Why catfish works for joint formulas
Catfish's soft, oily flesh is rich in natural collagen and omega-3s, which support joint health without the heavy cartilage some dogs struggle to digest. For a 40 kg Lab, these nutrients spread through a large body, so consistent daily dosing matters more than with smaller breeds. The fish base itself is unlikely to cause issues unless your dog has a known seafood allergy.
Check whether the chew uses farmed or wild-caught catfish — farmed versions may have higher fat content, which could lead to weight gain if the treat's calories aren't accounted for in his main meals. Big dogs on joint supplements often need adjusted portions to avoid creeping obesity, which defeats the supplement's purpose.
Decoding the 'other ingredients' list
Flip that package over right now — many joint chews hide risky additives behind healthy-sounding names. 'Natural flavor' could mean onion powder, 'sweetener' might be xylitol, and 'preservative blend' sometimes includes toxic propylene glycol. Labs are notorious for swallowing treats whole, so the faster-dissolving the chew, the quicker any problem ingredients hit their system.
Watch for subtle reactions like increased thirst, gum redness or scratchy ears after starting the supplement. These signal possible intolerance to fillers like wheat or soy that some brands use to bind the fish material. A 40 kg dog won't show distress as dramatically as a toy breed, so note any slight changes in energy or stool quality during the first week.
Balancing treats with a big dog's diet
That chew likely contains 30-50 calories — trivial for a Chihuahua but significant when multiplied across a Lab's daily routine. If he gets multiple supplements or training treats, the catfish chew could push him over his ideal intake. Weigh him monthly; gradual weight gain is easy to miss in large breeds until joints start straining.
Consider splitting the chew if the label allows it — half in the morning, half at night maintains steady nutrient levels without calorie spikes. Some joint formulas work better when paired with food, so check whether to give it with meals or on an empty stomach for optimal absorption in his size.
When to question the supplement's effects
Even safe ingredients can interact poorly with existing conditions. If your Lab has a history of pancreatitis, the fish oil in these chews might need vet-approved dosing. Likewise, dogs on blood-thinning medications require careful monitoring when adding omega-3s, which have natural anticoagulant properties.
Give it three weeks to judge effectiveness — joint supplements aren't quick fixes. If he's still stiff after rising or hesitant on stairs, the catfish formula might lack adequate glucosamine for his weight class. Big breeds often need combo therapies, so track his mobility changes honestly rather than assuming the chew is working simply because it's 'natural'.
The full verdict, portion guidance and serving notes are collected on the Catfish food facts page.