# E. coli UTI: Causes, Symptoms, and Treatment A urinary tract infection caused by Escherichia coli is the most common bacterial bladder infection in dogs, cats, and people. The short answer for owners is this: E. coli normally lives in the gut, but certain strains carry molecular tools that let them climb into the urinary tract, attach to the bladder lining, and trigger inflammation. Most simple bladder infections respond to a short course of an appropriate antibiotic, but the drug must match the bacteria. Because resistance is rising fast, urine culture and susceptibility testing are no longer optional extras. They are the standard of care. Use this triage summary to decide how quickly your pet needs to be seen. - **Straining to urinate with only drops of urine, or no urine at all, is an emergency.** A blocked urethra can be fatal within a day, especially in male cats and male dogs. - **Bloody urine, crying out while urinating, or urinating outside the litter box or in the house** needs a veterinary visit within 24 hours. - **Fever, vomiting, lethargy, or pain in the flank or belly** suggests the infection has moved up to the kidneys. This needs same-day care. - **A pet with diabetes, a urinary catheter, or a suppressed immune system** should be seen promptly even for mild signs, because these conditions raise the risk of a severe or complicated infection [1][2]. - **Never give leftover human antibiotics.** The wrong drug selects for resistant bacteria and delays effective treatment. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## At a Glance: Cystitis, Pyelonephritis, and Complicated UTI Veterinarians sort urinary infections into categories because the category decides how long treatment lasts, which drug is safe, and how closely the patient must be watched. The table below summarizes the practical differences. | Feature | Uncomplicated cystitis | Pyelonephritis | Complicated UTI | |--|--|--|--| | Location | Bladder and urethra | Kidney and renal pelvis | Any site, with a complicating factor | | Typical signs | Frequent small urinations, straining, blood, accidents indoors | Fever, lethargy, flank pain, vomiting, poor appetite | Variable, often vague or chronic | | Systemic illness | Rare | Common | Common | | Usual trigger | Ascending UPEC from the gut | Ascending UPEC that reached the kidney | Catheter, stones, diabetes, immunosuppression, anatomic defect | | Diagnostic focus | Urinalysis plus culture | Urinalysis, culture, bloodwork, imaging | Culture plus imaging and management of the underlying cause | | Treatment principle | Short course of a drug that concentrates in urine | Longer course of a drug that reaches kidney tissue and blood | Correct the underlying problem and treat with a culture-guided drug | | Prognosis | Excellent with correct therapy | Good with prompt therapy, risk of scarring | Guarded, depends on the underlying cause | Uncomplicated cystitis means a healthy, non-pregnant animal with a normal urinary tract and no underlying disease. Pyelonephritis is an upper tract infection involving the kidney. A complicated UTI is any infection in a patient with a factor that makes it harder to cure, such as an indwelling catheter, diabetes mellitus, immunosuppressive illness or medication, a kidney transplant, or a structural abnormality [1][2]. The same bacterium, E. coli, can cause all three, and the difference is largely about how far it has traveled and what the host brings to the fight. ## Why E. coli Dominates Urinary Tract Infections E. coli is the dominant uropathogen in humans and companion animals. In a study of catheterized patients, E. coli was the predominant uropathogen at 32.8 percent of isolates, ahead of Klebsiella pneumoniae at 17.8 percent and Enterococcus species at 14 percent [3]. In a hospital survey of 182 urine samples, E. coli accounted for 63.2 percent of positive cultures [4]. In dogs, E. coli is likewise the leading cause of bacterial cystitis, and its close relative Escherichia marmotae can even be misidentified as E. coli on routine testing while carrying the same urinary virulence tools [5]. The reason E. coli wins this competition is not luck. Uropathogenic E. coli, usually shortened to UPEC, is a subset of E. coli that has acquired genes for sticking to urinary tissue, damaging cells, and evading the immune system. These genes sit on mobile pieces of DNA, so they can spread between strains. That is why hybrid strains