24. Reproductive Disorders

CHAPTER 24. Reproductive Disorders

Patricia A. Schenck




PROSTATE GLAND DISORDERS






I. Clinical signs




A. Clinical signs are varied. Systemic signs include depression, anorexia, and vomiting. Hematuria or blood dripping from the prepuce are the most common clinical signs


B. Other clinical signs include urethral discharge, stranguria, fecal tenesmus, diarrhea, recurrent urinary tract infection, abdominal distension, caudal abdominal pain, lumbar pain, hindlimb stiffness, hypertrophic osteopathy, hindlimb pitting edema, urinary incontinence, infertility, impaired libido, perineal tumor, sepsis, or testicular tumor


II. Physical examination




A. Rectal examination is essential. Palpate ventrally for the prostate and dorsally for lymph nodes


B. Evaluate the prostate gland for size, location, symmetry, pain. Normally the prostate is symmetric, bi-lobed, within the pelvis, moveable, and not painful. As the prostate enlarges, it may move cranially; thus, concurrent abdominal palpation is sometimes useful


C. Abdominal palpation may reveal the presence of a mass, distension, or pain


III. Diagnostic tests




A. Laboratory findings




1. Neutrophilic leukocytosis is often associated with bacterial prostatitis. Increased alkaline phosphatase (ALP) may accompany bacterial prostatitis or neoplasia


2. Urine sediment examination or culture may be negative in dogs with bacterial prostatitis or abscess


3. Prostatic fluid cytology or culture is necessary for diagnosis of bacterial prostatitis


B. Imaging




1. Abdominal radiography may reveal associated disorders such as prostate enlargement or asymmetry, mineralization, lymph node enlargement, bone periosteal reactions, urine or fecal retention


2. Iliac lymph node enlargement and prostate mineralization are often associated with prostatic neoplasia


3. Ultrasound examination may evaluate prostate size and location and help to obtain biopsy specimens


C. Specimen collection




1. Ejaculate specimen




a. The dog should be handled in a quiet environment, and exposure to a female in estrus may be helpful


b. Advantages are that this technique is safe, inexpensive, easy to perform, and gives specimens for bacterial culture


c. Disadvantages are that this specimen is not useful for cytology, a positive bacterial culture does not localize the disease, and the animal must be compliant


2. Prostatic wash specimens are useful for microbiology and cytology




a. Urine or urethral contamination may occur, and if there is concurrent bacterial cystitis, microbiology results cannot be interpreted


b. Rectal massage may not reach the prostate and can rupture a prostatic abscess


3. Urethral brush specimen




a. Advantages include localization, urethral contamination is minimized, and useful cytologic and microbiologic information is obtained


b. However, the specimen brush cannot be reused, so the technique is expensive, the prostate gland may not be reached for effective rectal massage, and vigorous massage may rupture an abscess


4. Ultrasound-guided prostatic aspirate uses ultrasound to guide the insertion of a needle into the prostate gland




a. Advantages are that it localizes the source of bacterial infection and is relatively safe


b. Disadvantages are that sedation and anesthesia are usually necessary, specialized equipment and skill is required, and aspiration of an abscess or tumor can lead to peritonitis or seeding the abdomen with neoplastic cells


5. Prostate gland biopsy




a. Evaluate coagulation status


b. Approaches include transperineal, transabdominal, laparotomy, laparoscopy


c. Sedation or anesthesia is necessary


d. If ultrasound is not available, biopsy through laparotomy is the most accurate technique






A. Benign prostatic hyperplasia (BPH)




1. BPH is the most common prostate disorder


2. Dihydrotestosterone is the main androgen promoting hyperplasia


3. Castration is an effective treatment


4. Megestrol acetate or finasteride can be used in breeding dogs without a loss of fertility


5. Estrogens should not be used


6. Delmadinone acetate, an androgen inhibitor, can be used but is contraindicated for breeding dogs


B. Cystic hyperplasia




1. Multiple fluid-filled cysts result from obstruction of glandular excretory ducts


2. Usually associated with BPH and squamous metaplasia


C. Squamous metaplasia




1. Caused by estrogen stimulation either from an exogenous source or a Sertoli cell tumor


2. Castration is the treatment of choice. Discontinue any exogenous source of estrogen


D. Prostatic infection




1. Infection is usually ascending, and causes are prostatic hyperplasia or cysts, urinary tract infections, altered urine flow, urethral abnormalities, or immune dysfunction


