My seven-year-old lab/rottie mix, Logan, has what I always call moles.
Some are sized about halfway between a pea and an olive, and others are
the size of a small tick. They are in odd places - base of the ear,
shoulder blade, back of the thigh, back of the head. None have hair on
them. Most are hard and dome-shaped and feel like they go below the
skin, and others are more like a mushroom where the top part can wiggle
a little bit. They don't bother him a bit unless I nick one when I
comb him (which I have quit doing). One was surgically removed but
grew right back, as the vet expected. He has more now than he did 4
years ago. He also has several fatty masses (the vet's term).

What I'm wondering is, with all of this activity going on on his
exterior, how likely is it that he has weird stuff growing inside as
well? I get a little paranoid because he keeps to himself more than
the other dogs, then he has these days when he climbs up in my lap and
stays for an hour. I lost a beloved dog to something very aggressive
that was never really diagnosed but Lex died within about 3 weeks of
becoming more clingy and I don't want to miss the signs again.

How normal is it for either of these breeds to have alot of these kinds
of growths?

Thanks!