Hi chefadam
Welcome and good news about the pup - congratulations!
> I was a little concerned to learn that they test on animals!
Do they? If you are sure of your info do you know what level of testing is meant by that? It could be as innocuous as tasting rather than testing the food on animals. The testing element could be observations of behaviour and testing output (urine and fecal matter). I only ask as I read a few years ago about internet rumours that almost put a food company out of business. All well and good if it's fact but so much gets distorted, then repeated. It's also worth considering that it may be one element they buy in that is tested, rather than being their whole ethos.
After your research, if you do decide not to proceed with this food then do not make the change immediately. Keep him on what works well for the breeder and follow their advice about alternative foods and the timescales involved.
If you come back for specifics later you'll find there are as many food recommendations as there are dogs!! Might be simpler to start with breeder advice

Enjoy your pup xxx
Kindness is the language which the deaf can hear and the blind can see ~Mark Twain