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Mixed breed v Full Breed (Which is healthier)
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08-04-2012 7:05pmIn work the other day I was chatting to a couple of lads from out west (Mayo to be exact), both coming from a farming background.
They are adamant that any of their dogs have never had any health issues as they are all mongrels (mixed breeds) a mix of sheep dog, lab, shepherd and so on...
One of them has the opinion then that my 2 Rotts or anyone else's full breed dog will get sick or have some sort of health issue well before any of his dogs would ever....
When I tell him my dogs come from healthy bred parents and grand parent and so on and so on, his response is ah yeah but ye know what I mean. . .When I have been talking to anyone from a background in farming or a country person they all have this opinion.
Personally I think it that people like myself and a good lot of you boards people add to their theory because when our dog has an issue or is sick we would take them to the vets which adds to the thought that our dogs get sick more. Whereas a farmer wont bother most the time going near a vets if the dog get sick as it is "just a dog" and they are not seen as a pet as such and are more of a work tool or aide.
Am I right? Is there any truth in this? Would you agree?0
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My sisters collie/lab cross on her first visit to the vet was diagnosed with a heart murmur, a hernia and collie eye which are all hereditary problems connected with collie breeds, and few more problems which are not genetic. I don't know how anyone can state as a matter of fact that their dogs are healthy unless they have been checked for these issues. Non of the above required any in depth tests this was all picked up at from a general puppy health check.0
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I dont know myself but i can see where the farmer is coming from. My 6 year old lab has been to the vet so many times with ear infections, skin infections etc. But my 6 yr old terrier cross only had to go when he cut his paw on very hard ice. I also have an 11 year old collie cross that never needs to go. So you would wonder. i seen a programme before on tv about pure breads not being as healthy as they are only bred with other pure breads so they are in one sence all related and it begins to become a bit of in breeding. Where as a dog that is crossed with a different breed has no possability of in breeding. Again dont know how true this is but its a fair point.0
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It's basic genetics. A lot of defects occur when an animal has two copies of a recessive gene, and the wider you cast your net for mates the less likely that is to occur. This is why breeding siblings is terrible, cousins bad, and more distant relatives unwise. A mix of two breeds or just a random mongrel mix is less likely to double up on recessive genes. "Pure bred" dogs suffer from the same unwise but elitist attitudes that led European nobility to messing up their genetics. Studies with people have shown that, generally speaking, people of mixed race tend to be found most attractive - genetic diversity is a good thing.
These are just general principles though, you could have a perfectly healthy pure bred animal or a very unlucky mongrel.0 -
From my own experience of working in a few different practices as a student nurse (so take into account I only really see what is admitted, and not what is seen by the vet in each consult) I would say for some breeds that is true (middle aged boxers and cavaliers you can pretty much put money on each one as they walk through the door that they'l have heart problems). Cavaliers I think are probably the most unhealthy breed of all, nearly all of them over 5 have some degree of a heart murmur and loads of bad ear infections, the saddest part is loads of owners buy these dogs and are not prepared to pay for ongoing heart medication so there are loads of cavs out there suffering and not even getting the treatment needed. Westies with skin issues is another common patient.
I'v seen loads of dogs suffering because of their conformation, pugs with scratched eyes and bulldogs that can't breath.
I think the main difference I'v noticed off the top of my head is with mixed breeds you see just as many ailments but the dogs are often older. But I suppose the vets is a bad place to do any sort of survey on breed health as apart from vaccinations and routine spays and castrations you don't see too many healthy animals, you also don't get a copy of an animals pedigree so you can't say whether a purebred has come from a reputable breeder or a puppy farm. One thing I can definitely say is I'd never in a million years buy a cavalier as they'd break my heart.0 -
Personally I think it that people like myself and a good lot of you boards people add to their theory because when our dog has an issue or is sick we would take them to the vets which adds to the thought that our dogs get sick more. Whereas a farmer wont bother most the time going near a vets if the dog get sick as it is "just a dog" and they are not seen as a pet as such and are more of a work tool or aide.
Am I right? Is there any truth in this? Would you agree?
I don't agree with this part of your post at all. My two dogs are mixed breeds with a very mixed heritage - mainly Cane Corso with rotty, GSD, retriever, and dalmatian in the last 3 generations - the list goes on. If either have an issue or are sick, I call the vet. Thankfully, they are both very healthy, so I rarely have to bring them in for anything more than their shots. But in fact I would call the vet much faster for them than I would call the doctor for me. The fact that my dogs are not pure bred does not mean I would take any less care of them. I also think it is very unfair to make such a sweeping generalization about farmers, many of whom take excellent care of their dogs.
