Finding if dogs still exist from an old family ? General Chat

Wondering how to find out if its possible to track current families from a older sire ?

Depends on how far back you are going, and whether the breeding was well known.
If this is a historic pedigree, I think the Breed Club would be the best way forward. The older breeders have an encyclopaedic knowledge of their breed, and usually know what is at the back of all major lines.
Are you in the UK? If so, the Kennel Club's MyKC is invaluable as it shows ALL of the siblings and progeny of a registered dog - not just the ones that were shown. The drawback is that it only covers the period since records were computerised - in my case that is back to a 1983 litter.
You could always try naming the hound on here. There are a handful of IWH owners who may know of the line.