The urinary tract is made up of the ureters, urethra, bladder, and kidneys, and prostate gland in males. The urinary system is responsible for producing, storing, and eliminating urine. Genital organs are also involved in the elimination of urine. Urinary tract disorders are diseases, infections, or obstructions that affect any part of the urinary system in dogs. Any disease that affects these areas of the body results in the buildup of waste or toxins in the canine’s body. This accumulation can cause very serious side effects and must be treated. Some urinary tract disorders include incontinence, bladder infection, cancer, urolithiasis, prostate disease, renal dysplasia, acute renal failure (ARF), urinary infections, ectopic ureters, bladder stones, kidney failure, kidney disease, and chronic renal failure. Incontinence is the most common UT disorder in dogs over the age of seven years. Ectopic ureter is a very common congenital defect in the ureters, and causes the ureters to deposit urine into other areas of the body.
Causes
There are many things that cause urinary tract disorders: trauma, spinal cord abnormalities, excessive water drinking, cancer, congenital abnormalities, stress, inflammation, parasites, autoimmune haemolytic anemia, improper diet, poisoning, obstruction of the urethra, and accumulation of debris, stones, or crystals along the tract. Infections may be caused by fungal, viral, or bacterial exposure. Age-related incontinence is caused when the urinary sphincter muscles weaken. Endocrine diseases like diabetes mellitus and adrenal disease can make dogs prone to bacterial infections in the urinary tract. Urinary tract disorders are not contagious, unless they are infections passed by virus or bacteria. Acute renal failure may be brought on when a dog ingests antifreeze or has a severe case of leptospirosis.
Prevention
Prevention depends upon the type of disorder. The easiest way to prevent urinary tract disorders caused by stones or crystals in your pet is to feed it a proper, balanced, and healthy diet with plenty of fresh drinking water. These crystals and stones are caused by an excess of minerals in the urine. Those minerals form in to crystals and then stones. If left untreated, they grow in size or join together to form a blockage. Some medications can cause stones and crystals, as well. Speak to your vet if your dog is prone to this type of urinary tract disorder. Urinary tract infections may be prevented by keeping your dog away from environmental bacteria, or ensuring that intestinal bacteria do not enter the ureter. Avoid chronic antibiotic usage to prevent bacterial antibiotic resistance. Some antibiotics can damage the kidneys. Keep your dog away from antifreeze. Avoid having your dog play in areas where cases of leptospirosis are identified. Avoid the indiscriminate use of urinary catheters in your dog. Access to fresh drinking water will help flush bacteria and other microorganisms out of the urinary tract along with the urine. Renal dysplasia, which is abnormal development of the kidney(s), cannot be prevented. Some cases may be hereditary, so dogs with genetic renal dysplasia, and other genetic disorders of the urinary tract, should not be bred. Regular vet checkups can help prevent minor disorders from worsening into life-threatening conditions.
Symptoms
Some conditions, like bladder infections, are sub-clinical – which means the dog shows no symptoms. Others have very obvious signs, like change in urination frequency, or change in the colour, smell, or consistency of the urine. If your dog shows signs of pain while trying to urinate, straining, blood in the urine, or inability to urinate, get him to a vet immediately. Other symptoms of urinary tract disorders include a change of water intake, constant licking at the genital area, weight loss, urinating in inappropriate places, fever, back pain, loss of appetite, vomiting, depression, lethargy, and incontinence.
Dog Breed at Risk
Dogs with diabetes and older female dogs are most prone to developing urinary tract problems, but older male dogs are also prone to certain types of bladder stones. Some breeds are more prone to different disorders. For example, renal dysplasia is more prevalent in the Standard Poodle, Norwegian Elkhound, Chow Chow, Alaskan Malamute, Bedlington Terrier, Soft-Coated Wheaten Terrier, Shih Tzu, Samoyed, Golden Retriever, Doberman Pinscher, and Cocker Spaniel. Dogs at risk of developing acute renal failure are those that have other types of kidney disease, kidney stones, low blood pressure, and systemic disease.
Testing and Diagnosis
To diagnose a urinary tract disorder, the vet will perform a history, physical exam, urinalysis and urine culture, and possibly x-ray and ultrasound. Specific tests will depend upon the type of disorder suspected. Blood tests may also indicate some disorders. Urinalysis tests the pH and checks for crystals, bacteria, fungi, viruses, specific gravity, and minerals present in the urine. Specific gravity refers to the dilution of the urine; dogs that drink too much water will have diluted urine. Excessive water consumption may be caused by Cushing’s syndrome, diabetes mellitus, kidney failure, diabetes insipidus, and bladder infection.
Bladder infections are the most common cause of incontinence in dogs under seven years of age. Dogs with urinary problems should always be checked for diabetes mellitus.
Treatment and Prognosis
Treatment depends upon diagnosis. For disorders that result in a side effect of urinary tract problems, the underlying condition is treated. Other problems may be treated with antibiotics, dietary changes, increase in water intake, surgery to remove tumours or stones, surgery to correct any congenital abnormalities, supplements or medications, antibiotics, subcutaneous or intravenous therapy, or urinary alkalinizers or acidifiers.
Chronic kidney failure is generally untreatable and is fatal. Acute kidney failure may be reversed if the originating cause is determined and treated soon enough. Age-related incontinence caused by weak sphincter muscles may be treated with one of several medications like estrogen, anticholinergics, alpha-adrenergic agonists, or gonadotropin-releasing hormone. If medications don’t work, surgery may be an option. Most urinary tract disorders are treatable and the prognosis is fair once the original cause is determined.
Helena is aSenior Associate Veterinarian at Kleintierpraxis Wandsbek and an avid dog breed author.