So you just saw your cat peeing outside of the litter box and the urine that they deposited on your floor was not normal: it was pink. What is the cause of pink or blood tinged urine in your cat and what should you do?
A cat urinating blood is never a normal sign and there are several possible causes. The good news is the most common cause is one that resolves on its own within 1-7 days even without treatment: feline idiopathic cystitis (FIC). Feline idiopathic cystitis is sometimes called stress cystitis because stress can trigger inflammation in the bladder. Cats that suffer from irritable urination are lumped under the term “feline lower urinary tract disease” or FLUTD. The most emergently life-threatening cause of urinary discomfort and blood tinged urine is urinary obstruction from a urethral plug (almost exclusively in male cats). The main causes of FLUTD in order of frequency are listed below.
Table of Contents
Most common causes of feline lower urinary tract disease under age 10:
- Feline idiopathic cystitis (55-63%)
- Bladder stones (15-22%)
- Urethral plug (10-21%)
- Cancer (1-2%)
- Urinary tract infection (1-8%)
The most common cause for your cat urinating blood or peeing small volumes of urine around the house is feline idiopathic or interstitial cystitis
While this condition is considered “self-limiting” meaning it should resolve on its own, treating your cat for his/her symptoms of FIC will help to more quickly resolve their discomfort and symptoms. Feline idiopathic cystitis is caused by inflammation of the lining of the bladder that may be triggered by the nervous system. Stress plays an important role in the development in FIC in cats. Sometimes there are obvious household changes that have occurred directly before the development of FIC. Cats that don’t handle stress well (the more typical “scaredy-cats” may be more likely to develop FIC symptoms from changes in the home such as moving homes, the addition of a new pet, inter-cat conflict, moving furniture in the home, addition of a new person in the home etc.
In studies by referral veterinary hospitals of cats presented for urinary tract symptoms that were non obstructive, the top two causes in order of frequency were: 1. FIC (55-63%) and bladder stones (15%-22%).
Diagnosis of feline interstitial cystitis:
Technically, the diagnosis of FIC cannot be made unless a battery of routine tests have not identified a cause. These tests typically include urinalysis, urine culture, ultrasound or x rays of the bladder. Although this is rarely pursued, a fiber-optic camera guided into the bladder during a bout of FIC would show small hemorrhages on the bladder lining.
FIC is most common in cats between 2-6 years of age. It is very uncommon in cats under 1 year of age or older than 10 years of age. It is also more common in overweight cats fed a dry food diet. Recent movies, decreased water intake and being an indoor cat are all risk factors for FIC. Recurrence in cats with non-obstructive irritative voiding is 39% and as high at 45% in male cats who initially presented for urinary obstruction.
Treatment of feline interstitial cystitis:
Treatment of FIC is aimed at improving their environment to ensure they feel they have a safe space to rest, eat and eliminate, plenty of access to enrichment (scratching posts, toys) and opportunities to play and practice predatory behavior (catching mice toys and bird feather toys). Providing a consistent predictable human-cat social interaction is also important. Environmental modification has shown significant reductions in urinary signs and fearful and nervous behavior within 10 months.
Episodes of acute pain and discomfort from FIC are treated with pain relievers, antispasmodics, and subcutaneous fluid therapy to improve their hydration and dilute inflammatory mediators in the bladder. It is recommended that cats transition to a mostly wet food diet (canned food) and provided options to increase their water consumption (many available water bowls in the home and/or water fountains that attract cats that love moving water. A new product on the market made by Purina called Hydracare can help encourage good hydration. It is a packet of electrolyte rich gel that can be mixed into their food that helps improve a cats’ hydration.
In addition to increasing your cat’s hydration with canned food and products like Hydra Care, it is important to look at ways to decrease you cat’s anxiety. Reducing stress and providing environmental enrichment can really help your cat. A great product to use is a classic Feliway diffuser. This is a plug in diffuser that provides a calming pheromone only your cat can detect. There is a Multicat Feliway diffuser available on Amazon that is best for reducing inter-cat conflict if that is the main source of stress. The Ohio State Indoor Cat Initiative is a great resource to help you understand your cat and provide ways to reduce stress in your home.
Your veterinarian may prescribe a calming medication called gabapentin to help relieve bladder pain and reduce anxiety. You can read more about the benefits of gabapentin in cats here.
Straining to urinate in cats over 10 years of age:
If your cat is older than 10 years old and having blood tinged urine, there is less than 5% chance that your cat has idiopathic cystitis. More than 50% of the time a cat older than 10 years old will have a urinary tract infection with these symptoms. Cats with kidney disease, hyperthyroidism, diabetes, bladder stones, and previous urinary tract procedures (catheterization , surgery on the urethra) have an increased incidence of urinary tract infection.
What can make your cat peeing blood a life threatening event?
The most common cause is urinary obstruction (or when your cat cannot get enough urine out). Urinary obstruction happens almost exclusively in male cats.
How can you tell if your cat is obstructed?
