Do not cut the fur. If there are no abnormalities in the cat's ears, try to keep the fur inside and do not cut it. Because cats have large ears that open upwards or outwards, foreign objects such as water and insects can easily enter the ear canal without fur, causing ear damage. Healthy cats have a lot of fur inside their ears, which helps protect them. 
The following may occur after the fur on a cat's ears has been trimmed:
While ear hair doesn't affect a cat's intelligence, losing it can weaken a cat's ability to pick up sound and slow its reaction time, making it appear as if it's become less intelligent to many. Cats have very large ears, and without the protection of ear hair, dust, foreign objects, insects, and water can easily get inside. Ear hair acts like a curtain hanging over a cat's ears, serving as the first line of defense for their ear health.
