From Dog

Tramadol is a centrally acting synthetic analgesic used to treat moderate to moderately severe pain.

This drug is a very weak μ-opioid receptor agonist, induces serotonin release, and inhibits the reuptake of norepinephrine.

As an oral preparation, it can be used for treatment of chronic pain such as osteoarthritis or immune-mediated arthritis.

Recommended dose rate is 2 – 4 mg/kg twice a day.