Dogs and sizes and breeding and such

Do all dogs perceive each other as being of the same race? How can a Great Dane (insert large dog race) and Chihuahua (small dog race) see each other as possible competition / mating material? Left to their own devices would Great Danes and Chihuahuas form packs together? Is there a great variety in intelligence between the different races? Are big dogs more intelligent than small ones?

Are all dog races able to mate with each and produce liveable and non-sterile offspring?

It seems obvious a Great Dane in nature could never mate with a Chihuahua but if it was helped along in captivity (and provided the poor Chihuahua bitch didn’t explode) would the Chihuahua be able to give birth or would the foetus grow too big inside the womb? Would a Chihuahua even have a penis big enough to do any difference to a Great Dane? And a Great Dane artificially inseminated with Chihuahua sperm, would that produce liveable offspring?

Since very large and very small dog races seem unable to mate together without a human hand, wouldn’t it be more appropriate to classify them as different species?

Dogs seem to come in a very great variety, and yet they supposedly all come from the same ancestors a mere tens of thousands of years ago. Are dogs especially malleable, or could for instance humans be bred to the same variety? Would it be possible to breed a 30cm tall human or a 5 meter one - and still classify them as humans?

Right, I’ll stop here???

I watched a television show on English bulldogs where they said that it was common for them to require caesareans, due to a small birth canal. It made me wonder how many other breeds need human assistance to procreate.

I once heard (somewhere, and I’ve been unable to confirm it) that all puppies are roughly the same size, regardless of breed, and that the larger breeds just grow faster and for a longer time. Can anyone confirm or deny this? If it’s true, it would explain why a Chihuahua and a Great Dane could have puppies together, even if the Chihuahua were the mother.

Well, I can answer the smartness one - it’s not dependant on size.

Generally, border collies are considered the smartest dog, and they’re sort of mid-sized (about 45 lbs, I think).

Afgan Hounds are considred the dumbest dog, and they’re about the same size.

Standard poodles and german shepards are both sort of large, and are in the top 10 of smartness. However, the Papillon is also in the top ten, and they’re tiny.

So, smartness is not dependant on size, or even related very much.

This is the false assumption by which your argument falls apart. Dogs of vastly different sizes can and do breed unassisted. My neighbors had a litter of Doberman Chihuahuas. The Chihuahua was a teacup, and he was the stud. The Doberman was the bitch. No one witnessed the mating, but the vet hypothesized that she laid on her side to do the deed.

The puppies were born bigger than their father. He was one proud papa!

Babies of all animals are sized in relation to the mother far more than the father. That’s why little 4"10" women can easily and safely give birth to the babies of 6’8" men. I know no less than four couples where the woman can walk under her husband’s outstretched arm with room to spare, yet all have safely delivered babies from them. After the birth, they tend to grow bigger, but not while they’re in the womb.

I assume by “race” you mean “species,” or even “breed”, right? While I can’t say how dogs percieve anything, I’ve seen dogs of all breeds interested and able to interact with dogs of other breeds.

There is quite a variety in intellegence between breeds, but as far as I know the differences do not correlate with size. Teacup chihuahuas are quite smart and trainable, whereas Great Danes are sweet, but rather dim. Then again, standard poodles (large dogs) are very smart and pugs - er, notsomuch. Maybe **Colibri **will stop by with some more info.

The reason we classify all dogs as the same species is because genetic information can flow freely between all breeds, even if they’re not able to mate directly. A very large dog may not be able to mate with a very small dog, but both could mate successfully with a medium sized dog.

As for what dogs perceive, they don’t really care whether we think they’re in the same species or not. They see something and think “hey, I bet I could hump that!” whether it’s another dog, your leg, a couch…

Also remember that dogs recognize things much more by smell than by vision. If something smells doggy they will think it is a dog, if it smells like something else then it must be something else.

Dogs aren’t (or weren’t) especially malleable, but they have been domesticated for much longer than any other species. Plus they are smaller and more eay to control than cows, sheep, horses, etc. And because dogs are companion animals there is a lot more interest in breeding unusual dogs than unusual cows. Mutations are often preserved in dog breeds that would be culled by farmers looking for milk, meat, or fiber production from their stock.

I don’t know if they’re the same size, but some awfully big dogs start off as awfully small puppies. A friend once had a St. Bernard mix who was well over 100 pounds at maturity, but as a puppy, you could hold him in the palm of your hand. That said, though, I’ve never seen puppies of any of the toy breeds, so for all I know they might be even smaller yet.

And most of the mid-sized and large dogs I’ve known don’t seem to know quite what to make of toy breed dogs: They don’t react to them in the same way that they do to others their own size. Clearly, though, at least some dogs do regard toy breeds as fellow dogs, as evidenced by WhyNot’s neighbor’s puppies.

I think it might help the OP to get his head around his questions to realize that the concept of “breed” (or as he puts it “race”) is a categorization based on nothing more than looks. A Great Dane is no more different from a Chihuahua than a competitor in the Worlds Strongest Man competition is different from a jockey. There is no truly fundamental difference between them.

