According to veterinarians, digestive system problems are the most common problem they see in cats. The first part of the digestive system is the mouth from where the food enters. The food that enters the mouth is broken down by teeth and the digestive enzymes present in the mouth begin the digestive process by acting on the food. This is how the journey of digestion and absorption begins in the oral cavity. The mouth and stomach are connected through the esophagus which is a long muscular tube. Once the food enters the stomach, the acidic secretions separate the food constituents. After the stomach, the food enters the small intestine. Pancreatic and gall bladder secretions help the small intestine to absorb most of the nutrients. Next to the small intestine, lies the large intestine that is involved in the absorption of water and salt that is needed for the body from the material that is not absorbed by the small intestine. Problems in the digestive system are indicated by the following symptoms i.e., diarrhea, vomiting, weight loss, loss of appetite, or increased appetite with loss of weight and lethargy. Diseases within the oral cavity affect the overall health of your pet and are of major concern. One of the oral cavity diseases is periodontal disease which affects about 85% of pets that are older than 4 years of age. There may not be any obvious sign of oral diseases but foul-smelling from the mouth can be an indication of the presence of oral disease. The inside of the mouth of your pet is not clean as it is believed. Some microbes and infections can spread from the oral cavity to other organs in the body and cause disease. In most cases, the problems in the digestive systems are the results of sudden dietary changes and dietary carelessness. Other conditions leading to digestive system diseases include ingestion of foreign body, parasites, inflammation, hormonal imbalance, and cancer.