My dog's ears are red, swollen, and hot. Is it an ear infection?

It sounds like poor Mario may have an infection. Ear infections can be caused by bacterial, parasitic or fungal infection, or a combination of these, and can be associated with dietary or environmental allergies or sensitivities, immune system disorders, or a combination of the above. Mario needs to see a vet to have an ear swab done. Your vet can look at the sample under the microscope and treat appropriately based on what is found. Your vet will also need to examine the ear with a scope to see if the ear drum is intact, as some medications cannot be used safely if the eardrum is ruptured. Ear infections can be very painful, and can sometimes progress to include the middle or inner ear, where they can cause neurologic signs or permanent hearing loss. Please book an appointment to have Mario seen as soon as possible to help get him feeling better.