Interdigital Cysts - any preventative suggestions?

There is really no prevention, sadly they're a problem in short-hair breeds.

Since the cysts are recurrent, a good option is to have the cyst surgically removed and send it to a dermatopathologist, not a regular pathologist. It is expensive but it will greatly reduce the number of return trips to the vet. With that diagnosis, it will be easier to deal with future recurrences.

Foot dips in mitoban (diluted) followed by warm soaks in dilute chlorihexidine may clear it up. Fitting the dog with a rubber boot to protect the foot may help speed recovery following the removal of the cyst.

You also don't mention the underlying cause? There are a number of differential diagnoses to consider such as demodex, fungi, pyoderma secondary to atopy, dermoid cysts, etc. If your vet hasn't done a skin scraping have him/her do so.

My German shepherd has had one three times,all on the same spot.I drain the cyst with a sterile needle,then apply Panalog ontment and bandage with gauze and vetwrap.They heal very nicely this way.Luckily,she hasn't had one for over two years now,but she will give you her paw if you ask to see her "boo-boo." I don't know how to prevent them,but keeping the feet dry and clean would seem sensible.