Escherichia coli infections can be difficult to diagnose in cats due to subclinical presentations.

Escherichia coli infections can be difficult to diagnose in cats due to subclinical presentations.

If your cat has been struggling to use the litterbox, they might be suffering from a urinary tract infection (UTI)! While UTIs are less common in younger cats, these infections progress to feline lower urinary tract disorders in 40-45% of cats older than 10 years [1]. Feline urine even in a healthy state is not sterile, and is home to a plethora of bacteria; however, when pathogenic bacteria are able to outcompete healthy bacteria, urinary tract infections may manifest.

Escherichia coli has long been named the most common pathogenic isolate in feline urine, and is consequently associated with UTI manifestation [2]. UTIs have historically been one of the most common indications for antibiotic usage in veterinary medicine, which inadvertently contributes to antibiotic-resistant strains of bacteria [3]. Consequently, knowing the exact strain of bacteria and pathogenicity of that strain can have significant impacts on your pet’s health outcomes! If you suspect your furry friend is suffering from a UTI, visit a veterinarian as soon as possible to explore contemporary diagnostics and treatment options.

What is Escherichia coli?

The image above depicts Escherichia coli.

The image above depicts Escherichia coli.

Escherichia coli is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium that is often found in the lower intestine of warm-blooded organisms [2]. While most E. coli strains are harmless, specific serotypes can cause serious infections in their host and may even be resistant to certain antibiotics. Bacterial UTIs often result from normal skin and GI tract flora ascending the urinary tract and overcoming the normal urinary tract defenses that prevent pathogenic colonization. UTI rates are much higher in older cats, due to diminished host defenses from aging or other diseases, such as diabetes, renal failure, or hyperthyroidism [1, 4]. While feline UTI severity exists on a spectrum, the following UTI symptoms indicate that your cat may be suffering and needs to visit a veterinarian:

  • Increase in frequency of urination
  • Strain in urination
  • Urinating small amounts
  • Urinating outside of the litterbox
  • Bloody urine
  • Frequent licking of genitals
  • Crying out in pain when urinating

E. coli has been found to be the most commonly isolated pathogen in feline urine, and was involved in approximately 39-59% of positive cultures. It is important to note that many cats have asymptomatic (or subclinical) UTIs [1]. Occurring in approximately 1-29% of cats, subclinical UTIs are more common than symptomatic UTIs, with culture-based tests similarly indicating a significant number of opportunistic pathogens [1]. However, characteristic symptoms for subclinical UTIs may be too subtle or even absent to qualify for a UTI diagnosis.

Thankfully, contemporary research has made significant strides in characterizing E. coli, as a spectrum of virulent strains has been identified using Next-Gen Sequencing (NGS). For example, one study using multilocus sequence typing and virulence profile in uropathogenic E. coli isolates for cats identified the most frequent sequence subtype ST73 exhibited four multidrug-resistant isolates, while the second most common sequence type exhibited no drug resistance but carried the highest number of virulence genes [5]. This study has helped increase our understanding of E. coli population structure and virulence association in cats.

Predisposing Factors in Feline Urinary Tract Infections

Predisposing factors for UTIs vary between different countries due to geography, season, diet, and lifestyle. In general, female cats, cats older than 10 years, and cats with comorbidities including chronic kidney disease, diabetes mellitus, hyperthyroidism, and gastrointestinal diseases are significantly more likely to develop UTIs [1]. Notably, predisposing comorbidities are present in approximately 75% of cats that tested positive for subclinical UTIs or symptomatic UTIs. Cats with bladder stones are also more likely to suffer from recurrent UTIs [6].

Treatment and Previous Diagnostic Technology for Escherichia Coli

The image above depicts the culturing of Escherichia coli.

The image above depicts the culturing of Escherichia coli.

