What Causes UTIs (Urinary Tract Infections) in Cats (Vet Answer)
Urinary tract infections, or UTIs, occur when the body’s innate defenses are defeated, and microbes invade and infect the organs responsible for creating and storing urine. The urinary tract is a complex system, and a lot of things can go slightly wrong, so urinary tract infections are common.
Almost all UTIs in cats are caused by bacteria. When given the opportunity, these bacteria invade the urinary system by multiplying in both the urine and the mucosal walls of the tract itself. From there, the bacteria either continue to multiply in the same spot or spread along the tract.
Anatomy Review
The urinary tract starts at the kidneys, organs where the blood is filtered and urine is created. The urine then travels along a tube-like structure called the ureter to the bladder. And from the bladder, it flows along another tube called the urethra.
Bacteria That Cause UTIs
Most UTIs are caused by only one type of bacteria, as opposed to two or three species of bacteria, for example. Escherichia coli is the most common, but almost any type of bacteria can invade.
Other common types of bacteria are:
Types of UTIs
When bacteria invade, they can infect the entire urinary tract or singular parts of it.
Lower Urinary Tract Infections
Most UTIs are caused by what is called ascending tract infections—bacteria invade from the outside, up through the urethra, and into the bladder. Many times, the infection stops there, and it is classified as a lower urinary tract infection.
Some cats can deal with a mild lower urinary tract infection for a long time and are very good at hiding it. Therefore, it is actually good to watch your cat use the bathroom and know what is normal for them. That way, when even the smallest thing goes wrong, you will notice.
Signs of a Lower UTI Can Include:
If your pet is showing these signs, we suggest you speak to a vet.
Upper Urinary Tract Infections
Upper UTIs are almost always clinically worse than lower UTIs and need to be treated by a veterinarian immediately. The kidneys are responsible for filtering the blood and turning it into urine, so infection in these organs can quickly affect the rest of the body.
Plus, most upper urinary tract infections include the lower urinary system because the ascending bacteria have traveled up from the bladder and into the kidneys. If bacteria has come into the kidneys from upstream, from the blood, then the overall situation is severe indeed.
Signs of an Upper UTI Can Include:
How Bacteria Invade
The urinary tract is designed to defend itself; however, when something changes, even slightly, it is easier for bacteria to invade. Many features of the system work together innately to prevent infection.
Therefore, incontinence can both cause a UTI and be caused by a UTI. Sometimes it can be difficult to puzzle out which one came first.
The Problematic Indoor Cat
Indoor cats are prone to UTIs. The reasons for this are complex and multi-faceted. But inactivity, decreased water consumption, decreased urination frequency, and chronic stress all play a role.
In fact, there is a whole lower urinary tract syndrome, which probably deserves its own article, that predisposes cats to UTIs. The syndrome is called Feline Lower Urinary Tract Disease (FLUTD), and cats can end up not being able to pee at all. This is an urgent emergency!
A good strong pee flow, with lots of urine flushing out the system, acts as its own defense against UTIs. There are several things that we can do to help encourage cats to keep their urinary system moving along. The main goal is to encourage cats to drink water and, as a result, to urinate more frequently and not to hold their pee for long periods of time.
To Increase Water Consumption:
To Encourage Urination:
Conclusion
The urinary system has many methods of fighting off infection, but if bacteria manage to break through its barriers, an infection can quickly spread along the tract. UTIs are common in cats and can be caused by numerous predisposing factors.
Carefully monitoring your cat's normal urination patterns and bringing your cat to the vet when something changes is the best way of both preventing UTIs and catching them early.
Featured Image Credit: nanniezwawa, Shutterstock
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Dr. Chantal Villeneuve MS BVetMed (Veterinarian)
Dr. Chantal is passionate about the human-cat bond and improving pets' lives through their connections with their human companions. She has worked with almost every species of animal from dogs to guinea pigs, birds to amphibians, and even horses and mice - all are welcome. She is excited to use her writing to help people connect with their cats.
