Dogs can be very prone to fungal and bacterial ear infections, especially if their ears are not groomed properly, cleaned, dried and excess hair removed. Although all dogs are susceptible and require regular ear grooming, large dogs that are very active and often love water and swimming can be even more vulnerable, especially if they have floppy ears that trap moisture and have limited air flow to dry out wet, damp ears. With regular ear grooming, cleaning, and trimming the chances of the Johnsons' large dogs having future ear problems will decrease significantly.
Although your large dog may not love having his ears groomed, he certainly won't like having an ear infection, or the treatment required to resolve an ear infection. Convincing your big dog to get used to ear grooming will be much more pleasant for him in the long run than suffering from repeated infections. Incorporating ear grooming with bathing or regular grooming that your dog enjoys may make the experience more pleasant. Be sure to be gentle around your dog's sensitive ears so as not to cause him discomfort or injury. Working to gradually desensitize your large dog to having his ears handled is recommended so he is comfortable with ear grooming.
Although your large dog may not relish ear grooming, the hair on his ears needs to be addressed the same as the hair anywhere else on his body. Ears should be kept clean and excess hair that traps moisture and dirt removed from around and just inside the ear canal. Plucking is considered the most effective way of doing this, however trimming and clipping may also be employed. Large dogs can have their ears handled more easily when lying on their side, although standing a large dog in a bathtub may help to contain the mess from ear cleaning more effectively. You will need to figure out what is the most comfortable for you and your big guy.