The most common intervention for feline UTIs is a tailored antibiotic treatment plan, specific to the pathogens complicating your cat’s urinary tract [3]. Additionally, pain medication may also be prescribed depending on the severity of the infection. Culture-based urinalysis has conventionally been used as a diagnostic tool to inform an appropriate antibiotic treatment plan [2]. However, advancements in defining the feline urinary microbiome are complicated by antibiotic resistance, which makes it necessary for veterinarians to consider contemporary measures to identify and quantify the bacteria in your cat’s urine. Particularly, treatment for subclinical feline UTIs has become more clouded as recent research suggests that antimicrobial treatment has no significant impact on health outcomes for these patients [3]. E. coli infections also make UTI treatment difficult, as certain strains are able to invade deeper tissues and persist intracellularly through the formation of biofilm [1]. It is worth noting that antibiotics are currently recommended for cats presenting with subclinical UTIs that have historically suffered from recurrent UTIs. Differentiating subclinical UTIs from standard urinary tract infections is consequently difficult but necessary if modern veterinary medicine aims to curb the over-prescription of antibiotics.

Fortunately, the MiDOG All-in-One Microbial Test may provide the answer to the diagnostic conundrum that E. coli infections pose. Utilizing NGS technology to detect and quantify all microbial DNA through untargeted and comprehensive sequencing and quantitative comparisons to reference databases, the MiDOG NGS technology provides a useful opportunity to shed light on the microbial makeup of your cat’s infection for clinical application. This test is able to differentiate strains, assess virulence and pathogenicity, and breaks up biofilms for more accurate analyses. The MiDOG microbiome test is a microbial identification test grounded on scientific research that provides veterinarians DNA evidence for the guided treatment of E. coli infections.

The MiDOG Urine Collection Kit may be the solution to your dog's urinary tract infections.

The MiDOG Urine Collection Kit may be the solution to your dog’s urinary tract infections.

Find out if your vet uses MiDOG before you book your next appointment!


[1] Dorsch, R., Teichmann-Knorrn, S., & Sjetne Lund, H. (2019). Urinary tract infection and subclinical bacteriuria in cats: A clinical update. Journal Of Feline Medicine And Surgery, 21(11), 1023-1038. doi: 10.1177/1098612×19880435

[2] Dokuzeylül, B., Kahraman, B. B., Bayrakal, A., Siğirci, B. D., Çelik, B., Ikiz, S., Kayar, A., & Or, M. E. (2015). Bacterial species isolated from cats with lower urinary tract infection and their susceptibilities to cefovecin. Irish veterinary journal, 68(1), 2.

[3] Dowling, P. (2016). Bacterial Urinary Tract Infections – Pharmacology – MSD Veterinary Manual. Retrieved 7 April 2022, from

[4] Freitag, T., Squires, R. A., Schmid, J., Elliott, J., & Rycroft, A. N. (2006). Antibiotic sensitivity profiles do not reliably distinguish relapsing or persisting infections from reinfections in cats with chronic renal failure and multiple diagnoses of Escherichia coli urinary tract infection. Journal of veterinary internal medicine, 20(2), 245–249.[245:aspdnr];2

[5] Liu, X., Thungrat, K., & Boothe, D. M. (2015). Multilocus Sequence Typing and Virulence Profiles in Uropathogenic Escherichia coli Isolated from Cats in the United States. PloS one, 10(11), e0143335.

[6] Piyarungsri, K., Tangtrongsup, S., Thitaram, N., Lekklar, P., & Kittinuntasilp, A. (2020). Prevalence and risk factors of feline lower urinary tract disease in Chiang Mai, Thailand. Scientific reports, 10(1), 196.

Categories: Cats, Pet Parents, Urinary Tract Infection (UTI)

animal diagnostics

Validated by Veterinarians

“Clients expect their veterinarians to stay up to date on all matters that affect the health and well being of their non-human family members. The current technique that we have used to determine the presence and antibiotic sensitivity of organisms causing disease in our pets is over a century old.

With the emergence of dangerous antibacterial resistance, it is critical that veterinarians are able to offer laser focused diagnostics and treatment. MiDog enables us to offer care that exceeds the typical standard of care.”

Bernadine Cruz, DVM, Laguna Hills Animal Hospital Laguna Woods, CA

“I love the absolute abundance and comparing the fungal with bacterial infection. I do not worry as much about getting a false negative urinary infection reading as I do with traditional urine cultures. Several times the same urine would culture negative but MiDOG would detect pathogens.”

Michael Morgan, DVMQuail Animal Hospital, Tustin, CA

“The MiDOG All-in-One Test is amazing, I would use it instead of culture and sensitivity.  Such rapid and detailed results, I will reach for MiDOG before culture next time!

