Can you still buy pentobarbital in vet shops in Tijuana without prescription?

I finished talking to at least two veterinary clinics in Tijuana and the Centro Medico Vetenario Y Estetica Canina says they have connections with farmacias in town and can get "la medicina de mascotas" for you if you ask them in person. The other one said you need to present yourself and then speak to a supervisor. At least that's what I gathered talking to the receptionist on the cellphone in Spanish. I've just recently returned from Tijuana thru Otay Mesa and then Tecate.