Glendale Animal Hospital - The Family Veterinarian


The male reproductive tract includes the testicles, prostate, other associated sex glands and the penis. While diseases of this system are uncommon, several important conditions are commonly seen in veterinary practice



Hyperplasia denotes an increase in the number of cells of an organ; thus, benign hyperplasia occurs when the size of the prostate is increased as the number of cells therein increases. If fluid filled cysts also form, then a cystic hyperplasia occurs. While blockage of tiny ducts within the gland can cause cystic disease, more often the growth is due to normal male hormones (in normal dogs) or increased levels of female hormones (in dogs with certain testicular cancers).

While the condition is termed benign because it is not cancerous, there can be side effects of the prostatic enlargement including obstruction of the rectum, restriction of urine flow and prostatic inflammation. Most dogs will never have symptoms, but a few may exhibit urinary difficulty, constipation and straining to defecate and sometimes blood in the urine. Diagnosis is based on history, physical examination, X-rays and urinalysis. The testicles should be checked for the presence of tumors. ((Prostate Enlargement))


While asymptomatic dogs will require no treatment, dogs with clinical signs should be neutered which will almost always cause the prostate to shrink and become somewhat inert. Laxatives and stool softeners can be used to ease constipation problems. We always advise neutering males as early as possible to avoid this type of problem.



Prostatitis is inflammation of the prostate gland, often due to an infection and many times after benign prostatic hypertrophy has first occurred. The condition may occur suddenly but some dogs will have recurrent bouts resulting in a chronic prostatitis. As with benign prostatic hypertrophy, non-neutered male dogs are most frequently affected. Infection will most likely come from either the urinary tract or the blood stream. ((Prostate Enlargement))

The symptoms of prostatitis, depending on the severity, can include straining to defecate, constipation, blood dripping from the penis and/or bloody urine, mysterious pain, fever, loss of appetite and depression. Chronic disease has similar symptoms to the acute process. Some dogs may form actual Prostatic Abscesses where there are pockets of pus forming in or on the prostate. The symptoms here will also be similar, unless one such abscess ruptures and then symptoms of peritonitis can occur.

Diagnosis is based on history, clinical signs, physical examination including rectal palpation, X-rays, blood counts, prostatic washes and cultures. Sometimes, placing a needle in the prostate through the rectum is performed to obtain material for analysis and culture.


Most every dog will respond and improve by being neutered. In fact, most acute cases treated this way will never recur. Antibiotics are most always useful and medications for pain and constipation will help until swelling subsides. Rarer cases of abscessation may require surgical drainage but this is usually not needed.



This condition occurs when the testicles do not descend to the scrotum where they were designed to be. Testicles in the fetus start out near the kidneys and must travel through the abdomen, through the muscle wall and into the scrotum. They can be left either inside the abdomen or stuck in the groin area just under the skin. One or both testicles can be retained in this manner. If a dog has a testicle in the groin area, it is called inguinal cryptorchidism; abdominal cryptorchidism is the name for testicle(s) retained in the abdomen.

The condition is considered hereditary, and although dogs can be weakly fertile and produce litters, it is not advised, as the trait will then be perpetuated within the breed. Also, retained testicles are more likely to become cancerous later in life. Yorkies, Pomeranians, small Poodles, Schnauzers, Shelties, Siberian Huskies and the Chihuahua are most commonly affected.

Cryptorchidism can be diagnosed as early as 3-4 weeks of age, and if both testes are not present by 4-6 months of age, they most likely never will be. It has been documented where testicles do fall into place later than 4 weeks, but almost never after 6 months.


Neutering is always advised as this prevents later cancers as well as stops the breeding of defective dogs. Although human males are surgically "corrected", it is considered unethical to do so in dogs, if not even fraudulent and thusly not performed. 



Some dogs, especially older dogs, will have shrinkage and softening of the testicles which will correlate with a decline and/or cessation of sperm production. The cause of this condition is unknown but probably relates to alterations in hormone production by various glands or can occur after an infection, inflammation or trauma of the testicles has occurred. There is no treatment. Testicular Atrophy will most often decrease the fertility of the male dog.



Epididymitis is inflammation of the duct and storage area closely attached to the testicle.

Orchitis is inflammation of the testicle itself. As the two areas are very closely associated, it would be almost impossible for either to occur alone.

Brucellosis, systemic fungal disease, canine distemper, immune-mediated disease, traumatic injury and other miscellaneous bacterial infections can all lead to this condition. Clinical signs include swelling of the epididymis or testicles, pain, heat, fluid swelling (edema) of the scrotum, licking of the testicles, fever and poor appetite. Left untreated and sometimes despite treatment, testicular atrophy can occur later. Diagnosis is based on history, physical examination, cytology of semen, culture of the semen or from the testicles, brucellosis blood tests, blood counts and fungal serology.


Neutering (castration) is advised for all males, regardless of cause but especially if brucellosis is involved, followed by several weeks of antibiotic therapy. Antifungal medications are used if fungi have caused the disease with other conditions treated accordingly. Dogs with brucellosis should never be bred although most dogs will be, to some degree infertile.



