Ectopic Ureter in Dogs and Cats

Date Published: 07/16/2020

What is it?

Ectopic ureter is a birth defect in which one or both ureters connect to an abnormal location. This leads to the most common complaint of difficulty house training and the pet leaking pee (urine). Ectopic ureters cause involuntary dribbling of pee, uncontrollable need to pee (urination), and urinary tract infections. Ongoing urinary tract infections can be fatal if they reach the kidneys, so it is important to diagnose and correct the ureter placement through surgery.

Normal Anatomy

Each animal has two kidneys which make urine. Each kidney has a collection tube, called the ureter, that connects it to the bladder at a special location named the trigone. Urine is emptied from the bladder through a single tube called the urethra. Therefore, urine moves from the kidneys, through the ureters, into the urinary bladder, where the urine is stored until the animal purposely pees. When urination occurs, urine empties through the urethra outside the body.

Ectopic Ureter

Graphic courtesy Shalini Radhakrishnan

There are two types of ectopic ureters based on where these collection tubes connect inside the animal’s body. Ectopic ureters do not connect and open at the bladder trigone, like in a normal animal.

Intramural Ectopic Ureter

This is the most common type in dogs. The collection tubes attach to the bladder at the trigone but then tunnel through the bladder wall, finally opening downstream from the bladder (ie. urethra).

Extramural Ectopic Ureter

This type is rare in dogs and is more common in cats. This is when the ureters pass the bladder and connect and open downstream from the bladder. This connection can be further along the urinary tract or even to the reproductive tract (i.e. urethra or vagina).

Graphic courtesy Shalini Radhakrishnan

Who gets it?

Ectopic ureter is an abnormality which occurs during development of the fetus. This is a rare abnormality in dogs, and it is even less common in cats. Ectopic ureter is most commonly identified in young animals because this is the age when signs are first noticed.

Cats:

  • Sex: Both females and males equally
  • Breeds: Himalayan, Persian, Maine Coon
  • Age: Mostly young animals

Dogs

  • Sex: Females nine times more likely than males
  • Breeds: Labrador Retriever, Golden Retriever, Siberian Husky, West Highland White Terrier, Miniature Poodle, Newfoundland, and Soft Coated Wheaten Terriers
  • Age: Mostly young animals

What are the signs?

  • Urine leakage or dribbling (incontinence)
  • Hard to house train; lots of accidents
  • Urinary tract infection, more common in females
  • Licking of genital area
  • Rash on the genital area
  • Urine staining and persistent wetness of genital area
  • Male dogs can have fewer signs and develop signs of urinary incontinence later in life.
  • Not all cats and dogs with ectopic ureter will show signs.

How is it diagnosed?

A complete physical exam and basic diagnostic tests like a complete blood count, blood chemistry, and urine analysis and culture will be done first.

Diagnosis of an ectopic ureter requires imaging. The method chosen depends on availability, training, and your animal’s specific case. Radiographs and ultrasound are two imaging methods that show the kidney shape and size. There is no one imaging method that is the best, and multiple methods may be needed.

Contrast CT and Cystoscopy are two methods that are gaining popularity as they give a better visual of the ureters. Cystoscopy is a procedure where a small camera is placed at the pet’s urethral opening and goes into the body looking for the openings to the ureters. This gives the veterinarian a great visual of where the abnormality is located.

The type of ectopic ureter, location, and size have no effect on the prognosis and outcome of treatment. However, imaging is necessary in determining which type of surgery to perform and the surgical approach the veterinarian will use.

  • Radiographs are usually readily available and cost-effective, but is has limited ability to identify specifics.
  • Ultrasounds are non-invasive, visualizes much of the urinary tract, relatively readily available, may be able to diagnose ectopic ureters with this modality but it may be difficult to visualize of lower urinary tract
  • CT scans provide a good visual of entire urinary tract but are expensive and is not always available
  • Cystoscopy prives a good visual of entire lower urinary tract and sometimes a repair can be done right then.  It is mot always available.

What is the surgery and treatment?

The type of surgery used to correct the misplaced ureter depends on its location. Studies show that there is no significant increase in risk or complications between any of the surgeries. All the surgical options have similar long-term outcomes.

Ureteroneocystostomy

This literally means new ureter and bladder opening. The surgery fixes the extramural type by creating a new bladder opening for the ureter in the correct spot. This surgery may cause swelling of the ureter during healing, but it will resolve in a few weeks.

Ureteronephrectomy

This means removing the ureter and kidney. The surgery is done on animals with the abnormality that also have a nonfunctional or chronically infected kidney attached to it. However, it can be difficult to tell if a questionable kidney is not functioning.

Laser cystoscopy

This surgery is a new method specific to treating the intramural type. The laser cuts the new ureter opening into the bladder at the normal area. Surgery is less expensive because it can be done right after the initial cystoscopic diagnosis, while the patient is still under general anesthesia.

What is the aftercare and long-term outcome?

Depending on the type of surgery completed, the aftercare and time of recovery may vary. The main post surgery problems are continued uncontrolled peeing, leakage of pee into the body, swelling at surgical site, and urinary tract infection. Studies show uncontrolled peeing resolves in cats that get a ureteronephrectomy. For dogs undergoing any of the surgeries for the malformation, almost half will still have urinary leakage. If this occurs, additional medications will be needed for the rest of the pet’s life to help control urination.

It is not clear why some animals have continued urine leakage after surgery. Animals affected with ectopic ureters should not be bred.

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