In this text, the lower urinary tract is defined as every part of the urinary system except the kidneys. While the kidneys filter blood and produce urine, the remainder of the system is concerned with storage and elimination of this waste liquid. This includes the ureters, which carry urine from the kidneys to the bladder, the urinary bladder, and the urethra, which is the tube that carries urine out of the body.

By definition, cystitis is inflammation of the urinary bladder. Many dog owners erroneously confuse this with being a "bladder infection". While bacterial infections of the bladder do occur, yeasts and mycoplasma organisms have also been implicated. Furthermore, there may be other factors which influence the formation of bladder disease including drug therapy, diabetes, which causes excess sugar in the urine, reproductive tract infections, bladder stones, the formation of crystals in the urine which can irritate the bladder wall and traumatic damage to the bladder.

Infections of the bladder most commonly ascend there, meaning literally, they crawl up from outside. Thusly, female dogs more commonly experience this condition as an infection will have a shorter distance to travel from the outside. Infections can also make their way to the bladder through the blood, from the kidneys, through the lymphatic system and by extension from other nearby tissues.

Clinical signs include having to void frequently, straining to urinate, pain when urinating, blood in the urine, foul or unusual odor of the urine and sometimes an increased thirst. Diagnosis is based on these symptoms, physical examination, urinalysis, urine culture, blood counts, organ function tests, X-rays and sometimes biopsies. Most acute or one-time cases can be easily diagnosed while recurrent and chronic cases of cystitis require a more involved diagnostic work-up. ((Cystitis))

Unrelated or predisposing causes of cystitis always need to be addressed. Antibiotics, often for 3-6 weeks may be needed, anti-inflammatory medications to reduce swelling and bleeding are often used; special diets and giving canned foods or broth to help flush the bladder are also usually employed. All cases of recurrent cystitis should have a more complete diagnostic work-up performed if treatment is to be successful.

This condition refers to "stones" forming in the urinary tract. The location of such stones is most commonly the urinary bladder, but stones can also form in the kidneys, ureters and urethra. In the right location they can prevent urination and lead to acute renal failure. This would be considered a true urologic emergency. Most stones, however, cause irritation and damage the inside of the urinary tract.

The size, quantity and types of stones vary greatly with no specific formula as to their development existing. Common stone types include struvite, calcium oxalate, urate, silica, cystine and calcium phosphate. Formation is caused by complex combinations of kidney function (metabolism), minerals in the diet, urinary tract pH, infections and abnormal metabolites being present in the urine. Dalmatians have an unusual metabolic defect making them prone to urate urolithiasis. Dachshunds seem prone to cystine uroliths. The composition of the stone(s) is most important with regards to treatment rather than to the symptoms produced. 

Clinical signs of urolithiasis are often similar to that of cystitis and include blood in the urine, straining to urinate, frequent urination, increased thirst, urinating in unusual places or where inappropriate, urinating small volumes of urine, unusual urine odor and sometimes abdominal distention and pain. Some dogs have been known to exhibit no symptoms at all! Diagnosis is based on history, physical examination, X-rays including X-rays taken with dye being placed into the bladder, urinalysis, and urine culture. In some cases kidney function tests will also be needed. ((Bladder Stones))  ((Xray of Stones))

Some difference of opinion exists between veterinarians as how to best treat stones in the urinary tract. Surgical removal is effective, especially if the stones are in the bladder and the patient is not a high surgical risk. Certain drugs and diets can be used to dissolve stones, but certain stones cannot be dissolved, and to dissolve any stone assumes that one knows the chemical composition of the stones without doing any analysis. Also, while waiting to see if the stones dissolve, the dog still suffers the consequences of their presence. Therefore, this author greatly favors quickly removing the stones, performing a stone analysis, and then using special diets and/or medications to prevent further recurrence.

If a male dog has become obstructed with a urethral urolith, immediate attention is required. Back-flushing of the urethra to dislodge the stone(s) followed by catheterization and drainage of the bladder may be needed. In some more severe cases, surgical removal by opening the penis/urethra may be required. IV fluids and supportive care may also be necessary if kidney function has been compromised.

