I need to order more heartguard for the boys. My problem is, it's 26-50lbs or 51-100lbs. My husband weighed Tips as he could on our scale, and it said 46lbs. Last time he was at the vet a bit over a month ago he was 40lbs. He's almost 9 months now. Which one should I take? I only have 3 51lbs+ left, and the boys are due in 3 weeks... Should I just use those for both next time and order more 51+? I'm not even sure how much more Tips is going to grow, and I'm not sure it's ok to use some 51+ if he's only 46ish lbs? Do you think he will be 50+ in a couple months anyway? He's been fed on all lifestage foods, if it matters. Of course he's a mix so I have no idea how big he's going to get. I'm probably worried for nothing, but I would like your opinion... Thanks!