Back to Info Index
When a male dog reaches 8-years of age, he has a greater than
80% chance of developing prostate disease, but it is rarely cancerous
(benign or malignant). The gland serves the same function in the
dog as it does in man and suffers from all the same diseases.
Fortunately for the dog however, the incidence of life-threatening
conditions is much lower. Still, most unneutered canines will
at one time or another, suffer a lot of discomfort if not severe
pain due to the prostate gland.
The prostate gland is a bi-lobed structure that lays within the pelvis just behind the bladder and directly below the rectum. In a forty-pound dog it is normally about one to two inches in diameter. It surrounds and is open to the urethra its entire length of the gland. Small tubes or ducts deposit the fluids produced by the prostate directly into the urethra as it courses through the prostate. The prostate starts to develop before the dog reaches puberty and attains its maximum size by the time the dog is two years old. From that point on, its size is determined by the male hormone testosterone and/or various disease conditions.
The prostate gland is classified as an accessory sex gland. This means that in some way it is important for successful breeding but does not directly produce the sperm. Prostatic fluid is a major portion of the total ejaculated liquid, and is important both in nourishing the sperm cells and providing a greater volume to the ejaculate to make their movement much easier. The sperm cells are actually only a very small percentage of the total ejaculate and must travel all the way from the testicles of the male to the ovaries of the female. This may be a distance of greater than three feet depending on the breed! Although sperm cells are able to move on their own, most of the actual movement comes from the contracting musculature of the urethra, cervix, and uterus pushing the fluid along. A larger fluid volume makes it easier for these structures to propel the sperm cells the necessary distance. Prostatic fluids also have antibacterial properties that protect the sperm plus decrease the chances for infection in the female.
Effect of neutering on the prostate
Dogs that are neutered before puberty have very little prostatic tissue. Without the male hormone testosterone that is produced within the testicles, the prostate gland does not develop. If we were to surgically explore this area in one of these dogs, only a tiny bulge would be noted in the urethra. The small size causes no harm to the dog since the only known function of the prostate is support and nourishment of the sperm cells. If a mature dog is neutered, the gland will shrink to less that one-fourth of its previous size. Within a few months its functional cells will cease all or nearly all production of the supportive fluids.
Signs of prostate disease
Classically, in the dog an enlarged prostate causes painful defecation. Remember the prostate gland lies right below the rectum within the bony pelvis. The canal through the pelvis is only so big and it cannot get any bigger on an individual dog. Therefore when the prostate increases in size, it pushes up against the rectum, greatly decreasing the space available for the rectum. When stools pass from the large intestine through the rectum during defecation, there often is not enough room to accommodate everything. The dog will strain and strain to force the stool out and the stool puts pressure on the swollen and painful prostate. This is the most common cause of constipation and fecal straining in the male dog.
Dogs with painful prostates will often walk abnormally. They are attempting to keep anything from riding against or putting pressure on the swollen, painful gland. Their rear legs will be stiff and straight at the knee and hock and they will usually take very short steps. Some owners refer to this as "walking on eggs."
Other signs directly associated with prostatic infection are
discharges from the penis including blood and pus, straining to
urinate, and in rare cases, peritonitis which develops when bacteria
from the prostate leak out and enter the abdominal cavity.
Question and answer
What are prostatitis and prostatic abscess?
Prostatitis is the medical term for inflammation of the prostate gland. Prostatitis may occursuddenly (acute prostatitis) or may be present for a long time (chronic prostatitis). Prostatitis issubdivided into acute bacterial prostatitis, chronic bacterial prostatitis, and prostatic abscess. Prostatic abscess is an abscess (localized collection of pus surrounded by inflamed tissue) of theprostate gland. Prostatic disease is seen in male dogs.
What causes prostatitis and prostatic abscess?
Bacterial infection of the urinary tract in an intact male
dog usually leads to an infection of the
prostate gland. The infection leads to prostatitis or to development of a prostatic abscess. Bacteriausually gain access to the prostate gland by ascending the urethra (the tube that leads out of thebody from the urinary bladder) and overcoming the normal defenses of the lower urinary tract.Accumulation of normal prostatic secretions can become infected, resulting in chronic prostatitis orprostatic abscess. Infection of the sexual organs leading to prostatic infection is less common.
