Yes. And no.
Yes, domestic dog and coyote hybrids are biologically possible and have occurred; but no genetic sampling of coyotes has found evidence of domestic dog. Coy-dogs don't survive, and here's why.
- The coyote pair bond is strong and long-term, discouraging interlopers.
- Male and female are sexually active once a year, and only briefly.
- The female is receptive for 10 days, although general courtship activity that strengthens the pair bond can last for months.
- Pups are born in spring when food to feed hungry young is plentiful.
- Males are fully engaged feeding mate and young in the den, often with the help of older offspring.
Yes, a female coyote might pair with a domestic dog in the absence of a coyote mate, but a male dog lacks parental instincts and soon departs the scene. Starvation odds are high without his help, as well as predation of pups when the female leaves the den to hunt for food.
As a coy-dog hybrid, the rare survivor will reach sexual maturity in November, way off schedule with a true coyote's breeding season in February. If a coy-dog does succeed in finding another hybrid to mate with, the second generation coy-dogs will be born in January, not May. The depths of winter are a tough time for the female to find food for herself and her young.
As a third and final strike against coy-dog survival, mixing up the genes also mixes up the instincts that help true coyotes survive in the wild world.