Intestinal Obstruction -- Foreign Body
Any animal that ingests any object other than food is prone to developing an intestinal obstruction when the objects gets stuck in a piece of intestine and causes a back-up of ingesta resulting most commonly in vomiting, anorexia, abdominal pain and sometimes diarrhea.
Unlike dogs that eat just about anything, cats typically get obstructed after accidently swallowing foreign bodies they are playing with such as yarn, tinsel, fishing line, ribbon, Easter basket grass, or any other string like material. In some cases, the string gets stuck around the base of the tongue while the cat has swallowed the rest of the material. Unlike hairballs that are usually vomited up, the string passes into the intestine where it causes the intestines to kink and fold up on themselves, like an accordian, as the gut tries to pass the string down the intestines.
The intestines get bunched up and eventually the string will slice through the intestinal wall which then allows leakage of intestinal contents (specifically bacteria) into the abdominal cavity. Once this occurs, peritonitis (infection of the abdominal cavity or belly) develops and the animal dies soon after without emergency surgery.
On physical exam, the veterinarian can often feel bunching of the intestines in the abdomen and the cats are always in pain and and let you know it. The oral cavity should be examined to see if a piece of string is caught around the base of the tongue. Many cats will present with high heart and respiratory rates, and be weak and dehydrated. If the string has already perforated the intestines, the cats will be in shock with dark dry gums and weak pulses. Many are not responsive to being handled, and often have a low body temperature.
Surgery is required in order to remove the string foreign body. The belly is opened and small incisions are made into the intestine in order to remove the string that is within the intestine. Any sections of intestine in which the blood supply has been cut off or the intestinal wall itself is too damaged is removed and the healthy ends of intestine are sewn together. Lastly, the abdominal cavity is flushed out with several liters of fluid in order to rinse off any bacteria that may have leaked from the intestines. The belly is then closed with sutures and the cat is woken up from anesthesia. For several days after surgery, the cat is given IV fluids, antibiotics, and supportive care.
With early surgery and aggressive supportive care after surgery, many cats do well and live normal lives afterwards. The prognosis for cats who already have tears in the intestine and bacterial peritonitis is more guarded even with surgery. The key is to do surgery before there is too much damage to the intestines.