On occasion, the spermatic cord that attaches to the testicles will twist and blood flow to the testicles will be halted producing severe testicular damage. This most commonly occurs in cancerous retained testicles but can occur in normal testicles as well. The condition is very painful and other symptoms include fever, severe vomiting, reluctance to move, swelling to the testicle and if untreated, shrinkage of the testicle. Diagnosis is based on physical examination, X-rays and ultrasound.


Most dogs need stabilization with IV fluids, anti-vomiting medications, anti-inflammatory medications and pain relievers. After stabilization, surgical castration, even with intra-abdominal testicles, needs to be performed.



Balanoposthitis defines inflammation of the penis and prepuce, most commonly secondary to a bacterial infection, but sometimes secondary to trauma, such as dog bites and other wounds and foreign objects such as foxtails. The common clinical signs include licking the penis and finding a pus-like discharge dripping from the penis. Most owners of male dogs will see their dogs lick and see a discharge. This is almost a "normal abnormality". Diagnosis of this as a clinical problem depends more on the degree to which licking, discharge and inflammation are present. ((Balanoposthitis))


For "normal" dogs with this condition, exposing the penis and lightly cleaning the area with warm water and a mild soap will suffice. For dogs with a more serious degree of the problem, flushing the prepuce twice daily with chlorhexadine disinfectant, application of medicated ointments and oral antibiotics with or without prednisolone may all be used.



Intersex disease occurs when there is a lack of exact gender definition within a dog, male or female. Two types of intersex disease are recognized in the dog:

HERMAPHRODITISM occurs when one testicle and one ovary are present, along with outward female genitalia.

PSEUDOHERMAPHRODITISIM occurs when gonads (ovaries or testes) of one sex are present while female or ambiguous genitalia appear outwardly. A male pseudohermaphrodite will have testicles and the female equivalent will have ovaries.

True hermaphrodites have chromosomal (genetic) abnormalities and literally are genetically "confused" as to whether they are male or female. Pseudohermaphroditism occurs most commonly due to altered hormonal synthesis or exposure of the pregnant female to drugs containing hormones.

The clinical signs or physical characteristics typical of intersex disorders are highly variable but can include the following: enlargement of the clitoris in the female, abnormal location of genital openings, female dogs exhibiting male behaviors such as leg-lifting, male dogs attracting other male dogs, breast enlargement in males, cryptorchidism, male infertility or female infertility, irregular heat cycles, urinary incontinence and other signs compatible with endocrine abnormalities.

Diagnosis can be difficult but can be made through physical examination, X-rays, ultrasound analysis, biopsy and pathology of gonads, DNA testing and sometimes hormone analysis. Dogs with these conditions can live a normal and comfortable life, but all should be neutered no matter which gonads they have.



To successfully breed, a male dog must produce healthy sperm and be able to deliver that sperm to a female dog. While this may be a very simplistic definition of male reproductive function, this is the ultimate basics of male fertility. Thusly, disease or deformity of the testicles, spermatic ducts, prostate, other sex glands, penis, as well as alterations in hormone levels or other internal diseases can all lead to the inability to sire offspring.

It is then no short or simple issue to determine the cause of an infertile male dog. To compound the problem when breeding has not been successful, which partner is to blame? At first glance, either male or female could be the source of such a problem and thusly, diagnosis must be very "Holmes-like".

To help the doctor narrow the possibilities it will be important to know if this dog has ever sired litters before, if so how many and how many puppies were produced? Does the dog seem able to breed and have there been any illnesses or symptoms that have gone uninvestigated in the last 6 months?

From there, a complete physical examination, blood counts, serum chemistries and endocrine (hormone) levels analyzed, semen analysis, brucellosis testing and even testicular biopsy may be needed. Without a thorough diagnostic work-up, a diagnosis may be very elusive. It should be remembered that the failure to conceive could be a problem with the female dog and not the male.


Firstly, it will be nearly impossible to treat this problem without a proper diagnosis. Secondly, the treatment will vary with the root cause and may include antibiotic therapy, hormonal stimulation and other therapies. Treatment may not be successful, or, depending on cause, certain dogs should not be bred anyway. Neutering is then advised.



HYPOSPADIAS: an unusual urethral opening in the penis, may be surgically corrected.

FRENULUM: a band of tissue which may prevent the penis from movement or erection; treated with surgery.

PARAPHIMOSIS: where the penis remains exposed and does not return to the prepuce, often secondary to trauma. Treatable with medicated ointments, manual replacement or surgery.

PHIMOSIS: where the prepucial opening is too small to allow the penis out. Can be corrected with surgery.

URETHRAL PROLAPSE: a condition where the urethra comes "inside out" at the tip of the penis. May be secondary to infections or stones. Corrected with surgery. ((Urethral Prolapse))

PRIAPISM: constant erection not associated with sexual excitement, often neurological with the only treatment being to keep the penis moist and lubricated.