appear. One study identified hybrid enteroaggregative and uropathogenic E. coli in 8.5 percent of archived urinary isolates, and every hybrid carried the adhesin gene fimH along with iron-capture genes [6]. These hybrids combined intestinal and urinary virulence traits and showed strong biofilm formation, enhanced epithelial adherence, and high resistance rates [6]. ### The Gut to Bladder Route The cause of an E. coli urinary tract infection is almost always the patient's own intestinal flora. E. coli shed in feces colonizes the skin around the anus and the opening of the urethra. From there it ascends the urethra into the bladder. This is why female anatomy is such a strong risk factor. The female urethra is short and sits close to the anus, so the distance bacteria must travel is small. In companion animals, the same anatomy applies to female dogs and cats. A study of asymptomatic bladder colonization in pigs showed how catheterization changes this route. All pigs with indwelling catheters became colonized by the harmless E. coli strain 83972 after inoculation, compared with only one of eight pigs without catheters [7]. When the catheter was removed, the colonizing strain was spontaneously cleared [7]. The catheter acts as a physical bridge that lets bacteria bypass the flushing action of normal urination. ### The e coli meat uti study Question Owners sometimes ask whether eating contaminated meat causes urinary infections. The evidence points to the patient's own gut as the source rather than a recent meal, but the two are connected through the food chain. Resistant E. coli from food animals can colonize the human or animal gut, and those resistant strains can later cause a urinary infection. This is one reason antimicrobial resistance in urinary E. coli is treated as a food-safety issue as well as a hospital issue. The practical takeaway is that resistance in a pet's urinary infection often reflects resistance circulating in the broader bacterial population, which is why culture results matter more than guesswork. ## UPEC Virulence Factors: How E. coli Attacks the Urinary Tract UPEC is not a single organism. A study of five clinical UPEC isolates found substantial differences in genome architecture, mobile genetic elements, plasmid composition, virulence factor composition, and antibiotic resistance profiles [8]. That variability is the central challenge in treating these infections. The table below lists the main virulence factors, what they do, and why they matter clinically. | Virulence factor | Function | Clinical relevance | |--|--|--| | Type 1 fimbriae (fimH) | Adhesin that binds mannose residues on bladder surface proteins | Mediates bladder colonization and is the target of vaccine development [9][3] | | P fimbriae (papC) | Adhesin that binds galactose-containing receptors on kidney and bladder cells | Associated with upper tract infection and pyelonephritis [3][10] | | S fimbriae (sfa) | Adhesin that binds sialic acid receptors | Contributes to epithelial adherence and colonization [3][10] | | Afimbrial adhesins (afa) | Adhesins that promote attachment without visible fimbriae | Part of the standard UPEC virulence gene panel [10] | | Hemolysin (hlyA) | Pore-forming toxin that lyses host cells | Tissue damage, iron release, and more severe inflammation [3][1] | | Cytotoxic necrotizing factor (cnf) | Toxin that disrupts host [cell signaling](/blog/guides/cell-signaling) | Associated with extraintestinal virulence [3] | | Cytolethal distending toxin (cdtABC) | DNA-damaging toxin that disrupts epithelial barriers and suppresses acquired immunity | A cdt mutant was significantly disadvantaged in urine, bladder, and kidneys, and showed reduced kidney colonization [11] | | Aerobactin and yersiniabactin (aer, fyuA) | Iron acquisition systems | Support bacterial survival in the iron-poor urinary tract [6][3] | | Biofilm formation | Community of bacteria encased in a self-made matrix | Present in 92.4 percent of isolates in one series and linked to persistence and relapse [12] | | Curli fimbriae | Surface fibers that promote biofilm and adhesion | Detected in 87.6 percent of isolates in the same series [12] | ### Adhesion Is the First Step UPEC cannot cause infection by floating in urine. It must first attach to the bladder lining. Type 1 fimbriae, encoded by the fimH gene, are the primary tool for this. FimH binds mannose sugars on the surface of bladder cells, which anchors