Pet leaps in wildly (7)
I believe the answer is:
spaniel
'pet' is the definition.
The definition and answer can be both animals as well as being singular nouns.
Maybe there's a link between them I don't understand?
'leaps in wildly' is the wordplay.
'wildly' is an anagram indicator.
'leaps'+'in'='leapsin'
'leapsin' with letters rearranged gives 'SPANIEL'.
Can you help me to learn more?
(Other definitions for spaniel that I've seen before include "Dog with drooping ears" , "Dog with long silky coat" , "Gundog; obsequious type" , "Type of dog" , "Alpines (anag)" .)