How come my cats smell is making me feel nauseous even though I've never had a problem before?

Cat and dog allergies are extremely common. Allergy symptoms triggered by animals can include runny nose, nasal congestion, sneezing, itchy watery eyes, wheezing, chest tightness, coughing, itchy rashes and headaches. If these symptoms worsen with exposure to pets, they can indicate a possible animal allergy. Nausea in cats is a very common condition. It can occur on its own or just prior to the act of vomiting. In humans, nausea is also referred to as queasiness, having an upset stomach, or “feeling sick to your stomach,” and is associated with a feeling of discomfort in the stomach. Nausea is harder to define in cats, since animals can’t tell you that they feel unwell. In many instances, it is unclear that there is an issue until your cat vomits. The most common symptoms of nausea in cats are lack of appetite, licking, excessive chewing, hypervocalization (excessive meowing), restlessness, and drooling. Nausea can make cats feel uncomfortable and restless. Some cats will pace around while meowing, while others will lie in the same spot drooling.