the bacterium against the flow of urine [9]. Because FimH is so central to bladder colonization, it has become the leading target for a new generation of UTI vaccines. An mRNA vaccine encoding a FimH fusion protein raised functional antibodies in mice and rats and reduced infection in a recurrent UTI mouse model [9]. P fimbriae, encoded by papC, bind a different receptor and are more strongly associated with infection that reaches the kidney [3][10]. S fimbriae and afimbrial adhesins add further attachment options [10]. A strain with several adhesin genes has more ways to hold on, which helps explain why some infections are stubborn. ### Toxins That Damage Tissue Adhesion keeps the bacterium in place. Toxins do the damage. Hemolysin, encoded by hlyA, punches holes in host cell membranes, which releases nutrients and triggers inflammation [3][1]. Cytotoxic necrotizing factor disrupts host cell signaling [3]. A newer discovery is cytolethal distending toxin, or CDT, which damages host DNA, disrupts epithelial barriers, and suppresses acquired immunity [11]. In a mouse model of ascending infection, an E. coli mutant lacking the cdtABC locus was significantly disadvantaged in urine, bladder, and kidneys when competing against the wild-type strain [11]. In single-strain infections, the mutant showed reduced kidney colonization, which points to a specific role for CDT in pyelonephritis [11]. Bladders and kidneys from mice infected with CDT-producing E. coli showed higher inflammation and tissue damage in the kidneys at one and seven days after inoculation [11]. ### Iron Capture and Survival Urine is a hostile environment because it is low in iron, which bacteria need to grow. UPEC solves this with siderophores such as aerobactin and yersiniabactin, encoded by genes including aer and fyuA [6][3]. These molecules scavenge iron and bring it back to the bacterium. Iron acquisition genes are common in uropathogenic strains and appear alongside adhesins in hybrid strains [6]. ### Biofilm Formation and Relapse Biofilm is a structured community of bacteria embedded in a self-produced matrix. Biofilm protects bacteria from antibiotics and from immune cells, and it helps them persist on catheters and bladder surfaces. In one series, biofilm production was detected in 92.4 percent of UPEC isolates, and curli fimbriae were found in 87.6 percent [12]. Hybrid EAEC/UPEC strains also showed strong biofilm formation [6]. This is the biological basis for recurrent infections that seem to resolve and then return. Biofilm also explains why catheter-associated infections are so difficult to eradicate without removing or changing the catheter. ### Pathogenesis Flowchart The flowchart below traces the main path from gut colonization to kidney infection. ```mermaid flowchart TD A[Gut colonization by E coli] --> B[Contamination of periurethral skin] B --> C[Ascension through urethra] C --> D[Adhesion to bladder via type 1 fimbriae] D --> E[Biofilm formation on bladder surface] E --> F[Invasion of bladder cells] F --> G[Toxin release and inflammation] G --> H{Symptoms of cystitis} H --> I[Bladder only infection] H --> J[Ascension to ureter] J --> K[Kidney colonization via P fimbriae] K --> L[Pyelonephritis with systemic illness] ``` ## Risk Factors for E. coli UTI Risk factors fall into two groups: those that help bacteria reach the bladder, and those that weaken the host's ability to clear them. ### Female Anatomy The female urethra is shorter and closer to the anus than the male urethra. This shortens the distance bacteria must travel and increases the chance of contamination. In a study of hybrid EAEC/UPEC strains, most isolates came from female patients and children [6]. This anatomic disadvantage is the single strongest reason urinary infections are far more common in females across species. ### Urinary Catheterization An indwelling urinary catheter is one of the most important risk factors for complicated and hospital-acquired UTI. Catheter-associated urinary tract infections are among the most common nosocomial infections worldwide and cause significant morbidity and prolonged hospital stays [3]. In the pig model, an indwelling catheter allowed a harmless E. coli strain to colonize the bladder in every animal, while only one of eight animals without a catheter became colonized [7]. Removing the catheter led to spontaneous clearance [7]. Catheters also provide a surface for biofilm, which protects