2. Escherichia coli, Staphylococcus, Proteus mirabilis, Streptococcus, and Mycoplasma are the most common causes


3. Fungal organisms such as Blastomyces, Cryptococcus, or Coccidioides can also cause prostatitis


4. Antibiotics for treatment should be lipid soluble to penetrate the prostate. Most effective antibiotics include trimethoprim-sulfa, clindamycin, enrofloxacin, erythromycin, chloramphenicol, and oleandomycin. Antibiotics should be given for a minimum of 4 weeks


5. A good initial treatment choice is trimethoprim-sulfa, enrofloxacin, or chloramphenicol


6. Evaluate patient for septicemia or peritonitis


7. Castration decreases the potential for recurrence but should not be performed until the patient has been receiving antibiotics for a few weeks


E. Idiopathic prostatitis




1. Cause is unknown, but the signs are similar to those of bacterial prostatitis


2. Castration is probably beneficial. Antibiotics, corticosteroids, anticholinergics, and muscle relaxants have been used


F. Paraprostatic cysts




1. Paraprostatic cysts are adjacent to the prostate gland and result from fluid accumulation in embryologic remnants


2. Surgery is recommended. Antibiotics may also be needed if there is septicemia or peritonitis


G. Prostatic abscesses




1. Abscesses occur as a sequel to infection with obstruction of excretory ducts or as secondarily infected cysts


2. Surgery is recommended. Antibiotics may also be needed if there is septicemia or peritonitis


H. Prostatic neoplasia




1. Adenocarcinoma and transitional cell carcinoma are most common


2. Castration does not prevent the development of prostatic tumors


3. Metastasis to lymph nodes, bones, and organs is common


4. Intraoperative radiation therapy is the treatment of choice but is not recommended if metastases are present


5. Prostatectomy is associated with complications including urinary incontinence and urethral stricture


6. Castration is of questionable benefit, and chemotherapy is not effective


7. Total androgen blockade with luteinizing hormone (LH)–releasing hormone, or ketoconazole has benefit by blocking androgen synthesis


V. Surgical highlights




A. The hypogastric and pelvic nerves are closely associated with the vasculature and are necessary for micturition and continence. Avoid damage to these nerves during any surgical procedure


B. The prostate gland encompasses the male urethra at the neck of the urinary bladder


C. The prostate is found in the pelvic cavity until about 4 years of age and is entirely within the abdomen by about 10 years of age


D. Surgical procedures require a ventral midline incision


E. Urinary incontinence is common with total prostatectomy


F. If prostatectomy is performed because of prostatic neoplasia, metastasis is common to the median iliac lymph nodes, periprostatic tissue, urinary bladder, pelvic structures, and lung


DISORDERS OF THE TESTES






I. Clinical signs




A. Infertility is common. There may be no clinical signs


B. Pain and inflammation may be caused by infection, trauma, torsion, or immune-mediated disease. Swelling or a stiff gait may be noted, and licking of the scrotum may be observed


C. Feminization may result from Sertoli cell tumors


II. Physical examination




A. Two equal-sized and shaped testicles should be palpable in the scrotum. Testicular size can vary with breed and individuals


B. Cryptorchidism is diagnosed on physical examination. Undescended testicles may often be found lateral to the prepuce or in the inguinal area


C. An enlargement of one testicle suggests neoplasia, granuloma, spermatocele, varicocele, inflammation, or torsion


III. Diagnostic tests




A. Laboratory tests aid in the diagnosis of inflammatory diseases, infectious diseases, neoplasia, and infertility



C. Imaging: Ultrasound evaluation can detect undescended testicles or tumors


D. Semen evaluation




1. Collection of semen




a. Semen collection is relatively easy in the dog but difficult in the cat


b. Retract the prepuce caudally and manually stimulate the penis. Collect semen using an artificial vagina or into a sterile cup


c. There are three fractions to a canine ejaculate




(1) First: Small volume or clear prostatic fluid


(2) Second: Milky white sperm-rich fluid (0.5 to 5 mL)


