Is my puppy a healthy weight?

This is true, your dog may just be bigger due to having bigger muscles. Also growing bigger early on. At the same time, you need to factor in different things. I have many Cousins with dogs and I learned the following. If according to the weight range, your dog is too small or too big. Some things to check.

With a Border Collie, they need their own funds just in case. Depending on genes when breeding things may be fine or down the road, something comes up.

If they have any pain or if they are ill. You can schedule a visit with your vet to make sure everything is alright with your dog. Try scratching their belly, belly scratches. If they come up they may not like it but look at how they respond. If they have a wtf face, they got spooked, if it's a tired wtf face. They need to get checked out. This is just what I could gather myself. If you can not afford a vet, gather what you can and go online. Trust me becoming your pet's researcher will help. You can do this by just studying them and this helps to figure it out. Check that you are feeding your dog enough for its age. This is very important if you are feeding the right amount and if they are overweight. It could be inside or outside the problem. My cat had worms and was eating grain food. Do not feed dogs and cats grain! They will increase in size and the stomach will expand. You may need to change to wet and dry food too. So Wet food is more than dry. also helps with getting nutrients better. I am using your dog being a Border Collie for this. But if you do not do wet food. No grain in their dry food. Have water out, also see how much they eat from the bowl.

Make sure it is getting enough exercise. So you have a herding dog. Each herding dog is different. Border Collies are originally herding dogs. They are genetically built to run around in the field. Therefore, you should give your dog ample time for exercise. At times they may just need some puzzles. I have met these Border Collies who do not even want to run at all.

Make sure they are getting a sufficient amount of sleep. If they expend a lot of energy, they need enough sleep to replenish it. Not enough sleep causes stress, with stress you gain weight. True for us Humans too.

Remember when in doubt check it out! Even just checkign on the dog bag, also looking at their size. Look up skeletal and muscular outlines of a Border Collie. I use this for my cat, she is small for her age but this is due to her genes. She is healthy with the yearly worm medicine she's good.