1. Diarrhea, Constipation, or other Digestive Issue
Although they are more commonly attributed to disease or food intolerance, gastrointestinal issues such as diarrhea and constipation can also be brought on by anxiety. Speak to your veterinarian if the diarrhea, constipation, or other digestive issue is abnormally severe, especially if it has lasted longer than 24 hours or if the diarrhea is bloody. Blood in the vomit and/or stool can be an indicator of a food borne illness.
2. Decrease in Appetite
Dogs don't go on fasts or diets like we do, so it's important to consult a veterinarian if your pet suddenly loses interest in food or stops eating altogether. It could be due to stress or to an underlying health condition, including anorexia, which can cause your dog to refuse to eat totally and its food intake to decrease so much that it leads to drastic weight loss.
Some dogs like some alone time now and then. However, a dog that is constantly isolating him or herself from other pets or people may be suffering from anxiety or a sickness. Your veterinarian can help you identify the cause of this strange behavior.
4. Increased Sleeping
By now you will have become accustomed to your dog's sleeping schedule. Speak with your veterinarian if your dog is sleeping more than usual or seems overly lethargic. Lethargy is often the first symptom that a dog is sick, injured or traumatized. It can also be a symptom of conditions including diabetes, heart and liver problems, tumors, diarrhea and severe dehydration, hypothyroidism, anaemia and poisoning, among others.
5. Aggression Toward People or Other Animals
Aggressive actions toward animals or people can be a sign of a stressed or sick dog. Consult your veterinarian or a veterinary behaviorist before the problem gets worse. Many aggressive signs are accompanied by a fearful body posture and facial expression, and with submissive behavior. Treatment for aggresion focuses behavior management techniques to assist the dog with its anxiety and anger. Devices such as muzzles can also be effective when the dog is away from home, with all treatment being focused on preventing injury to humans, other animals, and to the dog.