There are many reasons why cats hiccup. Common causes include eating too much or too quickly, food that is difficult to digest, insufficient water intake, and food that is too cold or too hot. Substances such as smoke, dust, and pollen can irritate a cat's respiratory system and also cause hiccups. Other causes include, but are not limited to, stomach upset, hairballs, acid reflux, indigestion, esophagitis, and gastrointestinal inflammation.
Cats that are nervous or anxious may also hiccup, especially in new environments or when facing strangers. Over-excitement while playing or improper sleeping positions can also cause hiccups. Usually, there's no need to worry excessively, as this is likely a normal physiological phenomenon.
