Dogs and cats may be used in pet food outside of the US. They may even be used inside the US; however, large companies have no reason to risk their reps or their profits to do so.
Dogs and cats are rendered and used as fertilizer. It would not be surprising if some company somewhere uses the rendered remains as animal feed. This would show up in FDA testing though.
The FDA did find small amounts of pentobarb in pet food in 2002. Further testing for dog and cat protein was negative. So it had to be from euthanized farm animals.
I think what you are referring to is "meat and bone meal". I suppose the use of dogs in cats as part of this ingredient can't be proven or disproven unless somebody sends the food to an independent, unbiased, outside lab. I'm quite certain zero dog and cat proteins would be found in the US version of this food, however, so I personally would not waste my money.
Purina probably does believe in vivosection. All major companies have test animals. It is an incredibly sad reality, but this is very necessary. You'll have some companies that do palatability trials with their own pets and some that really don't do any testing at all. The problem with this is that there is a lot of room for bias, the food is not truly being given a trial, it proves nothing about the medicinal properties of foods, etc. This may be barely adequate for a small company that was formed overnight just trying to sell food with a pretty label. It is but adequate for companies that are actually attempting to help very sick dogs. These foods sometimes replace drugs for pets. They are a very important part of veterinary medicine. The big three dog food companies are actually trying to do genetics work relating to metabolism and such. And one of them just got a patent for a BioFilm to take certain supplements to certain parts of the intestinal tract. What small company that is lollipops and sunshine does this? None that I know of...
It is a matter of whether or not you think it is appropriate for your pets to be the guinea pigs for food manufacturers. It is not okay with me. So yes, I buy from companies that choose to do some testing. As cruel as it is, my pets come first. This is how we get medications for ourselves too. They have to be tested on something.
I understand the "Purina hate" and the dislike of using animals to experiment. I'm no fan of animals being traumatized either. But robots cannot do this for us. In my opinion, it is very necessary. Until there is another way, I have to support it. Purina is, in fact, probably saving my dog's life right now. So I will continue to feed it. On the other hand, as a company I think their OTC foods could be better and I don't recommend them. There are better foods out there, again in my opinion.
I do know that Science Diet has a promise that they will not do studies that involve animals that are the same as or very close to those previously performed and that is something that I really respect. I'm not sure how Purina and RC feel about this issue.
You can read more about euthanized pets being used in pet food on Dr. Remillard's website at
www.petdiets.com.