Objective: To describe the clinical manifestations and response to management of opioid dysphoria in 3 dogs.
Case summary: Three dogs being managed for post-operative pain were evaluated. All 3 dogs had been managed with various opioids including morphine, hydromorphone, and fentanyl following the surgical procedure. The 3 dogs exhibited vocalization that did not respond to interaction and did not change with administration of analgesic and anxiolytic agents. The dogs were treated with naloxone and, within 5 minutes of its administration, ceased vocalizing, and became aware and interactive with their environment. Further pain management consisted of non-steroidal anti-inflammatory medications, alpha-2 (α2) receptor agonists or the partial μ-receptor opioid agonist, buprenorphine.
New and unique information provided: Vocalization and lack of response to interaction with humans are clinical signs which can be seen in dogs with opioid dysphoria, and generally are not responsive to analgesics or sedation. Reversal with naloxone results in rapid resolution of vocalization and opioid-induced dysphoria.