Do Bacterial Infections Go Away In Cats?

Bacterial infections are common in cats, with the most prevalent types being skin infections, urinary tract infections (UTIs), and gastrointestinal infections. While some mild infections may resolve on their own, most require antibiotic treatment prescribed by a veterinarian to fully clear the infection and prevent complications or recurrence (Moon, 2022).

Skin infections like abscesses, infected wounds, and pyoderma are estimated to affect around 10-15% of cats at some point in their lives (Dorsch, 2016). UTIs affect approximately 3-7% of cats, usually caused by E. coli or Staphylococcus bacteria originating from the skin or feces (Litster, 2007). Diarrhea or vomiting caused by Campylobacter, Salmonella, Clostridium, or other bacterial overgrowth impacts over 20% of cats at vet clinics.

While cats have strong immune systems, bacteria that penetrate skin and mucous membranes can proliferate, spreading systemically and causing much more serious illnesses. Therefore, prompt diagnosis and treatment guided by a vet is crucial for clearing infections fully and preventing complications or transmission to humans.

Common Bacterial Infections

Some of the most common bacterial infections seen in cats include:

Upper Respiratory Infections

Upper respiratory infections, also known as URI, are commonly caused by bacteria like Bordetella bronchiseptica and Streptococcus species. These bacteria infect the upper airways and lead to symptoms like nasal discharge, sneezing, coughing, fever, and eye discharge. URI is very contagious between cats. Treatment involves antibiotics, rest, and supportive care. Without treatment, URI can progress to pneumonia [1].


Abscesses are pockets of pus under the skin often caused by bite wounds becoming infected with bacteria like Pasteurella multocida or Staphylococcus species. Common locations include the face, legs, and base of the tail. Abscesses cause swelling, pain, lethargy, and fever. Treatment involves draining the abscess and antibiotics [2].

Urinary Tract Infections

UTIs frequently occur when bacteria like E. coli or Staphylococcus infect the bladder. Symptoms include frequent urination, straining, bloody urine, and crying while urinating. UTIs are diagnosed through urinalysis and treated with antibiotics. Recurrent UTIs may indicate an underlying health issue [3].

Skin Infections

Bacterial skin infections often start as wounds or irritations that get infected. Common culprits are Staphylococcus and Streptococcus. Symptoms include redness, swelling, crusting, pain, and itching. Mild cases can be treated with topical antibiotics, while more severe infections require oral antibiotics and wound care [2].

Causes and Transmission

Bacterial infections in cats can spread through direct contact with an infected cat’s saliva, urine, feces or from contaminated objects or environments ( Common ways cats transmit bacterial infections include mutual grooming, sharing food bowls or litter boxes, bites from infected animals, and contact with contaminated soil or water.

Underlying health issues that can increase a cat’s risk of developing a bacterial infection include (

  • Weakened immune system due to FIV, FeLV or other illness
  • Dental disease
  • Diabetes
  • Kidney or liver disease
  • Cancer
  • Obesity

Kittens and senior cats may also be more prone to bacterial infections as their immune systems are not fully developed or are declining with age.


Bacterial infections in cats can cause a variety of symptoms depending on the location and severity of the infection. Common symptoms include:

Respiratory signs: Bacterial infections in the respiratory tract often lead to symptoms like coughing, sneezing, nasal discharge, wheezing, and labored breathing. Bacteria like Bordetella bronchiseptica can cause kennel cough in cats.

Skin lesions: Bacterial skin infections may cause scabs, pustules, papules, crusting, and hair loss at the site of infection. Common examples include abscesses, folliculitis, and cellulitis.1

Changes in urine: Bladder infections from bacteria like E. coli often lead to symptoms like blood in the urine, straining to urinate, and frequent urination. Kidney infections can cause vomiting and lethargy.

Fever: Bacterial infections commonly cause fever, with rectal temperatures over 103°F (39.4°C).

Loss of appetite: Sick cats tend to eat less. Bacterial infections, especially in the digestive tract, can lead to nausea, vomiting, and diarrhea which suppress appetite.


To diagnose a bacterial infection in cats, the veterinarian will first perform a thorough physical exam to check for any abnormalities. They may palpate the abdomen to feel for enlarged organs or swollen lymph nodes. The veterinarian will also check the cat’s vital signs like temperature, heart rate, breathing rate, and blood pressure, as bacterial infections often cause fever and other systemic signs.

The most common diagnostic tests used to identify bacterial infections in cats include:

  • Blood tests like a complete blood count (CBC) to check for increased white blood cells, which indicate infection. Blood cultures may also be taken to identify the specific bacteria involved.
  • Urine cultures can identify bacteria in the urinary tract causing issues like UTIs.
  • Skin cytology involves looking at skin cells under a microscope to diagnose conditions like fungal infections.