Add this to the fact that dogs (Cannis familiaris) have been bred to wolves (Cannis lupis), coyotes (Canis latrans), and jackals (Canis aureus) and have produced fertile offspring and even a concept like species becomes somewhat less distinct than some would like it to be. (Yes, I know, males of these hybrids are usually sterile, but not always, and females are almost always fertile)

Heck, a 2ft tall at the shoulder, 40 lb Serval cat (Felis serval) male can be bred to a 10lb, 8 inches tall at the shoulder domestic cat (Felis catus) female and produce fertile offspring. They’re called Savannah Cats and are the new hot craze for cat fanciers. (If I could pony up the $5K they get for one, I’d do it in a second)

In other words, concepts like race and breed mean about as much as concepts like tall and short. It seems to me the OP is worrying about distinctions that simply don’t exist.

We are so lucky that you know so much about Danes. :rolleyes:

I bred/showed Danes for 20 years. I could write a post that would choke the site, if I began telling stories of various wunderdog Danes. So I’ll limit myself, but please bear in mind that I could go on almost forever.

Exhibitors whom I knew with an obedience (male) Dane trained him (and I doubt it took very much, if they showed him just what they wanted) to use the toilet so they didn’t have to take him out and walk him in strange places, in bad weather. A photo of him squatting over the pot was published in a Dane magazine. I’ve never heard of any dog of any other breed (or mixture thereof) who learned to do that.

My Peaches (first brood bitch) learned how to open a door with her foot. Danes who learn how to use their mouth to turn a doorknob are common, so I wasn’t too surprised when I discovered she was opening a door. What kerflummoxed me was that there was no saliva on the doorknob. Then one day I happened to walk (quietly) into the room when she was doing it. If she hadn’t been concentrating on the door, I might never have seen it. What she did was to raise her right front paw (all the [COLOR=Red]other people in the household were right-handed, so naturally she used her right one)[/COLOR], press it against the doorknob until her toes splayed around the knob (gripping it), and turned her paw, opening the door. After that, I locked the door. Either she didn’t have the fine motor control to manage a key, or she didn’t get enough opportunities to watch us unlock doors, so I was safe. <whew>

Because of various other things she got into, I started keeping Peaches in the basement, with a half-height solid plywood gate to keep her down there, when no two-legged people were home. One day someone broke into my house. Peaches jumped the gate, (going up the stairs, and she wasn’t one of the slimmer, more greyhound-type Danes), and chased the bad guy(s). They barricaded my bedroom door and went out the window. She acted ashamed when I got home; I’ve always believed it was more because the burglar(s) got away than because she disobeyed me.

Some years later, I lost one of my favorite (stud) dogs to bloat. That night, as I was sitting on my couch, grieving, his 10 week old pup managed to clamber over obstacles to get out of his (mother’s) area, came through it all, climbed up in my lap and began to try to comfort me. First and last time he ever did the escape trick, although he was the grandson of the most brilliant escape artist I’ve ever known or heard of - Nickie. I named him Trouper for that episode.

Nickie could open any door - even locked ones. Her “owner” had a refrigerator with a step-to-open latch, (which he was too dumb to replace), so she always checked out what was available when she had the munchies. She always closed the door, but usually not hard enough for it to latch.

Both Nicky and Peaches were among Dane bitches I knew (and more that I knew about) who refused to conceive by a stud dog not of their own choosing. In order to get them to conceive, they had to be “courted” by a stud dog. My Eric was the one who was clever enough to be able to persuade both of them (about a year apart) to have their first litters.

I’ve always said that, with the exception of driving a car (or the dump truck), a Dane could do pretty much anything you saw in a Marmaduke cartoon … and that there are probably some Danes who are just looking for the right driving instructor. The only canids who compare with the really bright Danes (like Peaches and Nickie, and Trouper are wolves, and many of them readily outsmart people.

In a humor column, I once saw the reprint of an ad for free puppies. “Free puppies to good home. Mother, St. Bernard, Father, very determined Cocker Spaniel.”

I’m sorry if I stepped on your toes by providing specifics. I gladly concede that your knowledge of Danes in particular is wider than mine, as I’ve only owned four in my lifetime.

A quick survey reveals that Great Danes are of average intelligence . I don’t doubt that some of them are brilliant. The most intelligent and well-trained dog I ever had was a pug, not a breed known for their brains. According to Sue Coren’s Intelligence of Dogs, Great Danes rank 48 on canine intelligence tests. The highest rank is 1(Border Collie), the least intelligent is 79 (Afghan Hound).

However, it looks like the one I was most incorrect about in my examples was the Chihuahua. He only ranks 67. Guess the two I know well are very bright for Chihuahuas.

So, for the sake of the poor Chihuahuas and Great Danes, I’ll revise that paragraph to better illustrate my point, which was that size and intelligence are not positively correlated:

*There is quite a variety in intellegence between breeds, but as far as I know the differences do not correlate with size. Miniature Schnauzers (12) are quite smart and trainable, whereas Afghan Hounds (79) are sweet, but rather dim. Then again, Standard Poodles (2) are very smart and Pugs - er, notsomuch (57). *

Better. Accepted.

