Penile, testicular and prostatic disease

Question 1

What can you see on this ultrasound image of a testicule vs normal?

Answer 1

Small focal echogenic areas (fibrous tissue or calcification). Consistent with the consequences of a previous testicular insult - testicular degeneration

Question 2

What are 2 categories of mating problems in the stud? Give examples for each

Answer 2

Poor Libido
* Frequently results from inexperience or poor breeding management
* No evidence that it is caused by low plasma testosterone
* Do not give androgens! Would create negative feedback and spermatogenesis would slow.

Mating Difficulty
* Inexperienced stud dog
* Psychological problems
* Abnormal prepuce or penis
* (Inexperienced bitch)
* (Incorrect mating time)
* (Abnormal vulval, vagina)
* (Male-female size differences)

Question 3

What are common testicular/scrotal diseases?

Answer 3

In some sort of order relating to how common:
1. Testicular tumours
1. Abnormal testicular descent
1. Testicular degeneration
1. Torsion of the Spermatic Cord
1. Orchitis
1. Inguinal hernia

Question 4

What are the 3 common types of testicular tumours? What clinical signs are associated? How are they diagnosed? How are they treated?

Answer 4

• Leydig Cell Tumour
• Sertoli Cell Tumour
• Seminoma

Clinical signs
* Oestrogen production = feminisation: preputial swelling
* male attractiveness
* bilaterally symmetrical non-pruritic alopecia
* non-neoplastic testicle atrophies
* normal testicular tissue within abnormal testicle also atrophies

Diagnosis
* Clinical information, palpation, ultrasonography
* Cornification of preputial epithelial cells

Treatment
Hemi-castration or castration

Question 5

How can you differentiate between an anorchid and a monorchid dog?

Answer 5

Anorchid
* Absence of both testes - extremely rare
* Most cases are bilateral cryptorchid
* Diagnosis by lack of response of testosterone to intravenous injection of hCG

Monorchid
* A single testicle in the body - extremely rare
* Most cases are unilateral cryptorchid
* Diagnosis by response of testosterone to intravenous injection of hCG

Question 6

How should you treat cryptochidism?

Answer 6

Medical therapy is not ethical:
* Treatment is by removal of both testes to prevent neoplasia and breeding
* Surgical approach is to look dorsal to bladder for vas deferens then follow these to the testis

Question 7

What can cause testicular degeneration?

Answer 7

• High temperature / Local inflammation
• Vascular lesions
• Drugs
• Endogenous hormones (tumours)
• Exogenous hormones
• Toxins
• Auto-immune disease

Question 8

What are common penile/preputial diseases?

Answer 8

In some sort of order relating to how common:
1. Preputial discharge
1. Lymphoid hyperplasia
1. Balanoposthitis
1. Posthitis
1. Phimosis
1. Paraphimosis
1. Priapism
1. Canine herpes virus infection
1. Penile trauma

Question 9

How should you treat preputial discharge?

Answer 9

• Muco-purulent preputial discharge is normal
• Rarely there is a pre-disposing cause such as foreign body, preputual adhesion, penile abnormality, phimosis
• Careful inspection of the inner surface of the sheath and the penile skin is warranted

Treatment
* May be normal (don’t call it ‘abnormal’ or use antibiotic unless you are sure it is not normal)
* Removal of predisposing causes
* Flushing with saline
* (or antimicrobial or weak antiseptic solutions)
* parenteral drug administration has little value

Question 10

How does lymphoid hyperplasia present in penile disease?

Answer 10

• Raised nodule-like lesions on at the base of the penis, or preputial lining
• Normally pale in colour and firm (not vesicular)
• May bleed when prepuce is retracted or semen collected or at normal mating
• Requires no treatment
• Must be differentiated from Canine Herpes Virus lesions which are normally vesicular and red in colour or may be ulcerated in the later stage

Question 11

What is balanoposthitis? How is it managed?

Answer 11

• Inflammation of the penis (balanitis) and prepucial lining (posthitis)
• Usually associated with moist prepuce tip
• Overgrowth of commensal bacteria
• Commonly seen in dogs that frequently lick the prepuce (therefore common in dogs with a ‘normal’ prepuce discharge)
• May require topical cleaning / local antiseptic / topical antibiotic creams / systemic antibiotics

Question 12

What is balanitis? How is it managed?

Answer 12

• Inflammation of the penis
  
  • (technically balanitis = inflammation the glans penis)
  • (technically phallitis = inflammation of all of the penis)
  • in dogs we only really see balanitis
• Noted as haemorrhagic spots on the penile skin
• May progress to thickening penile skin
• May be associated with masturbation

Question 13

What is phimosis? What signs are associated? How is it managed?

Answer 13

Abnormally small preputial orifice
Congenital or the result of trauma or inflammation

Signs
* narrow stream of urine
* urine pooling within prepuce
* may cause balanoposthitis
* unable to copulate

Preputical wedge resection is normally curative

Question 14

What is paraphimosis? What is it caused by? How is it treated?

Answer 14

Failure of the glans penis to be retracted fully into the prepuce

Causes
* Small preputial orifice
* Inversion of the preputial skin / hair
* Hair ring (tom cat)
* Short prepuce

Penis may become dry and necrotic

Treatment
* Ensure that there is ability to urinate
* According to cause
* Prepucial wedge resection
* Removal of hair
* Preputial advancement
* Penile amputation

Question 15

What can cause poor semen quality? How can you treat dogs with poor semen quality?

