It’s 7 a.m. and you have gotten very little sleep after letting your dog out into the yard four or five times overnight. As you stumble to the kitchen to make coffee, your sweet pup—who never has accidents in the house—looks up at you and urinates all over the floor right in front of you. Shockingly, the urine is bright red and looks like blood, and your pup is whining and still straining to urinate even after she just did. You call your veterinarian, who says this sounds suspiciously like a urinary tract infection and encourages you to bring her in to the clinic.
The urinary tract consists of the kidneys, ureters (tubes that carry urine from the kidneys to the bladder), the bladder, and the urethra (tube that carries urine from the bladder to the outside world). The bladder is the most common location for an infection and if the infection is not treated, the kidneys can be impacted and the dog can become quite ill.
Typical signs of a urinary tract infection include increased frequency of urination, small amounts of urine with each attempt, blood in the urine, straining to urinate, crying/ whining or other signs of discomfort when urinating, inappropriate urination (i.e., urinating in the house even if perfectly housetrained), and sometimes an increase in hydrating. If the kidneys become infected, more systemic signs, such as vomiting, refusing to eat or drink, extreme lethargy or depression, and pain over the lower back can be seen.
So, now you are at the vet clinic and the nursing staff has gotten your dog’s vitals (temperature, pulse, and respiration) and obtained an accurate weight. They’ve recorded a history of your pet’s clinical symptoms, including their frequency and duration. The veterinarian performs a physical examination and will then recommend a urinalysis with culture and minimum inhibitory concentration (MIC) test. The urinalysis will help the vet determine if there is concern for an infection, crystals in the urine, or other findings that may indicate that another disease is also involved. For example, glucose in the urine is a common finding in newly diagnosed diabetic animals. These results may be available from the veterinary clinic or will come back from an outside lab within a few days, usually the next day. The urine culture and MIC will determine if there is a confirmed infection, reveal which bacteria are problematic, and help assess which antibiotics will effectively clear the infection.
These tests are not inexpensive; however, it is important to confirm that an infection truly is present and that your pet’s doctor is using the correct antibiotics to treat the problem. Antibiotics are also expensive and giving one that won’t solve the problem is both a waste of money and leads to antibiotic resistance (i.e., the day when none of our current antibiotics will kill bacteria any longer). The culture/ MIC results can take up to a week to come back from the lab, so be prepared to wait. Depending on the severity of the symptoms and your dog’s previous history of urinary tract infections, a carefully chosen antibiotic may be sent home after discussion between you and the vet. Frequently, however, your doctor will wait for at least the preliminary results before prescribing the most appropriate antibiotic. Pain medication may also be given to help with the discomfort.
Let’s say your pet’s culture ends up testing positive for two bacteria, and the vet prescribes your dog a targeted antibiotic. Within 48 hours, her clinical signs improve and she is feeling great. You finish out her two weeks of antibiotics and it appears all is well. But then, one week later, her clinical signs return! You are very upset because once again, your pet is suffering and you’ve spent hundreds of dollars on this problem that isn’t fixed! You call your veterinarian, who explains that sometimes, one course of antibiotics is not enough to fully resolve the problem and the doctor prescribes two more weeks of medication.. The vet also explains that bladder stones (uroliths) can form in the bladder and cause irritation to the bladder lining, as well as serving as a source (nidus) of infection. Accordingly, the doctor recommends X-rays of the bladder to find out if this is a problem as well.
Now let’s say the X-rays reveal a large stone in the bladder. The veterinarian advises you that the two main options for treating bladder stones are surgical removal or dietary dissolution. If the stone(s) are causing an obstruction that is inhibiting your dog from urinating, emergency surgery is needed to save the dog’s life. Dietary dissolution of the stones is a less invasive option but does not work on all types of stones, and it may take several weeks or a few months to dissolve a large stone. What’s more, not all dogs will eat the special prescription diet used to dissolve the stones.
After much discussion, you elect to try dietary dissolution of the stones and are sent home with the prescription food and a recheck exam appointment. Some 30 days later, the doctor takes another set of X-rays to see if the diet is working.
Bladder cancer, while less common, often initially presents as a urinary tract infection. X-rays of the bladder may reveal suspicion of cancer but frequently an abdominal ultrasound (sonogram) is needed to visualize the cancer in the bladder.
Although the symptoms are the same, urinary tract infection is caused by bacteria, while feline idiopathic cystitis is a sterile disease, in which no bacteria are present.
Lastly, the above discussion has been on urinary tract infections in dogs. Cats are not only an entirely different species but they have a very different urinary tract disease situation. When cats show the typical signs of a urinary tract infection as discussed above, most of the time they are suffering from feline idiopathic cystitis (FIC). This is a type of feline lower urinary tract disease the causes inflammation of the bladder in cats. Although the symptoms are the same, urinary tract infection is caused by bacteria, while FIC is a sterile disease, in which no bacteria are present.
FIC is characterized by interstitial inflammation; that is, the space between the cells in the bladder become very swollen and can, in extreme cases, cause an obstruction of the urinary tract and prevent your cat from being able to urinate. This is a medical emergency and needs an immediate trip to the nearest emergency veterinary hospital. If you see your cat straining to urinate in the litter box but nothing is coming out, please go to the ER immediately!