That works. I can’t disagree with the rating on Mini Schnauzers, fershure. :slight_smile: And Corgis are another (actually, two - Pembrokes and Cardigans) breed(s) that are fairly small and quite intelligent.

However, I suspect that, where both Danes and Afghans (and other gazehounds descended from the primordial Middle Eastern Saluki-like dogs) are concerned, the quite different personalities that many (Danes) to most (Afghans, and to a lesser extent, Salukis, Greyhounds, etc.) dogs descended from this lineage (in part or in whole) lead most people to believe that they aren’t quite bright (among Danes, especially the blacks and blues; sometimes the harleys and fawns, but rarely the brindles). T’ain’t so. It’s a different kind of intelligence. And then, there’s (AIUI) a big hunk of brain that’s devoted to processing visual input in critters that hunt by sight. Their ancestors did hunt by sight, y’know. And you can fascinate most of them with bright, moving objects just like a kitten. :dubious: Try it sometime. :slight_smile: Most of them are playful, and playfulness in adults is usually correlated with intelligence. Just because they look dignified… :stuck_out_tongue:

Despite the mismatch between that kind of personality and the very idea of obedience training (which can be pretty @nal-retentive), I’ve heard of at least one Afghan U.D.; there have been a fair number of Dane U.D.s over the years, as well as a scattering of U.D.s through all the gazehounds (possibly excepting Italian Greyhounds). And the ability to earn advanced obedience degrees is generally regarded as the definitive test of a breed’s ability to learn.

Dogs actually show quite high levels of variation in both nuclear and mitochondrial DNA. Even within dog breeds, which are relatively inbred, genetic variation has turned out to be greater than expected.

Some data suggest that, although dogs are descended from wolves, the two lineages have been mostly separate for over 100,000 years. (However, there have evidently been some backcrosses to wolves more recently.) This is in contrast to the archeological data, in which the oldest recognizable dog remains go back only about 14,000 years. Possibilities include (1) dogs are descended from a now-extinct wolf lineage that split off well before domestication; (2) although domesticated, dogs didn’t change much morphologically before 14,000 years ago; (3) the genetic estimate is in error; another genetic study suggests a figure of 15,000 years ago, which would jibe with the archeological data.

More information on dog and wolf genetics can be found here.

Humans could perhaps be selectively bred within a height range of 60 cm to 2.5 m (near the present maximum limits for viable individuals). For more than that some physiological limits would start kicking in. These could perhaps eventually be overcome to some extent with selective breeding over a long period of time. However, since human generation time is about 10 times that of dogs, selective breeding would take many centuries.

As I end up saying in almost every thread about species and hybridization, the mere fact that two forms are capable of producing fertile hybrids does not indicate they are the same species. The requirement, according to the Biological Species Concept, is that fertile hybrids are not regularly produced in nature. All species in the genus Canis (dogs, wolves, coyotes, jackals) can produce fertile offspring in captivity, and some occasionally do so in nature. However, since natural hybrids are rare, there is no doubt about their specific status according to the BSC.

The Biological Species Concept cannot really be applied to domestic animals, since it only applies to the situation in nature. However, domestic dogs today are generally considered to be conspefic with wolves. Domestic dog breeds are also considered to belong to the same species because, even though there may be problems in crossing some of the most extreme breeds, these breeds are connected by a chain of other breeds with which they can produce hybrids.

If you eliminated all dog breeds except Great Danes and Chihuahuas, you might perhaps consider the two forms different species because they would have a great deal of difficulty interbreeding (even if they occasionally might do so). However, as domestic animals this wouldn’t really be a case to which the Biological Species could be applied. Feral dog populations generally revert to a rather similar form resembling the Dingo. Feral populations resembling Great Danes or Chihuahuas could probably not be established.

As mentioned canid intelligence does not track with size. However, I think it is easy to get the impression that large dogs are smarter than small dogs because the medium to large breeds are used for work whereas small breeds almost never are. A seeing-eye Papillon would be silly even if the dog is quite capable of learning the skills to do it.

As humans bred dogs for this or that trait those dogs selected for high intelligence were probably breeds that the people wanted to do work for them. Toy breeds weren’t selected so much for brains but for size and looks. As a result there seems to be a distinct skew in the number of large (or medium to large) breeds represented in the “smart” dog category.

In the “Top Ten Smartest Dogs” list only the Papillon is small. All the rest are breeds with a working purpose in mind.

Toy and miniature poodles are small, and they are lumped in the number two spot with the standards. All sizes of poodles are scary smart.*

*This does not mean that all poodles are scary smart. I’m sure there are really stupid poodles of all sizes out there as well.

True but along with my premise of why the dogs were bred the Standard Poodle was developed as a working dog and not originally for its looks as many lap dogs were. Working dogs generally need more size to be considered actually useful in most tasks (although sometimes small size was sought for specialized tasks like going down holes) and so it was with the poodle. The Standard Poodle was the “original” poodle with the other sizes following shortly afterwards and they inherited their ancestor’s brains.