This ear is so infected that it has completely swollen up so that you can not look into the ear canal.
As with many hairy dogs, Terriers have always had a predisposition for ear infections. Many have yeast infections at the same time. If your dog has brown feet and smelly ears, it's likely a yeast infection.
Your vet will instruct you on how to keep your dogs ears clean and free from ear infections.
He will likely prescribe a triple antibiotic salve with a steroid which really heals the ear quickly. Most prescriptions are Animax, Dermavet and Panalog, all mostly the same. Each Vet will sell you the brand he is promoting and which he will make a profit.
Same with food. A vet will have certain foods in his business, all of which he will make a 50% profit
Health Problems in Canines