Feed for particular nutritional purposes
Feed for particular nutritional purposes (often called dietetic feed) may be marketed as such only if its intended use is on the list in Regulation (EU) 2020/354 and it has the essential nutritional characteristics set there (Regulation (EC) No 767/2009, Articles 9 and 10).
What does a list entry look like?
Entry No 13, "Reduction of ingredient and nutrient intolerances", applies to dogs and cats: a complete feed with selected protein sources or hydrolysed protein, labelled with a recommendation to seek a veterinarian's opinion before use.
Can any food make that claim?
No. Article 13(3)(b) of Regulation 767/2009 rules out claiming that a feed meets a listed particular nutritional need unless it meets the listed requirements.
Sources
Guide: How to read a dog and cat food label: a guide to Regulation (EC) No 767/2009
Educational information about the rules, not veterinary advice.