The veterinary prescribing cascade (part 1): Equine

Host: Welcome to the Bova UK Podcast, where we discuss diseases from diagnosis through to management. These podcasts are aimed at registered veterinary surgeons and veterinary nurses. If you’re listening as a pet owner, please consult your local veterinary surgeon if you have any concerns about your animal.

Today, we’re demystifying the veterinary prescribing cascade and looking at how it enables prescribing vets to select the best medicines for their patients. We’re joined by Mark Bowen.

Emma: Just to introduce Mark—he’s an RCVS Specialist in Equine Internal Medicine with several specialist qualifications. He spent 25 years in UK academia and was a founding member of Nottingham Vet School. He now works in postgraduate education in Europe as Director of Education for EBVS and VetCEE, alongside running his own specialist consultancy in the Midlands.

Mark has extensive experience with the veterinary medicines regulations. He helped develop BEVA’s ‘Protect Me’ toolkit for antibiotic use, served on BEVA and FVE medicines committees, and sits on the VMD’s Veterinary Products Committee. He’s authored numerous articles on the cascade.

Emma: Mark, thank you for joining us today!

Mark: Hi Emma, thank you.

Understanding the Veterinary Prescribing Cascade in Equine Practice

Emma: Can you take us through the steps of the cascade?

Mark: Absolutely. The cascade changed slightly post-Brexit, so it’s good to revisit. You apply the cascade if there’s no suitable UK-authorised medicine for the condition in your target species.

1. First step: Use a UK-authorised veterinary medicine for another species or a different condition.
2. Second step: Consider human medicines authorised in the UK or veterinary medicines authorised in another country (post-Brexit, this now includes outside the EU).
3. Third step: Use an extemporaneously prepared medicine (a ‘special’) ideally sourced from an authorised manufacturer for quality assurance.

Bonus: In exceptional cases, you can apply for a special import certificate to use human medicines from outside the UK—this is per-animal and strictly regulated.

Applying the Cascade in Practice

Emma: So how do you actually use the cascade in day-to-day practice?

Mark: We use the cascade every day, often without realising it. For example, using phenylbutazone (“bute”) to treat colic—despite its UK authorisation only covering orthopaedic use—is a use under the cascade.

Emma: And do you need off-label consent in these cases?

Mark: Technically, yes. But practically, we prioritise consent when using medicines authorised in another species or human meds. It’s not feasible to get written consent every time you use bute for colic.

Examples of Cascade Use

Emma: What about corticosteroids?

Mark: Yes, prednisone is authorised for equine asthma but often used off-label for skin disease or IBD. I might start with injectable dexamethasone and switch to oral options. However, crushing tablets isn’t ideal—there are compliance and safety concerns. In these cases, a palatable special formulation is often better.

Emma: What about human meds?

Mark: They’re the second step. But strength and volume issues limit their use in horses. Importation is also possible but challenging due to lack of centralised product data. Still, turnaround time for special import certificates is now just a day or two in many cases.

Antibiotics and Responsible Use

Emma: Let’s talk antibiotics.

Mark: The VMD prioritises responsible antimicrobial use—even over strict cascade order. If using a cascade-compliant option reduces resistance risk or avoids a critically important antibiotic, that’s encouraged.

Doxycycline is a great example. It’s a good oral option, but doxycycline hyclate is acidic and can cause irritation or gastric ulceration. Doxycycline monohydrate is less acidic and better tolerated, but it’s a special.

Emma: So compliance is key?

Mark: Exactly. Antibiotics only work if they’re actually ingested. Formulations like palatable pastes help ensure that.

Justifying Use of Specials

Emma: How do you justify going straight to a special if there’s already a licensed product?

Mark: The cascade centres on suitability. If a licensed product isn’t practical (e.g., poor compliance, formulation issues), a special may be appropriate.

Take doxycycline: oral powders for pigs are acidic and hard to administer. If a horse has poor compliance or risk of ulcers, a special paste formulation is more suitable—even though the active ingredient is the same.

Emma: So vets should apply the cascade thoughtfully but confidently.

Mark: Yes. There’s no “cascade police.” What matters is whether you made a sound, patient-focused decision. The cascade is a tool to support your clinical judgement—not restrict it.

Consent and Documentation

Emma: What about consent forms and information leaflets?

Mark: There are great resources. BEVA and the VDS offer consent templates. BEVA also provides client info leaflets explaining off-label meds—including QR codes for digital access. Informed consent means explaining potential side effects, handling, storage, etc.

Final Thoughts

Emma: Any closing thoughts?

Mark: Yes—remember this is about doing what’s best for the animal in front of you. If you follow a logical, case-by-case decision-making process, you are using the cascade correctly. Another vet might choose differently—that’s okay. What matters is your justification and the welfare of the patient.

Emma: Thank you so much, Mark. This has been a really useful and reassuring discussion on using the cascade compliantly in equine practice.

Mark: Thank you, Emma.

These podcasts are aimed at registered veterinary surgeons and veterinary nurses. If you’re listening as a pet owner, please consult your local veterinary surgeon for any animal health concerns.