If your cat is struggling to breath and is not eating or moving, it could be a sign of trauma in cats. A steep fall, collision or dog attack can result in internal injuries, which can affect your cats lung capacity. An internal hemorrhage, intense pain, fractures or pneumothorax constitute as emergencies that can cause fast, superficial abdominal breathing in cats.
There are various different causes for rapid breathing which may include infections, pain, heart disorders, dehydration among other causes; a cat’s respiration should be below 30 breaths per minute when at rest but if it is significantly above this rate at rest I would suggest visiting your Veterinarian for an examination to determine a cause. Regards Dr Callum Turner DVM