Urinary Tract Infection in Dogs

The urethra and bladder are normally sterile environments. However, infectious agents can invade the urinary tract and easily colonize, especially if the normal urinary tract defenses are compromised. Defenses against bacteria can be diminished because of factors such as aging or disease (diabetes for example). E Coli (Escherichia coli) is the most common bacterium to cause a urinary tract infection (UTI).

A urinary tract infection (UTI) occurs when bacteria adhere to the urinary tract and begins to multiply. Bacterial urinary tract infections are relatively common in canines, with females being more susceptible than males. If not attended to, a urinary tract infection can lead to serious complications, including scarring and eventual kidney failure.

Some dogs may be asymptomatic with a urinary tract infection. Signs that a dog is suffering from a bacterial invasion can vary, depending upon the extent of the infection and whether underlying diseases are complicating the illness. If you feel that your dog is having difficulty urinating, or is exhibiting any of the following behaviors, take him to the veterinary clinic without delay.

• Licking of the urinary opening
• Apparent difficulty urinating
• Urinating in small amounts, frequently (pollakiuria)
• Slow, painful voiding (stranguria)
• Cloudy or malodorous urine
• Blood in urine (hematuria)
• Incontinence
• Voiding large amounts of urine (polyuria) because of increased thirst (polydipsia)
• Lethargy
• Anorexia
• Vomiting

Types

Urinary tract infection is usually classified in two ways.

• Uncomplicated UTI
• There is no underlying structural, functional or neurological abnormality found
• The UTI will usually improve within 48 hours of commencement of treatment
• The treatment course is 5 to 14 days
• Complicated UTI
• There is a predisposing cause for the UTI
• Treatment could involve a therapy course of 4 to 6 weeks

While bacteria is one reason that a urinary tract infection may develop, there are many other factors that can predispose your canine family member, or further complicate the instance of a UTI.

• Immunosuppression from medication or steroids
• Diabetes mellitus
• Hyperadrenocorticism
• Prostatitis
• Neurological abnormalities
• Polyps
• Tumors
• Bladder stones
• Stress
• Anatomic abnormalities
• Reduced mucosal defense

When you decide to transport and bring your canine companion to the clinic, the veterinary team will be ready to quickly diagnose the reason for your pet’s discomfort. The veterinarian may begin the visit with the following questions.

• How long has your dog been unwell?
• Can you tell us about the behavioral changes you have noticed, such as dietary habits or activity level?
• Has your dog been prescribed any medications of late, and how did he respond to the treatment?
• What kind of urinary changes have you observed?

A physical exam will take place and will most likely include palpation of the abdomen to check for pain or renal abnormalities. Diagnostic tests could comprise of a biochemical profile (to check for underlying disease), and a complete blood count (to verify the increase in white blood cells). A urinalysis will likely be recommended, which may indicate the presence of proteins, pus, and blood, and to analyze the PH level of the urine. The urine may then be cultured in order to grow and verify the bacteria responsible for the UTI. (The existence of bacteria is a pretty definitive way to diagnose a UTI.)

The veterinary specialist may also want to perform an ultrasound or radiograph, to look for stones or lesions. A contrast study could be possible because it is an excellent way to look for anatomic defects.

Treatment of an infection of the urinary tract is typically straightforward. In cases of an uncomplicated UTI, treatment will be the administration of antimicrobials (an agent such as antibiotics, that destroys or inhibits the growth of microorganisms). The treatment will last between 5 to 14 days and is usually administered orally. There are also injectable options available.

In the case of a complicated UTI, antimicrobial therapy may be prescribed for 4 to 6 weeks, with a urine culture advised before starting treatment. If a tumor is involved, surgery may be an option. Any underlying cause or complication must be addressed along with the treatment for the urinary tract infection to have complete resolution. In both complicated and uncomplicated UTI’s, pain relief medication will be given if needed.

Repeated urine cultures are sometimes necessary to verify if the antimicrobial agents have done the trick. In the case of a complicated UTI, the usual culture after one week of treatment will be repeated, prior to the end of the medication period, and then again a week to 10 days after the treatment has stopped. This may seem excessive but is absolutely essential in order to conclude if the chosen protocol will cure your pet of the pain and infection.

Though most UTI’s clear up without complication once the treatment has begun, there can be instances where the antimicrobials do not seem to be effective.

• Noncompliance by the pet owner. Never stop the treatment before the veterinarian gives the go-ahead.
• The treatment may need to be repeated because the initial course was not long enough.
• There could be an antimicrobial resistance, in which case a different one will need to be prescribed.
• There could be an underlying cause that was not previously discovered or recognized.

Chronic urinary tract infection might require low dose continuous therapy.  Low dose therapy might be discontinued once the veterinarian verifies, through urine culture, 6 months of bacteria free urine.

Studies are in process to determine if giving your dog cranberry juice, or extract can be beneficial for non-adherence of bacteria to the urinary tract (the same as it seems to for humans).

As always, contact the veterinary team at any time if you have questions or concerns about the treatment prescribed for your furry family member.

Urinary tract infections can be expensive to treat. If you suspect your dog has a urinary tract infection or is at risk, start searching for pet insurance today. Brought to you by Pet Insurer, Wag! Wellness lets pet parents compare insurance plans from leading companies like PetPlan and Trupanion. Find the “pawfect” plan for your pet in just a few clicks!