Switching a Border Collie off working-dog food

A 7-year-old Border Collie on a working-dog formula is quite a common situation — and if the activity level is coming down, that high-calorie working food can start causing weight gain pretty quickly, which puts extra stress on joints that are already entering their middle-age phase. Senior dogs generally need fewer calories, better digestibility, and more joint support, but the timing depends on the individual dog. To point you in the right direction: does your Border Collie have any current health conditions — joint stiffness, digestive issues, anything the vet has flagged? And roughly how active are they now compared to before?

That tells me exactly what I need to know. A slightly overweight, healthy 7-year-old Border Collie stepping down from an active working life — this is a classic case where the food needs to change before the weight becomes a real problem. High-protein working formulas are designed for dogs burning serious energy; an hour of walking a day is solid, but it's nowhere near what that food was calibrated for. You don't necessarily need a "senior" label yet — Border Collies age well and seven is still relatively young for the breed — but you do need lower calorie density and ideally some joint support built in. Can I ask: roughly how much are you feeding him per day, and does he eat dry kibble only or do you mix in wet food?

Good — the fact you're measuring matters a lot. At 400g of a high-calorie working formula, he's almost certainly getting more than he needs for his current lifestyle, which explains the weight creep. Here's what I'd recommend: switch him to Hill's Science Plan Adult Light with Chicken. It's a well-researched, genuinely lower-calorie kibble — not just a "diet" food but properly formulated for less active adult dogs. It has added L-carnitine to support lean muscle while he loses the extra weight, and it contains glucosamine and chondroitin for joint support, which is worth starting now at seven rather than waiting until you see stiffness. It's widely available on Amazon UK, decent price per kilo, and the kibble size suits medium breeds well. I'd transition over two weeks — start 75% old food, 25% new, and move gradually. His portion will likely drop to around 300–330g depending on his actual weight, so check the feeding guide on the bag against his current weight rather than his target weight initially.

It's a fair concern, especially with an active breed like a Border Collie where muscle condition matters. Hill's Adult Light isn't a low-protein food — it sits at around 25% protein which is adequate for a moderately active adult dog. The reduction is in fat and overall calories, not protein. The L-carnitine in the formula also specifically helps the body use fat for energy while preserving lean muscle, which is exactly what you want here. As long as he's still getting daily walks and some mental stimulation — which Border Collies need regardless — he'll hold his muscle tone fine. If you were dropping activity to almost nothing and he was much older, I'd think differently, but that's not your situation.

Realistically, 10–14 weeks to see meaningful progress, and 4–6 months to reach his target weight — assuming he's only moderately over rather than significantly obese. Slow and steady is right for dogs; losing weight too fast can actually cause its own issues. Weigh him every two to three weeks rather than daily, and adjust portions by small amounts if progress stalls. Your vet can give you a target weight to aim for if they haven't already — it's worth a quick call to confirm the number. But with the food switch, correct portions, and daily exercise, Border Collies generally respond really well to this kind of recalibration.