Talking about the cats, in particular, Like a cat parent, it is important to recognize the signs and symptoms of common illnesses so you can seek veterinary help for your feline friend promptly if necessary. Read on for information about diseases and other medical inflictions that frequently impact cats. Cats that are ill will usually show changes in overall appearance, energy level, sociability, coat appearance, and/or amount of shedding, appetite, litterbox usage, breathing, or discharges from the eyes or nose. In general, any sudden change should alert you that your cat needs veterinary attention.