>How many dogs can I keep on one property.
Are you in the UK? Do you mean legally or ethically? Private residence, rented accomodation or commercial kennels?
I'm not sure there is a legal limit in English law but it depends on your circumstances as above and, presumably, the standard of care you are offering. Following successful prosecution of cruelty cases I believe a court can order a restriction on numbers but those would be case by case decisions