Such skin reactions should resolve with patch removal and application of a topical coritsone product. The euphoria effect can lead to an excessive appetite though in some animals, nausea results from the fentanyl leading to a reduced appetite. Fentanyl is not felt to be a sedative in the cat but in the dog some sedation may be observed. A wobbly gait may be a sign of sedation. There is some variability in the blood levels achieved by different individuals.
Some individuals require additional medication for breakthrough pain.
Your veterinarian may require you to return any used patches for documentation of proper disposal. Human deaths have been reported in patients with patches sleeping on heated water beds. If your pet has a fentanyl patch, be sure to avoid situations where the patch could be excessively heated. Fentanyl patches may be toxic if swallowed by small children. Be conscious of any children curious about the patch or attempting to manipulate it.