Any unexplained changes in your pet’s normal activity level, temperament, or mobility warrant a call to your veterinarian. Next, be aware of the physical and behavioral signs that could mean your dog is sick or your cat is sick. Signs of a Sick Cat or Sick Dog Without a doubt, you know your pet better than anyone. Here are 10 common signs that your cat or dog is sick: Decrease in appetite accompanied by weight loss, Bad breath or foul odor coming from the ears or skin, Excessive thirst or urination, Unexplained aggression or other behavioral changes, Trouble walking or climbing stairs, Inability to urinate or have bowel movements, Respiratory problems: sneezing, coughing, excessive panting, trouble breathing, Lethargy, hiding, Frequent vomiting or diarrhea, Abnormal whining, crying, or other vocalizations. The best way to know for certain if your cat or dog is experiencing a pet emergency is to contact your pet’s doctor. However, some symptoms are clear signs that you should seek immediate treatment, including the following: Hard, distended abdomen, Inability to urinate, Excessive diarrhea and/or vomiting, Seizures, Trouble breathing, Lack of coordination/inability to stand.