Lecture 22: Reproductive 1 Flashcards
What are the 3 phases of development?
- determine sec chromosomes
- either XX or XY - establish a gonadal type
- early in embryo = bipotent gonad
- if XY the SRY region on the Y chromosome is the testis determining factor - establish tubular and external genitalia
- paired mesonephric ducts
- paramesonephric ducts
Explain how tubular and external genitalia form in males
Wolffian development: male
- paired blind ended mesonephric ducts form
anti-mullarian hormone is secreted from sertoli cells causing regression of paramesonephric ducts - testosterone is secreted from interstitial cells causing development of epididymus, deferent duct, vesicular glands, and ampulla
- the urogenital sinus and tuberacle form the prostate, bulbourethral gland, scrotum, and penis
Explain how tubular and external genitalia form in females
Mullarian development: female
- paramesonephric ducts open into the coelomic cavity
- mesonephric tubules for the rete ovarii
- mesonephric ducts regress
- paramesonephric ducts form the uterine horns, uterine tube, uterine body, cervix, and cranial vagina
- urogenital sinus and tuberacle forms the caudal vagina, vestibule, vulva, and clitoris
Define what ‘disorders of sexual development’ are. What are 2 alternate names and their respective meanings?
DSD = congenital abnormalities of the reproductive tract
- can be either minor or major
aka
true hermaphrodite: both ovaries and testes
pseudohermaphrodite: either ovaries or testes
- do not match the sex of the other parts of the repro tract (ex. external characteristics)
List 3 types of DSD
- chromosomal
- XX
- XY
Explain what chromosomal DSD’s are?
they are an abnormal number of chromosomes
rare
either X_ or XXY
Do male calico cats have a DSD? If so, what is it. What about female calicos?
yes
calico coat colour is an X linked trait
- inactivation of one X in females causes the mixed colour pattern
It can occur in males that are XXY
Explain the DSD affecting freemartin cattle. How does that manifest and why?
Freemartin cattle: male and female twins in which the placental vessels anastomose causing exchange of blood and hematopoeitic tissue
They both become chimeras
- no/low impact on males
Females:
- inhibit ovarian growth and favour testes development = infertile
- ovotestes development due to exposure to testes determining factor from male twin
- small hypoplastic gonads and uterine horns due to anti-mullarian hormone exposure
- vesicular glands due to testosterone exposure
- vagina may not be patent due to impaired urogenital sinus development due to testosterone
= phenotypically female (vagina +/- patent) with prominent clitoris and hair tuft
Explain what XX DSD’s are
the majority are ‘normal’ (external genitalia and chromosome) female
Explain what XY DSD’s are
the majority are ‘normal’ (sry and chromosome) male
Provide an example of a XX DSD
segmental aplasia
- no development of a segment of internal structures (uterine body/horns)
Provide 2 examples of XY DSD
cryptorchidism
testicular aplasia
List the main anatomic parts of the male reproductive tract (non-penile structures)
scrotum > testes > epididymus (head/body/tail)
spermatic cord
-creemaster muscle
- pampiniform plexus
- deferent duct
vaginal tunic
- outpouching of peritoneum
temperature dependent function
- should be 2-3C below body temp
- changes can cause testes atrophy and degeneration
What are the 4 portals of entry of pathogens to the male reproductive tract. Provide examples.
blood (brucella)
ascending infection from prepuce
direct (bite)
peritoneum (FIP/neoplasia)
What is the blood testes barrier? How is it maintained? Why is it important?
the sertoli cells form barrier in seminiferous tubules
immuno-protected area
- if contents escape = foreign body reaction/inflammation
- granulomatous reaction = spermatic granuloma
What are 3 causes of ‘too small’ testes in an otherwise normal male
cryptorchidism
testicular hypoplasia
testes atrophy and degeneration
What is cryptorchidism? How does it usually present?
incomplete descent of testes related to an autosomal recessive trait
common
the testes can be found anywhere along/close to the inguinal canal
- usually unilateral (the side can be species dependent
retained testes = hypoplastic
Why is cryptorchidism a problem?
It can increase neoplasia risk (even in the contralateral testes)
can cause torsion
- common
- especially if neoplasia present
What is testicular hypoplasia
congenial
reduced development of testes
common either uni or bilateral
can be concurrent with conditions like cryptorchidism
What is testes atrophy and degeneration
Reduction in testes size after puberty/development
common either uni or bilateral
due to many causes
- age
- toxin
-obstruction
- neoplasia
- fever/local inflammation
- hormonal
- trauma
apoptosis of germ cells
How to differentiate testicular hypoplasia from atrophy and degeneration?
must use the history and any change of size to differentiate
cannot differentiate visually
both =
- small/soft/flabby/yellow
- no bulge when cute
- will become firm and mineralized over time
List 4 causes of testes being ‘too big’
spermatic granuloma
epididymitis
orchitis
testicular neoplasia
What is a spermatic granuloma? How does it form? How does it present clinically?
ruptured seminiferous tubules cause a spermatozoa leak = chronic inflammation and fibrosis resulting in obstruction and sperm stasis
- positive feedback loop
in epididymal head = congenital
in epididymal tail = secondary to epididymitis
results in a caseus-abcess granuloma and infertility
What apecies are most affected by epididymitis
rams and dogs
What is epididymitis? What are the main causes? How does it present?
inflammation of epididymus (can be concurrant with orchitis)
mainly bacterial cause
- usually affecting the tail because it is closer to the environment
can cause spermatic granuloma due to obstruction and vessel leakage
What are the common bacterial types that cause epididymitis
hematogenous
- brucella canis or ovis
ascending infection
- actinobacillus seminis
- histophilus somni in ram
- E. coli in dog
What is orchitis
inflammation of testes
less common than epididymitis
can be necrotizing
Why is brucella important?
