Canine Urinary Tract Infections: What You Need to Know

Analysis by Dr. Karen Shaw Becker

canine urinary tract infection

Story at-a-glance

  • Urinary tract infections (UTIs) occur in an estimated 14% of dogs, and E. coli is responsible for about half of all infections
  • UTIs are often caused by a change in a dog’s immune defenses that allows pathogenic bacteria to flourish in the urinary tract
  • There are several symptoms that occur with UTIs in dogs, including dark or cloudy urine, urine dribbling and accidents, and straining to urinate
  • A urinalysis is necessary to confirm a UTI, and a culture and sensitivity test is a must to determine the type of bacteria involved and the correct choice of medications to resolve the infection; the reason many UTIs don’t resolve is that the wrong antibiotic is selected and/or the length of therapy is inadequate
  • Inflammation of the bladder without bacterial infection (cystitis) is a common condition that occurs prior to developing a UTI, and can be treated naturally, without antibiotics
  • To prevent cystitis and UTIs in your dog, it’s important to monitor urine pH levels and feed a low-carb, starch-free, nutritionally optimal, species-specific, preferably fresh diet

Estimates are that about 14% of dogs will develop a bacterial urinary tract infection (UTI) at some point in their lives.1 As is the case with humans, UTIs are seen more often in female dogs than males.

E. coli bacteria are responsible for about half of all UTIs in dogs and are most often the result of a change in a dog’s immune defenses that allows pathogenic bacteria to proliferate and persist in the urinary tract. Most UTIs develop in the bladder, but they can also occur in the kidneys, ureters, and urethra.

Urinary tract infections can also be caused by a disease process, the dog’s individual anatomy, the use of catheters, and certain drugs. Dogs at higher-than-normal risk for UTIs include:

  • Diabetic dogs
  • Dogs with Cushing's disease (hyperadrenocorticism)
  • Dogs who receive repeated administration of steroids (e.g., prednisone)
  • Hospitalized dogs who are catheterized

Bladder infections occur when bacteria move upwards into a microbially-balanced bladder from a dog’s genitals, perineum, or rectum. Unless there’s a strong, frequent flow of urine out of the body, pathogenic (harmful) bacteria will continue to ascend toward the bladder. In dogs with inadequate immune defense mechanisms or unnatural pH, bacteria can rapidly multiply, colonize, and proliferate in the folds and lining of the bladder, causing an infection.

Symptoms of a Urinary Tract Infection

Signs your dog may have a urinary tract infection include:

Suddenly starts urinating in the house

Persistent licking of urinary openings

Dark or cloudy urine; visible blood in the urine

Loss of bladder control; urine dribbling

Inability to pass urine or passing very little urine

Vomiting, lethargy, lack of appetite

Straining to urinate or crying out in pain during urination

Drinking more water than usual

These are all signs that indicate a potentially serious issue with your dog's urinary tract or bladder. It's important to get your dog, along with a urine sample caught in a sterile cup (provided by your veterinarian) or an ultra-clean container with a lid, to your veterinarian as soon as possible.

The Importance of an Accurate Diagnosis

Your vet will use your sample (or take a sample from your dog) to run a urinalysis, which will provide important information about her condition. In addition to providing information about the presence of blood, protein, glucose, ketones and bilirubin, a urinalysis will also determine how well your dog is concentrating urine, which is an indicator of kidney health.

An issue I’ve experienced within the holistic pet care community is that pet parents often assume they can resolve all urinary issues themselves, lumping UTIs, cystitis and crystals into the same category, without getting a diagnosis to determine exactly which of these conditions is present.

This is where things can go from bad to worse in a hurry, and where I’ve seen people with good intentions end up with critically ill pets suffering from terrible kidney infections that they incorrectly assumed they could fix on their own.

This is a situation in which more information and partnering with your veterinarian is crucial. If your dog is exhibiting any signs of urinary discomfort, the first thing you must do is get more information as to why, which is where the urinalysis comes in.

The urinalysis will also detect white blood cells (WBCs), indicating there is inflammation and/or infection. WBCs will be present with both infection and inflammation (cystitis) of the bladder; the differentiating factor between UTIs and cystitis is the presence of bacteria.

Your vet will determine if there are bacteria present in the urine sample by spinning the urine in a centrifuge, staining the sediment and looking at it under a microscope. If there are bacteria present in the urinalysis, your vet will recommend culture and sensitivity testing.

