SOME FREQUENTLY ASKED QUESTIONS AND ANSWERS

 

WHAT ARE THE SYMPTOMS OF L-2?

Symptoms can vary from dog to dog but basically there may be seizures of an epileptic style or you may see a change in the way the dog moves. Often after or during exercise (exercise intolerance), or in stressful situations the dog’s muscles begin to seize up and you would notice stiffness around the hind legs and an arching of the back, resulting in the dog being unable to walk normally. This can range from slight incapacity to almost total loss of co-ordination and the dog having full-blown seizures. There are other possible symptoms you may notice: an apparent loss of recognition of normal surroundings, staring at walls, appearing to have altered behaviour.

MY DOG`S BACK LEGS SHAKE WHEN HE`S STANDING STILL OR HE IS STIFF AFTER EXERCICE - DOES HE HAVE L-2?

Lots of Staffords have `muscle tremble` when they are standing - this isn’t indicative of L-2. If your dog is stiff after exercise ask yourself, has this always been the case or has it happened as he has become older (simple ageing) or following an injury (possible arthritis of a joint).

MY DOG APPEARS NORMAL - SHOULD HE BE TESTED FOR L-2?

If you have no concerns that your dog may have L-2 from the classic symptoms there is NO need to test unless the dog is going to be bred from. ALL breeding stock should be tested prior to the mating to determine it’s genetic status. You may think that as your dog has no clinical signs of L-2 that you don’t need to test but it is impossible to know whether or not your dog is a carrier of the rogue gene without the DNA test.

IS THIS A PROBLEM IN ONLY SOME BREEDING LINES?

ABSOLUTELY WRONG!  This is a problem in Staffordshire Bull Terriers, within the breed as a whole, not within any particular breeding line. The reason that initially only certain lines were showing the problem is because, having produced affected pups, responsible breeders within those lines joined the research for the DNA test. As testing is becoming more commonplace L-2 carriers are showing up across the broad in various `lines`. It is thought that this problem goes back probably over at least eight generations of Staffords - look at the majority of Stafford pedigrees and you will find common ancestry when you start delving back.

WHAT IS THE PROGNOSIS FOR AN L-2 AFFECTED DOG?

L-2 can vary from dog to dog, so in the worst case scenario the severity of the seizures can be so awful that the owner decides the best course of action for the dog is to have it put to sleep to save further suffering. The medication necessary to control the condition is anti-convulsant (phenobarbitone) and therefore strong and powerful, as well as expensive! It also needs to be administered at very regular intervals to have the correct effect. A dog on such medication needs a VERY regular routine to be able to live a normal life. Some more mildly affected dogs have lived without medication, owners dealing with the symptoms by keeping out of stressful conditions, maintaining an even keel so as not to stimulate seizures. Herbal tranquillisers have had effect. Similar to epilepsy, it can be progressive and have spells where the dog remains the same for a period of time, to later deteriorate.

WHAT IS THE DNA TEST?

The DNA test is a one-off test that will determine the genetic status of your dog. There are three possible outcomes of the test. It will be:

CLEAR (UNAFFECTED or NORMAL)-that is NOT affected by L-2,nor a carrier of the mutant gene which produces L-2

CARRIER - that is not affected by L-2 but carrying one copy of the mutant gene, which will be passed on to, on average, 50% of it’s offspring

AFFECTED - affected by the L-2 condition and carrying two copies of the mutant gene

HOW DO I GET MY DOG TESTED?

Testing is now simple - your vet needs to take 3mls of blood (this can be done while you are at the vets for any other routine procedure) and send it to the Animal Health Trust at Newmarket for DNA testing. The DNA test costs £60 and forms information on the test can be found on the AHT website (click here) or by contacting Vikki Lett, Genetic Services, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk. CB8 7UU. Tel: 01638 750659 ext. 1223.

When research was underway urine samples were used to determine whether or not the dog was affected (not for carrier status) - this is no longer applicable

In the future testing may be via buccal (cheek cell) swab rather than blood but for the moment blood sampling yields better quality DNA for testing

HOW LONG DOES TESTING TAKE?

Testing can take around six weeks for results to come back so make sure you have submitted blood samples long before you plan your matings.

WHAT WILL THE RESULT MEAN FOR ME WHEN I AM BREEDING FROM THE DOG?

The result will mean that you can breed responsibly with the knowledge that by making sure you only ever breed clear to clear, or clear to carrier that you NEVER produce affected puppies. If you have a carrier dog and decide to breed from it, the mating MUST be to a clear dog and then you must test all puppies to determine their genetic status. It is sensible to then endorse the registration papers of the carrier pups so that progeny of these pups cannot be registered with the KC and explain the importance to their new owners that they should NOT be bred on from without serious consideration and the responsibility (ie. mating only to a tested clear dog and then testing and endorsing pups). Some breeders may chose to ensure that any subsequent carrier pups will be neutered when they are old enough

  

 

HOW CAN PUPPIES BE TESTED?

Puppies can be tested by submitting 3ml of blood in the same way as adults. Obviously pups will have to be old enough to have blood taken, probably around 4 weeks, and it will be necessary to be totally accurate about identifying the individual puppy. It is proposed to begin testing by taking a buccal (cheek cell) swab in the near future. This may be an easier and less traumatic way of testing puppies, again the pup would need to be 4 weeks old to swab

WILL THE RESULT BE ACKNOWLEDGED ON DOCUMENTATION?

The Kennel Club has been approached by the SBT Breed Council to ensure that future KC registration documents will results of L-2 HGA tests. The results will also be published in the Breeds Record Supplement. This should be effective from the beginning of 2006

COMBINED GENETIC TESTING

The genetic test for Hereditary Cataract is now available to the public. For anyone who has already submitted blood for L-2 testing, the same blood sample can be able to be used by the AHT for HC testing. It is possible to test for both HC and L-2 HGA from one blood sample and using one combined form, paying £100 for both tests

DNA PROFILING

DNA profiling has been underway for quite a while now as a means of identifying beyond dispute an individual dog’s parentage. Although the DNA for any dog profiled will be recorded it is not possible to use this for genetic testing. Each test requires specific differing methods of extracting the DNA, therefore separate swabs would need to be used

IDENTIFYING DOGS

It is advisable to ensure that individual dogs are microchipped, then when samples are taken for genetic testing, whether by blood or swab, the details of the microchip can be entered on the accompanying form. Although it will be possible for swab kits to be sent out to individuals for `home use` it may be best if the swabs are actually used under veterinary supervision for third party integrity and also to ensure that the swabs are used correctly. If the swabs aren’t handled properly you will find they are returned - another length of time before you will get your results!. It will be essential that any litters of puppies DNA tested are identified accurately. If pups aren’t obviously different by their coat markings they could wear differing coloured collars, have differing coloured nail varnishes applied to nails on one foot or perhaps cut a small piece of fur from differing areas of the coat

THE FUTURE

In an ideal world we should all use DNA testing on all our breeding stock from now on, mate only clear to clear or clear to carrier then test pups. It is unlikely that many people will choose to mate carrier dogs, partly because of the expense involved in testing a whole litter (£60 per pup). In this way within a few generations the condition will become self-limiting and carriers would be phased out. It must be accepted that only responsible breeders will use the test, leaving the rogue gene still out there unseen

In the future once the Kennel Club registration documents contain the result of L-2 testing it will be accepted that pups from two L-2 tested clear parents will be hereditarily clear and recorded as such without need for further testing

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