Omega-3 cat food for British Shorthairs

Your vet's advice to increase omega-3 through food rather than supplements is solid — fish-based whole-food sources are better absorbed and less likely to cause digestive upset in older cats. Cats are obligate carnivores with specific nutritional needs many commercial foods don't fully meet, and wet food is generally the right base for a 10-year-old anyway, given how critical hydration is for kidney health at that age. Before I point you toward something specific — is your British Shorthair male or female, and is the vet's concern mainly joints, coat, or something like early kidney markers? And what are you currently feeding?

That makes a lot of sense. The Royal Canin British Shorthair dry is breed-specific but it's not particularly rich in omega-3, and dry food as a base means she's likely mildly under-hydrated, which compounds everything at 10. For a cat her age with joint stiffness and a dull coat, you want a wet food where oily fish — sardine, mackerel, salmon — is the primary protein, not just a flavouring. Does she have any known sensitivities, or is she generally a good eater who tolerates fish well?

Perfect — that actually works in your favour here. My recommendation is Forthglade Complete Grain Free Wet Cat Food in the Ocean Fish with Sardine & Salmon variant. It's a genuinely high-meat recipe where oily fish makes up the bulk of the protein, giving you meaningful omega-3 from whole food sources exactly as your vet intended. It's grain-free, has no artificial additives, and the texture and smell tend to go down very well with cats who like something robust. The moisture content supports kidney health, and the EPA and DHA from the oily fish combination will work on both the coat and joint inflammation over time. Switch her to this as her main wet food — ideally twice daily — and keep the Royal Canin dry to a small top-up or phase it out if she takes to it well. You should see coat improvement within 6 to 8 weeks.

It's widely available on Amazon UK — a pack of 18 x 100g trays typically comes in around £18 to £22 depending on the deal, which works out to a very reasonable cost per meal for a quality ingredient list. It's also available in larger multipacks which bring the price down further. Worth setting up a Subscribe & Save if she gets on with it, as the price drops another 15 percent or so. Given she's eating twice a day and you're replacing a significant part of her diet, a multipack is the practical starting point.

Gradual is always safer with older cats — their digestive systems are less adaptable than they were. Over about a week, mix increasing amounts of the Forthglade in with what she's already eating: roughly a quarter new food for the first couple of days, half by mid-week, three-quarters by day six, then fully over. Given she's a good eater and you're switching to something with a stronger smell she'll likely enjoy, you probably won't have any issues — but the gradual approach protects against soft stools if her gut needs a little time to adjust to the higher fish content.