Legally? Disney could allow it. There is nothing in the contract that dictates room occupancies, including animal occupancy.
Practically, given the housekeeping issues, I doubt they would allow it on points reservations. The pilot adds significant nightly cost via a housekeeping fee, and that kind of thing is harder to deal with in DVC given the reduced schedule.
Like, but disagree.... a contract omission could just as easily "allow" cannibals

. That which is not included, is NOT in the CONTRACT. At the time you signed it.
REAL question: NOT IN the contract? Effect on Maintenance fees? Breakage? Allow Dogs, and a case could be made that members are no longer responsible for these items, as the CONTRACT was unilaterally changed. Here comes a class action....
Second effect: Outstanding contract points, unsold. WDW - do you really want to do this? The effect would be that no one could actually TRUST the CONTRACT. POISON DVC Contracts? Bad idea....
Now - as we hit Break Even in 2018? No problem. We can sell 270 BRV Points for $1, and excuse ourselves from a Dog Kennel. And loose NOTHING over discounted Room Rates, previous 6 years. $1? Can anyone say ROFR?

. Imagine the effect if HUNDREDS of DVC members did this.... Likely a very BAD business decision.
Ahead of time, as I will be "branded" - no, not anti dog. Just anti dung in MY DVC - it's NOT in the CONTRACT. Do this in main rental rooms, and track how quickly folks begin to request "no dog rooms".
All personal opinion - I'm not necessarily right, no one else is necessarily wrong.