bacteria from antibiotics. ### Diabetes Mellitus Diabetes increases both the risk and the severity of urinary infection. In a mouse model of type 2 diabetes, UPEC loads were significantly higher in the urinary tract of hyperglucosuric diabetic mice, with a higher incidence of systemic dissemination and more severe cystitis and bladder inflammation compared with controls [2]. Even diabetic mice without induced hyperglucosuria had higher bacterial titers than healthy mice [2]. Glucose in the urine feeds bacteria and impairs host defenses. A separate study of the diabetes drug dapagliflozin found that a higher dose increased UPEC titers in urine, bladder, and kidneys in one mouse strain, while the effect varied by dose, strain, and diabetic status [13]. The interaction between glucose control, diabetes medications, and urinary infection risk is complex and should be discussed with a veterinarian. ### Immunosuppression and Transplantation Patients with weakened immune systems clear bacteria poorly. Kidney transplant recipients are a clear example. In one study of transplant recipients with urinary infection, resistance rates were extremely high, including ampicillin at 94 percent, cefazolin at 88 percent, cefotaxime at 80 percent, and ciprofloxacin at 62 percent [1]. These patients also carried virulence genes including ompT, fimH, and hlyA [1]. Immunosuppressive therapy plus a urinary tract that has been surgically altered creates a high-risk combination that demands culture-guided treatment. ### Other Contributing Factors Urinary stasis from stones, tumors, or anatomic defects gives bacteria time to attach and multiply. Incomplete bladder emptying from neurologic disease has the same effect. Advancing age and any condition that reduces urine flow or immune function add risk. In cats, bladder inflammation from feline idiopathic cystitis can coexist with infection and confuse the clinical picture, so culture is needed to tell them apart. ## Symptoms: What Owners See Symptoms depend on whether the infection is in the bladder or has reached the kidney. ### Signs of Cystitis - Frequent trips to the litter box or outside with small amounts of urine - Straining or squatting for a long time - Crying or vocalizing while urinating - Blood in the urine, which may look pink, red, or brown - Urinating outside the litter box or in the house in a previously reliable pet - Licking the genital area more than usual - Urine with a strong or unusual odor ### Signs of Pyelonephritis - Fever - Lethargy and reluctance to move - Vomiting and poor appetite - Pain when the belly or flank is touched - Weight loss in chronic cases - Signs of cystitis plus systemic illness ### Signs of Complicated UTI Complicated infections often produce vague signs. A catheterized patient may show no obvious symptoms until the urine is tested. A diabetic patient may have worsening glucose control. An immunosuppressed patient may show only lethargy. This is why surveillance urine testing is part of care for high-risk patients. ### Emergency Red Flags - **No urine produced despite repeated straining.** This suggests urethral obstruction and is life threatening. - **A hard, painful abdomen with a large bladder.** This is a classic obstruction pattern in male cats. - **Collapse, extreme weakness, or unresponsiveness.** This suggests sepsis or severe systemic infection. - **Repeated vomiting with fever and flank pain.** This suggests pyelonephritis with systemic involvement. - **Sudden inability to walk or severe back pain.** This can indicate kidney involvement or another serious problem. ## Diagnosis: From Urinalysis to Culture Diagnosis follows a stepwise path. Each step answers a specific question. ### History and Physical Examination The veterinarian asks about the frequency and character of urination, blood in the urine, accidents in the house, water intake, appetite, and any prior urinary infections. A history of catheterization, diabetes, or immunosuppressive medication raises the index of suspicion for a complicated infection. Physical examination includes palpation of the bladder and kidneys and a check for fever and dehydration. ### Urinalysis Urinalysis is the first laboratory step. It checks urine concentration, pH, protein, glucose, blood, and the presence of white blood cells and bacteria. A positive dipstick for blood or protein supports inflammation but does not confirm infection. Microscopic examination of urine