The duration of a dog's allergic reaction can range from a few hours to several weeks, depending on the factors mentioned above. In general, mild reactions may last for a day or two, while more severe reactions can persist for up to two weeks or longer. If the trigger is removed and appropriate treatment is provided, most allergic reactions in dogs will resolve within 7-10 days. However, in some cases, the reaction may be more prolonged, especially if the trigger is not identified or if the dog's immune system remains highly sensitized. The duration of a dog's allergic reaction can vary widely depending on several factors, including: Trigger Exposure: If your dog continues to be exposed to the allergen, the reaction may persist or worsen. Severity of the Reaction: More severe reactions, such as those involving respiratory distress or extensive skin inflammation, may take longer to resolve. Treatment Effectiveness: The speed and effectiveness of the treatment, whether it's medication, dietary changes, or environmental adjustments, can impact the duration of the reaction.