Foamy Cat Urine: Signs and Causes

Last Updated on: June 26, 2024

From time to time, your feline pet may exhibit some unique symptoms that are quite alarming, with the most common one being foamy cat urine.

Sure, there were a couple of times that our cats dismissed foamy or cloudy urine, but do you know that it can be a sign of an illness? It can be a sign of kidney disease, liver issues, or Feline immunodeficiency virus.

The Common Causes of Foamy Feline Urine

Foamy urine can be a sign of various underlying issues, and it’s important to consult with a veterinarian for a proper diagnosis and treatment. Common causes of foamy cat pee can include:

Urinary Tract Infection

UTI in cats can sometimes be associated with foamy urine, although foamy urine alone is not a definitive indicator of a UTI. UTIs in cats can cause various changes in urine appearance and behavior. Here’s how UTIs can relate to foamy urine:

  • Increased Frequency and Urgency: Cats with UTIs often urinate more frequently than usual and may have a sense of urgency when they need to urinate. 
  • Discomfort: UTIs can cause discomfort or pain during urination. Cats may strain while urinating or vocalize when using the litter box. This discomfort may also result in the cat’s urine appearing foamy.
  • Blood in Urine: UTIs can sometimes lead to blood in the urine (hematuria). Blood in the urine can cause it to appear discolored and potentially foamy.

Urinary Tract Stones

Foamy cat pee can also be associated with urinary tract stones, also known as uroliths or bladder stones. When a cat has urinary tract stones, they can irritate the urinary tract lining and cause changes in the urine, potentially leading to foamy pee. Here’s how these stones can relate to foamy feline urine:

  • Irritation of the Urinary Tract: The presence of stones in the urinary tract can irritate and damage the lining of the bladder or urethra. This irritation can lead to inflammation and changes in urine appearance, including foaming.
  • Obstruction: In some cases, urinary stones can obstruct the flow of urine, causing the bladder to become distended. When the bladder becomes overly full or distended, the urine may come out with more force, potentially causing foaming as it exits the cat’s body.
  • Blood in Urine: Urinary stones can also cause microscopic damage to the urinary tract system, leading to blood in the urine (hematuria). Blood in the urine can affect its color and texture, potentially contributing to foaming.
  • Discomfort: Cats with these stones may experience discomfort or pain while urinating. This discomfort may result in changes in urination patterns, such as urinating more frequently or straining, which can lead to foamy urine.

Feline Idiopathic Cystitis (FIC)

Feline idiopathic cystitis (FIC) is a complex and often frustrating condition in cats that can lead to various UTI symptoms. Foamy pee can sometimes be associated with FIC, although it is not a definitive diagnostic sign. Here’s how FIC can relate to foamy pee:

  • Inflammation: FIC is characterized by inflammation of the bladder and sometimes the lower urinary tract. This inflammation can irritate the lining of the bladder and urethra, potentially leading to changes in urine appearance, including foamy or cloudy urine.
  • Pain and Discomfort: Cats with FIC often experience pain and discomfort while urinating. They may strain, urinate more frequently, or vocalize when using the litter box. This discomfort can result in the cat’s urine appearing foamy.
  • Blood in Urine: FIC can cause blood in the urine (hematuria), which can affect the color and texture of the urine. 
  • Stress: Stress is believed to play a significant role in the development and exacerbation of FIC. Stress can lead to changes in a cat’s behavior and overall well-being, which can affect their urinary habits and urine appearance.


Foamy pee can be associated with proteinuria, which is the presence of excess protein in the urine. While proteinuria itself may not always directly cause foamy urine, it can contribute to changes in urine appearance and may be indicative of an underlying health issue. Here’s how proteinuria can relate to this condition:

  • Increased Protein Levels: When there is an excess of protein in the urine, it can affect the composition and consistency of the urine. The presence of protein can make the urine appear frothy or foamy.
  • Underlying Kidney Disease: Proteinuria is often a sign of kidney disease in cats. When the kidneys are not functioning correctly, they may allow larger molecules, including proteins, to pass through into the urine. Kidney disease can also lead to changes in urine concentration and composition, which can contribute to foamy cat urine.

Other Causes of Foamy Feline Urine

  • Kidney failure: Chronic kidney disease can affect the kidneys’ ability to filter waste products and maintain the proper balance of fluids in the body, which can lead to foamy pee.
  • Feline foamy virus (FFV): Feline foamy virus refers to a type of retrovirus that infects domestic cats and some other feline species. Feline foamy virus is unique among retroviruses in that it typically does not cause overt disease in infected cats and has a relatively benign impact. 
  • Diabetes: Cats with diabetes may have increased sugar levels in their urine, which can affect their appearance.

How Can I Detect the Foamy Cat Pee?

Regular vet care, including lab work, can help us detect health issues earlier; in fact, an old cat can benefit from annual checkups. To be on the safe side, we have to monitor their urine and note its smell, color, and how foamy the urine is. With the above details, you’ll notice a change in its health. 

Start by Monitoring the Litter Box

If you notice that it’s producing foamy urine, then you should monitor its behavior when urinating and how often it urinates. You’ll have to clean the litter box regularly to notice if urinating frequency has increased or reduced. 

So if your cat produces foamy urine and you suspect UTI, then you should do the above. If it’s vomiting, make sure you examine it and even take samples to the lab for testing.

Examine the Cat’s Overall Health

After noticing the change in your cat’s urine, you should also look out for other symptoms. So you should start by examining its eating habits, which includes the type of cat food it consumes. Confirm if its overall behavior changes and if it’s vocalizing excessively or sleeping more.

The above symptoms are signs of discomfort or stress caused by internal problems like chronic kidney diseases. Monitor the color of its eyes, especially yellowing in the whitish part of its eyes. When dealing with a long-haired cat or an older cat, you should monitor its weight. 

Since infected cats don’t show signs of pain like most animals, you should look out for a change in their behavior, particularly in a male cat.

Final Thoughts 

If you suspect that your pet has a UTI, then you should start by examining their daily urine conditions and levels. Monitor the changes in the color of its tongue and eyes, but don’t jump to conclusions; instead, use the collected data with the vet and determine if it has any of the above conditions.

It may be something as small as stress or a serious health condition. Therefore, it’s always a good idea to talk to the vet. Your pet may have to undergo a number of tests to find out the cause of the problem.

Frequently Asked Questions

Is it normal for your cat to produce foamy pee?

No, but a foamy pee doesn’t always mean that your cat has a serious health issue. It may be something as simple as stress or a serious health issue like UTI.  

How can I treat cat proteinuria?

Treatment may involve managing the primary condition, such as kidney disease or inflammation, as well as addressing any associated symptoms.

Can a stressed cat produce foamy pee?

Yes, Cats can develop stress-related urinary issues, which may result in changes in urine appearance, including foamy/cloudy cat urine.

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