That part aside though, I think Zillah explained it very well above. The BBC did a documentary on it a few years back called Pedigree Dogs Exposed that you might find interesting: http://www.myspace.com/video/bordercollie19/documentary-bbc-pedigree-dogs-exposed/44215931 (mods please delete link if the content is not allowed)
Of course, you can get sickly dogs of any breed or mix, just as you can get healthy ones.0 -
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God topic Garkane, it's come up here before. Any breed, bred for the show, bred for what breeders consider 'good looks' and exaggerated characteristics will suffer. When dogs with silly, ill desired "defects" such as the wrong colour or the incorrect bite are phased out of the gene pool and it gets shallower, resulting in inbreeding and dogs susceptible to disease, ailments, disabilities and syndromes.
Do you think hunters, bear baiters, bull baiters, dog fighters, and sled dog people gave a shyte if their dogs colour was a bit off?
Do you think modern day professional dog handlers give a shyte if their guide dog, drug sniffer, retriever or police dog's ridiculous back leg slope isn't in accordance to a breed standard?
The only defects in our companions now are because of bad breeding, fashion and the show...
I'm afraid, the only good use for the papers you receive with your expensive pure bred puppy is to mop up the puppy pee.
I hope it's the end of the road for the show, and the sooner the better. There are lots of dogs suffering because of the hangover from the Victorian era of forced evolution and fashionable accessory dogs. I am 100% guilty of this in the past, but have seen the suffering and seen the light.
This HAS to effect the behavior of dogs, look at the amount of huskies in Ireland now, ten years ago there were hardly any! Are they all being bred from the same lot? Will we have unstable huskies knocking around soon? I don't have the answers, but it's worrying.
Sorry if my post is harsh, but I have seen the suffering, it's not nice.0 -
I don't agree with this part of your post at all. My two dogs are cross breeds with a very mixed heritage - mainly Cane Corso with rotty, GSD, retriever, and dalmatian in the last 3 generations - the list goes on. If either have an issue or are sick, I call the vet. Thankfully, they are both very healthy, so I rarely have to bring them in for anything more than their shots. But in fact I would call the vet much faster for them than I would call the doctor for me. The fact that my dogs are not pure bred does not mean I would take any less care of them. I also think it is very unfair to make such a sweeping generalization about farmers, many of whom take excellent care of their dogs.
While I'm not disagreeing with you I can see where Garkane is coming from. There are good and bad farmers just as with any group of people but just from my experiences I can tell you I know of one who drove over their dog with a lawnmower and left it overnight to be put down the next afternoon as they didn't think it was in pain (it had horrific injuries), also know plenty others who only seen the dog as a very valuable working animal, a bit like a valuable piece of machinary and weighed up the cost of treating something (such as a broken leg) against the cost of training up a new sheepdog.0 -
Too difficult to say. There are many pure breeds which have differing health issues. Some suffer from none while others are so bad they suffer their entire lives. I'm sure some people will say that cross breeds are healthier but there is no definitive proof as any study would have to look at all breeds.0
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Originally Posted by Kash
I don't agree with this part of your post at all. My two dogs are cross breeds with a very mixed heritage - mainly Cane Corso with rotty, GSD, retriever, and dalmatian in the last 3 generations - the list goes on. If either have an issue or are sick, I call the vet. Thankfully, they are both very healthy, so I rarely have to bring them in for anything more than their shots. But in fact I would call the vet much faster for them than I would call the doctor for me. The fact that my dogs are not pure bred does not mean I would take any less care of them. I also think it is very unfair to make such a sweeping generalization about farmers, many of whom take excellent care of their dogs.
And I am not disagreeing with you either. (Aren't we a civil bunch today) What I am saying is that bad owners exist for all types of animals - whether they be working dogs, show dogs or family pets. I am sure that for every farmer mistreating his working dogs, you would find an owner of a pure breed mistreating theirs. Unfortunately, a record in a stud book is just a line of text, it does not bestow upon the owner any additional knowledge, common sense, or ability to look after their dogs properly.
