Yesterday we had a rather unusual case of the dog who "can’t go". The "take-home message" is that we always take this complaint seriously.
"Acting constipated" is a not uncommon description of a pet’s situation. Upon receiving this complaint, the thoughtful veterinarian’s next step is to ask the owner what the pet is actually doing. Is he straining and producing only small amounts of hard, dry stool? That would certainly indicate constipation. If, on the other hand, the pet is "trying to go to the bathroom and nothing happens" or is "squatting a lot and straining", more information is needed.
Often pets who are squatting and straining without producing anything are actually unable to urinate. [As I discussed in a previous post.] This is a life-threatening situation, and prescribing laxatives over the telephone would be a bad idea. Yeah, we need to see him (or her). Urinary stones, tumors, blood clots, prostate gland troubles — all can cause life-threatening blockages of the urinary tract. When the back-pressure builds up too much, the kidneys are unable to do any filtering and waste accumulates in the bloodstream until the patient is poisoned by his own metabolic waste. More than once I have been presented with a patient whose owner had been giving laxatives for two or three days while the animal’s kidney’s were shutting down.
Certainly pets can become constipated to the point of great distress. This often happens with dogs who consume bones. They love to eat them, but they really cannot digest them. While larger slivers of bone may become lodged in the mouth, throat, esophagus, stomach or intestine, the more common situation is to have chips of crunched-up bone forming a concrete-like mass in the rectum which is very difficult to pass.
One of our cat patients had repeated episodes of severe obstipation (so constipated it’s basically a non-moving, concrete blockage). His owner noted that the episodes coincided with the cat’s escapes outdoors, but had only been going on since construction began in the neighborhood. He speculated that the cat was acquiring sheetrock dust in his wanderings. When he groomed himself, he was making plaster inside his bowel. We never actually documented this, but when all the lots in the neighborhood had houses on them, the cat’s problems ended.
Most animals with mild constipation will respond to gentle laxatives like mineral oil or psyllium muciloid (Metamucil). Sometimes enemas are needed. On rare occasions, I have had to physically break down the mass of hard stool with external massage and intra-rectal instruments (while the pet is anesthetized, of course). The first year that I was out of school, we actually had to perform surgery to remove a mass of stool from a Bassett Hound’s colon. It weighed three pounds, and (after removal) could not be broken down without a hammer. Lots of bones in that guy’s diet.
Hunter was a much more unusual case. He had been straining a great deal since the previous evening. His owner had seen him urinate freely, so that blockage was ruled out. The dog had vomited once and his folks commented that it was very foul-smelling "… like stool, but it came out his mouth." Not only is this a disgusting situation, vomitus with an odor of stool most likely indicates a blocked intestine. The dog was quite painful when I touched his abdomen, so an X-ray was the next step.
It looked as though someone had inflated his large intestine with a tire pump. It was huge and gas-filled. His next step (after heavy-duty pain medication) was exploratory surgery. Upon opening the guy, we find not only an enormously inflated large bowel, but a small intestine that looks as though it is no longer alive. The entire length of small bowel was blue and looked "pitted". The lymphatic vessels draining the bowel were distended and overfilled with lymph, making the membranes that support the intestine (called mesenteries) appear to be milk-filled.
Further examination revealed something I had previously seen only in horses (and that at post-mortem). The large bowel had become twisted 180 degrees. This prevented the exit of stool and gas, hence the ballooning of the colon. As the pressure increased, the torsion increased and the main blood supply to the entire intestinal tract had become compromised. I decompressed the bowel with a tiny needle, and "untwisted" things back into their normal alignment. Within minutes, I was surprised and pleased to see the small intestine recover a normal appearance. Fortunately, it appears that its circulation was only disturbed for a short time. The large bowel had not fared so well, still looking somewhat unhealthy.
Twenty-four hours later, Hunter seems to be making steady progress and we have high hopes that he will recover.