16.8.4: Penile, testicular and prostatic disease Flashcards
What are the 3 common testicular tumour types?
- Leydig cell tumour - these are often endocrinologically active
- Sertoli cell tumour
- Seminoma
Clinical signs of testicular tumours
- 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
True/false: androgens are an effective way of increasing libido in a reluctant stud dog.
False
Androgens will have a negative feedback effect and cause testicular atrophy
What are the most common causes of poor libido in a stud dog?
a) Inexperience/poor breeding management
b) Low plasma testosterone
c) Cryptorchid
a) Inexperience/poor breeding management
No evidence that poor libido is caused by low plasma testosterone.
This is a testibular ultrasound. What abnormal finding can be seen?
Sertoli cell tumour
What testicular pathology is shown here and what might have caused this?
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
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
a) common in entire dogs, may be normal, but could occasionally find a cause e.g. FB, preputial adhesion, penile abnormality, phimosis
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
What must this be differentiated from and what treatment does it require?
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
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
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
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
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
Treatment of paraphimosis
- Ensure there is ability to urinate
- Address underlying cause e.g. preputial wedge resection/removal of hair/ preputial advancement/ penile amputation
What might make a semen sample poor quality?
- Semen contamination
- Abnormalities of number/motility/morphology of sperm
Azoospermia
Apparently normal ejaculation but no sperm.
Causes:
* Incomplete ejaculation
* Obstructive azoospermia = obstruction of vas deferens
* Gonadal dysfunction (may be congenital or acquired)
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
c) 60 days
This allows for 2 spermatogenic and epididymal cycles
What diagnostic techniques can be used to assess the prostate?
- 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)
What is the most common prostatic disease seen in dogs and what are the clinical signs?
Benign prostatic hyperplasia
Clinical signs
* Faecal tenesmus
* Haematuria
* Haemospermia (earliest sign = blood in ejaculate)
Signalment for benign prostatic hyperplasia
Older entire male animals
Rectal palpation findings for benign prostatic hyperplasia
- Symmetrical, freely movile, non-painful enlargement
Radiographic findings with benign prostatic hyperplasia
- Prostatomegaly
- Dorsal displacemet of the colon
- Cranial displacement of the bladder
- Narrowed prostatic urethra
- Urinary retention
Ultrasonographical findings with benign prostatic hyperplasia
- Prostatomegaly
- Hyperechoic regions
- Narrowed prostatic urethra
- Small cystic lesions
Cytological findings with benign prostatic hyperplasia
- 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
Treatment of benign prostatic hyperplasia
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