But getting back to the issue of health - the wikipedia article cites some interesting studies done on the topic - notably an American one which assessed the longevity of a pure breed versus a mixed (with mixed breeds living, on average, 2 years longer), and a similar study in the UK which showed similar results but noted that a few breeds (notably Jack Russell Terrier, Miniature Poodles and Whippets) lived longer than mixed breeds.
http://en.wikipedia.org/wiki/Mixed-breed_dog#Health0 -
Yes. As another poster said its basic genetics. It's called hybrid vigour.0
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A cross breed can just be as unhealthy ie if you have a Golden Retriever and a Poodle cross (some people call them Goldendoodles) they can have hip dysplasia. So it really depends on the actual parents and the hereditary lines.0
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Moderators, Science, Health & Environment Moderators, Society & Culture Moderators Posts: 60,163 Mod ✭✭✭✭Join Date:Posts: 59091
Irishchick wrote: »Yes. As another poster said its basic genetics. It's called hybrid vigour.
*that said working out the definition of species has wrecked the heads of some of the greatest minds in science.
**jackals make bloodhounds look like they have corks in their nostrils. Similar was found with wolf dog(Lupo Italiano) crosses for SAR work in Italy. They acquire and follow a scent faster than bloodhounds.Rejoice in the awareness of feeling stupid, for that’s how you end up learning new things. If you’re not aware you’re stupid, you probably are.
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Irishchick wrote: »Yes. As another poster said its basic genetics. It's called hybrid vigour.
No, it isn't called hybrid vigour.
Hybrid vigour is the term used when you breed two animals and the progeny happen to exhibit the strongest elements of both parents. It's not a guaranteed outcome of crossbreeding at all. You don't automatically get hybrid vigour just because you've crossed two breeds.
When you breed two animals you can also get inbreeding depression, where the progeny inherit the worst traits of both parents.
There are plenty of labradoodle owners, for instance, with an angsty dog that has a coat that sheds and the shedding coat gets caught in the poodle wool that doesn't shed, which results in a constantly matted coat. The dog may also exhibit the poor genetic traits of both parents, which means it can have the inherited diseases of two breeds instead of just one.
Hybrid vigour is a term too loosely bandied about by profiteering breeders of random small-white-fluffies and -oodle breeds. Crossbreeding isn't a guarantee of health.
Saying that, proper farm mongrels are often extremely healthy dogs, because there is no line breeding in their heritage, the sickly puppies are frequently culled at birth and the dogs are good, strong working lines. Then again, usually dogs bred by folks who need a strong working dogs - well, those folks don't muck about, so yes, you can get a good strong dog. Similarly, you should be able to get a healthy pure bred dog from a responsible breeder who health tests.
Otherwise, being a first generation cross of two pure bred dogs is no guarantee of health or longevity.0 -
I have never owned a pedigree dog, from my teenage years when my family had dogs, we always had mutts/cross breeds (whatever you want to call them), the first one had luekemia and had to be pts before the age of 5, the next one was healthy and lived to a ripe old age of about 14/15 before having to pts due to general ill health and old age, the next one was diagnosed with dilated cardiomyopathy at age 2 and died nearly 3 years later, the next one (who is still alive and kicking!) has a heart murmur, early onset arthritis from an earlier injury and suffers from depression, the most recent addition is in good health according to the vet which is a relief and she's the first healthy dog I personally have ever owned (excluding the earlier pets who belonged to mum, dad, brother & me)
I guess my point is, you just never know!! With a pedigree at least, the parents would (should) have been fully health tested and given a clean bill of health so your risks are low but still there are no guarantees. All we can do is love our dogs and if they get ill give them the best care we can.0 -
In work the other day I was chatting to a couple of lads from out west (Mayo to be exact), both coming from a farming background.
When I tell him my dogs come from healthy bred parents and grand parent and so on and so on, his response is ah yeah but ye know what I mean. . .When I have been talking to anyone from a background in farming or a country person they all have this opinion.
Personally I think it that people like myself and a good lot of you boards people add to their theory because when our dog has an issue or is sick we would take them to the vets which adds to the thought that our dogs get sick more. Whereas a farmer wont bother most the time going near a vets if the dog get sick as it is "just a dog" and they are not seen as a pet as such and are more of a work tool or aide.
Am I right? Is there any truth in this? Would you agree?
Well I myself am from 'out west' coming from a farming background of several generations. And I'm a little offended at the seemingly sweeping statement that farmers wouldn't bring their working dogs to the vet or take adequate care of them.
