Most Spaniels, and this includes the Cavalier King Charles can have problems with their ears. The long ears are a breeding ground for fleas and ticks and if your dog knocks his ears when he gets over excited this can cause problems. You should always check the insides of your dogs ears on a regular basis as they are prone to getting a build up of wax. This can become infected and will eventually affect the dog's hearing.
If your dog is shaking his head on a regular basis and/or scratching at his ears then there might be an infection. You should always check ears if you see this happening with your dog. It could also mean wax build up or ear mites. At the very least you should be aware that if your dog is doing this then he or she is uncomfortable for some reason. In the summer months dogs can get grass seed stuck in their ears. This needs to be addressed straight away or it could lead to problems.
Because the ears of a Cavalier King Charles Spaniel are long and heavily fringed it is difficult for any air to get to the ears and this can lead to infections. You should check your dog's ears on a regular basis and keep them as clean as possible. Once an infection takes hold it is not easy to dislodge in long eared dogs and this could cost you a lot of money in vets' fees. Repetitive ear infections can lead to premature deafness in your dog so you do need to look after their ears. Fleas and mites are not easy to dislodge once they get caught in that long silky hair - the mites tend to attach themselves to the hair inside the ears and so this should be checked regularly.
Another problem that you have to watch out for with your Cavalier King Charles Spaniel is that the ears are so long they are likely to get covered in food at meal times. You either need to find some way of preventing this from happening or else you have to be on hand with a mopping up cloth and a brush. There is nothing worse than seeing the ends of those long, silky ears covered in food debris.
Like any other dog the Cavalier King Charles Spaniel needs taking care of. Unfortunately it is not within the dog's powers to keep his or her own ears as clean and vermin free as they should be - that is up to you as the owner. Just a final reminder, check your dog's ears regularly and especially if they are shaking their heads or scratching - that way you will be doing your best to avoid ear problems.