Emancipet can do it for free or at a very low cost. In the Austin area there are also free mobile clinics that absolutely do it for free for Austin "travis county" residents. You have to get there very early though, will be in line for a long time usually and expect to pick your pet up later that day. I hope that helps.
Contact Emancipet. They focus on low cost, free pet vaccinations and spay/neuter.
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