It's true that the dog has a job to do living on a farm, but working on the farm can be quite lonesome and the dog is the farmers companion and work mate throughout the daily routine.
Contrary to popular opinion, it's quite difficult in finding a very good working dog which can do the specific jobs the farmer requires out of the current dog on the farm. Ie. having a dog that can work efficiently in both cattle and sheep, having the dog with the instinct to not snap at a lamb but merely shoulder/nose it back to the flock, stand at the back door sending the dog up the mountain and working from a distance. Most farmers I know wouldn't wish to replace the dogs they have and more often than not, a new dog brought onto the farm is trained off the existing dog.
I have come across many a grown man tear up re-collecting a good dog they may have lost for whatever reason, the current dog only being half as good as the last. Every farmer I know ensures that their dogs health is up to date and have seen the vet get called out late at night if they feel the dog is in serious pain. Those unfortunate enough to lose a dog or face the decision of putting it down never remain stony faced.
The last two dogs we lost were 18 and 14 respectively, the latter was a huge loss as she was capable of doing the aforementioned jobs. No dog will ever have the intellect she had with working with lambs!! We have a pup from her who is now 6 and since the death of the 14yr old, she's become less of a worker as she worked as part of a team. She's useless for work, but my father has still to make the decision to bring on another dog. When the day comes that a new dog should be brought on, the pup will either work as a team or enjoy her retirement with us.
I understand this thread is about the healthiness of purebred vs mongrel, but I felt the need to raise my opinion and experience of farmers and their dogs. They're not always the gun happy intensive farmers which some believe them to be. Most working dogs I know also know what toys are, how it feels to be part of the family and get taken for walks should there be insufficient work on the farm for a period of time.
My experience is here in Sligo, so while Zapperzy has seen the more negative side, I myself have seen the strong relationships farmers have with their dogs and the confidence/dependence they have in them for getting the job done how they see fit.
Never seen as an object which depreciates in value over the years, but as an invaluable and irreplaceable living animal which makes the working day easier!!
Sorry for such a long post, must have been important for me to rant on about it0 -
John_Rambo wrote: »The only defects in our companions now are because of bad breeding, fashion and the show...
I don't agree with this at all, a lot of the most serious problems in dogs these days has arisen from the massive demand for the pet market which has resulted in a population explosion of dogs, the vast majority of which have been produced by puppy-farms and back-yard breeders, the main issue is not that pedigree and health in these dogs has been taken into account - but the fact that it hasn't. A collie cross lab with no papers doesn't mean the dog is the cross of a collie and a lab, for all you know it could be a cross of two collie x labs - the parents could well have been from the same litter themselves for all you know. Very, very few pet homes are capable of catering for the needs of a true working dog resulting in serious mental issues for a lot of dogs.John_Rambo wrote: »I'm afraid, the only good use for the papers you receive with your expensive pure bred puppy is to mop up the puppy pee.
I can trace the ancestry of my soon to be new puppy right back to when the breed registry was formed, the dam (show lines) and the sire (working lines) have very different bloodlines and come from two very distinct strains. The sire is descended from a very old working strain of the breed bred for health and for function, whereas the dams line are show dogs but also bred for function and for health. This can be determined from the dogs papers, so actually papers I have not even received yet have been instrumental in me making the decision as to whether or not I actually want the dog in the first place. A dogs registration papers also have the results of any BVA tests for congenital problems that have been submitted to the BVA for assessment. Aside from that, sticking the name of any dog on that pedigree into google will throw up a wealth of information from show results to working trials results to general information on that dog. If you look far enough into it, it may even be possible to estimate the potential life span of a dog based on it's heritage. So in conclusion these little pieces of paper have been a valuable source of information and not something I'd be using to mop up puppy pee off the floor with.
The vast majority of farm dogs I know of are border collies, generally 'farm' dogs are bred with nothing in mind other than working ability, often the pick of the bunch are kept for working purposes and the rest are destroyed or sold to people who are unable to meet the necessary requirements for satisfying the drive of these dogs both of these methods of 'disposal' are completely unacceptable in anyone's terms. 'Farm mongrels' are usually the product of not bothering to try to avoid accidental matings (with the exception of droppers etc.which are bred for hunting in any case and not farm work.0 -
adrenalinjunkie wrote: »I don't agree with this at all
Well, we will agree to disagree then, but the name dog show says it all really, it's a show of looks, not health, companionship and suitability. As usual with these endeavors the dogs will suffer, not the owners.0 -
John_Rambo wrote: »Well, we will agree to disagree then, but the name dog show says it all really, it's a show of looks, not health, companionship and suitability. As usual with these endeavors the dogs will suffer, not the owners.