A urine culture and sensitivity test will determine the most effective medication needed to eliminate the type of bacteria present. In about 25% to 30% of dogs with UTIs, one or more additional pathogens are present with E. coli, and these cases can be considerably more difficult to resolve without determining what antibiotic will effectively treat all the pathogens that are present.2

If a bacterial infection is present, antibiotics will most likely be needed to treat the problem. However, pets often develop inflammation (cystitis) or urinary crystals with no bacteria present, which can result in very similar symptoms. In this case, a different set of supplements may initially be needed, but ultimately, in both situations, this is often a sign that it may be time to change your animal’s diet and supplement protocol (more about that shortly).

The most important thing to remember is to not assume the problem is inflammation when it could be a serious infection. Because all infections also incite an inflammatory response, UTI symptoms can be temporarily reduced with natural supplements that address inflammation.

The problem is the bacteria creating the infection are not eliminated, so although the symptoms are temporarily better, the unaddressed infection is allowed to travel from the bladder up the ureters to the kidneys (and sometimes into the bloodstream, creating a life-threatening situation).

Because the symptoms can be identical, the only way to know exactly what you’re dealing with — infection vs. inflammation vs. crystals — is to have a urinalysis performed by your veterinarian for a correct initial diagnosis, and then rechecked frequently until the problem is completely resolved.

Please don’t attempt home treatment until this step has been completed, or the infection may spread, and your pet can become much more ill, potentially with permanent kidney damage; after all, if you don’t know exactly what you’re treating it’s impossible to formulate an effective treatment plan.

Avoiding UTI Treatment Pitfalls

As I mentioned above, most UTIs are treated with antibiotics. For the treatment to be successful, it’s important not to guess at what drug will resolve the infection. The appropriate drug must be selected (which requires a culture and sensitivity test), and the length of therapy must be adequate.

There are many side effects of antibiotic use, especially if the correct antibiotic has not been identified (no culture test completed), including gastrointestinal (GI) symptoms that can lead to the dog’s owner not giving the drug as prescribed, the dog refusing the drug, and/or decreased absorption leading to inadequate levels of antibiotic in the blood or urine.

These issues can interfere with the elimination of the bacteria that is causing the infection, and can also contribute to antibiotic resistance. When a dog has recurring UTIs, it can be the result of a too-short course of antibiotic therapy, or the inability of the drug to reach the location of the bacteria.

If no culture was performed, or if the bacteria were only partially sensitive to the medication, or if the drug was discontinued too early, relapses can occur very quickly after a course of antibiotics is finished. In addition, the partially treated UTI can reappear after some time has passed and be mistaken for a new infection.

In addition, antibiotic resistance is a growing problem in both human and veterinary medicine. A 2008 study revealed that bacterial resistance is highest in dogs with recurrent E. coli-related urinary tract infections,3 and an earlier study identified E. coli bacteria in two dogs that proved resistant to 12 different antibiotics over the span of two weeks.4

If your pet’s urine culture reveals a drug-resistant strain of bacteria, I recommend you do two things:

  1. Ask your vet to complete extended spectrum testing, which evaluates other medications that may be more effective at treating resistant infections.
  2. Seek integrative veterinary care immediately. Functional medicine veterinarians have an entirely different set of tools in their medical “toolbox” that can dramatically bolster innate bladder defenses.

For aggressive infections, both approaches are necessary to cure the patient, in addition to providing a quality source of probiotics to re-seed the beneficial gut bacteria wiped out by administering any type of antibiotic.

How to Help Keep Your Dog’s Urinary Tract Healthy

Given the serious nature of bacterial infections and the risks associated with antibiotic therapy, it’s important to do what you can to prevent urinary tract infections in your pet.

One effective approach is to catch bladder irritation, cystitis, before it weakens bladder defenses enough to allow for infection to occur. Routinely check your dog’s urine pH levels by purchasing urine test strips over the counter at a local drug store, for example, or online. The test strips will give you some idea of what’s happening with your pet’s urine, including revealing trace amounts of blood, white blood cells and urinary pH.

Dogs are carnivores and should have a slightly acidic urine pH, ideally 6-6.5. (The higher the urine pH, the more alkaline it is.) Vegetarian mammals like rabbits and horses naturally have a very alkaline urine pH (above 8.0). Human urine is slightly more alkaline (between 6.5 and 7) than that of canines.

It’s important to keep your dog’s urine pH slightly acidic (below 7), because urine maintains its natural defenses when kept in the appropriate 6 to 6.5 range. When the pH creeps up toward the alkaline side, urine begins to lose its natural defenses against pathogens, which creates a more hospitable environment for bacterial growth and the development of struvite crystals.

