Well the answer to this, you will be glad to hear is…. it depends. It depends on your dog mainly. A small short haired doggy that takes only 15 minutes or so to cut can easily be managed by hair clippers designed for humans. Human clippers are designed to deal with human hair (obviously) so if you have a larger dog with shaggier hair then they will not cope with the excessive strains produced by this.
The electric motor in the clippers will overheat and the cutting blades simply will not cope with thick clumps of doggy hair. There is a certainty that the clippers will catch and clog resulting in discomfort for your dog due to the hair being torn out rather than clipped. If your doggy sat still for you to begin with then she certainly won’t be keen to do so after going through that painful scenario!
My family dog is a cross between a Golden Retriever and a Welsh Collie. She has a huge bushy golden coat that always manages to produce dreadlocks in defiance of careful and regular brushing. Her coat is more like sheep wool than doggy hair. And yes, she seems to be permanently shedding. Even after brushing its not unusual to see clumps of shed hair rolling tumbleweed like in her wake. The idea of using human hair clippers on her coat is,frankly, laughable.
We invested in some good quality doggy clippers that trim her nicely but even so we have to firstly brush her, then use some good quality large scissors (we have some made by Fiskar. They are excellent quality and keep their shape edge seemingly forever.), to remove any of those pesky dreadlocks we find. It may not be necessary, but I also use the scissors first on her before employing the clippers to even her coat out. I do this as a precaution because we know how thick and shaggy our dogs coat is and I do not wish to risk the clippers clogging or dragging her hair out of her skin.
The bottom line is, no one knows your dog better than you. If like me you are battling to keep your doggy matt free then don’t even think about using human clippers. Any doubt about whether they cope then forget it. Invest in quality clippers and scissors for your dog. She will thank you for it.