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Blocked Bladders in Cats

cat urinary bladder stones cystitis

Cats are known for conducting their toilet habits with utmost dignity and discretion. Therefore, it would be most unusual if a cat suddenly starts going in and out of their litter box, while yowling bloody murder! Most importantly, these behaviours indicate a potential blocked bladder. A blocked bladder is a painful, life-threatening medical emergency! Not sure what a blocked bladder is? Afraid that you may miss a blocked bladder in your cat? This article will describe blocked bladders and why they are life-threatening emergencies. This article will also elaborate on the signs of a blocked bladder, the risk factors for a blocked bladder and how you can reduce the risk.

What is a blocked bladder?

Time for a brief anatomy lesson! The kidneys produce urine, which travels to the bladder and is stored there. Urine leaves the body from the bladder via a tube called the urethra. When the urethra is partially or fully blocked and urine cannot be emptied from the bladder, a “blocked bladder” is the result.

Many things can block the urethra in cats, including:

-Bladder stones

-Scar tissue

-Severe Inflammation


-Blood Clots

-Mucus plugs (mucus plugs are made up of debris, cells, crystals and proteins)

Why is a blocked bladder life-threatening?

If urine is unable to leave the bladder, it accumulates and exerts pressure on the kidneys. This causes the kidneys to swell, which disrupts their ability to produce urine. In this way, a blocked bladder causes kidney failure.

The kidneys filter excess potassium and other waste products from the body and remove them through the urine. When the kidneys fail, potassium reaches dangerously high levels in the blood and disrupt the body’s acid-base balance. This can disrupt the heart’s rhythm and pumping ability, which can be fatal! 

Picture a balloon that keeps swelling … until it bursts! This can happen to a blocked bladder that is left untreated. Sounds painful, doesn’t it? Once a distended bladder has ruptured, urine floods the abdomen. This leads to excess waste products in the bloodstream, which wrecks with the heart. In addition, if there is a pre-existing urinary tract infection, the bacteria can trigger a life-threatening condition called “sepsis”. Sepsis can cause multiple organ failure. The scariest part is that blocked bladders can turn life-threatening really quickly.

If a blocked bladder is left untreated in a cat, the poor cat can sometimes die within 24-48 hours!

Signs of a Blocked Bladder Signs of a partial or full bladder blockage include:

-Straining to urinate without any urine production (if completely blocked)

-Going in and out of the litterbox often

-Frequently licking the genitals

-Frequently urinating small amounts

-Urinating outside the litterbox

-Bloody urine

-Some affected cats may vomit frequently, suffer from lethargy and/or refuse to eat.

However, veterinarians have encountered bright and alert cats with blocked bladders! Bottom line – if you notice any of the above symptoms, consult a vet immediately!

Risk Factors for Blocked Bladders (and how you can manage each risk factor!)

Male Cats

The urethra is short and broad in females, but long and narrow in males. As it is much easier for narrow urethras to get blocked, male cats are more likely to suffer from blocked bladders! 

Insufficient Water

Cats on just dry food are more likely to suffer from blocked bladders then cats who also eat wet food. Dry food reduces the amount of water that is filtered through the kidneys into the urine. Adequate water helps to “flush” out sediments and crystals in the bladder, and reduces the likelihood of them clumping together. To complicate matters, cats usually drink very little water. Cats descend from desert animals, which adapted to their environment by relying on their prey for their fluid intake. In this way, they could survive. However, surviving is not the same as thriving!


Chonky cats are prone to urinary issues as the excess fatty tissue is biologically active, secreting inflammatory hormones and creating oxidative stress on various body tissues and subsequent damage. Several studies show that overweight cats are more prone to blocked bladders. One study shows that the risk of lower urinary tract issues was four times higher in overweight cats than in non-overweight cats! Urinary issues aren't the only condition that fat cats are prone to, as diseases like Diabetes also tend to occur in heavier cats.


Studies show that stressed cats are more vulnerable to blocked bladders. It is thought that stress erodes the inner protective layer of the bladder wall and over-stimulates the nerves that supply the bladder wall, hence causing bladder inflammation and predisposing them to blocked bladders. Cats in multi-cat households are more prone to stress  due to cat politics. Cats are naturally solitary, territorial beings, and it can be difficult for a cat to defend their turf if they have to share resources (e.g. litter boxes) with other cats!

Cats also get stressed when their routines are disrupted (e.g. when their human housemates are at home more often because of lockdown restrictions or vice versa) 


Wet Food:

Consider introducing your cat to wet food! However, do note that tummy upsets can occur if new food is introduced too rapidly. Consult your vet before giving new food to your cat! Based on your cat’s medical history, your vet will let you know what kinds of wet food your cat can try, as well as how to introduce it safely.

Water Supplementation:

A hack i personally love doing with my cat is sneaking in extra water into her dinner of wet food. This ensures that she consumes water as she eats! For finicky cats,i recommend gradually increasing the water inclusion to a level that the cat will accept (additional high value wet form treats can also be added to enhance palatability). If you do have an extremely picky cat with the palate of a diva, then a specialized veterinary flavoured water supplement for cats can also be a good alternative to ensure optimum hydration.

Water Fountains:

Many cats prefer the sound and movement of flowing water! Cats prefer wide, shallow bowls that keep their whiskers from touching the bowls. Also, cats can be very particular about the bowl’s material and location. Therefore, it is worth placing several water bowls of varying materials in multiple locations. Also, place the water bowls in a different location from the food bowl. Cats dislike eating near their water source. Remember to replace your cat’s water regularly. Felines are finicky, and will reject unclean water! 

Weight Management:

Speak to your vet about developing a customised weight loss plan for your cat! Your vet can help your cat lose weight in a safe and controlled manner (i.e. not too rapidly). In the meantime, the following weight loss tips will be useful:

-Minimise treats for your cat

-Limit the number of people who feed your cat (a family member may be sneaking treatos to your cat behind your back!)

-If you have multiple cats, feed them separately as cats like to steal one another’s food! 

Resource Management:

Provide more resources per cat: Each cat should have their own area with hiding spaces and separate beds, litter boxes, food bowls and water bowls. Fun fact: The optimal number of litter boxes is the number of cats + 1!

Behavioural Management:

Maintenance of routine/gradual change - Cats get stressed if you alter their routine in any way, even if you do something seemingly trivial like changing the location of a litterbox or the litter type! Therefore, please keep their environment as constant as possible. Also, remember to clean the litter tray regularly. This minimises litter-related anxiety in cats.

Supplementation - Consider Feliway: Feliway comes in a spray or a diffuser. It mimics the relaxing effects of natural feline hormones, and is used in anxious cats! Supplements such as Zylkene also have a calming, soothing effect on stressed cats which can help reduce disease risk. Other urinary supplements such as those containing cranberry extract and/or antioxidants help maintain optimum urinary tract health and prevent recurrent urinary issues. Probiotics may also help reduce the incidence of Urinary Tract Infections, which can be a consequence of blocked bladders/ bladder sediments.

Research has shown that cats who have suffered from past bladder blockages are more likely to developed blocked bladders in the future. Therefore, prevention is better than cure and we hope that the above pointers can help you better manage your cats' urinary health.

If your cat keeps suffering from blocked bladders despite your best efforts, it is worth talking to your veterinarian about a concise management plan customized to suit you and your cat.

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