I think this is quite likely incorrect - "...... so if one sibling has
it, then the male and female siblings **will** (my emphasis) be carrying the
same
genetics ......"
I'd suggest that depending on the inheritance pattern, it would be **could**
be carrying.
?
Ros
Thanks Chrissie, doing some more reading – I’m aware that it is a genetically linked condition, it was the ‘imperative’ of ‘will be carrying’ that I was questioning.....
I have heard of Vizslas with undescended testes... not many, but certainly it’s one of the things breeders always check for when assessing their 8 week old puppies.
Certainly agree completely that cryptorchid dogs should not be bred from – one wonders if they have a retained abdominal testis or have had that removed?
Cheers
Ros
How is cryptorchidism inherited?
Although the condition is of course seen only in male dogs, both males and females can carry the gene for cryptorchidism. Heterozygous males and females, and homozygous females, will be physically normal, but can pass the gene on to their offspring. Homozygous males are cryptorchid. Thus cryptorchidism is thought to be a sex-limited autosomal recessive trait
This is the most common mode of inheritance for genetic conditions in dogs. To be affected, the animal must inherit 2 copies of the gene (genotype pp), 1 from each parent. Dogs with the genotype PP (normal) or Pp (carrier) will be clinically normal but the carrier will pass the affected gene to approximately half the offspring. As long as carriers (Pp) are mated to normal animals (PP), the offspring will be unaffected but some will remain carriers. If 2 carriers are mated, some of the offspring (approximately 25%) will be affected.
For a male dog to be cryptorchid, he must inherit this abnormal gene from both his sire and his dam. If a female dog gets two copies of this abnormal gene from her sire and her dam, she will not express it because she has no testicles, but each of her puppies will be at least a carrier. If she is bred to a male carrier, who has both testicles in his scrotum, but who has one abnormal gene, she may have affected males. If a female with two copies of the abnormal gene is bred to an affected cryptorchid male, all male puppies will be affected. If a cryptorchid male, likewise, is used at stud, all his puppies will be at least carriers, and if he is bred to a carrier, male puppies will be carriers or affected, and females will be carriers.
Here are the percentages:
1) If male and female both have all normal genes, all puppies will be normal and non- carriers or affected.
2) If the female is a carrier of a single abnormal gene, and the males is normal in both of his genes, each puppy has a 50% chance of being a carrier, a 50% chance of being normal.
3) If the female is a carrier of a single abnormal gene, and the male is a carrier of a single abnormal gene, each puppy will have a 25% chance of being totally normal, each puppy will have a 50% chance of being a carrier of a single abnormal gene, and each puppy will have a 25% chance of having two abnormal genes. In this case females carry two abnormal genes, and the males are cryptorchid.
Thanks Chrissie,
I think that google must have been running hot on cryptorchidism in dogs today! J
So, with autosomal recessive, there is a also that other 25% of offspring that will (in modelling) will NOT be carriers as I understand it (and really, I always say – I just don’t ‘do’ genetics! I know that I should have a better grasp, it’s just not something that computes in my head. J)
That was the point of my comment on your statement – not ALL puppies will necessarily be carriers IF it’s an autosomal recessive inheritance mode.
Still reading, and chatting to someone else about this subject...
Cheers
Ros
From: ukvi...@googlegroups.com
[mailto:ukvi...@googlegroups.com] On Behalf Of Chrissie Diron
Subject: Re: Cryptorchidism and breeding
Snippets (no pun intended!) as I find them ...
----- Original Message -----From: Chrissie DironSent: Tuesday, September 07, 2010 10:47 PMSubject: Re: Cryptorchidism and breeding
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My thought on this was -
But... do people *really* take hips seriously? I sometimes wonder when I see
the BRS reports with hip scores in the UK club journal... there are a
significant number of litters that appear to be born to parents scores WELL
above breed average... I find it very disappointing.
And it's interesting... the dog that Chrissie mentioned had produced 3
cryptorchid puppies in 25 litters. 25!! Gosh, not many dogs produce that
many litters, and so one wonders if the dog that produces only 5 litters
also carries the same gene, with the same potential to produce cryptorchid
puppies, but just doesn't produce enough puppies for people to see it
happen?
Karyn O made this comment in a conversation we had about the subject -
"That is, if a line or breeder seems to have no incidence of a certain
defect in their dogs, do you assume the genes for the defect are not present
in their line? If you were worried about cryptorchidism in the breed and
excluded breeding from the stud dog and from litters he sired, what else
might you lose from the breed; are there health traits such as longevity or
reduced incidence of cancer in his lines compared with other lines?"
