Nicola Martin, who began working at the animal shelter as a student, is "absolutely devastated" at being made redundant.
The SPCA announced a few weeks ago it was undertaking an independent review of financial and business processes to be sustainable in the future.
A spokeswoman for the SPCA, who didn't want to be identified, said as a result of the review, Ms Martin had been made redundant.
She said Ms Martin had been an enormous asset and would be missed.
"Nicola's knowledge and selfless commitment to the organisation will be sorely missed by everyone. She is a role model for all young women as she puts her needs second to the animals on every occasion ... the committee and staff all wish Nicola well in any future endeavours."