Can I ask what you have based your opinion on this on? I am aware that show people exist who put no emphasis on the health of their dogs but I have actually only encountered one or two personally. On the other hand I know someone who breeds so-called 'healthy' straight backed working german shephards and crosses of them when the reality is that she does nothing whatsoever to confirm the health of her dogs unless you count fabricating lies that the dogs are hip scored when they are not. I've lived most of my life on a farm and I've never heard of a single farmer who has not had a litter of pups and introduced at least some of them to a barrel of water. I've mostly found your posts to be very sensible but I'm afraid that this makes no sense at all. If show breeders were to follow suit and cull everything that did not have perfect health would this be acceptable to you? I have never heard of a farm mongrel being tested for the congenital issues that affect the breeds involved, and very few unless they have ended up in rescues have any sort of veterinary care or health check throughout the course of their lives past puppy vaccs (if they even get that).
Where can a person get one of these healthy farm mongrels with it's health guaranteed to the same degree as my pedigree puppy and how do I verify that what I'm being told by the person who bred it is in fact true?0 -
adrenalinjunkie wrote: »I've lived most of my life on a farm and I've never heard of a single farmer who has not had a litter of pups and introduced at least some of them to a barrel of water.
Again not true from my parts. Whilst it was common practise in the past (and I'm certain my grandfather was a culprit) it's in no way considered nowadays. Most working dogs I know are well fenced in when not supervised. Primarily because the farmer doesn't want nearby livestock worried or indeed the dog getting itself injured off the farm. Again a good working dog is not easy to replace and most farmers don't allow their dogs to wander.
In my area, I've never seen a working dog have an unwanted litter. The bitch is put into pup largely on account of the dogs reputation for its work ethic raising interest from nearby farmers. Thereby rarely having unwanted pups. A bitch with pups isn't going to work so why would a farmer allow any dog near it, or indeed have insufficient fencing or penning to allow a mating to occur.
I understand accidents can happen but believe it or not, even farmers are more clued in than most pet owners that there's a canine alternative preventing the pitter patter of tiny paws
It's a little disheartening to me that some are still of the belief that farmers act in a brutal manner and have no feelings towards their dogs. Yes some act like total scumbags, (no more so really than surveying another populace of people ie. city dwellers) but the majority that I see don't.
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Again not true from my parts. Whilst it was common practise in the past (and I'm certain my grandfather was a culprit) it's in no way considered nowadays.don't.
I know of two cases in my locality in the last 6 months. It's no longer PC or legal, so people don't exactly shout it from the rooftops. Outside of this scenario I have have never heard of a farmer producing cross breeds for the purposes of producing working dogs. What is the point of having a border collie that is a fantastic sheepdog if you are going to dilute those traits by crossing it with a different breed?
Maybe I'm missing something here?But working dogs are still selectively bred if they are bred on purpose, and if there is no papers then there will still be inbreeding if a certain family line is excelling at it's job.
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The Sweeper wrote: »Hybrid vigour is the term used when you breed two animals and the progeny happen to exhibit the strongest elements of both parents. It's not a guaranteed outcome of crossbreeding at all. You don't automatically get hybrid vigour just because you've crossed two breeds.adrenalinjunkie wrote:I don't agree with this at all, a lot of the most serious problems in dogs these days has arisen from the massive demand for the pet market which has resulted in a population explosion of dogs, the vast majority of which have been produced by puppy-farms and back-yard breeders, the main issue is not that pedigree and health in these dogs has been taken into account - but the fact that it hasn't.Rejoice in the awareness of feeling stupid, for that’s how you end up learning new things. If you’re not aware you’re stupid, you probably are.
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Look at many established breeds of today with all their papers up to date and then look at the difference in the same breeds 100 years ago. That crippled GSD type didn't come from nowhere, or out of the blue. That was breeders breeding to an ever fcuked up standard. Ditto for boxers, bulldogs, cavs etc Check out "respected" breeders websites and look at what too many are pushing as "healthy" and get back to me. When you see for example bulldog breeds that can't mate naturally and when they give birth the majority end up requiring caesarean sections to do so, all under the banner of "responsible breeders" then TBH some bloke on donedeal selling off his mutt pups from an unfortunate encounter with the neighbours bowler starts to look a lot more healthy and moral.