The flip side of the coin is a urine pH below 6, which can cause a different type of problem — calcium oxalate stones. If your dog has had one or more infections or other problems with the urinary tract, I recommend stocking up on pH strips to check urine pH at home, so you know when it’s in or outside the desired range.

Urine samples should be collected in the morning before you feed your dog. You can either hold the urine test strip in the stream of urine while your dog is voiding, or you can catch a urine sample in a container and dip the tape into the sample to check the pH. This should be done immediately with a fresh sample to ensure accuracy.

How Diet Affects Urinary Tract Health

In my experience, poor or improper diet is the culprit in most cases of dogs with chronic urinary tract problems, including crystals, cystitis and UTIs. A prescription urinary diet, which many conventional veterinarians recommend, typically combines high-carb foods with medications to lower your dog’s urine pH.

This is never my approach. Instead, I transition dogs to a diet that eliminates pro-inflammatory alkalizing carbohydrates and unnecessary amounts of minerals found in the synthetic nutrient premixes pet food companies use.

When we feed carnivores a cereal-based diet, their urine becomes alkaline as a result. Meat-based diets are naturally acidic, whereas alkalizing starch-based diets are frequently the cause of chronic UTIs, because as I mentioned earlier, lack of acidity removes the antimicrobial activity in urine.

Alkaline urine can also create cystitis (bladder inflammation), crystals, and even uroliths (stones) that require surgery.

Often, a dog’s urine pH can be maintained naturally between 6 and 6.5 by feeding a nutritionally optimal, species-specific, preferably fresh food diet. To reduce urine pH, you must feed a low-carb, starch-free, potato/tapioca/lentil-free (so no grain-free kibble), and preferably non-dried diet for the increased moisture content.

There are products on the market to reduce urine pH that contain the acidifying amino acid DL-methionine. This is a safe addition to your dog’s diet, if she needs it, but a more logical approach is to simply stop feeding grains and alkalizing foods.

Excessive calcium and vitamin D added to pet foods in the form of synthetic vitamin/mineral premixes also contributes to recurrent calcium oxalate bladder issues, especially for predisposed breeds. Excessive vitamin D has been one of the major reasons for pet food recalls in recent years and is also a contributing factor to many cases of current urinary oxalate crystals leading to secondary bladder infections.  

Feeding a moisture-rich diet (no kibble) with optimal (not excessive) levels of vitamins and minerals coming from whole food sources reduces the likelihood of recurrent urinary issues. When animals receive their required nutrients from moisture-rich, fresh ingredients (instead of the bulk synthetic premixes found in most dry pet foods), they don’t excrete excessive amounts of leftover nutrients in their urine, reducing the potential for crystals and stones to form.

A thoughtfully designed, species-specific homemade pet food recipe provides nutrition from real foods in the correct proportions, avoiding mineral deficiencies and excesses (and the metabolic and urinary stress that comes with too much or too little). Thankfully, more transparent pet food companies offering optimally formulated, human-grade pet foods are entering the market at lightning speed.  

Raw, gently cooked, freeze-dried and dehydrated commercially available pet foods that contain ideal amounts of human-grade nutrients are now widely available; make sure you reconstitute all dry foods (including freeze-dried and dehydrated pet food) prior to feeding to avoid creating super-concentrated urine, a pre-disposing factor for recurrent bladder issues.

When it comes to UTIs, once you’ve eliminated the unnatural bacteria from your animal’s bladder and corrected any dietary contributing factors, you might be asking yourself what else you can do to prevent bladder infections from occurring.

In a 2016 study, scientists evaluated the effects of cranberry extract on the development of urinary tract infections in dogs. Their study results showed that cranberry extract appears to be as or more effective in preventing E. coli-related urinary tract infections in dogs as short-term antimicrobial treatment — without the side effects. In addition, cranberry extract can help fight multi-drug resistant bacteria in dogs with recurrent E. coli UTIs.5

I recommend choosing an organic cranberry extract with D-mannose, which is a simple sugar closely related to glucose that occurs naturally in cranberries, peaches, apples, other berries, and some plants.

D-mannose is fully absorbed (but does not prompt an insulin release or rock blood glucose levels, so there’s no negative systemic side effects) and quickly travels to the kidneys, then the bladder, and is excreted in urine. D-mannose works in your dog’s bladder, adhering to E. coli lectins. Almost all the D-mannose winds up in urine, which in turn coats the E. coli bacteria so it can’t stick to the walls of the bladder and is rinsed out of the body when your dog urinates.

I also use a variety of herbs, including olive leaf, horsetail and buchu to prevent urinary infections in high-risk animals.



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