You have already realised the answer! Keep them short! While most working dogs never seem to need their nails cut, many that are only worked on soft ground can grow too long.
Get your vet to show you how to clip them properly and to advise you on the best clippers to use.
Split nails should be carefully smoothed with a nail file to remove cracked, sharp edges.
Nails that become ?hinged? away from the quick need to be removed to avoid infection tracking up and into the joint.
Those that are hanging off can be sorted with a quick confident pull after gripping them with a pair of pliers but others will need general anaesthesia and veterinary expertise to strip out the damaged part.
The exposed quick is fairly sensitive and prone to further damage so may need protection until the nail re-grows.
I always like to give these patients a few days of antibiotics as joint infections inevitably require partial toe amputations; a disastrous outcome from a trivial injury.
Continuous problems with toe nails in the absence of obvious trauma suggests fungal or bacterial infection.
Affected nails can be removed, stuck in culture medium and sent to the lab for specific diagnosis. Treatment often needs to be prolonged.