Wouldn't have any of em tbh, but the original question is a bit like asking how long is a piece of string, it depends is the answer, but no risk assessment (as per unknown heritage) is not better than a proper analyses of the potential issues with decisions made accordingly. People should cross breeds to their hearts content but there is no records kept of health/genetics/blood relationships. As it is crosses are made from the first dog that happens to be there, no-one has ever travelled the length of the country to find a collie free eye problems so they can cross it with a lab free of bone and joint issues, the current state of a young dogs health is no indication that problems won't occur in a years time (etc.) There are a few 'oodle' breeders in the UK that apparently do actually put this effort in but again you are basicly trusting the records that they themselves have kept as there is no formal documentation process in place. I'm all for out-crossing projects but these would be recognised and documented with the same process as any other kennel club registered dog (where out-crossing has approved).0 -
adrenalinjunkie wrote: »Wouldn't have any of em tbh, but the original question is a bit like asking how long is a piece of string
Yeah I agree with this. You'd need to compare like with like I think eg age, diet, exercise, environmental factors etc etc?0 -
adrenalinjunkie wrote: »I know of two cases in my locality in the last 6 months. It's no longer PC or legal, so people don't exactly shout it from the rooftops. Outside of this scenario I have have never heard of a farmer producing cross breeds for the purposes of producing working dogs. What is the point of having a border collie that is a fantastic sheepdog if you are going to dilute those traits by crossing it with a different breed?
Maybe I'm missing something here?But working dogs are still selectively bred if they are bred on purpose, and if there is no papers then there will still be inbreeding if a certain family line is excelling at it's job.
Sorry for the delayed reply, flat out at the moment.
Perhaps I wasn't clear. I was merely responding to the negative comments in relation to you having never encountered a farmer who hadn't drowned a litter. Being a farmers daughter myself, having studied Ag Science and with the majority of my working life situated in differant agricultural surroundings, I can ensure you that I've never witnessed this.
Since you and another poster are in the same demographical area as myself, I felt it was important to emphasise that the majority of what I have witnessed has been the opposite to your experiences. For the two horrific experiences you've encountered in the last 6 months, I could name at least 20 farmers offhand who managed to ensure their animals didn't come into pup at all.
As for the argument of mixed vs purebreed dog, well this conversation has been going on for decades and will never reach a conclusion. For working dogs with no papers, yes the possibility of course is there for inbreeding. However my experience with farmers both of this generation and the older set, is that they have an uncanny ability of remembering where their dogs line and heritage come from. Not a perfectly reliable system of course I know.
As for diluting the border collie gene. Well it has been, in terms of the Irish sheep dog we have today. We don't have a border collie working our farm. If anything she looks a little more like a greyhound as she has such a large lung capacity. True there's border collie in her, but I'm certain there's a bit of welsh sheep dog in her too. There are plenty of good herding dogs of differant breeds which have been mixed throughout the years keeping the working line quite healthy IMO.
I mean the last two dogs we lost were 18 and 14 respectively. That's a fine age for an animal working the majority of its life. We still know of at least one of the 14yr olds siblings still living, he's going on 16 now.0 -
Not a hard-and-fast rule but the more outcrossed the dog is the better it tends to fare health-wise, at least as far as genetics go. That's where you get inbreeding depression, and that's why hybrids are used for poultry etc.
Sheepdogs tend to be more landrace-y (?), rather than being in an actual breed, and so they tend to have higher rates of genetic diversity, and longer lifespans. Of course one doesn't equal the other, it just betters your odds a bit. Within a breed it doesn't seem to have much effect.
It's not a magic wand- cross two genetic wrecks and you'll just get a third. Stuff like the particular breed, the progenitors of that dog, size, shape etc all have as great or greater effects. So that random lab-collie mix would be less risky than any bulldog, for example, because of the breed and conformation factors.
http://www.thekennelclub.org.uk/item/570
Have a look at the pet insurance companies, they generally charge you less to cover a mixed breed dog. They're not in the business of losing money, and they're about the only people keeping serious statistics on this kind of thing.
http://www.allianz.ie/Pet-Insurance/
http://www.petinsure.ie/index.cfm/page/plans_discounts0
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