Visiting Veterinarian : Blocked up
Red, an elderly Shetland sheepdog (commonly called a Sheltie), had been treated in the past by his mainland vet for chronic constipation. "Doc told me quite some time ago that there was something wrong with the muscles back there," his owner explained, then added in a whisper, "I even learned how to give him enemas at home."
His mom had been managing things the best she could, but recently had noticed a firm swelling right next to his...well...you know...under his tail. The swelling had rapidly increased in size, so she took him to another veterinarian who advised her that the mass was occluding Red's normal bowel function. Unless the family was ready to proceed with major surgery to remove the mass, the vet said, they should consider euthanasia.
"We really can't afford such a procedure," the owner explained when she brought Red to me for a third opinion. "He's so old, and the vet said it might leave him incontinent. On the other hand, he's still eating, and doesn't seem to be in pain. Isn't there anything we can do for him besides surgery?"
As always, I started my exam at the head, noting Red's general attitude. He was an old man, no doubt about it, but seemed in relatively good spirits. He was on the thin side, with a few matts and a mild heart murmur, but I found nothing dramatically abnormal - until I got to his hind end. Now don't be squeamish. I'm going to use scientifically correct terminology here. Keep this column away from children under the age of, say, 18, as they would surely find it necessary to laugh hysterically and make inappropriate jokes. You, however, are more mature. Okay. Ready? Back to Red's caboose.
Lifting his tail, I could see that Red's anus, which should have been dead center, was pushed way over to one side by a swelling the size of a large orange. "That's a pretty big growth," I commented, palpating the mass. "Firm, too," I continued, thinking that anal sac carcinoma was a likely diagnosis, and that I would have nothing but more bad news for this distraught owner. "Let me just check internally," I hedged, pulling on a rubber glove.
I expected to find that the swelling was indeed a solid tissue mass occluding the rectum and confirming cancer as the probable diagnosis. Instead, my finger slid beneath Red's thinly stretched skin and located a big, solid lump...of poop. That's right. Red had a huge outpocketing on the side of his rectum, called a rectal sacculation or diverticulum. Whenever he pushed to defecate, feces squeezed into the pocket and got stuck. As he strained day after day, the mass of impacted fecal matter grew, pressing into a hard ball of brick-like density, now way too large to pass. So large, in fact, that it was preventing any feces at all from passing normally out the anus.
Red's old Doc on the mainland had been correct. There was something wrong with the muscles back there. Although the problem might be confined to the rectal sacculation, it was likely that initially an underlying condition called a perineal hernia had caused Red to strain, and the straining had then led to the diverticulum. Perineal hernia is a condition found predominantly in older intact male dogs. There are a number of breeds particularly prone to this problem, including Boxers, Collies, Boston terriers, Pekingese, and Old English Sheepdogs.