Do animals like pets and mounts age in the mythal of Myth Drannor, before the fall?
To clarify, I am asking about the Mythal in its full glory, circa 600~660 DR. Before the weeping war.
According to the Myth Drannor Campaign Guide of the Ruins of Myth Drannor boxed set, the mythal has (page 29):
up to 18 "secret powers" (two for each of the nine wizards who laid it), as well as any number of additional powers, added by the other mages who helped in the weaving, ...
One of those secret powers is longevity (page 31):
Beings who continuously dwell within the mythal for more than four years gain effects equal to imbibing a potion of longevity. ... Thereafter, they do not seem to age, though their actual lifespan is not extended; death comes swiftly if they ever leave the mythal.
The word "being" should cover pets and mounts, but since the examples in the relevant section are related to humanoids, there might be some room for each DM's own interpretation.