Watery discharge from a cat's ears can be caused by a variety of factors, including water getting into the ears during bathing, otitis media, ear mites, bacterial or yeast infections, trauma, and allergic reactions.
If your cat has recently had a bath, the watery discharge is likely due to water getting into its ears during the bath. However, if it's something else, you should consider whether it's caused by an underlying medical condition. For example, otitis media and ear mites are common ear problems in cats, which can cause watery or sticky discharge, and the cat may exhibit symptoms such as restlessness, head shaking, ear scratching, and ear sensitivity and pain. In addition, bacterial or yeast infections, trauma, and food or environmental allergies can also cause ear inflammation and watery discharge in cats.

In this situation, it is recommended to take your cat to a veterinary hospital for examination as soon as possible to determine the location and cause of the illness, and then follow the doctor's advice for treatment. If there is discharge in the cat's ears, it may be necessary to clean the ears with ear cleaning solution and apply medication. At the same time, to prevent the cat from scratching the affected area and worsening the infection, it is recommended to have the cat wear an Elizabethan collar during treatment.