sediment can reveal bacteria and white blood cells. In many cases, bacteria seen on sediment plus compatible signs are enough to start treatment, but culture is still needed to choose the right drug. ### Urine Culture and Susceptibility Culture is the definitive test. A urine sample is collected by cystocentesis, which means a needle is passed through the abdominal wall directly into the bladder. This avoids contamination from the urethra and skin. The sample is plated on agar, and any bacteria that grow are identified. Susceptibility testing then exposes the isolated bacteria to a panel of antibiotics to see which ones inhibit growth. This is the only reliable way to know which drug will work. Culture is essential in several situations: - Any pet with a history of prior urinary infection or recent antibiotic use - Any pet with a complicated UTI, including catheterized, diabetic, or immunosuppressed patients - Any pet with signs of pyelonephritis - Any pet that fails to improve on the first antibiotic - Any pet with recurrent infection ### Bloodwork and Imaging Bloodwork assesses kidney function, blood cell counts, and glucose. It is especially important in suspected pyelonephritis and in patients with diabetes or kidney disease. Imaging with radiographs or ultrasound looks for stones, tumors, anatomic defects, and kidney changes. These findings can change treatment and prognosis. ### Molecular Testing [Polymerase chain reaction](/knowledge/molecular-biology/polymerase-chain-reaction) testing can detect specific virulence genes and resistance genes such as blaCTX-M, blaTEM, blaSHV, and qnr [10]. These tests are used mainly in research and surveillance settings. They help track which resistance mechanisms are circulating in a region, which informs empirical drug choices while culture results are pending. ## Treatment: Culture-Guided Antibiotics The core principle of treatment is simple. Match the antibiotic to the bacteria. Empirical therapy, which means treating before culture results are available, is sometimes necessary in a severely ill patient, but it should be adjusted as soon as susceptibility results return. ### Why Culture-Guided Therapy Matters Resistance among urinary E. coli is rising worldwide. In one study of 100 UPEC isolates, 46 percent were multidrug resistant and 40 percent produced extended-spectrum beta-lactamases [14]. The highest resistance rates were to trimethoprim-sulfamethoxazole at 55 percent, amoxicillin at 51 percent, and ampicillin at 45 percent [14]. In another series of 179 isolates, 75.4 percent were multidrug resistant and 52.5 percent were ESBL producers, with blaCTX-M-15 as the dominant gene [15]. A study of fluoroquinolone-resistant community isolates found 100 percent resistance to ampicillin [16]. These numbers explain why guessing at an antibiotic is a losing strategy. ### Antibiotic Classes Used in Veterinary Urinary Infections Veterinarians choose from several drug classes based on culture results, the site of infection, and the patient's kidney and liver function. The main options include: - **Beta-lactams**, including amoxicillin and amoxicillin-clavulanate. Resistance is common, so these are used only when susceptibility is confirmed. - **Trimethoprim-sulfonamide combinations.** Resistance rates are high in many regions [14][4]. - **Fluoroquinolones.** Effective for many infections but resistance is increasing, and these drugs are reserved for serious cases because of their importance in human medicine [16]. - **Nitrofurantoin.** Concentrates in urine, which makes it useful for bladder infections. A mouse study found that its activity against E. coli in urine is driven by the ratio of drug exposure to the minimum inhibitory concentration, and that larger single doses were more effective than the same total dose divided [17]. This drug is not appropriate for kidney infections because it does not reach tissue concentrations. - **Fosfomycin.** A bactericidal option for resistant bladder infections. In a study of 79 canine E. coli isolates, 86.06 percent were susceptible to fosfomycin, including multidrug-resistant strains [18]. However, the [mutant prevention concentration](/knowledge/bacteria/general/mutant-prevention-concentration-a-pk-pd-approach-to-predicting-antimicrobial-resistance-suppression) was high, which means susceptibility testing and ongoing resistance monitoring are critical [18]. - **Aminoglycosides.