My Cat Can’t Pee! Feline Urethral Obstruction: Be Aware

Author: Dr. Jason Nicholas

Published: January 13, 2012

Updated: May 17, 2021

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cat suffering from urinary obstruction Let me start by saying this…

A cat that cannot pee is a cat that’s going to die, unless appropriate veterinary medical care is provided immediately.

Urethral obstruction is a severe, acute, and critical medical emergency.

If you take nothing else from this initial installment in my article series about feline urethral obstruction, I hope you will at least appreciate the importance of being able to promptly recognize this common pet emergency. The second and third installments will deal with ‘what to do’ in the event of a urethral obstruction and the steps you should take to minimize its likelihood or prevent it altogether, respectively.

If you’ve come to this post after having typed “help my cat can’t pee” (or something along those lines) into the search field of your favorite search engine… stop reading, step away from the computer, and take your cat to the vet immediately.

There are no safe and effective first aid steps that you can, or should, perform at home for a blocked cat. If they are to have any hope of survival, they must receive appropriate medical treatment at once. Then, only when your cat is safely at the vet and treatment has been initiated, come back to this series of blog posts to learn what you might expect and what you should do to prevent another episode from happening in the future.

Hopefully, you’ve come to this post prior to your cat becoming blocked. If so, I encourage you to read on so that you can avoid ever having to deal with the costs, frustrations, and potential heartbreak of having a cat with a urethral obstruction.

cat constantly in litter box is an emergency

What are the signs that my cat may have a urethral obstruction?

The signs your cat is likely to exhibit when they have a urethral obstruction will, in part, depend on the period of time for which they’ve been obstructed. As with many conditions, the earlier you recognize it and appropriately act upon it, the better your pet’s chances for survival are (and the lower your financial costs will typically be).

Below are the signs that an obstructed cat may exhibit. They are (roughly) listed in order of earlier signs to later signs. Though in medicine, as in life, few things ever really ‘follow the textbook’.

The important thing to note here is that you should be paying attention to your cat’s energy level, appetite, eliminations, and behavior on a daily basis — you will be more likely to catch a problem earlier in its course if you do. This is particularly important in cases of urethral obstruction since a cat can die if they’re obstructed for as short a period of time as 24 hours, and potentially less. Don’t forget… A cat that cannot pee is a cat that’s going to die unless appropriate veterinary medical care is provided immediately.

Signs that may indicate urethral obstruction in cats include:

  • frequent trips to the litter box
  • lack of urine in the litter box after you know they’ve been in there
  • vocalizing or straining while in the litter box (many owners mistake this for a sign of constipation)
  • excessively licking their penis
  • loss of appetite
  • sudden onset excessive drinking
  • vomiting
  • abdominal pain (often expressed by them trying to bite or scratch you when you try to pick them up)
  • hiding
  • collapse
  • death

Not to belabor the point, but if you are noticing any of these signs in your cat — especially if they are male, or have any of the other predisposing factors — take them in for immediate veterinary medical evaluation and treatment. Even if it's not a urethral obstruction, it's always better to error on the side of caution. Both for your cat’s sake and for the sake of your pocketbook as well. And here's what to expect when taking a cat for urethral obstruction treatment.

So, what's a 'urethra' anyway?

Most people know what the kidneys are, and what the bladder is, but not many are familiar with the urethra (or its tubular cohorts, the ureters). Think of it this way… if the bladder is the warehouse where a ‘product’ (in this case, urine) is stored, and the litter box is the customer that this ‘product’ needs to get to, the urethra is the interstate that UPS (or whomever your favorite carrier is) depends upon to deliver said ‘product’ to its final destination. If that interstate becomes impassable, for whatever reason — be it a rockslide, traffic jam, an earthquake, or any other cause — the product can’t be delivered to its final destination.

While the scenario above will certainly prove to be a hassle to both the manufacturer and the customer, it isn’t likely to result in the death of either. In the case of a urethral obstruction though, if the urine cannot be delivered to its final destination — the litter box — a dangerous build-up of electrolytes and metabolic by-products will result and multiple organ systems will fail. Of utmost importance amongst those organ systems, at least as relates to the continuation of life, is the heart. The build-up of potassium and other substances will prevent the heart from pumping, leading to cardiac arrest. Hence my original statement… A cat that cannot pee is a cat that’s going to die unless appropriate veterinary medical care is obtained immediately. Do you see why?

