Answer:
If something is overwhelming, it is very intense and hard to deal with.
Explanation:
The adjective overwhelming can be used in different contexts. For example, it can be used to describe something that is difficult to fight against (e.g. an overwhelming urge to do something) or something very great or large (e.g. an overwhelming majority). Here, it is used to describe a difficult situation. Ashley has to take care of about thirty animals in a single day, which is a very difficult (i.e. overwhelming) task.
This is why we can say that, if something is overwhelming, it is very intense and hard to deal with,
