my hand swelled up when i got bit by a dog too and i know they're not venomous.
the exact enzymes or proteins in the saliva/venom need to be identified, isolated and tested to see if they cause the damage.
then the animal needs to be able to deliver it effectively to be considered "venomous" by definition. otherwise they just have toxic spit. (venomous gilas do have an effective delivery system, poisonous toads do not)
let's not forget that even we humans have enzymes in our saliva that breaks down our food, and if injected under our skin, will cause swelling and itching. then again, saline solution or even just the prick from the needle, can have the same effects on people...
