When you are exposed to a pet allergen, your body’s immune response kicks in and begins sending out histamines that inflame the area, as though your body is being attacked by a pathogen. However, stinging nettle is a powerful herb that can directly inhibit the production of histamines, thus preventing the itchy eyes, runny nose and inflammation associated with pet allergies. Stinging nettle can be brewed into a tea, and drunk regularly if you spend a lot of time around pets, and is also available in capsule and supplement forms.