I hope she won't mind me passing on a few more of her words of wisdom. I
really enjoy discussions with Karyn - she brings a very practical and broad
spectrum point of view generally... And my thoughts are it's worthy of more
than just my eyes... :-)
Quote: " Similarly, a dog or bitch could produce 3 litters together, with
all 25 pups being fine specimens. Then they have a fourth litter. Everyone
tut tuts about a fourth litter for the poor girl... that final litter
produces 2 longhaired puppies. Now we have lines that had been considered
"free" of this which are not. "So what!" I hear you say, "it's only
cosmetic." What happens if you substitute epilepsy, polymyositis or
cryptorchidism for longhair? Do you consider that all problems are equal,
or do you mentally separate them into boxes such as this condition "may
seriously impair or shorten life" and this "does not materially affect the
function of the dog"? Something like clinical hip dysplasia and epilepsy
might be in the first "disease box", and longhair and cryptorchidism in the
second. Some breeders would choose to possibly breed from dogs in the
second box but never from those in the first, whilst others would choose to
breed from neither.
In the past, in order to "eradicate genetic disease" purging all carriers of
a problem from the gene pool has been encouraged, if not practiced. Some
people extend this to all potential carriers such as litter mates of
affected dogs and/or litter mates of the parents - any of whom may or may
not be carriers, depending on how the condition is inherited. Some of these
purged dogs carried health defects, others cosmetic faults such as producing
or having too much white. To breed from carrier or faulty dogs was usually
seen as nothing more than poor, or backyard breeding. The result is we have
people not wanting to be open about problems in their dogs, and in doing so,
propagating the myth they are breeding from perfect dogs. Some people may
even have decided not to breed from their dogs because they were obviously
not 100% perfect, and decided to use one of the stud dogs who everyone else
was using because obviously, he was. For those who would consider using
probable or known carriers to breed with clears in their breeding plans, it
can be difficult to not double up on 'bad genes' if you cannot find out what
'bad genes' already exist in your own dogs, let alone in other lines. All
of which if it doesn't diminish the gene pool, compounds the problem of a
small gene pool.
I am not saying that one should breed from carrier dogs as a matter of
course and a badge of honour for "genetic diversity", but one needs to
consider the whole. IMHO;
It's not so much that you produce a dog with a problem, it's what you do
about the problem that is important, and has wider impact.
Just because a condition isn't seen in any puppies does not mean that it is
not in the lines.
Every breeder must make their own decision, but it will not change the fact
that no dog is perfect.
It can be difficult to make informed breeding decisions in a climate where
open-ness is not embraced by all, and there is a stigma attached to having
anything less than a perfect dog to breed with.
I think the discussion around breeding from known or potential carriers is
not a simple yes/no problem. I think it's great that people want to discuss
these sorts of problems, as I think it the answers are not necessarily easy,
and often we'd rather not talk about difficult things."
Cheers
ros
-----Original Message-----
From: ukvi...@googlegroups.com [mailto:ukvi...@googlegroups.com] On Behalf
Of Strassenbahnhaltestelle
Sent: Saturday, 11 September 2010 8:19 AM
To: ukvizsla
Subject: Re: Cryptorchidism and breeding
--
Some thoughts -
Only you - and the owner of the bitch who would choose to use Hamish - could
really answer your questions.
My belief is that though *actual* manifestation of temperament may not be
inherited, I do believe that *tendency* for those behaviours can be passed
on... As most people know, I don't breed. However, last year I did lease my
bitch for a litter. I think she has the MOST laid back easy going,
uncomplicated temperament of almost any Vizsla I've ever known. But she has
many more qualities that I also considered to be desirable that could be
passed on.
I (we - the registered breeder and I )*specifically* chose a dog to use
that has equally great temperament, but perhaps a little more 'up' and
bouncy. I would NOT have chosen a dog who has trouble coping with things in
day to day life, lacks bounce-back, etc, regardless of whether it may be due
to his environment, or his upbringing. I simply would not want to take the
risk.
So, Ross - it's a matter of the usual things - who will use Hamish? Is their
bitch the best possible combination for using with Hamish? What do they
carry in their pedigree? Will the owner be experienced enough to raise the
litter to the best possible standards of socialisation, etc? Will they have
the best options of perfect new owners, or will they compete with breeders
who have a 'reputation' for great Vizslas? Will they be experienced enough
to give good/great info to the new owners should *they* have similar needs
for assistance as you did with Hamish? Etc etc etc ... we've been down this
track before, you know the drill <VBG> there are many more questions on the
list..
