Can a G. Dane have a Chihuahua's pups?

Factual Questions
1

This just came up under the “incest” post. Technically, they are both dogs and should be able to breed. The size difference obviously prevents breeding from happening naturally. But what if some mad scientist impregnated a Dane using Chihuahua sperm? (I think the reverse would kill the Chihuahua if she actually got pregnant, so we’lll set that aside). Would viable puppies result? And what would they look like? Or would the two breed types have such radically different genes that the resulting puppies would die in teh womb or shortly after birth?

Anyone know for sure?

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Stoidela

2

Refer to the “dog mating(woof)” thread, last posted 5/28. Don’t think it’ll answer all your questions, but it should help.

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3

Yes. A Great Dane can have a Chihuahua’s pups. No, a Chihuahua cannot have a Great Dane’s pups. For the same reason a grape can fit into the space of a watermelon, but a watermelon cannot fit into the space of a grape. They are the same species, and can interbreed the same as any other breeds of dogs can.

4

While we are on this subject, I have a question about wolves. Most people consider wolves and dogs to be separate species, but I have read that there is no genetic difference between dogs and wolves. In fact, all dogs are (I believe) descended from domesticated wolves.

Any comment?

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5

EJC:

This is more of a comment than an answer. I wouldn’t go so far as to say there is no genetic difference between a dog and a wolf, but that’s probably close. Even among different types of dogs, there are large genetic differences. I think they mainly consist of different expressions of the same genes.

Wish I had my old biology book with me, because it helps to explain what actually makes something a distinct “species”. It involves the capability to interbreed and produce viable offspring. There are many different barriers to this. One is physiological, on is mechanical and another is geographical. By “mechanical”, I’m talking about why the chihuahua couldn’t breed with the Great Dane (without human intervention).

6

Snippy comment - if there’s no genetic difference between two animals, it’s called “twins”.

Having got that out of my system, wolves and dogs are close enough genetically that they interbreed quite easily. In fact, in a pure sense, the differences are probably at the “breed” level rather than the species level. Scientific nomenclature was initiated in the Victorian era. Determining where specific animals belonged was somewhat arbitrary, based on observed differences and probably traditional names, rather than genetic niceties.

BTW, there we had a half german shepard, half wolf dog when I was growing up. Dumbest dog I’ve ever known. And there are people out there selling dog/wolf mixes. These are very dangerous animals, because they have the challenge the alpha male characteristic that has been bred out of dogs, with the aggressiveness of the dog species. (These animals usually bred & sold as “macho” dogs, so the breeders are using very aggressive breeds)

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7

While I am not sure about the chihuahua bearing the great dane pups (Mr Borges! I knew you were twisted, but this… :slight_smile: ) I do know that a female basset hound can have a golden labs pups, and there is a pretty large size difference there. Brother has a basset / lab mix, should have named the dog Tank. Height of a basset and head of a basset, musculature of a lab.

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8

While I am not sure about the chihuahua bearing the great dane pups

I don’t see why a chihuahua couldn’t give birth to a great danes pups. The genes of the chihuahua would make the result much smaller then if the great dane were to give birth. On another note…I wonder if anyone has ever tried to breed a cat with a dog. I don’t see why it wouldn’t work but I really don’t know anything about genetics.

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9

It’s probably important to differentiate between mating and reproducing. Any animal can mate with another animal, it’s the reproducing part that’s limited.

As far as the initial dog question goes, there really is no question because there’s no difference between dogs of different breeds. Puppies from parents of different breeds wouldn’t be one breed or the other, they would just be dogs and I doubt that they would ever be so big in the womb so as to pose a danger to the mother. Maybe, but even if they were big they wouldn’t be too big to be thrown. I think nature would prevent this in some way. Maybe not, but I doubt it.

I haven’t taken biology since junior high, but I think that one factor that affects reproduction is the number of chromosomes. Dogs and wolves have the same number, and are similar enough genetically, that they can have offspring. Each parent provides 1 chromosone to each pair - if the parents have different numbers of pairs, then there’s no match and the reproductive cells are incomplete. I’m sure it’s more complicated than that, but I think that’s how it works.

So, dogs and wolves are close enough genetically to have an equal number of chromosomes, 39. I don’t know if they’re technically the same species, but their offspring are fertile.

