Ear trouble
Dogs with allergies often have problems with their ears. Is your dog scratching their ears more than usual, shaking their head or losing any fur around the ears? If yes, a seasonal allergy could be the culprit. If an infection is present, there will most likely be a bad smell and possibly discharge to be found coming from the ear area.
Wheezing
This is an uncommon symptom when it comes to allergies but some dogs do suffer respiratory problems as a result of seasonal discomfort. Look out for watery eyes, a runny nose, coughing, wheezing and sneezing.
Obsessive licking
If your dog is constantly licking themselves (especially paws, belly, or any other part of their body that may have been in direct contact with grass or pollen), an environmental allergy could be the reason.