I really respect romanticism.. :-) Goodness knows we need it in this world.
But I'm not sure it makes the best dog breeding choices.
Oh, and I didn't breed from the most wonderful dog I've ever owned.. she may
have had some traits I'd not necessarily want to pass on.. including some
issues of temperament which were in all likelihood from my inexperience as
a Vizsla owner... but I do see some of her in the puppy I have kept from
last year's litter.. in a more laid back persona. (The sire I used was a
nephew of my first Vizsla, so I do believe that it's possible to gain the
things you desire in a puppy in a more indirect way. I don't necessarily
think we need 'son of ...' to get those much loved traits.)
You asked - "I don't know enough about breeding so I'd love to hear from the
group
what steps you would take to breed out temperament 'flaws'. Would you
just not breed from that dog whatsoever? Is it possible to breed out
these things? What does happen when you breed a nervous dog with a
'bomb proof' dog? Do you just get some nervous and some 'bomb proof'
offspring or do you get a more 'balanced' temperament. I know this is
crude but I'm curious to know about breeding from the perspective of
temperament."
If ONLY genetics and inheritance were that simple. And if only there was not
the 'nature vs nurture' complication. But with all the quick criticism of
breeders' choices that occurs and appears to have overtaken us... I think as
always some caution and critical thinking is required.
And yep, I think sometimes we try to oversimplify breeding to 'good' and
'bad' breeders (gosh I think that we've become a 'blame' society!)... it's
just not that easy
Hugs to Hamish the Handsome. :-)
Cheers
Ros
-----Original Message-----
From: ukvi...@googlegroups.com [mailto:ukvi...@googlegroups.com] On Behalf
Of Londonfieldsboys
Subject: Re: Cryptorchidism and breeding
Some thoughts -
Cheers
Ros
--
Apologies to the list
Ros
----- Original Message -----
From: "Londonfieldsboys" <ROS...@sky.com>
To: "ukvizsla" <ukvi...@googlegroups.com>
Sent: Monday, September 13, 2010 3:50 PM
Subject: Re: Cryptorchidism and breeding
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07:35:00
Hi Chrissie,
This paragraph interested me..
…..
All this I have learnt through discussions on lists like this one. Not only that, I also have other breeders now thinking that they need to be sure that their boys have 2 fully descended testicles before they place them, or at least have a compensation system in place with the puppy buyer, should the problem manifest. This makes for good breeder/buyer relations - we can all do better!
....
I’m not a breeder, but have been privileged enough to be invited to look at quite a few litters at 8 weeks when they are being ‘sorted’ for show, work, etc. On all of those occasions – without exception – the males have been checked for two descended testicles, and if not in the scrotum, then checked to see that they are in the inguinal canal. I know also that vets check for those testes at their 6 week vaccinations... Pat Hastings discusses checking in her Puppy Puzzle lecture/DVD. She also mentions – and I’d have to go and check which way it is! J - but she suggests that in her (pretty extensive!) experience that if one particular side is not down in the scrotum or canal, it will never come down and if it’s the other side, it’s quite likely to come down a little later. (related to embryonic development from memory)
So I’m really surprised that breeders are not already checking and are considering that a puppy even with a unilateral lack of descent is suitable to sell as a show/breeding prospect until such times as both testes are descended.
Helen, I’m sorry you thought that you’d been flamed. I think you did add to the conversation, as have all the other posts on the subject. It’s an interesting one which went on to discuss other breeding dilemmas – all good open discussion I think... just what we should be encouraging.
Regards
Ros
Hi Chrissie,
Just found a quick reference to the Pat Hastings comments – can’t completely validate it, as I haven’t looked at my notes/dvd yet. But the mention I found is that if the left is descended, the right may still come down, but if the right is descended and not the left, it’s unlikely that the left will descend.
Cheers
Ros
Also found this reference in the ANKC (Australian National Kennel Control) regulations
SECTION 9
Disqualification from Conformation Exhibition
.......
9.3 For Conformation purposes, a dog six months of age or over shall not be accepted as
physically entire unless both testicles have fully descended and are in the scrotum.
Any dog disqualified for this reason at a Conformation Show will have its registration
suspended until it can be proved to the satisfaction of the Member body that it is
physically entire. (05/00)
9.4 Any dog suspended in accordance with 9.3 shall not be accepted for stud purposes
and any litter sired by the dog will not be accepted for registration. (05/00)
9.5 Any dog over the age of twelve months which is proven to be non entire shall be
deregistered or transferred to the Limited Register. (05/00)
Ros