The simple answer is that cats have 19 pairs and dogs have 39 pairs. But I’ve been thinking about this and have more questions.

Now Donkeys (31 pairs) and Horses (32 pairs) can produce mules. I don’t understand why, exactly, in light of the theory postulated above. And furthermore, mules are almost always sterile because they have an extra chromosome. Can someone explain how mules are possible? And I also think (not sure) that the mother must be a horse. Why is that?

The answer is likely to be that Donkeys and Horses are so similar genetically, and their chromosome pairs so similar, that they can reproduce. But that gets me thinking about humans.

Chimps and Humans are only 1.5% different from one another, and like horses and donkeys, there is only one extra pair of chromosomes (humans 23, chimps 24). Why can’t humans reproduce with chimps like a horse and a donkey? I think it’s clearly a taboo subject in society, but scientifically, is it possible?

10

A woman I know just gave birth. She’s under 5 feet tall; her husband is about 6’2".

Near the end of her term, the baby was so large compared to the rest of her, that she began to have trouble breathing because of the pressure on her lungs. She barely managed to complete a vaginal birth instead of a C-section, but she lost a couple of pints of blood in the process; if there had been no doctors around to give her stitches, she could easily have bled to death.

All this, and the father is not even 125% as big as the mother. A Dane is several times the size of a Chihuahua. Still think that they could have puppies naturally?

11

Chimps and Humans are only 1.5% different from one another, and like horses and donkeys, there is only one extra pair of chromosomes (humans 23, chimps 24). Why can’t humans reproduce with chimps like a horse and a donkey? I think it’s clearly a taboo subject in society, but scientifically, is it possible?

Well Johnny, I’m not sure about you…but I don’t think many humans would want to mate with a chimp.

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12

A couple of comments:

Cats and dogs are totally unrelated species. They could never interbreed.

Chihuahuas and Great Danes could breed. The chihuahua’s size would keep the size of the puppies small enough that some might survive, since the nourishment of the mother has an impact on the size of the fetuses.

Horses and donkeys are closely related. I don’t know the numbers of chromosomes, but I do know that mules are usually sterile. Sometimes a fertile mule comes along, and in those cases they tend to be very very fertile. One of the equine record holders for most foals was a fertile female mule. Go figure. The horse doesn’t always have to be the dam in mule breeding. There are different names for mules bred from jack and mare and stallion and jenny.

For strange breedings, some horse combinations are almost as strange as the chihuahua and the great dane. A woman I know had a little gelding who was the result of an accidental breeding between a draft stallion (+/-2000 pounds, 17.3hh) and a connemara pony mare (+/- 800 pounds, 13hh). That’s a pretty odd combination.

Also, in Australia, the premarin industry uses whatever straws of semen come their way with any currently open mare. Since they then find uses for the resulting foals (unlike the US and Canada which sell them as meat), you can see many unlikely horses in the country. Many are the result of pony or light breeds crosses with heavy draft breeds. Many are useful for sport purposes, though most end up in the bush.

The great dane and the chihuahua question is interesting in the extreme, not for whether it is possible or not. It is possible. What interests me most is this:

What would you expect the result to look like?

I’ll just ponder that for a bit…

13

This all reminds me of the Disney movie <a> href=“http://us.imdb.com/Title?Ugly%20Dachshund,%20The”>The Ugly Dachshund</a>, where a Great Dane puppy is weaned by a mother Dachshund and believes himself to be a Dachshund.

When the vet asks the Dachshund’s owner’s husband to take care of the newborn GD puppy, it appears not to be sizably different from the Dachshund pups. So aside from natural mating problems, I’d say a Dachshund female could carry a litter of GD/Dachshund pups.

14

This all reminds me of the Disney movie The Ugly Dachshund, where a Great Dane puppy is weaned by a mother Dachshund and believes himself to be a Dachshund.

When the vet asks the Dachshund’s owner’s husband to take care of the newborn GD puppy, it appears not to be sizably different from the Dachshund pups. So aside from natural mating problems, I’d say a Dachshund female could carry a litter of GD/Dachshund pups.

