SPCA Otago executive officer Sophie McSkimming said Lotteries Minister Peter Dunne gave $50,000 from his discretionary fund to redevelop buildings belonging to the non-profit organisation.
"It is a very welcome boost," Ms McSkimming said.
This grant takes the fundraising total to $766,000, more than 50% of the targeted $1.5million.
The fundraising campaign started in June.
Organisers aim to raise the funds by Christmas.
The construction project will be completed in three parts: priority services including veterinary consultation rooms and the education facility; improved quarantine and treatment areas and an extension of the adoption facility to ensure adequate separation from the quarantine area.