Your night time wheeziness, along with your allergy to dogs and seasonal symptoms, suggests that you should be tested for asthma, rather than settle for ad hoc use of your Ventolin inhaler. Do you also cough more at night than during the day? Ask your GP to refer you for spirometry; your treatment can then be tailored to the results that you achieve.
Ventolin is a short acting 'reliever', but its action can last a few hours. A steroid inhaler used regularly twice a day will help with your symptoms and allow you better night time rest, and then you will only very rarely need the Ventolin. But, you do need spirometry testing.