Four acts belong to the licensed veterinarian alone, in every state veterinary practice act: diagnosing, prognosing, prescribing, and performing surgery.
That boundary comes from the model definition of "the practice of veterinary medicine" in the AVMA's act, and the two enacted state statutes this page quotes converge on the same four acts.
No technician credential, specialty certification, or years of floor experience moves it.
For a veterinarian running a team, this is not trivia — it is the fixed point every delegation, hiring, and supervision decision in the practice has to sit on top of.
The model definition behind the four acts
The reason these four acts read as a single, unmoving unit rather than four separate rules is that they all come from one definition.
The AVMA Model Veterinary Practice Act (2019) defines "practice of veterinary medicine" as, in relevant part: to diagnose, prognose, treat, correct, change, alleviate, or prevent animal disease, illness, pain, deformity, defect, or injury by any method or mode — including the performance of any medical or surgical procedure and the prescription, dispensing, administration, or application of any drug, medicine, biologic, or anesthetic.
That definition is where diagnose, prognose, prescribe, and surgery all trace back to.
It is a model act — guidance the AVMA drafts for state legislatures, not law in any state on its own.
But two enacted state statutes independently converge on the same core: California Business & Professions Code §4826 defines the practice around diagnosing, prescribing, administering treatment, and performing surgical or dental operations, plus holding oneself out as a veterinarian; Utah Code §58-28-102(11) defines it as diagnosing, prognosing, or treating any animal condition, plus administering, prescribing, or operating, plus its own title-holding-out clause.
Different states, same shape.
The four reserved acts, briefly
Diagnose — naming what's wrong with the animal, not just running the test that shows it.
Prognose — predicting how the case will go.
Prescribe — deciding the drug, dose, and condition it treats, and authorizing it; administering a drug someone else prescribed is a different act.
Perform surgery — creating an incision, as opposed to closing one a veterinarian already made, which the rules in states like Colorado, Maryland and Iowa treat as a separate, delegable task.
This page doesn't re-walk each of those four in full — the task-by-task breakdown, state variation on the delegable edges (suturing an existing incision, simple dental extractions), and what a specialty credential does and doesn't change is covered from the staff side in what a vet tech can't do.
What matters here is the mirror image: these four acts are what your license actually is, not just what your staff's license isn't.
Colorado's veterinary professional associate framework is the only enacted attempt — as of September 2026 — to build a role a level below that line; where it is actually authorized, state by state, is tracked in the mid-level role state tracker.
Why the authority sits with your license, not your experience
A credentialed technician with a decade in emergency medicine and a brand-new veterinarian three weeks out of the NAVLE are not close to interchangeable on these four acts, and that is by design.
The authority to diagnose, prognose, prescribe, and operate is granted by state licensure — the NAVLE plus a state's own requirements — not earned incrementally through time on the floor.
A technician who has watched a thousand diagnoses made still cannot make one; a newly licensed veterinarian can, on day one.
That gate has teeth on its far side too.
Practicing veterinary medicine without a license is what a practice act's enforcement provisions exist for: California Business & Professions Code §4825 makes it unlawful to practice veterinary medicine, or any branch of it, unless the person holds a valid, unexpired, and unrevoked California license at the time, and Texas Occupations Code §801.251 goes further than practicing — offering or even attempting to practice without a Texas license is prohibited as well, except as allowed by the chapter's exemptions in §801.004.
The penalties are set state by state, and they don't stop at the person holding the instrument.
In California, violating the Practice Act — or aiding and abetting a violation — is a misdemeanor punishable by a $500–$2,000 fine and/or 30 days to one year in county jail.
In Florida, violating any prohibition in Florida Statutes §474.213, including practicing without a valid, active license and knowingly employing unlicensed persons in the practice of veterinary medicine, is a third-degree felony — so the practice shares the exposure for an unlicensed hire.
That is what makes checking a candidate's license part of the hire itself rather than an HR formality: the employer-side walkthrough, state board lookup by state included, is in how to verify a veterinarian's license before you hire.
The same license discipline runs one layer down: prescribing, dispensing, and administering drugs sit inside the reserved definition, controlled or not — the registration, inventory and recordkeeping mechanics are covered in the controlled-substances guide.
The pattern shows up in ownership too: premises-permit states — California and Florida among them — register the facility and name a specific licensed veterinarian as the party responsible for it, even when a non-veterinarian owns the practice.
The license is the actual unit of authority in a veterinary practice — everything else, including a job title, sits downstream of it.
Colorado's veterinary professional associate framework — the only enacted one in the country as of September 2026 — is the live test of that arrangement; see how the technician, mid-level and DVM scopes compare in statutory text.
The model act reaches beyond the exam room
It's easy to read "practice of veterinary medicine" as something that only happens with an animal on the table, but the model act's own commentary is explicit that the definition reaches further: it says the definition "stresses that the practice of veterinary medicine includes the use of telephonic and other electronic communications for the rendering of advice or recommendation for the diagnosis, treatment, correction, alteration, relief, or prevention of animal disease," adding that the intent is to regulate telemedicine, not to stop non-veterinarians from discussing animal care.
That is the same reasoning behind the rule that a veterinarian-client-patient relationship (VCPR) cannot be established solely by telephonic or other electronic means in the model act, and it's why a front-desk staffer relaying a veterinarian's instructions stays outside the definition, while a staffer offering their own advice or recommendation on diagnosis or treatment steps inside it.
The full VCPR picture — including the separate federal VCPR that governs extralabel drug use and doesn't always line up with your state's — is covered in the VCPR and telemedicine guide.
What this means for delegation on your team
Framed from your side of the practice act, delegation isn't a list of what a technician or assistant is allowed to do — it's a duty you owe: to delegate only what can be delegated, to someone you've determined is competent for that specific task, at the supervision level it requires.
The four acts above are the one part of that duty with no state variation and no exception for a specialty credential — not even a Veterinary Technician Specialist changes who may diagnose, prognose, prescribe, or operate.
The only enacted framework built below that line is Colorado's veterinary professional associate, whose delegated scope is still being defined by board rulemaking — see what a veterinary professional associate is for the dated tracker.
Everything below that floor is genuinely state-dependent — which supervision level attaches to which task, covered in the supervision-levels guide — and when delegation goes wrong, the discipline for improper delegation or failure to supervise lands on the veterinarian who made the call, while a staff member who performed a reserved act anyway is exposed too, as an unlicensed practitioner.
The full framework for what can and can't be delegated, including the two separately disciplinable ways it goes wrong, is in what you can legally delegate in a veterinary practice.
General information, not legal advice
What this means for hiring
A job posting that blurs these four acts into a technician's or assistant's listed duties creates a problem before the hire even starts — either for the practice, if it's genuinely asking for reserved work, or for recruiting, if capable candidates read the listing and assume the role requires authority it doesn't.
Describing scope accurately in a posting is one of the more overlooked ways a practice signals it actually understands its own delegation model.
It cuts the other way too on the veterinarian side of hiring: an associate's contract, production terms, and autonomy all sit on top of these same four acts being theirs alone the moment they're licensed, regardless of tenure at the practice.
Browse open veterinarian positions to see how practices describe the scope of the role.