Four years of paying full price for a cat’s monthly flea or thyroid medication can quietly cost hundreds of pounds more than it should, simply because nobody ever handed over a Comparison sheet. That’s the maddening truth behind a system that, until recently, relied on pet owners not knowing they could ask.
Here’s the reality: when your vet prescribes medication for your pet, they have two options: dispense it themselves from their in-house pharmacy, or issue you a written prescription that you can take to any registered veterinary pharmacy. The vast majority of pet owners simply buy medication directly from their vet, because it’s convenient and most people don’t realise they have another option. That single administrative form, the one nobody mentions unless you ask, is the difference between paying surgery prices indefinitely and shopping around like you would for anything else.
Key takeaways
- A document exists that could save you up to 70% on your pet’s monthly medication—but almost no vet mentions it unprompted
- Four years of overpaying on a single medication could total £400-£800, enough to fund major veterinary procedures
- Regulatory changes are finally forcing transparency, but you already have the legal right to ask today
The Sheet Nobody Hands You
The numbers involved aren’t trivial. Getting a prescription from your vet and buying medication from a trusted online pet pharmacy is cheaper, with some medications costing as much as 70% less to buy online instead of from the vet. Other comparisons land in a similarly wide range: online pharmacies are typically 30-70% cheaper than vet dispensaries. For a cat on a lifelong medication, thyroid tablets, heart medication, insulin, that gap compounds month after month into a genuinely painful sum.
Independent price-comparison analysis backs this up in pounds and pence rather than percentages. Buying online with a written prescription typically saves £100–£200 per year on common long-term medications, and sometimes significantly more. Multiply that by four years and you’re looking at a sum that could have covered an entire course of dental treatment or a decent pet insurance excess. The frustrating part is that none of this requires a loophole. Owners don’t need to worry about asking their vet to write a prescription, because vets have an obligation to help pet owners get their medication in the way that’s cheapest and most convenient for them.
Why This Has Been Allowed to Happen
The obligation exists, but for years the incentive structure worked against it. Prescription fees themselves became a quiet deterrent. As one analysis put it, some veterinary practices charged £30 or more just to provide a written prescription, and while a high price might usually encourage someone to shop around, in this industry it often had the opposite effect, acting as a “barrier to entry” because the medication found online had to be at least £30 cheaper before an owner even began to save money. Charge enough for the paperwork, and the saving evaporates before it starts.
This isn’t a fringe grumble. The Competition and Markets Authority has been investigating exactly this dynamic since September 2023, and its provisional findings concluded that the veterinary services market for household pets is not functioning effectively, noting that average veterinary prices have risen by more than 60% since 2016. A separate CMA-linked guide found that in 2025, over 40% of first-opinion practices still did not display any prices on their websites, and the regulator received around 45,000 contacts from pet owners during its investigation, a scale that tells you this wasn’t one disgruntled cat owner’s imagination.
What’s Changing (and What You Can Do Right Now)
The good news for anyone still handing over full price every month is that the rules are tightening. Following its final report, the CMA is introducing standard price lists for defined veterinary services and the most commonly sold pet parasiticide products, prescription fee caps, and a price comparison website. Under the incoming cap, prescription fees are expected to be set at around £21 for the first item and £12.50 for additional medications on the same prescription, replacing a patchwork where, previously, fees typically ranged from £10 to £35, with some practices charging more.
None of this means you need to wait for the paperwork to catch up. Legally, you already have the right to ask, and vets already have to comply. Under RCVS rules, vets must provide a written prescription if you request one, and they cannot refuse to encourage you to buy from them directly; they can only charge a “reasonable fee” that should reflect the administrative cost, not act as a deterrent. A prescription isn’t a one-off either. A prescription is valid for up to six months from the date it was signed, giving you time to shop around, and it’s worth asking specifically for a repeat prescription so you don’t have to renegotiate the same conversation every few weeks.
Safety matters just as much as savings, though. Cheap and dodgy are not the same as cheap and legitimate, so buying pet prescriptions online is completely legal in the UK, provided the pharmacy is registered with the Veterinary Medicines Directorate (VMD) and you have a valid prescription. Before you order anything, check the retailer against the VMD’s own register rather than trusting a badge on a website. It takes two minutes and rules out counterfeit or badly stored medicines, which is a genuine risk with unregulated sellers.
Practically, the conversation with your vet should be short and unembarrassing: ask for a written prescription at the end of the consultation, ask whether a repeat prescription is available for ongoing treatment, and ask for an itemised bill so you can see exactly what the medication line costs versus the consultation fee. None of this damages your relationship with the practice or implies you don’t trust their clinical judgement. It simply means you’re treating your cat’s long-term health the way any sensible household treats a recurring bill, by checking whether the same box, the same dose, the same active ingredient, is being sold cheaper five minutes down the road. Your vet still does the diagnosing. You just get to choose where the tablets come from.
Sources : comparemyvet.uk | vbb.com