There is no correct answer to this, and no correct time. Some people need another animal in the house within weeks, because the silence is its own kind of grief and a presence helps them breathe. Some people can’t imagine it for years. Some never do it again, and that is a whole and reasonable way to love. None of these is the right one. They are just different shapes of the same heart.
Two fears tend to sit underneath the question. The first is that getting another pet would be a betrayal — as if the love were a fixed amount, and giving it to a new animal meant taking it from the one you lost. It doesn’t work that way. Love is not a quantity that runs out. A new animal is not a replacement, and choosing to love again is not erasing anyone.
The second fear is quieter: that you couldn’t bear to go through this again. That one is honest, and worth sitting with rather than arguing away. Loving an animal is signing up, knowingly, to almost certainly outlive them. Whether you can open that door again is a real question, and only you know the answer, and the answer is allowed to be no.
If you do, someday, find yourself drawn to another one, that pull is not disloyalty. It is the same capacity for attachment that made this loss hurt so much, still intact, still working. The one you lost is part of why you know how to love an animal at all.