How does this urethral 'interstate' become obstructed?

I’m glad you asked. In fact, a cat’s urethra can become obstructed through a variety of mechanisms, one of which is pretty much a rockslide! (see list below).

The ways in which your cat’s urethra can become blocked include:

  • the formation and lodging of a urinary mineral stone (‘urolith’)—that’s your ‘rockslide’.
  • the formation and lodging of urinary ‘sand’/’grit’, or a plug of mucus secreted from an inflamed bladder wall or urethral lining.
  • the formation of a blood clot resulting from bleeding within the urinary tract.
  • the presence of a tumor (cancerous or not) arising either from within the urethra itself or from a structure surrounding the urethra which compresses it from the outside.
  • the development of scar tissue within the muscle that surrounds the urethra — this is a urethral stricture, it narrows the diameter of the urethral lumen through which urine can pass, potentially resulting in an obstruction.
  • spasm of the urethral muscle — which can have a similar result on the urethral lumen diameter as a urethral stricture.
  • the presence of a ‘foreign body’ — such as a previously placed, but not fully removed, urethral catheter is but one of the reasons why cats with indwelling urethral catheters must always wear E-collars and why they should never be left overnight in a clinic/hospital without on-site supervision.

Are all cats at risk of this condition?

Though all cats (and dogs) are at risk of urethral obstruction, the condition tends to happen most often in cats-and amongst them, the most commonly affected are the make cats and those with certain other predisposing factors. These are risk factors:

  • Male cats are at higher risk than female cats.
  • Overweight cats are at greater risk than cats of good body condition.
  • Cats that eat only (or even predominantly) dry food are at greater risk than those that eat exclusively (or predominantly) wet food.
  • Cats that have previously had a urethral obstruction are at increased risk of obstructing again (especially if their management hasn’t changed).
  • Cats with recurrent bouts of bladder inflammation (cystitis) are at increased risk of developing a urethral obstruction.
  • Stressful situations (e.g., home renovations, family trip, new baby, etc.) also increase the risk of urethral obstruction in many cats. Know what signs of stress to look out for and read this article by board-certified veterinary behaviorist, Dr. Chris Pachel, on the causes and prevention of cat stress.
  • Neutered cats and those that are indoor-only also appear to be at greater risk than sexually intact cats and those that spend time outdoors. However, both of these factors also tend to predispose cats to obesity — mostly because people overfeed them relative to the amount of calories they actually need — and therefore are more likely indirect risk factors for the development of urethral obstruction (with obesity providing the link). And since having your cats neutered and keeping them indoors confers far more health and safety benefits than the relatively small increase in risk they may confer in relation to the development of a urethral obstruction, I still recommend that you do both, and focus on changing the more important urethral obstruction risk factors.

Thanks to my friend Dr. Tim Trevail of Trevail Imaging Referrals in the UK for fantastic radiographic (X-Ray) image below of a cat’s urinary bladder, the wall of which has become thickened from chronic inflammation (cystitis). The thick greyish band between the two black arrows is the bladder wall, it is significantly thicker than it should be. This cat would be at increased for urethral obstruction from its chronic cystitis.

cat can't pee feline urethral obstruction xray

Since an ounce of treatment is better than a pound of cure, I hope you're now wondering what you can do to decrease your cat's chances of suffering from a urethral obstruction. Thankfully there are plenty of things you can do to help prevent your cat (and your heart) from experiencing urethral obstruction.

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About the author

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Dr. Jason Nicholas

Dr. Nicholas graduated with honors from The Royal Veterinary College in London, England and completed his Internship at the Animal Medical Center in New York City. He currently lives in the Pacific Northwest.

Dr. Nicholas spent many years as an emergency and general practice veterinarian obsessed with keeping pets safe and healthy. He is the author of Preventive Vet’s 101 Essential Tips book series.

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