Certainly an old dog can start to lose bladder control even one that has been very clean indoors previously. I cant see why it would be a behavioural thing although if the grandchild keeps his grandparents very busy they might not have time to let the dog out as often to relieve himself!. It is most likely to be due to a loss of bladder sphincter muscle tone. It is worth having this problem assessed by a vet because there might be something that can be given to help relieve or reduce the problem. Soiling indoors is a difficult problem for dog owners to cope with and can be stressful.
Cathy Wickenden BVet Med MRCVS
Barton Lodge Veterinary Centre
1 Midland Road, Hemel Hempstead, Hertfordshire, HP2 5BH
Tel: 01442 216048 24 hours
[
www.bartonlodgevets.co.uk]