Prostatitis is a bacterial infection of the prostate gland.
Infection of the prostate may be caused by disease of the urethra (the
small tube where urine flows from the bladder through the penis), other
urinary tract infections, or may be secondary to a more serious prostatic
disease. This disease occurs more commonly in male dogs who have not been
neutered. Older dogs are at greater risk than younger dogs. Prostatitis
can occur in an acute (sudden) and chronic (long standing) form; however,
animals with the acute form are generally more debilitated
than with the chronic form.
Sign and Symptoms
Clinical signs of prostatitis vary with the severity of the
infection and whether the disease is acute or chronic. The following symptoms
could indicate the presence of this condition:
- cloudy or bloody discharge from the penis
- blood in the urine
- abdominal discomfort
- stiff gait
- straining to urinate or defecate
- weight loss
- chronic intermittent urinary tract infections
- infertility in a breeding male
If your dog exhibits any of the above symptoms, take him to
your veterinarian. Your vet will check your dog's history and most likely
perform a physical examination including the following:
- digital rectal exam
- check the culture and sensitivity of the urine
- cytological (microscopic) evaluation of seminal or prostatic
- prostatic massage and wash for cytology, culture and
- abdominal radiographs (x-rays)
- abdominal ultrasound with or without prostatic aspiration
- clotting profile
- complete blood count
- biochemical profile
The most common cause of prostatitis is believed
to be ascending infection from the urethra. The prostate can also become
infected from infections in the bladder, kidneys or blood. If other forms
of prostatic disease are present, such as cysts, neoplasia or squamous
metaplasia, the prostate may be predisposed to developing a secondary infection.
E. coli is the most common bacterium that causes infection.
There are actually two different clinical presentations of prostatitis
in the dog: acute and chronic. These two forms of the disease often present
very differently, and require a different clinical work-up and different
therapy. In acute prostatitis, animals are usually quite ill and may even
require emergency care. Animals are usually feverish and may have significant
abdominal pain. Some dogs may even shows signs of a critical
blood infection (septicemia). On the other hand, dogs with the chronic
disease are generally much more stable or sometimes exhibit no clinical
Other diseases that may cause similar clinical signs
Urinary Tract Infections - bacterial infections
of the urinary bladder or kidneys may cause blood in the urine, fever and
abdominal pain. It is not uncommon for an animal to have a urinary tract
infection together with prostatitis.
Prostatic Abscess- an abscess is a walled
off pocket of infection containing white blood cells, bacteria and cellular
debris. Abscesses occasionally form within the prostate gland in cases
of chronic prostatic infections. They may get to be quite large and cause
compression of both the colon and urethra. Animals may be straining when
they defecate or urinate, and most animals will feel ill.
Benign Prostatic Hyperplasia (BPH) - BPH is
the most common form of prostatomegaly (increased prostate size), with
virtually all intact (not neutered) male dogs; who generally acquire the
condition as they age. BPH is caused by an increase in the number and size
of the prostate cells as the intact dog ages and is exposed to normal hormonal
influences. This is a benign condition that usually does not cause any
clinical signs. Occasionally a urethra discharge is present, which can
be bloody. The majority of the time this condition is found incidentally on routine
physical examinations. Dogs with chronic prostatitis sometimes have very
Prostatic Neoplasia (cancer) - may closely
mimic chronic prostatitis. Animals with prostatic neoplasia tend to be
systemically ill, and have a history of weight loss. Tumors of the prostate
are almost always malignant. The most common tumors involving the prostate
are adenocarcinoma and transitional cell carcinoma. Most
other types of prostatic disease, and prostatic cancer occur with the
same frequency in both intact and neutered dogs.
Squamous Metaplasia - is a change in the
prostate gland due to elevated blood estrogen levels. The main cause of
this is an estrogen-producing tumor, such as a Sertoli cell tumor. Long-term
oral estrogen supplementation can also cause these changes. Sertoli cell
tumors can also cause a chronic debilitating disease due to the suppressive
effects of estrogen on the bone marrow.
A complete history and physical examination is the first step
in obtaining an accurate diagnosis. An intact male dog with a fever, pain
in the area of the prostate, and blood or pus in the urine has a high percentage
of having acute pancreatitis. Dogs with acute prostatitis are usually quite
ill and their prostate is generally painful. The diagnosis is usually more
apparent in the acute condition and may require fewer diagnostics than
in the chronic disease.
Achieving a diagnosis of chronic prostatitis is more difficult
as there are less consistent clinical signs. In chronic prostatitis, it
is even typical that there is no prostatic pain. The diagnostic evaluation
and potential results vary significantly depending on whether or not
the disease is acute or chronic.
The treatment for prostatitis varies depending on whether the
disease is acute or chronic. Acute prostatitis is a much more critical condition
than chronic prostatitis and requires more immediate and aggressive care. When
evaluating a dog for chronic prostatitis, it is generally appropriate to wait
until a definitive diagnosis has been established prior to beginning therapy.
In this way, appropriate antibiotic therapy may be started based on culture and
sensitivity results. This may not be an option in some of the acute cases since
the animal may require emergency treatment before the diagnostic test results
The decision as to when to begin therapy depends on the clinical
assessment of the patient. In general, a more rapid treatment is required
for the acute disease, and a longer treatment course is needed for the
chronic condition. Although animals are sicker with the acute disease,
it is generally easier to achieve a complete cure than with the chronic
disease. Dogs with chronic prostatitis are more likely to have a continued
intermittent problem despite therapy. Chronic prostatitis is a difficult
disease to cure.
are typically given for a minimum of four weeks. Intravenous fluids may
be required in acute prostatitis cases, along with analgesic or pain medications,
and in some instances neutering may also be recommended. Antibiotics that
are effective include: erythromycin, clindamycin, chloramphenicol, trimethoprim/sulfonamide
and the quinolones.
Home Care and Prevention
Recheck examinations 7 to 14 days later are strongly suggested,
as follow-up prostatic palpation is recommended. Abnormal blood tests should
also be re-evaluated. The urine or a sample of the prostatic fluid may
also need to be re-cultured at this time.
Make sure the urine color is becoming more clear if it was an
abnormal color when your pet was ill. Your pet should continue to improve
on therapy at home, but relapses may occur, especially with chronic disease.
If there is any deterioration in condition, or recurrence of clinical signs,
notify your veterinarian immediately.
Your veterinarian may also recommend that cultures of the urine
and or prostatic fluid might be recommended after finishing the antibiotics
to be certain the abnormal condition no longer exists. Neutering a dog
before reaching sexual maturity may help decrease the incidence of prostatitis.