16.8.4: Penile, testicular and prostatic disease

Question 1

What are the 3 common testicular tumour types?

Answer 1

• Leydig cell tumour - these are often endocrinologically active
• Sertoli cell tumour
• Seminoma

Question 2

Clinical signs of testicular tumours

Answer 2

• Oestrogen production -> feminisation
• Preputial swelling
• Male attractiveness
• Bilaterally symmetrical non-pruritic alopecia
• Non-neoplastic testicle atrophies
• Normal testicular tissue within the abnormal testicle also atrophies

Question 3

True/false: androgens are an effective way of increasing libido in a reluctant stud dog.

Answer 3

False
Androgens will have a negative feedback effect and cause testicular atrophy

Question 4

What are the most common causes of poor libido in a stud dog?
a) Inexperience/poor breeding management
b) Low plasma testosterone
c) Cryptorchid

Answer 4

a) Inexperience/poor breeding management
No evidence that poor libido is caused by low plasma testosterone.

Question 5

This is a testibular ultrasound. What abnormal finding can be seen?

Answer 5

Sertoli cell tumour

Question 6

What testicular pathology is shown here and what might have caused this?

Answer 6

Testicular degeneration
* The testis develops normally, but after an insult, fibrosis and degeneration occur.
* Semen quality deteriorates over several months
* Common insults: high temperature, vascular lesions, drugs, endogenous hormones (tumours), exogenous hormones, toxins, autoimmune disease e.g. autoimmune orchitis in spaniels and labs

Question 7

Preputial discharge is:
a) common in entire dogs, may be normal, but could occasionally find a cause e.g. FB, preputial adhesion, penile abnormality, phimosis
b) common in neutered dogs, may be normal, but could occasionally find a cause as above
c) abnormal in both entire and neutered dogs

Answer 7

a) common in entire dogs, may be normal, but could occasionally find a cause e.g. FB, preputial adhesion, penile abnormality, phimosis

Question 8

Answer 8

Lymphoid hyperplasia
There are raised, nodular-like lesions on/at the base of the penis or preputial lining
These are normally pale in colour and firm rather than vesicular
There may be bleeding when the prepuce is retracted/semen collected/at mating

Question 9

What must this be differentiated from and what treatment does it require?

Answer 9

This is lymphoid hyperplasia
* This does not require treatment
* It must be differentiated from canine herpes virus which would be darker/more vesicular - if concerned, send swab for PCR

Question 10

Answer 10

Balanoposthitis: inflammation of the penis and prepucial lining
* Usually associated with moist prepuce tip; seen in dogs that lick frequently
* There is overgrowth of commensal bacteria
* May require topical cleaning/local antiseptic/topical antibiotic creams/systemic antibiotics

Question 11

Answer 11

Balanitis: inflammation of the glans penis
* There are haemorrhagic spots on the penile skin-> may progress to thickening of this skin
* May be associated with masturbation e.g. dog rubbing self on carpets, causing trauma
* Treatment: neuter/GnRH depot agonist to remove sexual drive. May be learned behaviour

Question 12

Answer 12

Phimosis: abnormally small preputial orifice
* May be congenital or result of trauma/inflammation
* Signs: narrow stream of urine, urine pooling within prepuce, unable to copulate
* May cause balanoposthitis
* Treatment: preputial wedge resection = normally curative

Question 13

Answer 13

Paraphimosis: failure of the glans penis to be fully retracted into the prepuce.
* Causes: small preputial orifice, inversion of preputial skin/hair, hair ring (esp tom cats), short prepuce
* Penis may become dry and necrotic

Question 14

Treatment of paraphimosis

Answer 14

• Ensure there is ability to urinate
• Address underlying cause e.g. preputial wedge resection/removal of hair/ preputial advancement/ penile amputation

Question 15

What might make a semen sample poor quality?

Answer 15

• Semen contamination
• Abnormalities of number/motility/morphology of sperm

Question 16

Azoospermia

Answer 16

Apparently normal ejaculation but no sperm.
Causes:
* Incomplete ejaculation
* Obstructive azoospermia = obstruction of vas deferens
* Gonadal dysfunction (may be congenital or acquired)

Question 17

You suspect a dog to have azoospermia and want to take repeat samples to assess semen quality. How far apart will you take your samples?
a) 6 mins
b) 6 hours
c) 60 days
d) 90 days

Answer 17

c) 60 days
This allows for 2 spermatogenic and epididymal cycles

Question 18

What diagnostic techniques can be used to assess the prostate?

Answer 18

• Rectal palpation: assess size, pain, moveability, sublumbar LNs, rectal and pelvic wall
• Radiography
• Ultrasonography
• Prostatic massage and semen evaluation
• Urinalysis
• Prostatic aspiration
• (If chronic disease/suspicious of neoplasia: prostatic biopsy, haematology, blood culture)

Question 19

What is the most common prostatic disease seen in dogs and what are the clinical signs?

Answer 19

Benign prostatic hyperplasia
Clinical signs
* Faecal tenesmus
* Haematuria
* Haemospermia (earliest sign = blood in ejaculate)

Question 20

Signalment for benign prostatic hyperplasia

Answer 20

Older entire male animals

Question 21

Rectal palpation findings for benign prostatic hyperplasia

Answer 21

• Symmetrical, freely movile, non-painful enlargement

Question 22

Radiographic findings with benign prostatic hyperplasia

Answer 22

• Prostatomegaly
• Dorsal displacemet of the colon
• Cranial displacement of the bladder
• Narrowed prostatic urethra
• Urinary retention

Question 23

Ultrasonographical findings with benign prostatic hyperplasia

Answer 23

• Prostatomegaly
• Hyperechoic regions
• Narrowed prostatic urethra
• Small cystic lesions

Question 24

Cytological findings with benign prostatic hyperplasia

Answer 24

• Prostatic massage produces a poor harvest of cells; may see a few normal prostatic epithelial cells
• Semen evaluation: normal except haemospermia
• Prostatic aspiration: normal prostatic epithelial cells

Question 25

Treatment of benign prostatic hyperplasia

Answer 25

Options:
* Castration
* Progestogens e.g. osaterone
* GnRH depot agonist e.g. deslorelin
* Finastride: a specific 5-alpha reductase inhibitor which prevents the conversion of testosterone into dihydrotestosterone - human drug used for baldness, useful in stud dogs as it stops testosterone from stimulating the prostatic gand but does not compromise semen quality