You’ve noticed your dog is drinking more water and urinating more frequently. They have even had an “accident” indoors. “It’s probably a UTI,” you think to yourself. Or could it be something more?
Your dog’s symptoms certainly could indicate a bladder infection. But they could also signal a potential kidney infection, kidney disease, kidney failure, diabetes or even Cushing’s syndrome (overactive adrenal glands). The only way to know for sure what’s afflicting your dog is to have them examined by your veterinarian.
Not only do signs of different urinary tract disorders overlap but, if left untreated, one problem can lead to another. The terms used to describe various urinary tract issues are similar — all of which can be confusing for pet parents. In this post, we’ll explain the differences between urinary tract disease, urinary tract infection (UTI), kidney infection, kidney disease and kidney failure.
What is urinary tract disease?
Urinary tract disease is a broad, all-encompassing phrase that describes any one of several disorders affecting any part of the urinary tract. The urinary tract of dogs, like ours, is made up of four parts:
- Two kidneys, which filter waste compounds from the blood and make urine
- Two ureters, which are the tubes that move urine from the kidneys to the bladder
- The urinary bladder, which stores urine
- The urethra, which is the tube that transports urine from the bladder to the outside of the body.
Some of the more common urinary tract issues in dogs are bladder infections, bladder stones, kidney stones, kidney infections, acute (sudden) kidney injury, chronic kidney disease, kidney failure and urinary incontinence (involuntary loss of urine).
Is it a urinary tract infection, bladder infection or kidney infection?
Urinary tract infection is another general term that describes a bacterial infection of one or more urinary tract structures, such as the bladder or one or both kidneys. In other words, all kidney infections can be considered urinary tract infections (more specifically, upper urinary tract infections), but not all UTIs are kidney infections. What many pet owners — and even some veterinary professionals — mean when they talk about UTIs is actually a bladder infection.
Although the urinary tract is normally bacteria-free and resistant to infection, it’s possible for certain kinds of bacteria to travel up the urethra against the normal flow of urine to the bladder. Bacteria may enter the urethra from outside the dog’s body or from the prostate gland (male dog) or vagina (female dog). While bacteria may arrive at the bladder via the bloodstream or kidneys, it’s far more common for bacteria to migrate up the urethra. Once in the bladder, bacteria can attach to the bladder wall and multiply, causing an infection and inflammation.
A kidney infection results when bacteria invade one or both kidneys. While kidney infections can occur spontaneously, there’s typically a preexisting condition — such as a bladder infection, kidney stones, partial urinary blockage or chronic kidney disease — that impairs a dog’s ability to fight infection. Most often, a kidney infection results when bacteria from an existing bladder infection migrate up one or both ureters to one or both kidneys.
Some dogs with a kidney infection only (no bladder infection) may show only mild signs of a problem that go unnoticed. If undetected or left untreated, kidney infections can have serious consequences, including acute (sudden) kidney injury, chronic kidney disease, sudden kidney failure, sepsis (bacterial infection of the blood) or worse. That makes both treatment and confirmation of treatment success very important to your dog’s health.
What’s the difference between kidney infection, disease and failure?
Kidney disease is a broad term used to describe many conditions that can affect the kidneys. However, kidney failure describes a condition in which kidney function is reduced to the point that the kidneys can’t effectively remove toxins and other waste products from the blood, maintain hydration or properly regulate key electrolytes (such as sodium, potassium and bicarbonate). Kidney disease and kidney failure, which are often used interchangeably, include acute kidney injury and chronic kidney disease (aka chronic renal insufficiency).
Acute kidney injury is the phrase veterinarians use to describe sudden damage to the kidneys, which can range from mild to life-threatening. While a kidney infection is considered a common cause of acute injury to canine kidneys, other causes include toxins such as those found in grapes, raisins and antifreeze; certain infections, such as leptospirosis and Lyme disease; and underlying health issues like high blood calcium levels or shock. The condition can develop rapidly, and damage to the kidneys may be reversible with appropriate treatment.
In contrast, chronic kidney disease has a slow, gradual onset. Dog parents often don’t notice the signs until the disease is quite advanced. Although kidney damage associated with chronic kidney disease is irreversible and permanent, it can be managed through a therapeutic kidney food, medications and fluids. Chronic kidney disease is also progressive, and eventually kidney failure occurs.
The kidneys have a limited ability to repair themselves. And often, damage to the kidneys can be permanent. To protect your canine companion’s urinary tract health, talk to your veterinarian at the first sign of a change in your dog’s urinary habits.