$ Paying for Small Business Startup $

I am a veterinarian, currently an associate at a large animal (mostly dairy) practice. I am transitioning into working ~3 shifts a week at a small animal emergency clinic and starting up an equine practice on the side. My question is primarily financial. I am trying to acquire equipment (mostly used because it’s cheaper) while I maintain working at the dairy practice, earning a salary, but how do most people find the capital to start up a small business that requires specific equipment to even get started. I tried applying for a small business loan at my bank and they denied me because I didn’t have 2 years proof of business transactions. This seems backwards to me. How are you supposed to obtain equipment to start if you can’t get the loan for said equipment?