What are the signs of prostatitis or prostatic abscess?
The signs of prostatitis or prostatic abscess vary, depending
on whether the inflammation is acute
or chronic and if the prostate gland is abscessed. Clinical signs are useful in differentiating acute
and chronic prostatitis and prostatic abscess. Dogs with acute prostatitis are usually very ill; they
are depressed, feverish, and the prostate gland is painful or tender to the touch. Dogs with chronicprostatitis often have no signs. Dogs with prostatic abscesses usually have signs similar acuteprostatitis. A prostatic abscess can put pressure (impinge) on the urethra (tube leading out from the urinary bladder) and block urination.Common signs of prostatitis or prostatic abscess include lethargy, blood or pus dripping from the penis (not necessarily associated with urination), and straining to defecate (tenesmus). Occasionally, the dog may have a stiff hind limb gait. Less commonly, the dog will have fluid build up in the tissues of the penis or hind limbs or the dog may go into septic shock.
How is prostatitis or prostatic abscess diagnosed?
Prostatitis or prostatic abscess is diagnosed by a good medical
history and a thorough physical
examination. Diagnostic testing, such as complete blood count (CBC) and urinalysis, will be
performed. Most dogs with acute prostatitis have pus, red blood cells, or bacteria in their urine as
well as characteristic changes in the white blood cell (WBC) count. Some dogs with chronic
prostatitis have pus, blood, or bacteria in their urine. Most animals with prostatic abscesses have
pus, blood, or bacteria in their urine as well as characteristic changes in the complete blood cell
count (CBC). Dogs with prostatic abscesses frequently have changes on their blood chemistry
panels. These may include high , high , or low blood sugar (hypoglycemia).
Bacterial culture and microscopic examination of fluid from the prostate gland confirms the
diagnosis of bacterial prostatitis. Ultrasound (visualization of deep body structures by recording
ultrasonic waves) of the prostate gland is helpful in differentiating acute and chronic prostatitis from prostatic abscess. Examination of an aspirate (taken from an abscess by using a needle and
syringe) can confirm prostatic abscess; however, this procedure must be performed carefully
because it could lead to rupture of the abscess.
How are prostatitis and prostatic abscess treated?
The treatment for prostatitis and prostatic abscess depends
upon the clinical signs and whether the inflammation is acute
or chronic and if the prostate gland is abscessed. Administration
of carefully chosen antibiotics is an important part of the treatment
regimen. The antibiotic should be chosen on the basis of bacterial
culture and susceptibility testing. Bacterial culture and sensitivity
determines which antibiotics will kill the bacteria causing the infection effectively. Treatment is
necessary for 3 to 4 weeks or longer. Dogs with prostatic abscess require a minimum of 8 weeks of antibiotic treatment. Dogs with acute prostatitis or prostatic abscess are given fluids intravenously (in the vein), especially if they are in shock. Fluids containing sugar (dextrose) may be given if low blood sugar is suspected. Administration of antibiotics intravenously may be necessary because of generalized (systemic) illness or infection (sepsis). In this situation, the antibiotics should be administered intravenously until the dog is stable, at which time antibiotics may be administered by mouth (oral). Dogs with prostatic abscesses probably need surgery to drain the abscess. Other more extensive surgery may be required. Dogs with prostatic disease should be castrated (after infection resolves) to prevent recurrence.
What is the prognosis for dogs with prostatitis or prostatic abscess?
The prognosis (outcome) for dogs with prostatitis or prostatic
abscess varies. Dogs with acute or
chronic bacterial prostatitis usually respond well to treatment; however, the potential for recurrent
prostatic infection exists. Dogs with prostatic abscesses often need prolonged follow-up and
reassessment. Dogs with generalized (systemic) disease or infection (sepsis) and shock may have
poor outcomes, depending on their response to aggressive treatment. Dogs that are poor
anesthetic risks, but must have surgery, may not survive. Some dogs can lose control of urination
(become incontinent) immediately after surgery, especially for prostatic abscess. Those dogs may
regain partial or complete control of urination with the help of medications.
The majority of the information in this page is has been taken from VetMedCenter.com. For further information about this useful source of informtion follow the link or look, on the internet, at www.vetmedcenter.com.