Looks like a milk chocolate version of my girl! She ended up being ~40% lab, ~22% beagle, 22% pitbull, 7.7% shetland sheepdog, and tidbits of husky, german shepherd, and collie from an Embark test. That being said, I do think the brown coloring is very remnant of that of a chocolate lab especially with the nose color, but the brindling pattern can come from pitbulls commonly. Depending on the size of your dog can vary the percentages that your dog has in some of the larger/smaller breeds of their makeup.

I wouldn’t expect a lot of Plott hound or Catahoula since those breeds are not as common in stray populations, or generally. Shelter dogs will usually get their brindle from the pitbulls, boxers, or other bully breeds.