Veterinarians may also collect samples for culture and sensitivity testing to determine the most effective antibiotic for treatment (source). Imaging tests like x-rays or ultrasound may be used to locate infections in organs like the lungs, liver, or spleen.


Treatment for bacterial infections in cats often involves antibiotics to kill the infection. Some common antibiotics used include amoxicillin, doxycycline, enrofloxacin, and cefovecin (Source). The type, dosage, and length of antibiotic treatment depends on the type of infection, severity, and the cat’s response to treatment. Antibiotics may be given orally, by injection, or topically.

In addition to antibiotics, supportive care may be needed to help the cat through the infection. This can include fluids, nutritional support, pain management, and treating nausea or vomiting. Cats with fever may need cooling support as well.

It’s also important to identify and address any underlying conditions that may have allowed the infection to take hold, such as dental disease, wounds, foreign bodies, or a weakened immune system. Treating these underlying issues is key to preventing recurrent or chronic infections (Source).

With appropriate antibiotic treatment and supportive care, most otherwise healthy cats can recover fully from common bacterial infections. However, prompt veterinary care is essential, as untreated infections can quickly become life-threatening.

Home Care

If your cat has a bacterial infection, there are some things you can do at home to help care for them and prevent the infection from spreading:

Administering Medication
Be sure to give your cat all medications as prescribed by your veterinarian. Antibiotics should be given according to the schedule and for the full duration to be sure the infection is completely cleared. Carefully follow all instructions for any topical treatments as well.

Keeping Your Cat Comfortable
Make sure your cat has easy access to food, water, and litter at all times. Keep their environment calm and quiet to avoid stress. You can place warm compresses on painful or inflamed areas to help soothe your cat.

Preventing Spread
Wash your hands before and after handling your cat or applying medications. Disinfect any surfaces your cat contacts frequently. Avoid contact with other household pets. Wash bedding regularly and discard things like food bowls that cannot be fully disinfected. Separate infected cats from others whenever possible.

Follow up with your vet until the infection is fully resolved. Call them right away if symptoms worsen or you have any concerns about your cat’s condition or treatment. With proper care at home and veterinary treatment, most bacterial infections in cats can be cured.


Bacterial infections in cats can lead to serious complications if left untreated or if the cat has a weak immune system. Some potential complications include:

Sepsis – Sepsis occurs when chemicals released by the immune system into the bloodstream to fight an infection trigger inflammation throughout the body. This can lead to organ damage and even death. Cats with sepsis require intensive hospitalization and treatment. [1]

Organ damage – Certain types of bacteria like E. coli and Staphylococcus can migrate from the original infection site and spread to other organs. This may result in potentially life-threatening conditions such as pneumonia, hepatitis, or kidney damage. Prompt antibiotic treatment is necessary to prevent permanent organ injury. [2]

Antibiotic resistance – The overuse and misuse of antibiotics allows bacteria to mutate and become resistant to certain drugs. Multidrug resistant infections are difficult to treat and prone to recurrence. Veterinarians will culture samples from the infection site to identify the bacteria and determine the most effective antibiotic. [3]


The prognosis for bacterial infections in cats is generally good if treated promptly and properly.[1] Most uncomplicated bacterial infections will resolve within 1-2 weeks with appropriate antibiotic therapy prescribed by a veterinarian. However, the prognosis can vary depending on the type and severity of infection, as well as the cat’s overall health.

Certain types of stubborn bacterial infections, like recurrent urinary tract infections, may have a tendency to recur even after treatment. In some cases, an underlying condition may need to be addressed to fully resolve the infection. Kittens, senior cats, and those with weakened immune systems may also take longer to recover and be at higher risk for complications.

Overall, with prompt veterinary attention, most bacterial infections are very treatable. However, neglecting treatment or stopping antibiotics prematurely before the infection has fully resolved can lead to a poor prognosis. Close monitoring and follow-up care are important, especially for recurrent or chronic bacterial infections, to ensure they are completely eliminated.



There are several steps cat owners can take to help prevent bacterial infections in their feline companions:

Vaccines – Certain bacterial illnesses like bordetella and chlamydia can be prevented through regular vaccination. Work with your veterinarian to determine which bacterial vaccines may be recommended for your cat based on risk factors.

Hygiene – Keeping your cat’s environment clean can reduce exposure to harmful bacteria. This includes regularly cleaning the litter box, washing food and water bowls, and disinfecting beds, toys and other surfaces in the home. Maintaining good hygiene for your cat is key.

Reducing Stress – Stress can negatively impact your cat’s immune system, making them more prone to bacterial infections. Providing adequate environmental enrichment through toys, scratching posts and windows with outdoor views can help keep your cat happy and less stressed.

Veterinary Care – Regular wellness exams allow early detection and treatment of bacterial infections before they become more serious. Annual exams, prompt treatment when signs of illness arise, and completing any recommended testing helps veterinarians keep your cat’s health in check.

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