(3) Third: Large volume of clear prostatic fluid


d. Do not collect semen from an animal with obvious inflammation of the testes


2. Color, consistency, and cytology




a. Presence of blood may indicate a traumatic collection or prostatic disease


b. A nonopaque second fraction indicates oligospermia, and flecks of discolored debris are consistent with purulent material


c. An air-dried slide of semen can be stained. Inflammatory cells or organisms may be identified


3. Sperm count




a. Use of hemocytometer to determine the number of sperm per milliliter of ejaculate. Multiply by the volume of the ejaculate to determine total sperm count


b. A normal ejaculate contains more than 200 million sperm cells


4. Motility and morphology




a. Evaluate a drop of ejaculate placed on a warm microscope slide; 70% of sperm should be motile


b. Morphologic abnormalities should not be present in greater than 20% of sperm


c. Primary abnormalities include cytoplasmic droplets, thickened midpiece, or misshaped heads. Distal cytoplasmic droplets may indicate epididymal disease


d. Secondary abnormalities such as coiled or bent tails or detached heads occur in the epididymis and distally


5. Semen ALP




a. Epididymis produces ALP, and a low activity in semen indicates the absence of epididymal fluid


b. Azoospermia can result from blockage of the epididymis. Normal semen ALP is above 4000 international units per liter


6. Semen culture




a. To diagnose infectious orchitis-epidiymitis, use either semen sample or testicular fine-needle aspirate


b. Contamination from the urogenital tract can occur


c. With infection, there should be more than 10 5 colony-forming units/mL. Chronic infections can yield negative cultures


E. Fine-needle aspiration and biopsy




1. Can reveal organisms, inflammatory cells, neoplasia, sperm. Chronic inflammation makes collection of fine-needle aspirates difficult


2. Biopsy is indicated to investigate azoospermia if no other cause is found. Orchitis is an uncommon complication


F. Testicular feminization syndrome. Demonstrate bilateral testes, XY chromosomal status, and positive response to human chorionic gonadotropin



V. Acquired disorders of the testes




A. Infectious orchitis-epididymitis




1. Can arise from trauma, hematogenous spread, urinary tract, or prostate


2. Aerobic bacteria are the most common. Brucella canis is also an important cause. Mycoplasma, Blastomyces, canine distemper virus, feline infectious peritonitis, and rickettsial infections may also occur


3. Castration and antibiotic therapy are curative


4. Brucellosis is not always eradicated even if long-term antibiotic therapy is used. These dogs should be castrated


B. Immune-mediated orchitis: An immune response to spermatozoal antigens occurs when the blood-testis barrier is broken. Orchitis results with lymphocytic infiltration of the testes


C. Testicular neoplasia




1. Common in dogs; uncommon in cats. More common in cryptorchid dogs


2. Primary tumors include Sertoli cell, interstitial cell tumors, and seminoma. They are typically slow to metastasize and are usually an incidental finding in older dogs


3. Sertoli cell tumors can cause feminization, including hair loss, testicular atrophy, and squamous metaplasia of the prostate


4. Castration is the treatment of choice


D. Trauma can lead to inflammation or ischemia


E. Testicular torsion




1. Can occur in descended or undescended testes


2. There is an acute onset of pain with swelling of the testicle and spermatic cord


3. Castration is the treatment of choice


F. Secondary testicular disorders occur secondary to endocrine diseases such as hypothyroidism, diabetes mellitus, and hyperadrenocorticism


G. Other testicular diseases




1. Spermatocele is a dilation of the duct system that contains sperm. It is usually benign


2. Varicocele is a dilation of the spermatic vein. It can be benign but may thrombose


3. Sperm granuloma develops when sperm cells accumulate in the spermatic ducts

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Apr 6, 2017 | Posted by in GENERAL | Comments Off on 24. Reproductive Disorders

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