Photo credit: IstoletheTV, via Flickr.

If you've ever had a pet, you may have wondered if your dog or cat can be gay. You may have seen your dog mount another pup at the dog park — or watched as your cat seemed only to groom her female litter mates while ignoring her brothers. Since house pets don't often couple up with a significant other, these questions may just be speculation. However scientists and anthropologists are paying close attention to the possibility.

Same-sex behavior has long been noted in animals of many different species. In 2014, the BBC reported on a pair of male Humboldt penguins who raise orphaned eggs together at a zoo in Kent, England.

Scientists often study two things when trying to determine whether animals can be gay: exclusivity and longevity. Exclusivity considers whether these animals are participating in sexual relations only with members of the same sex. A study in the “Frontiers in Neuroendocrinology” journal found that about 8 percent of rams appear to mate exclusively with other males, but domesticated sheep seem to be the only non-human mammal with deliberate same-sex mating behaviors.  

Other animals, such as Japanese macaques, bottlenose dolphins and bonobos (one of our closest primate relatives), mate and cuddle with partners of both genders, notes the BBC — exhibiting more fluid behavior that is closer to what we would call bisexuality.

So can dogs be gay? Can cats be gay? The jury is still out.