- They may be vomiting, hiding, not eating and straining to produce only dime sized clumps to quarter sized clumps of urine the litter box
- A palpable a firm enlarged bladder that cannot be emptied with gentle pressure
- Painful when touching belly
Female cats almost never develop urinary obstruction because their urethra (the exit pathway front the bladder) is larger than their male cat counterparts. Male cats can more easily get obstructed because the urethra that travels through the penis is a very narrow tube. Crystalline grit can combine with mucus and form a plug that seals up the urethra and prevents urine from flowing out. Over several hours time, the cat’s bladder will fill with urine and they will become painful and can get very very sick. These cats must have immediate decompression of their bladder by unplugging the obstruction and passing a urinary catheter. If a cat presents very late for this procedure they risk dying due to a precarious rise in their blood potassium. This rise in blood potassium can affect how the heart beats and cause arrhythmias and sudden death. This is why male cats should always be evaluated by a veterinarian if they are having trouble urinating.
Chances are, if your cat is under age 10 and is acting normally other than producing small amounts of urine (blood tinged or not) in or out of the litter box, they have idiopathic cystitis. The second most common cause of irritable urination in cats less than 10 years old is a bladder stone.
How does your veterinarian diagnose a bladder stone?
Bladder stones can readily be identified by imaging of the bladder with either an abdominal xray or a quick ultrasound of the bladder. Many veterinary clinics have a portable ultrasound unit that can readily detect bladder stones.
Types of bladder stones in cats:
Of all cats that present for FLUTD signs, 15-22% of cats will be diagnosed with a bladder stone. The two most common types of stones are calcium oxalate and struvite. Struvite is a stone that can be medically dissolved with a prescription food and occurs most often in cats under age 7. Most struvite stones can be dissolved in under 5 weeks on this diet. Middle aged and older cats are more likely to be diagnosed with a calcium oxalate stone. Calcium oxalate stones cannot be dissolved and must be removed.
Unfortunately, bladder stones cannot be identified as calcium oxalate or struvite by appearance alone. The stone must be sent to a stone laboratory and analyzed to determine its composition. Because the stones are inside your cat, this can’t be done easily . Clues can be taken from the composition and pH of your cat’s urine. Struvite stones develop in alkaline urine and the converse is true for calcium oxalate.
If your cat is comfortable enough to wait a few weeks to assess the response to a dissolution diet, this is a reasonable first step after diagnosis of a bladder stone. If medical dissolution fails after a few weeks, then surgical removal should be performed. There is a minimally invasive surgical approach called percutaneous cystolithotomy that can be performed using a 1-2cm incision into the abdomen and into the bladder. It uses a rigid fiberoptic camera and basket to retrieve stones. This type of procedure is done at a veterinary speciality hospital. Most skilled general surgeons can perform a traditional cystotomy (surgery into the abdomen and bladder to remove stones) with an incision that is realistically only a few centimeters longer. It may be worthwhile to speak to your veterinarian further when considering your options.
Bladder tumors in cats:
Cancer in the bladder is pretty rare in cats and only accounts for less than 1-8% of cats presenting with urinary discomfort symptoms. The most common bladder tumor in cats is called urothelial cell carcinoma (formerly called transitional cell carcinoma). The median age of cats with this cancer is 10-15 years of age. It can be diagnosed by imaging a mass in the bladder and finding irregular cancerous transitional cells in the urine. If no identifying malignant cells are identified on a urinalysis a diagnosis may need to be made by performing a needle biopsy of the mass. Performing a needle biopsy into a bladder mass is debated as there are documented reports of animals having their tumor seeded along the needle track from the skin into the bladder. Some veterinarians feel that most patients’ survival rate is generally shorter than the time it would take the tumor to grow elsewhere. A needle biopsy can provide a fast and easy diagnosis. Unfortunately, the median survival of cats with aggressive treatment of their urothelial cell carcinomas (surgery, chemotherapy and non steroidal anti-inflammatory medication) still only survive 8 to 12 months.
Urinary tract infections in cats:
Urinary tract infection is rare in cats under age 10 (1-8% of cats with FLUTD symptoms). To diagnose a urinary tract infection, your veterinarian will collect a sterile sample of urine from your cat by directing a needle into the bladder to extract urine. This urine will be sent to a reference lab for a test called a urinalysis with culture and sensitivity. The urine will be analyzed under the microscope for evidence of an infection, screened for abnormal casts in the urine (sloughing of the kidney tubules into the urine) or evidence of crystals. The urine pH will be measured, and the urine will be tested for things like ketones and urine glucose. Once a urinary tract infection is diagnosed, your cat will most likely be placed on a first tier antibiotic for the urinary tract (amoxicillin, amoxicillin/clavulanic acid, or trimethoprim-sulfonamide) for 3-7 days.
Take home message about what it means if your cat is urinating blood and straining to urinate:
There are a number of considerations to be made when trying to understand how serious it is that your cat is urinating outside the litter box and producing blood tinged urine. The first consideration is whether your cat seems sick (vomiting, inappetence, painful or hiding). If your cat is male, then you may not want to wait at all. It is generally best to have your veterinarian evaluate your cat to make sure there is no obstruction to urination. If your cat is under 10 years of age and over age 1 they most likely have feline idiopathic cystitis. However, a bladder stone may also be likely. Tumors and infections are a lot less common.
If your cat is 10 years of age or older and have an underlying disease like kidney disease, hyperthyroidism, or diabetes they have an increased risk for a urinary tract infection. They are also at increased risk for tumors in the bladder.
Your veterinarian can pretty quickly rule out a variety of causes for your cat’s urinary signs and can most likely start a treatment plan that can help your cat feel better more quickly.