The SPCA says that the bids are going to be opened and homes will be screened. This is slightly better than an open auction which would mean that the SPCA could not refuse a sale and the horses could be bought for meat. Sealed bids probably means that the the SPCA can refuse any bid.

But it still is in no way about animal welfare and it certainly has the perception that it is about revenue.

Selling the horses at auction means that any horse-lover without the funds could not give these horses a safe, forever home. Did the SPCA approach any horse rescue groups? It did not approach the Horse Protection Society as far as we know. Did it post on its web site that it was looking for homes?

It is possible that the SPCA stands to make more money by selling the horses at auction than it could ask for if it "adopted/sold" them itself.

Historically this is how the SPCA has disposed of the livestock it boasts to the media and the public that it has "rescued". Not bad - money from gullible horse lovers, and money from horse traders.