Could my dog be a chimera (hybrid)?

Question

My pet Lola was born of an abandoned spitz-cross stray in Feb 2012. She had a thick white coat with brown ears and face mask, and a big brown spot on her rump where her tail is joined. Big deep chest and body but thin short legs (like that of the Pomeranian). Her tail is short and lifted up in sickle formation like a JRT cross. She had a few tiny brown spots on her legs.

Since last couple of years (after she turned 4+) she has begun to develop small brown patches all over her white body? Do dogs change their coats as they grow ? Is there more to this ? Could she be a chimera? Her unmaternal mother tried to bury her in our compost pit soon after she was born. Her body was shaped like a piglet and is still is big for her height.

Should I get her DNA tested? Could being a chimera and not knowing it cause problems when treating for any infections ?

Answer 1

Genetic chimera https://en.m.wikipedia.org/wiki/Chimera_(genetics) are organisms that have cells of two different genotypes. This phenomenon occurs as the organism is developing in the womb or egg. Therefore, even if your dog is a genetic chimera, that is not the cause of the change in its coat. It at best would be an explanation for the fact that its coat has patches of color.

Genetic chimeras are a rare occurrence, so it's more likely your dog is not a genetic chimera, and its coat just happens to be patched. It is however, still not impossible. You could only be sure through genetic testing. Genetic testing might not even give a true answer, because if the animal is a chimera, you'd still have to collect cells of both genotypes to verify it. It's possible to not sample both types of cells, and miss that the animal is in fact a genetic chimera.

Dogs can change coat color, which has been discussed here before. The causes can be environmental (bleaching in the sun, for example) or genetic. Certain breeds, like the dalmatian, are known for their coats changing as they mature. Dalmatian puppies are born white.
https://en.m.wikipedia.org/wiki/Dalmatian_dog

Chimerism can have some health reprocussions, particularly autoimmune related, when cells of one genotype may start attacking cells of the other. But if your dog had this type of problem, you'd probably have already noticed by now, as autoimmune problems are pretty noticeable. I'm unaware if there are other types of health problems that particularly affect genetic chimera.

Answer 2

A Chimera is an animal which has the DNA of two distinct species (normally) - It's highly unlikely your 'dog' is a chimera. (Breeds of dog aren't distinct species, no matter how different they look). Your dog is likely just a hybrid of two rather distinct breeds.

In biology, a hybrid, or crossbreed, is the result of combining the qualities of two organisms of different breeds, varieties, species or genera -- https://en.wikipedia.org/wiki/Hybrid_(biology)

The change in coat colour is likely nothing to worry about however if there's any change in the coat texture then you should take her to a vet in case it's cancer of some form, or a skin infection.

There is many reasons why dog's coats can change, from genetics, to simply getting their 'winter/summer' coats. See the below link for some interesting examples of what may cause coat changes.

Why has my dogs coat changed colour?

There isn't many animals a dog could concievably breed with, however some dog/wolf hybrids do exist (however there is an arguement they aren't a new species and that dogs and wolves are of one species.

The Wolfdog on Wikipedia