change due to the extreme pain. The eye may look congested around the white area (Sclera) the centre part of the eye (pupil) may have a bluish tinge.

The risk factor CAN be screened for and affected dogs removed from the breeding programme.

Treatments-

Medical- Eye drops may be tried and may reduce the production of fluid in the eye and increase the drainage of the fluid.

Surgical-
a) Can try and destroy the fluid production part in the eye (Ciliary Body) with laser.
b) A tiny valve can be inserted within the eye to aid drainage.
c) Removal of the affected eye

The closed angle Glaucoma has a high inheritability, likely to be more than one gene involved, therefore complex inheritance.

If the abnormality of the angle is 20-25% or above then breeding is advised against from this dog.
There may be a possibility to breed to a clear, but we need full breed appraisal from the geneticists before this should be undertaken.
For breeds on Schedule “A”, new thinking is that they may require retesting 3 yearly as in Flat Coat Retrievers.
The Research will compare DNA from dogs –
1) From dogs that have clear eyes and are 5yrs and over
2) Dogs with Pectinate Ligament Dysplasia (PLD) as there is a positive association between this and Glaucoma.
3) Dogs with Primary Glaucoma.

For the Vizslas so far tested -110 dogs approx. lower than 10% affected, so as breeds go we are the best breed tested so far , but we must keep it that way and know what we are breeding from and further reduce or eliminate this painful disease.
Research costs-
To look at entire DNA from 5 dogs cost £300 per dog therefore £1,500.
To then fine comb the DNA is £2000 per dog.

It is hoped one breeds research may help another breed, but more samples are needed so we must continue to test our dogs’ eyes and donate our Vizslas DNA for this worthwhile research.

Quinn the Vizsla featured on the flyer for the Vizsla Day was spoken of as he really is the ambassador for this disease having lost one eye and had a valve inserted into the other 2yrs ago, James said it was a remarkable achievement that it has lasted so long and been so successful – long may that be so for this lovely boy.

BVA Hip & Elbow Scheme- Dr Ruth Dennis- Head of Diagnostic Imaging and Chief Scrutineer for the BVA Panel.

Ruth being the last speaker as always happens, was left with less time than we hoped for, but managed to deliver a lot of information on the hip scheme and Hip Dysplasia, but sadly had to compress the talk on Elbows but we managed a few questions at the end.
First she explained about the BVA scoring as there are a lot of myths about how they get to the result they do.
The sessions have two panellists who independently score the same submitted image, and should end up with virtually same score.
For quality control every week, two identical images are given to pairs of scrutineers and results are compared to maintain a high standard of scoring.
All scrutineers are qualified to the equivalent of a Consultant Radiologist in Orthopaedics in the human field and there are 10 of them.
The scheme was started back in 1984 with the German Shepherd breed.

HD (Hip Dysplasia) is thought to be 60% Genetic and 40% Environmental. If there is a laxity in the hip joint it does progress as the dog ages. Ruth went on to say that we should remember the image taken is only a moment in time. Although we can get the X-Rays’ done at 12mths old she feels that it does not necessarily give the true picture. As the score maybe lower than it would have been be if we had waited until the dog had matured which ideally is around 14-15mths approx. The score then would be a more accurate one.

The X-Ray (Most are submitted these days as digital images)
Should show the hips in a good position – i.e. the picture should be symmetrical the femora parallel and rotated inwards.
The panel are rejecting many more these days because of bad positioning. Some of the rejected images were shown to us and it is incredible that they actually came from Vets.
There has now been software developed to measure the Norburg Angle so there is no possibility of human error or misinterpretation.

Scoring Criteria-
0-10- Minimal Changes near perfect
11-20- Borderline to mild HD
21-30- Moderate HD
31-50- Marked HD
51-112- Severe to Gross HD

The BVA web site has a much more information on these schemes and well worth a look, also there is information on how a breed’s average score is reached.

Interestingly only one cat breed suffers from HD and that is the Maine Coon.

Elbow HD was discussed briefly as I said earlier, but what came over clearly was that we should not breed from a dog with an Elbow Score of 1- unless we can go back several generations which many cannot in this breed. Even then it should only be done with discussion with Geneticist and Orthopaedic input.
Maybe now is the time to routinely have the Elbow scored when we have the hips done on our breeding stock.

The day was extremely well planned, we were made to feel very welcome by everyone. We all came away I am sure with more knowledge than when we arrived.
We should feel privileged that such a prestigious Charity as the AHT is taking steps to help this breed rid itself of some of its diseases and I hope we will show the willingness we have shown with the DNA collection for the Glaucoma Research, if we are called on again as a breed for further research.
If you have not been to the AHT it is well worth a visit –there are lovely dog walks well marked, a gift shop and coffee shop where you can get a hot meal. The web site also tells you of forth coming events.

Sue Millson
Breed Health Coordinator

Please see also our Glaucoma page