Complex sentence: Kittens are also very sensitive and ivermectin should never be used on kittens less than 10-12 weeks of age, nor should it be used on any weak, dehydrated or debilitated animal except in dire situations.
Split into simpler sentences: Kittens are also very sensitive and ivermectin should never be used on kittens less than 10-12 weeks of age. Nor should it be used on any weak, dehydrated or debilitated animal except in dire situations.