15

Speaking of crossbreeds, I was poking around in a bunch of Boston Terrier rescue pages and saw an ad for a BT/Whippet mix up for adoption. Now there’s a dog I couldn’t even begin to imagine what it looked like.

I want it. And I can’t get it 'cos I live in an apartment. Dang!

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16

It’s been a while since I took that cell bio course that covered fertliziation. The cell biology answer is that the receptors on the human sperm won’t bind the proteins on the chimp ovum. I think. The genetic differences between chimps and humans probably include differences in these egg/sperm proteins.

Interestingly enough, fertility tests for men involve human sperm, of course, and hamster eggs. The protein coat that would normally block the fusion of non-hamster sperm is removed.
Alphagene

17

This is slightly off topic, but not entirely irrelevant to the discussion of what qualifes as a species and as interbreeding.

When I was a bio student (way back at the dawn of time, when Reagan was still the president) I remember reading about some species of field mice in the Rocky mountain states, four genetically distinct groups with an interesting feature.

One group lived on the east side of the mountains, one on the west, one to the north in Wyoming where the mountains are relatively easy to cross, and one in New Mexico, where the mountains are also relatively small. These mice couldn’t climb over the very tall part of the Rockies in Colorado and, unsurprisingly, the group just east and just west of the mountains couldn’t interbreed. However, both species could interbreed with the group just north and just south of them. In this way, it is possible for genes to get from the eastern group to the western group even though they couldn’t interbreed. The northern group and the southern group couldn’t interbreed either, but their genes could reach each other via the eastern and western groups.

Taxonomically, they were classifed as four species. This was used as an example of the evidence in favour of evolution.

Is there any chance someone knows the details? It was a long time ago and I’d like to be able to cite a reference in telling that story.

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18

I once knew a Chihuahua that impregnated a Great Dane, but I’m pretty sure somebody put him up to it.

19

I was reading (Fox News Web Page I think under Etcera segment of weird stories from all over) That some person successfully sued another when his prized rottweiler became pregnant by his neighbors…chihuahua. I cannot image what the offspring looks like, but I bet the rottweiler’s owner didn’thave to look to far for the father to point a finger. It must have been pretty obvious. I wish pictures were included in the segment.

20

Ok, I’m not a geneticist but I do breed cats and have a slight amount of knowledge about genetics. Have some interesting info, too! (At least in my opinion!). There are several barriers to fertilization between species besides the obvious physical ones. First of all, the head of the sperm has a structure called the acrosome that releases enzymes that soften the outer shell of the ova so that penetration by the sperm can occur. However, before this can occur a process called capacitation has to occur. When sperm first enter the vagina, the acrosomal shell is tough - after exposure to what are, as far as I know, unknown substances in the vagina this shell becomes softer and more fragile, thus allowing the acrosomic enzymes to be released. Once these are released and the outer coverings of the ova (the corona radiata and the zona pellucida)are penetrated, there are receptors and binding apparati on the sperm and ova that must match up.

So, first the species must be compatible enough that capacitation can occur. If it does, then the acrosomal enzymes must be of the right chemical construction to affect the outer covering of the ova. The, the binders/receptors of the sperm and ova must be compatible.

Some species are similar enough in these areas to make fertilization possible, some are not. Of course, then the chromosomes must be able to combine and produce a viable embryo.

In case anyone is interested, there are several species that are very different in general appearance that have successfully interbred, besides horses/donkeys and dogs/wolves:

horses/zebras
dogs/coyotes
lions/tigers
domestic cats/Asian Leopard Cats
domestic cats/Jungle Cats
domestic cats/Servals
domestic cats/Bobcats
domestic cats/Lynxes
domestic cats/Fishing Cats
domestic cats/Geoffrey’s Cats
domestic cats/Caracals
domestic cats/Scottish Wildcat
domestic cats/European Wildcat
domestic cats/Egyptian Wildcat

There a quite a few more of the domestic cat crosses but I don’t have my source available to look them up. I’ve heard it mentioned, but can’t locate a source, that many biologists speculate that almost all of the small cat species, including the domestic cat, are closely related enough to interbreed. While these crosses usually produce sterile males, the females are usually fertile, and,at least in one case, have been the foundation for the development of a new breed of domestic cat. (Several others are in development at this time.)