On a recent windy afternoon, two construction workers wearing hard hats heft sheets of plywood off a truck and carry them through the sliding metal doors of a sprawling two-story warehouse. The building takes up half a block behind the SF/SPCA complex at the eastern edge of the Mission District. Inside, banging hammers and whirling electric saws echo in the cavernous space as workers busily transform the structure into the 44,000-square-foot Leanne B. Roberts Animal Care Center. It will be the second-largest pet hospital in North America.

The SF/SPCA's current plan is that the new hospital, expected to open in the spring of 2009, will offer market-rate veterinary services for those who can afford it. The profits will subsidize the nonprofit's charitable pet care services, which currently run about $1.5 million a year. The new center will also house the SF/SPCA's feral cat program and intake offices. Once completed, the center will double the capacity of the SF/SPCA's current veterinary hospital. And planners promise the average number of spay/neuter procedures performed each year will double, to 13,000.

But there are financial concerns. The original estimate of $15 million has doubled to $30 million, and that figure could increase significantly based on rising fuel costs alone. The $17 million donated by the Roberts Family Trust specifically for the hospital long ago ran out, and the board of directors has taken out a two-year line of credit to bridge a $7 million funding gap while it scrambles to find contributions to pay for the project.

While the majority of funding has come from contributions specifically intended for the hospital, the SF/SPCA has also dipped into its general fund, which has riled donors who thought their contributions were going directly toward helping animals, not speculation on a for-profit hospital. The board of directors pulled $1.4 million from the general fund for architectural fees and other preliminary work in 1999. After the hospital is opened, it is expected to run at a first-year deficit of at least $700,000, which will have to be made up from the general fund, as will lines of credit and loan interests, which could cost hundreds of thousands of dollars.

The Cat Crusaders say the cost overruns are responsible for the service cutbacks and new euthanasia policies. They promise to challenge the SF/SPCA until it retrains its focus and resources on the principles of a no-kill shelter. And right now, their primary target is president Jan McHugh-Smith.