Puppy, perhaps, we found in litter or otherwise (10)
I believe the answer is:
rottweiler
'puppy perhaps' is the definition.
(Rottweiler is a breed of dog)
'we found in litter or otherwise' is the wordplay.
'found in' means one lot of letters goes inside another.
'otherwise' indicates an anagram.
'litter'+'or'='litteror'
'litteror' anagrammed gives 'rottiler'.
'we' placed inside 'rottiler' is 'ROTTWEILER'.
(Other definitions for rottweiler that I've seen before include "Large black/tan dog" , "Large and powerful dog, originally from Germany" , "Fierce dog" , "Powerful German dog" , "Highly aggressive sort" .)