One could make the argument that dressing a dog or cat in clothing is inherently and totally gay--and that's true. People who want to force their pets to be "supportive" of their masters' gayness should stick with generic items like rainbow leashes, collars, and kerchiefs. But if you think your pet is gay, test it out. Start slow, and gradually introduce them to gayer outfits.
Try out the moderately flaming costumes first, using the websites listed at the end of this article. "Zorro Dog" is pretty gay, but it's still masculine enough to allow further sublimation of their homosexuality. A better choice might be the "K-9 Fire Rescue" outfit, the "Giddy Up Little Doggy" cowboy outfit, and "Fairy Tail" fairy outfit. All look pretty fucking gay.
If your cat or dog seems comfortable, up the ante. "Biker Buddy" or "Biker Babe" sets of sleeveless, studded leather vests and caps come in black or pink. Another flaming option is a "Pirate Cat" outfit. Homo statements like "Queen Cat" emblazoned on royal velvet robes can be cutened up with tiny crowns, as well.
If you've come this far without any major cat fights, it's safe to come out and say what's on your mind with everyday accessories. You can get collars that say "FAG DOG," "BUTCH BITCH," or "PROUD PUSSY." These can be attached to a variety of S&M-inspired collars that look just like mini versions of those found at Spartacus--adorable!
Make it known that your pet's alternative lifestyle is accepted at home too, with a fully queer dog or cat chaise. Some good styles are the "Molino," which comes in pink or blue leopard print, the "Casting Couch," trimmed in chenille, or "Muff," in black faux mink and suede.
Now that your pet is fully outfitted in their preferred degree of gayness, pat yourself on the back for being such an open-minded, modern bastion of the alternative lifestyle. Your pet could have never possibly expressed its own preference for the amusement of humans without your help!