BARF is an acronym for biologically appropriate raw food, which is a kind of pet diet in which owners feed their pets raw food (some pet owners swear by it, I personally think it’s nonsense). This product looks like a pure supplement that is only meant to be added to raw food for extra nutrients.
Very important point, just one technical remark, because I see this a lot: You don’t necessarily want or need random samples in surveys. What you want is a probability sample, which means that you know the probability with which a person enters the sample. A random sample is a special type of probability sample, where each person has the same probability to enter the sample.
The large sample used for this “survey” in the OP is a convenience sample, which is a non-probability sample, where the persons’ probabilities to enter the sample are simply unknown. And this is often not a useful basis for a survey, because it’s affected by all sorts of response biases that are difficult to adjust for in non-probability samples.