Hmm, good question! but i guess can be any size? however, what about snake as I think some ppl treat snake as their pet -,-''
Best is to go and ask the management of said condo for a copy of the rule book as agreed by residence and JMC via the Deed of Mutual covenant.
Also do take note, local council have the ultimate say on what pets are/are not allowed in what premises. I.e. DBKL does not allow dogs in any building above 2 stories/ with a strata title/ without a gated house parameter. Their say ultimately overrides the management's rules.
Based on my understanding 'pet-friendly' mainly means cats & dogs. Smaller pets like fishes, hamsters, turtles or anything that doesn't make a lot of noises which creates disturbance to residents should be fine.
Most new condos nowadays will not allow pets, but older condos or I know of some Duplex who allow dogs.
I guess it's quite common where some apartments / condos which used to allow pets, in the end due to frequent complaint by other residents, they change it to not allowed.
Was just with a client last week looking to sell his Five Stones unit because they somehow didn't let him keep his 13 year old dog now in the condo. Dog's too old to live alone and away from owner, and needs the daily morning walks at the garden. So in the end the owner only had the option to move back to landed and thus letting go of his unit. He's been informed of the complains and said he would only move the dog out once they've sent an official letter to him. Till then, he's got some time to sell his house.
Lovely people and lovely dog, kinda feel bad for them. Really shouldn't be in this position in the first place.