Thank you very much MiDOG, for sharing the opportunity to try your technology.”

Martha Smith-Blackmore, DVM, President of Forensic Veterinary Investigations, LLC – Boston, MA

The MiDOG All-in-One Microbial Test is our new gold standard of pathogen identification. The results are so accurate and valuable – especially with assessing both bacterial and fungal infections with the same sample.

Thank you MiDOG!”

Kathy Wentworth, DVM, Diplomate ABVP Canine and Feline Practice – PetPoint Medical Center, Irvine, CA

“The MiDOG staff was extremely helpful and supportive.”

Cathy Curtis, DVM – London, UK

“I have had great results using the MiDOG® Test. Compared to traditional culture tests, I am better able to target the treatment for dogs because the MiDOG® Test is so sensitive that it identifies all pathogens including bacteria and fungi, as well as antibiotic sensitivity.

The cost and turnaround time are about the same as a culture test, but I get much more data. The test has great performance and I believe the NGS technology will be a game changer for veterinarians treating dogs with lesions or other infections.”

Michael Kavanagh, DVM, Practice owner – Saddleback Animal Hospital, Tustin, CA

“It’s helpful to have an NGS spectrum because it gives you a broader insight of what’s happening and what might be going on.”

Richard Harvey BVSc DVD DipECVD PhD FRSB FRCVS – European Specialist in Veterinary Dermatology – Head of Dermatology, Willows Veterinary Centre & Referral Service – Solihull, England UK

“I have been using MiDog for over 4 years now and exclusively as my test of choice for all cultures for 3 years.  It is so great to submit a culture and feel confident there will be a result when it comes back, especially for urine cultures.  The reports were intimidating at first because they contain so much information.  After the first few, I am now quickly able to glance over it and pick out the highlights.  I can then come back later and pour over all the details.  I have been extremely pleased with my patients’ results using the test as well.  I don’t envision ever going back to traditional culture and susceptibilities again.”

Brian M. Urmson, DVM, Columbiana Veterinary Associates

“As an exotic veterinarian, there are numerous tests we have to consider to check specific bacterial and fungal organisms based on the species. MiDOG eliminates the need for many of these separate samples and provides definitive results quickly to help us treat our patients more efficiently and effectively. The lab is wonderful to work with and has never rejected our samples- they even processed a lizard toe we amputated and determined the cause of skin infection.”

Dr. Melissa Giese, Chicago Exotics Animal Hospital

“MiDOG’s diagnostic approach offers the unique ability to identify pathogens that evade traditional culture and sensitivity testing. I have found that adding a molecular based testing approach in the form of Next Generation Sequencing (NGS) from MiDOG to my routine diagnostic cultures can be extremely helpful in the identification and diagnosis of uncommon pathogens in veterinary medicine.”

Dr. Wayne Rosenkrantz, Animal Dermatology Clinic – Tustin

“She [Dr. Krumbeck] really did a great job of making complicated concepts accessible and demonstrating the value of your services. I’m really looking forward to working with MiDOG on my research project!”

Dr. Yaicha Peters, Animal Dermatology Clinic – San Diego

“As a proud collaborator with MiDOG, I deeply appreciate their dedication to fostering partnerships between industry and veterinary experts. Their commitment to enhancing diagnostic quality for veterinarians is commendable. In my experience, their support has been invaluable, earning them a ‘Double A+, Triple Star’ rating. Their assistance has been faultless, contributing significantly to the success of my projects and studies. I eagerly anticipate our continued collaboration.”

Dr. Richard Harvey, BVSc DVD DipECVD PhD FRSB FRCVS; European Specialist in Veterinary Dermatology

“We’re seeing that, if we prescribe too many antibiotics or they’re taken too frequently, animals are developing inappropriate or pathogenic strains of bacteria. We’re also seeing that our antibiotics are just not working against them anymore… It’s a good example of why we need better diagnostic testing, like MiDOG, so that we’re selecting the correct antibiotic every time our patients have an infection.”

Dr. Alissa Rexo, DVM, CVA, DACVD, Mid-Atlantic Veterinary Dermatology