Yes dog may have 5 mg of aspirin per lb of his weight every ten hours for only two days.
He should be seen by his vet tomorrow as ear infections are very painful and require antibiotics.
Ear infections are very common in dogs, although less so in cats. Two types are most often seen: otitis externa, infection of the external ear canal, and otitis media, infection of the middle ear. Although any dog or cat can get an ear infection, some breeds appear to be more prone than others. Dogs with pendulous ears, like Cocker Spaniels and Basset Hounds, or dogs with hairy inner ear flaps, like Miniature Poodles and Schnauzers, tend to have a higher occurrence of ear infections. In cats, the Persian breed seems to be more prone to such infections.
Most ear infections are easily and successfully treated. But if left untreated, they could result in serious damage.
Bacteria or yeast are most often the culprits of otitis externa. Other causes include an accumulation of wax, thick or matted hair in the ear canal, debris, a foreign body, a tumor or impaired drainage of the ear. Sometimes, infections of the external ear canal are a secondary result of some other bodily infection or ear mite infestation.
Otitis media usually results from the spread of infection from the external ear canal to the middle ear. Also, foreign bodies, debris, ulceration or improper ear cleaning can rupture the eardrum and allow infection to reach the middle ear"
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Use white vinegar and water 50/50 mixture to dab on and in the ear tonight.
I hope he feels better very soon.