** Used in some serious infections, with resistance rates varying by region [1]. The choice of drug, dose, and duration is a medical decision that depends on the specific culture result and the patient's condition. Owners should never use leftover medication from a previous illness or from another pet. ### Treatment Duration Uncomplicated cystitis is typically treated for a short course, often several days. Pyelonephritis and complicated infections require longer courses, sometimes several weeks, because the infection involves tissue that antibiotics penetrate less easily. The exact duration is set by the veterinarian based on the patient's response and the site of infection. ### Follow-Up and Recheck Timing A recheck is standard after treatment. For uncomplicated cystitis, many veterinarians recommend a urine test after the course is finished to confirm the infection has cleared. For pyelonephritis and complicated infections, follow-up culture may be repeated during and after treatment. For patients with recurrent infections, a longer monitoring plan is needed. Owners should ask when the next urine test is due and keep that appointment even if the pet seems normal. ### Managing the Underlying Cause Antibiotics alone will not cure a complicated UTI if the underlying problem remains. A catheter must be removed or changed. A bladder stone may need surgical removal. Diabetes must be managed. An anatomic defect may need repair. Immunosuppressive medication may need adjustment in consultation with the prescribing veterinarian. Treating the infection without addressing the cause leads to relapse. ### Emerging Alternatives Bacteriophage therapy is an active area of research. In one study, five lytic phages were isolated against clinical UPEC strains, and one phage showed broad antibacterial activity [8]. In a mouse model, a cocktail of two phages significantly reduced UPEC colonization in the bladder and kidney [19]. These approaches are not yet standard care, but they represent a promising direction as resistance grows. ## Unsafe Home Remedies and Common Mistakes Several home remedies circulate online. Most are ineffective, and some are harmful. - **Giving human antibiotics.** Doses and drug choices for people do not translate to pets. Some human antibiotics are toxic to animals. - **Using leftover antibiotics from a previous infection.** The bacteria may be different, and the drug may no longer be effective. This also drives resistance. - **Cranberry products as a substitute for veterinary care.** Cranberry may have a role in prevention discussions, but it does not treat an active infection. - **Withholding water to reduce urination.** This concentrates urine and worsens the problem. Fresh water should always be available. - **Waiting to see if it resolves.** A bladder infection can ascend to the kidney. Early treatment is easier and safer. - **Stopping antibiotics early because the pet seems better.** Bacteria can survive a partial course and return with resistance. ## Prevention Prevention focuses on reducing bacterial access to the urinary tract and supporting normal bladder function. - **Provide plenty of fresh water.** Good hydration dilutes urine and promotes frequent voiding, which flushes bacteria. - **Keep litter boxes clean.** A clean box encourages regular use and reduces bacterial buildup. - **Maintain a healthy weight.** Obesity contributes to urinary and metabolic problems. - **Manage diabetes and other chronic conditions.** Good glucose control reduces the risk and severity of infection [2]. - **Minimize catheter use.** When a catheter is necessary, it should be removed as soon as possible. The pig model showed that colonization cleared after catheter removal [7]. - **Consider preventive strategies for recurrent infections.** An mRNA vaccine targeting the FimH adhesin reduced infection in a recurrent UTI mouse model, which points to a future option for high-risk patients [9]. - **Schedule regular veterinary checkups.