reportable in canada
zoonotic
only found in northern canada in wild animals (bison/caribou)
How does one get orchitis? What bacteria typically cause it?
hematogenous
- brucella abortus = bull
- B. suis = boar
- B. canis = dog
How are testicular neoplasias typically differentiated?
gross appearance
either single or multiple
What are the common testicular neoplasms in dogs in ascending order of prevalence
- interstitial
- seminoma
- sertoli
What a common testicular neoplasm affecting horses
seminomas
What are 4 types of testicular neoplasms
interstitial/leydig cell tumor
seminoma
sertoli cell tumor
teratoma
What are the gross features of interstitial cell tumors?
spherical
well demarcated
soft
tan-orange with some hemorrhage and necrosis
Are interstitial cell tumors associated with cryptorchidism?
no
What species are most affected by interstitial cell tumors
1 testicular neoplasia in bulls, dogs, and cats
What are the gross features of seminomas
homogenous
white-pink
soft
bulge when cut
What is the relationship between seminomas and cryptochidism
they are related
What species are seminomas most common in
1 testicular neoplasia in stallions
- # 2 in dogs
What is the gross appearance of sertoli cell tumors
well demarcated
multilobar
tan-white
firm
What is the relationship between sertoli cell tumors and cryptorchidism
1/3 of these tumors are found in cryptorchid testes
= associated
What species are sertoli cell tumors most common in
3 testicular neoplasia of dogs
What are the clinical signs of an animal with a sertoli cell tumor? Why?
feminization and hyperestrogenism
alopecia
attraction of males
bone marrow suppression
pendulous prepuce
gynecomastia (mammary gland enlargement)
prostatic hyperplasia and squamous metaplasia
pancytopenia:
non-regenerative anemia
thrombocytopenia
neutropenia
because these tumors are hormonally active
but metastasis is rare (usually benign)
What type of tumor (benign or malignant) are testicular neoplasms
mainly benign
- metastasis is rare
What causes prostatic hyperplasia and what animals does it mainly occur in?
age related
hormone related
mainly intact males
- castration result in atrophy
What are the clinical signs and gross appearance of prostatic hyperplasia
clinically: constipation and tenesmus
gross: bilaterally symmetrically enlarged
- +/- cyst
- non-painful
What causes prostatitis?
bacteria
blood: brucella
ascending infection: E. coli or Proteus vulgaris
What are the clinical signs and gross appearance of prostatitis
clinically:
- toxemia
- signs of UTI (difficulty urinating, blood and/or pus in urine)
- can have concurrant prostatic hyperplasia or squamous metaplasia (more common if intact)
gross
- asymmetrical enlargement
- painful
- can become chronic and from abcess
What is the main neoplasm affecting the prostate?
carcinoma of the prostate
What is the cause of carcinomas of the prostate?
unknown
neutering is not protective
What are the clinical signs and gross appearance of carcinomas of the prostate?
clinically
- cachexia
- mobility problems (metastasize to spine/plexus)
- urethral obstruction
gross
either
- enlarged, irregular and non painful
or
- not enlarged and causing urinary obstruction
What is the prognosis of carcinomas the of the prostate
poor
metastasis common
What is vesicular adenitis? What animals does it mainly affect?
young bulls in their 1st season
it is a chronic bacterial infection of vesicular glands
What are the clinical signs and gross appearance of vesicular adenitis
clinically
- reduced fertility due to increased inflammation causing reduced survival of sperm in freezing conditions
gross
- enlarged
- firm/fibrotic
- reduced lobation
Define phalitis
penis inflammation
Define balanitis
inflammation of penis head
Define posthitis
inflammation of the prepuce
List 3 types of inflammatory diseases affecting the penis/prepuce
asymptomatic
genital herpes
pizzle rot/ovine posthitis
What are 2 causes for asymptomatic inflammatory disease of the penis/prepuce?
Tritrichomonas fetus
Campylobacter fetus supsepcies venerealis
What animals are mainly affected by asymptomatic inflammatory disease of the penis/prepuce? What is the consequence of disease?
bulls are carriers
cause abortion/embryonic loss/infertility
What does genital herpes cause clinically?
balanoposthitis
What animals does genital herpes affect?
many
cows
- abortion
- BHV1
horses: EHV3
What is ovine posthitis? How is it caused?
wethers
corynebacterium renale produces urease
- when eating a high protein diet there is more urea in the urine
- C. renale converts it to ammonia
- chemical ulceration of prepuce
- inflammation/swelling
- urethral obstruction
+/- death
What are 3 types of neoplasms that affect the penis/prepuce?
penile squamous cell carcinoma
penile fibrosarcoma
canine transmissible venereal tumor
What animals are most affected by penile squamous cell carcinoma? What causes it?
horses
causes:
- exposure to UV
- equine papillomavirus 2
What is the behaviour and clinical picture of penile squamous cell carcinoma
It is locally infiltrative and agressive = hard to remove
metastasizes to regional lymph nodes
it is the top differential for an ulcerated and exophytic mass on the penis
What animals are commonly affected by penile fibrosarcomas? What causes it?
young bulls
cause: bovine papillomavirus 1
What are the gross features of penile fibrosarcoma?
multiple
large
grey/white
exophytic
hyperplastic epithelium surrounded by fibrous tissue core
What is the prognosis for penile fibrosarcoma?
usually benign but can cause pain during breeding or urination
What is canine transmissible venereal tumor? What causes it?
It is transmitted directly between dogs during sexual contact
tumor of canine histiocytes
- form primary neoplasm of external genitalia and face (when contact genitalia)
What is the prognosis of canine transmissible venereal tumor
it will spontaneously regress
it can metastasize if in poor health
