The clinic provides veterinary care for pets whose owners rely on a pension or benefits such as Universal Credit.
It underwent a large refurbishment last year, reopening in December.
Clinic manager Nicola Rose said: “It is a huge shock and extremely upsetting for the whole team.
“We have worked so hard on the recent refurbishment to provide a top-tier facility for local animals, and to see it targeted in this way is heart-breaking”
Income generation manager Derrick Yapp said he was worried it would still be left out of pocket.
He added: “Every penny that’s taken away just means that’s possibly another animal we can’t help.”
The centre managed to reopen for business as usual two days later.
