I call "BS" on the "Big dogs kill little dogs" nonsense. Might be true if two strange dogs meet. But a now-retired co-worker had a Yorkie that lorded over a Golden Retriever - they were best buddies. Both are now in 'doggy heaven'.
She now has a Lab she rescued as a puppy one dark and stormy night, then later acquired two JRT females. Those little mistreated JRT girls were understandably skittish of the Big Dog at first - now, he's their doting big brother and protects them. And they know it! Any trouble, they run up under Big Brother!
I once knew a woman who worked for the SPCA - they are a goon squad. Totally agenda-driven Libtard Whackos.......