Pseudomonas Aeruginosa is a bacterial infection that is considered "opportunistic," which means it will take advantage if the body is compromised.  It rarely causes disease in healthy animals but multiplies freely infecting those who are already sick or who have weakened immune systems.

Pseudomonas aeruginosa is a very rare type of bacteria considered by many as a facultative anaerobe as it is well adapted to proliferate in conditions of partial or total oxygen depletion which makes it difficult to treat as it is resistant to almost every antibiotic.  When a dog has reoccurring infections, most likely a plethera of antibiotics have been tried.  When this happens, most of the bacteria is killed off, but not all.  What remains is a strain that is extremely resistant.

A culture of the dog’s ear discharge is taken and if a diagnosis of pseudomonas is given, 3–4 weeks of treatment with a high dosage of oral antibiotic such as Enrofloxacin or Orbifloxacin will be needed as well as a topical antibacterial wash.  Small doses would just make the bacteria more resistant.   If all this fails to clear up the infection the next step would be for an experienced veterinarian to surgically open the vertical canal.  The ear is then easily and completely cleaned out and treated.

Consistent ear infections can cause a dog's ear canal to become scarred.   In some cases, this scarring can become so severe that the canal becomes almost closed.  In these cases, a specialist veterinary surgeon can perform a surgical procedure called an Ablation.  This is the final option and only done is the most severe health cases with dogs in which no cause can be determined and medication just does not help.  In this procedure, the entire ear canal of the dog is removed.  Healthy tissue then regrows.