When the ureters, which bring urine from the kidneys to the bladder, insert into the lower urinary tract in an abnormal position it is called ectopic ureter(s). One or both ureters may be involved and often the bladder is completely bypassed. Clinical signs include a constant urinary incontinence that begins at an early age, often before the dog reaches 6 months of age. Some dogs will urinate normally at times, while others may never exhibit normal urination. Diagnosis is based on the fact that a young dog is incontinent, physical examination, urinalysis, X-rays including dye studies of the entire urinary tract and exploratory surgery. ((Ectopic Ureters))

After infection and other conditions are ruled-out or treated, surgery is possible to correct the defect. A specialist or other surgeon skilled in this type of procedure should be sought, as the reconstruction is very delicate. Usually we will wait until the dog is 4-6 months old.

Loss of bladder control is a very common problem dealt with in veterinary practice. Incontinence would be considered a loss of some degree of voluntary bladder control. The storage of urine and proper voiding is a complex mechanism involving several muscle and nerve groups. Dysfunction of any part of the system can result in bladder control being lost.

Most micturition disorders result from loss of nerve function, low hormone levels, ectopic ureters, cystitis, urolithiasis and other assorted problems with the muscles of the urethral passage. Commonly, dogs with this problem are female and older than eight years of age. The history will include the fact that the dog does go outside and urinate normally but where she lies a wet spot (sometimes large) is found. Other dogs may dribble urine while seemingly unaware of the fact that anything is going on. Other cases may involve an inability to urinate, total voiding when lifted or touched, straining to urinate and some abdominal pain.

The most common version of this problem, in older female dogs, is what is known as hormone-responsive incontinence or estrogen incontinence. These dogs have been spayed and without the estrogen in their system later develop bladder control problems. On occasion, castrated males can have the same type of problem. ((Urine Scalding))

Secondarily to this condition, dogs with spinal cord disease either due to trauma, disc disease, spondylosis deformans or degenerative myelopathy can all suffer from loss of control secondary to the loss of nerve function. The other common syndrome seen in practice is that of stress incontinence, or more properly, urethral incompetence. Commonly this describes the puppy that urinates whenever excited. These dogs generally have no abnormalities found on X-rays or urinalysis and can void normally. The Cocker Spaniel is most likely to be affected with this condition.

Diagnosis of this/these conditions is based on historical findings, physical examination, urinalysis, X-rays including dye studies, blood counts, serum chemical analysis and sometimes trial therapy with certain drugs. Most dogs can be helped as long as spinal cord lesions are not present. A neurological exam may be necessary in these cases.

Treatment for this disorder, if secondary to neurologic problems, will depend on how well the nervous system can recover and restore function. Manipulation and acupuncture have proven successful in some of these dogs. Cases of ectopic ureter will require surgery. Most other cases will respond to either hormonal therapy or treatment with drugs that improve the holding capabilities of various urinary system muscles. Most dogs can be successfully treated in some fashion.

The urinary bladder has quite a holding capacity and its thick wall can stretch greatly. Nevertheless, in cases of untreated urolithiasis or subsequent to traumatic injuries, the bladder may rupture. This leads to a urinary peritonitis and kidney failure as wastes that were being excreted from the body are now being recycled and building up in the blood more rapidly. Clinical signs include abdominal pain, weakness, bloated abdomen, shock, vomiting, coma and death. Diagnosis is based on history, clinical signs, physical examination, X-rays, aspiration of abdominal fluid and exploratory surgery.

The abdomen must be opened, urine drained from the peritoneal cavity, and the defect repaired. The patency of the urethra must be re-established if it was plugged or damaged. The abdomen must be flushed and cleaned, and IV fluids and diuretic medications are used to flush the system of toxins and restart kidney function. The prognosis depends upon the degree of kidney damage or organ failure brought on by shock and the peritonitis.

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