** Early detection of urinary problems is easier to treat than advanced infection. ## Prognosis The prognosis for uncomplicated cystitis is excellent when the correct antibiotic is used. Most pets improve within a few days. The prognosis for pyelonephritis is good with prompt treatment, though kidney scarring is possible in severe cases. The prognosis for complicated UTI depends on the underlying cause. Infections in kidney transplant recipients and other severely immunosuppressed patients carry a guarded prognosis because of high resistance rates and impaired host defenses [1]. Recurrent infections are common when biofilm or an underlying anatomic problem is present [12]. ## Limitations and When to Contact a Veterinarian This article provides general information. Every patient is different, and only a veterinarian who examines your pet can make a diagnosis and prescribe treatment. Contact a veterinarian promptly if any of the following apply: - Your pet strains to urinate and produces little or no urine - Your pet cries out or shows signs of pain while urinating - You see blood in the urine - Your pet vomits, becomes lethargic, or loses appetite - Your pet has a fever or pain in the flank or belly - Your pet has diabetes, a urinary catheter, or a suppressed immune system and develops any urinary signs - Your pet does not improve within two to three days of starting treatment - Symptoms return after treatment ends - Your pet has had three or more urinary infections in a year Do not adjust or stop prescribed medication without speaking to the veterinarian first. ## Frequently Asked Questions ### What causes an E. coli urinary tract infection? E. coli from the patient's own gut contaminates the area around the urethra and ascends into the bladder. Certain strains carry adhesins, toxins, and iron-capture systems that let them attach, damage tissue, and survive in urine. ### Is E. coli UTI contagious to other pets or to people? The infection itself is not spread from pet to pet in the usual sense. The bacteria come from the patient's own intestinal tract. However, resistant bacteria can circulate in the environment and in food, so hygiene around urine and feces is sensible. ### How do veterinarians know which antibiotic to use? They collect a urine sample by cystocentesis and send it for culture and susceptibility testing. This identifies the bacteria and shows which antibiotics inhibit their growth. Treatment is then matched to the result. ### Can my pet recover without antibiotics? A true bacterial urinary infection needs antibiotic treatment. Some mild bladder inflammation is not infectious, but only a veterinarian can tell the difference. Waiting risks the infection spreading to the kidneys. ### Why does my pet keep getting urinary infections? Recurrent infections often involve biofilm, an underlying anatomic problem, incomplete bladder emptying, diabetes, or immunosuppression. Biofilm protects bacteria from antibiotics and helps them persist [12]. A full workup is needed to find the cause. ### Are some pets more likely to get E. coli UTI? Females are at higher risk because of their shorter urethra. Diabetic patients, catheterized patients, and immunosuppressed patients, including kidney transplant recipients, are also at higher risk [1][2]. ### What is the difference between cystitis and pyelonephritis? Cystitis is an infection limited to the bladder and urethra. Pyelonephritis is an infection that has reached the kidney and usually causes systemic signs such as fever, lethargy, and flank pain. ### Can urinary infections be prevented? Good hydration, regular voiding, clean litter boxes, weight management, and control of diabetes all reduce risk. Minimizing catheter use also helps. For recurrent infections, discuss preventive options with your veterinarian. ## Related Articles - [Urinary Tract Infection Symptoms Cats Treatment](/knowledge/veterinary-medicine/symptom-guides/urinary-tract-infection-symptoms-cats-treatment) - [Can a Urinary Tract Infection Cause Litter Box Avoidance in Cats?](/knowledge/veterinary-medicine/anxiety-and-behavior-support/uti-cat-litter-box-avoidance) - [Symptoms Of Urinary Tract Infection In A Cat](/knowledge/veterinary-medicine/symptom-guides/symptoms-of-urinary-tract-infection-in-a-cat) - [Urinary Tract Infection In Cats Symptoms](/knowledge/veterinary-medicine/symptom-guides/urinary-tract-infection-in-cats-symptoms) - [Cat Urinary Tract Infection Symptom](/knowledge/veterinary-medicine/symptom-guides/cat-urinary-tract-infection-symptom) - [What Can Cause A Urinary Tract Infection In A Cat](/knowledge/veterinary-medicine/clinical-methods/what-can-cause-a-urinary-tract-infection-in-a-cat) - [Gastrointestinal Tract Infections: Causes and Care](/knowledge/veterinary-medicine/digestive-and-urinary-care/gastrointestinal-tract-infections-causes-and-care) ## Sources 1. 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