So if you are just tuning in from three weeks ago, you'll recall I asked you to drink a large glass of ice water and hold on until now. How'd it go? Not so good, huh? Had to give in and "use the facilities" didn't you? Uh huh, just as I expected. Okay then, pour yourself a fresh cup of coffee and try to get through this without stopping to use the facilities.
If you have no idea what I'm talking about, I'll sum up. We continue our discussion of urethral obstructions: being able to make urine, and store it in the bladder, but being unable to urinate or pass the urine outside the body.
Receptionist: "Mrs. Smith is on the phone. She says Tiger has been going in and out of the litterbox a lot for the past few days, and he's crying a lot. He won't eat today, and she said that he doesn't seem to be doing anything in the litterbox, even though he seems to be straining to go. She says he may be constipated."
Veterinarian: "How soon until they get here?"
This conversation is a classic. It is repeated many times over in veterinary hospitals everywhere throughout history. The "blocked" cat: a true emergency. Why would we assume this case to be a potential urethral obstruction rather than constipation (unable to have a bowel movement) as the owner opined? Actually, it's just a hunch. An educated hunch backed by the law of averages. You see, most of the cats with a history like this have urinary issues, not bowel issues. One is a serious emergency. Which hunch do you want to play? We generally don't play hunches, and get them in ASAP. Better safe than sorry, right?
When Tiger comes in, and the diagnosis of urethral obstruction is made, he may be alert and normal-looking, excepting his painful, blocked bladder. Or he may be flat-out, nearly comatose. It all depends on how long he has had the blockage.
Daverio is a veterinarian at Williamsport West Veterinary Hospital.
Tiger needs some assistance to relieve his blockage. This usually requires heavy sedation or anesthesia, so that a small, rubber or plastic catheter tube can be introduced into the urethra and advanced into the bladder. Anesthesia, because cats don't much appreciate our efforts to help them, especially when helping involves sticking a tube someplace objectionable to the cat. And cats are equipped with various effective weapons to make even simple restraint rather difficult.
The process of urinary catheterization may take multiple attempts, copious flushing with sterile fluid, and a great deal of patience - another reason anesthesia usually is a must.
Once the blockage is relieved, the catheter usually is left in place for at least 24 hours to maintain an assured free flow of urine, and to keep the bladder empty. Anybody who has ever had the pleasure of experiencing a urinary catheter themselves will attest - it makes one a bit cranky. A lot of cats don't take much prompting to reach "cranky" moods. Cats with indwelling urinary catheters can be downright ornery, making them more demanding patients in general.
Kidney function may be affected after a blockage, which may result in permanent damage.
Blood tests always are recommended after a blockage has occurred to evaluate organ function. Fluids may be administered to any animal that has experienced a blockage, to support the kidneys and help correct electrolyte and fluid imbalances. If the bladder has been overstretched (like a big, floppy, balloon) it also may be permanently damaged.
X-ray pictures of the abdomen are necessary to assess organ size, shape, position and consistency. We look for uroliths (urinary stones) that may be present in the bladder, urethra or even in the kidneys. Kidney stones are not part of this discussion - they occur with much less frequency as compared to bladder stones. But not all blockages are caused by stones.
Urethral obstructions can be caused by a variety of problems, all of which are basically plumbing problems (a mechanical plug of sorts in the drain). The most common cause in cats is a matrix of mucus and sandy material that lodges typically in the farthest portion of the urethra. Urinary stones may also cause blockages, of course, if they are small enough to lodge in the urethra. On some occasions, urinary blockages can be caused by tumors or trauma to the pelvis. A swollen prostate gland also may be responsible for slowing or even stopping the flow of urine.
Blockages happen most often in males, both dogs and cats, because the urethra is longer and narrower than in females. Urethral obstructions in females are almost uniformly surgical emergencies, as it is notoriously difficult to catheterize the bladder of female animals. Fortunately, this type of scenario doesn't happen very often in females. That is not to say female animals aren't afflicted with the same urinary tract diseases as males - they are. However, they don't tend to suffer urethral obstructions with the same frequency, thank goodness.
Treatment and diagnostic tests are pretty much the same for all species, provided a urinary catheter can be passed to relieve the obstruction. Male dogs are a bit more difficult to unblock because of the os penis. Totally not being rude here - that is the name of the bone that is part of the male dog's "boy parts." This bone is long and narrow and the urethra passes through it. Many of the blockages seen in dogs occur at the os penis, which makes unblocking them a big challenge if the catheter being introduced will not pass. A temporary but lifesaving surgery may need to be performed in some of these more difficult cases, sometimes followed by more permanent surgical solutions.
The outcome of any of these cases is dependent on a few key factors: the length of time the animal has been blocked, the location and nature of the obstruction and the ease and effectiveness with which the obstruction is relieved. In many cases, particularly with bladder stones or feline urinary tract syndrome (the mucousy-sandy plug in cats), a repeat performance is expected. If or when this will occur is anybody's guess.
Sometimes we can suggest dietary changes that will help prevent these problems from recurring, especially in the case of bladder stones.
While this topic is discussed in entire chapters of veterinary medical and surgical textbooks, and is given hours of lecture time in continuing education meetings, space and time here are limited. Besides, I'm sure you've drained your coffee cup by now, and need to take a break. You can stop holding it now - time to go.