Although I agree with you that perhaps this is a possible explanation, I can assure you that my paroxy swamp dragon was well taken care of and still decided to go poof. Even more ridiculous was that it happened while he and I were both dead. My hunting partner saw my dragon ghost standing next to me and waited for me to dissapear. I died as a result of a disconnect. when I came back, I was still in the Stygian Abyss - dead - but my dead swamp dragon was not there. I don't think you know what you are talking about exactly, and frankly, it is annoying to read such an hautain post when so many people have experienced the same thing now.
I know exactly what I am talking about and I am afraid you have little clue why your dragon went poof. Here's the reason why YOURS disappear and this will get a bit technical, and hopefully you can follow.
There used to be an excellent Japanese website (it was shut down because one of the founder was part of the team that has access to the "codes" and was deemed to leak too much insider info) that has detailed info about exactly how taming/loyalty/commands work in UO. I am trying very hard to recall the details just for you.
Loyalty value is ranged from 0 to 100. (Hard cap is always 100)
A successful command (pet will respond with a "roger" sound) gives +1 point in loyalty.
A unsuccessful command (pet will respond with a "**** you" roar) is -3 in loyalty.
A fed is always +100 loyalty. Stacking food has no effect whatsoever.
-Now the following is according to my memory with the #s provided by the JP site.-
Loyal is always lost overtime. (including afking with your pet out or mounted on your pet)
---If the tamer is within the vicinity of the pet (within 15? tiles) the rate of loyalty reduction is minimal. It's either one points lost per RL hour.
---If the tamer is outside the vicinity (where pets no longer hears your command) the rate of loyal loss is sped up greatly (5? or 6? points per RL hour).
---Sometimes when pets do not log out (improperly logout/pets loaded/server down while pets are out) with the tamer the rate of loyalty reduction is at max... I cant remember the exact amount the site did have it listed but if memory serves it takes at most 6 hours for a pet with 100 loyalty to go wild.
Ok now you said you died due to dc... which you are physically disconnected from the game while your pets didnt logout properly with you (see above, loyalty loss at max). This scenario is most seem and can be easily reproduced by having your pet out and let the server go down. And in this case assuming you have a greater dragon out, sometimes when you log in you will see your control slot being 0/5 while your pet standing next to you or wandering around. If your pet hasnt gone wild yet by issuing a command your pet "might" respond to you and if it did the 5 control slot will instantly be added back to your character, and congrats you just saved your pet.
Sometimes things can go seriously wrong where your pet will stay blue and stay "tamed" but will no longer accept your commands and you wont be able to re-tame it before it finally goes wild (this usually happens when doing a shard transfer where one or more of your packies didnt get transferred with you... and after you xfer your character back to the starting shard, you will have no control over the pet whatsoever. The pet will go wild at the longest 5 hours (max loyalty reduction).
So again in your case after you dc, you didnt log in right away to secure your pet. The pet is now rapidly losing its loyalty because the owner is not logged in in the game world. And tough luck you just lost your pet when you logged on the next day. Also when you dc if your pet is at low in loyalty already you "will" lose it very quickly.
Also in the case of proxy swampy/vollem, some of them do get bugged and can be xfered between players (with high enough taming is what I heard).
So there I just explained all the possible reasons why you lost your pet. Be more careful next time
But you can always say (making **** up or not) "but but but my pet was at 100 loyalty and i dc and logged back in in 1.25 real life seconds and it went poof" but then again I am just providing some more indepth info on how UO works, so people who actually cares would not encounter this issue again.
Safe journey.