Reproductive Failure:
Anatomy & Physiology
Animal
Breeding
Pensacola
Jr College
Common Aspects of Reproductive Failure
w Development
problems
w Reproductive
tract injuries
w Cysts
w No
cycling
w Disease
(next lecture)
Development Problems
w Freemartin
w Infantile
reproductive system
w Incomplete
or blocked structures
w Hermaphroditism
w Cryptorchidism
1. Freemartin
w The
female of male-female twins (esp. in cattle)
Embryonic membranes of twins
fuse before reproductive organs develop
Cell mixing brings some Y
chromosomes into female
Oviducts, uterus, and cervix
do not form correctly
Always sterile
Cause of Freemartin
2. Infantile reproductive system
w Failure
to develop to maturity
w Most
often seen in underfed female animals
w Generally
reversible
3. Incomplete or blocked structures
w In
females: permanent defects in oviducts, uterus, cervix, or vagina (still cycle)
w In
males: permanent defects in vas deferens or urethra
w Genetic
cause (inbreeding)
w Usually
sterile
4. Hermaphroditism
w Presence
of anatomical structures of both sexes
w True
hermaphrodite:
Has both male & female
gonads (separate or as ovotestes)
Genetic defect (XXY or XO)
4. Hermaphroditism (contd)
w Pseudohermaphrodite
Has either testes or ovaries
(determines sex classification)
Has combination of other male
and female reproductive tract structures
Caused by hormone or enzyme
deficiencies
Ovotestis
in true hermaphrodite
w Pseudo-hermaphrodite
w male cat
Male dog pseudohermaphrodite
5. Cryptorchidism
w Testes
fail to descend into scrotum through inguinal canal
w Genetic
defect
w Unilateral
cryptorchid
only
one testis descends, reduced fertility
w Bilateral
cryptorchid
Neither testis descends,
sterile
Cryptorchid
dog tumor (top)
Reproductive Tract Injuries
w Uterine
or vaginal tears
w Prolapsed
uterus
w Broken
penis
1. Uterine or Vaginal Tears
w Usually
occurs during either assisted delivery or manual removal of retained placenta
w Small
tears in normal delivery do not usually block reproduction
w May
require surgical correction
2. Prolapsed Uterus
w Uterus
moves partway or completely through vaginal canal
w Generally
occurs following parturition due to:
Dystocia
Retained placenta
High estrogen pasture/grazing
Prolapsed Uterus cow
Prolapsed Uterus - bitch
3. Broken Penis
w Penis
bent and blood vessels ruptured during copulation at a sharp angle
w Most
common in species with fibroelastic penis (less
erectile tissue to provide resistance to breakage)
we.g.
see hematoma on page
Cystic Ovaries
w Ovaries
form abnormal fluid-filled sacs
Caused by ovulatory
failure
w Follicular
cysts:
Thin-walled cysts
Produce estrogen
May cause chronic heat
Rupture w/hormone treatments
Follicular cyst
Cystic Ovaries (contd)
w Luteinized
follicles:
Thick-walled cysts
Produce progesterone
May develop FROM follicular
cysts
Cause anestrus
Regress with hormone
treatments
Ultrasound luteinized follicle
Lack of Cycling
w Anestrus
= absence of estrus
w Most
common cause = pregnancy!!!
w Other
common causes:
Postpartum anestrus
Lactation
Seasonal anestrus
Anestrus
as Reproductive Failure
w Physical
problem
w Disease
problem
w Poor
nutrition (especially low calorie intake)