The most common and most likely answer to this crossword clue is the 6 letter word MOUSER
I've seen this crossword clue in Independent
M
O
U
S
E
R
More clues leading to the result MOUSER
- More tricky trapping American cat
- Doctor with client's cat
- Tick, one exploiting cat?
- After short time employer gets cat
- Cat’s right under part of PC
- One employing doctor as pest controller
- Cat, one in the doctor’s surgery?
- Cat, perhaps – one with a particular way of working?
- Cat runs after short time to exercise
- Doctor gets addict a useful cat
Buddy explains!

The straight part
We know that "Cat, perhaps" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cat, perhaps = mouser.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does MOUSER mean?
MOUSER noun- A cat that catches mice, kept specifically for the purpose.
- A moustache.