Answer 15

• Semen contamination
• Abnormalities of:
  
  • Number
  • Motility
  • Morphology

Treatment
* Often more about establishing prognosis
* May require repeated sampling to establish if values are stable, improving or deteriorating
* Normally done with a gap of 60 days
* Most medical treatments are useless

Question 16

What is azoospermia? What are possible causes?

Answer 16

• Apparently normal ejaculation but contains no sperm so usually clear fluid
• Possible causes
  
  • Not producing sperm - Gonadal dysfunction (either congenital or acquired)
  • Incomplete ejaculation
  • Obstructive azoospermia (obstruction of the vas)

Question 17

What diagnostic techniques are available for the prostate gland? What can you assess with each technique?

Answer 17

• Rectal palpation
  
  • Gland size
  • Pain
  • Moveability
  • Sublumbar lymph nodes
  • Other structures (rectal wall, pelvic wall)
• Ultrasonography
• Semen evaluation
  
  • Useful for assessment of first and third fractions of the ejaculate
  • Colour
  • Cellular content
  • Bacteriology
• Radiography
  
  • positive constrast study by filling bladder - highlight where gland is
• Prostatic massage
  
  • Identification of additional cellular material
• Urine analysis
  
  • Common sequelae is lower urinary tract infection which needs treatment
• Prostatic aspiration
  
  • Fine needle aspiration either by palpation or by ultrasound guidance
• Prostatic biopsy
• Haematology
• Blood culture

Question 18

What are common prostate diseases?

Answer 18

• benign prostatic hyperplasia
• acute bacterial prostatitis
• chronic bacterial prostatitis
• prostatic abscessation
• prostatic cysts
• prostatic neoplasia

Question 19

What are the causes and consequences of benign prostatic hyperplasia? How is it diagnosed? How is it treated?

Answer 19

Hyperplasia of the prostatic epithelium begins early in life associated with altered androgen/oestrogen ratios

In later life the enlarged gland impinges on the pelvic viscera
* faecal tenesmus
* haematuria
* haemospermia

Diagnosis
* Rectal palpation; symmetrical, freely mobile, non-painful
* Radiography; prostatomegaly, dorsal displacement of colon, cranial displacement of bladder, narrowed prostatic urethra, urinary retention
* Ultrasonography; prostatomegaly, hyperechoic regions, narrowed prostatic urethra, small cystic lesions
* Prostatic massage; poor harvest of cells, normal prostatic epithelial cells (few)
* Semen evaluation; normal except haemospermia
* Prostatic aspiration; normal prostatic epithelial cells

Treatment
* Castration
* Progestogens (e.g. osaterone [Ypozane],
* GnRH depot agonist (deslorelin [Suprelorin]
* Finasteride (human medicinal POM)
* A specific 5-alpha reductase inhibitor which prevents the conversion of testosterone into dihydrotestosterone (marketed as Proscar)
* Can be used under cascade

Question 20

What causes acute bacterial prostatitis? What clinical signs are associated? How is it diagnosed? How is it treated?

Answer 20

Ascending infection commonly E. coli.

Clinical signs include systemic illness, with vomiting and caudal abdominal pain

Diagnosis
* Rectal palpation; asymmetrical, moveable associated with great pain
* Radiography; normal size or marginally increased, loss of detail in caudal abdomen indicating local peritonitis
* Ultrasonography; large, hypoechochoic / marbled, sub-capsular oedema
* Prostatic massage; painful
* Semen evaluation; usually not capable of producing an ejaculate
* Urinalysis; often many bacteria present

Treatment
* 3-4 week duration antibiotic therapy
* Blood/prostatic fluid barrier not intact therefore good antibiotic penetration
* Urinalysis and examination of prostatic fluid to ensure that does not become chronic infection
* Castration

Question 21

When does chronic bacterial prostatitis occur?

Answer 21

• Acute lesions may become chronic, and pockets of purrulent exudate form
• Often in the form of micro-abscesses and diffuse inflammation (May later lead to prostatic abscessation)
• Signs are often recurrent cystitis

Question 22

What causes prostatic abscessation? What clinical signs are associated?

Answer 22

• Chronic prostatitis where purulent exudate accumulates in the parenchyma of the gland
• Clinical signs variable but can be similar to:
  
  • Acute bacterial prostatitis although less fulminating
  • Or, progress to exaggerated signs of chronic prostatitis

Question 23

What are the 2 types of prostatic cysts? How are they treated?

Answer 23

Parenchymal retention cysts
* Start within the parenchyma of the prostate, causing distortion of its outline
* Usually there is an underlying prostatic disease (BPH or metaplasia (Sertoli cell tumour)

Cystic uterus masculinus
- Originate adjacent to the prostate gland but attached by a thin stalk

Treatment
* Castration
* Surgical excision
* + Omentalisation

Question 24

What is the most common type of prostatic neoplasia? How is it diagnosed? How is it treated?

Answer 24

• Adenocarcinoma are most common
• Tend to metastasise to iliac and sub-lumbar lymph nodes, and to caudal lumbar vertebrae
• Castration not protective

Diagnosis
* Rectal palpation; usually large and painful, may be sub-lumbar swelling
* Radiography; prostatomegaly, sub-lumbar swelling, vertebral involvement
* Filling defect to prostatic urethra
* Reactive changes associated with sub-lumbar lymphadenopathy
* Ultrasonography; disruption of normal architecture, areas of increased echogenicity, areas of fluid accumulation
* May be iliac lymph node involvement

Treatment
* Palliative hormonal treatments
* GnRH Depot Agonist
* Progestogens
* NSAID’s
* (Intra-operative radiation treatment)
* (Prostatectomy)