Pathology Pregnant Genital Tract Flashcards
(47 cards)
Define embreyo
- time fertilised embreyo begins to develop a long axis to the time that major structures begin to develop (incomplete orgnaogenesis)
- horse/cattle ~ <35-45d
Define foetus
developing viviparous organism after embreyonic stage and before birth
Define abortion
Premature EXPULSION of the produces of conception from the uterus (not just death)
Which species are dependent on the CL for the whole pregnancy?
- cattle, goats, pigs, dogs
Which species are only dependent on the CL for early pregnancy?
- horse, sheep, cat
WHat initiates parturition?
- foetal stress (including foetal/maternal illnes, hyperthermia)
- foetal ACTH -> foetal GCs -> ^ oestrogens from placenta -> ^ myometrial OTRs and ^ PGF2a -> myometrial contraction, luteolysis, v P4 -> relaxin secretion -> placental separation from endometrium -> fresh non-autolysed foetus
What type of pregnancy loss does salmonellosis/septacaemia cause?
- rapid foetal death
- autolysed foetus
Reasons for embreyonic/foetal loss?
- failure of zygote to attach to endometrium > early embryonc losses - chromosomal abnormalities [commonest cause] - inherited disordered - uterine environmental factors > late embreyonic loss - similar causes > foetal losses - placentitis -> ischaemia - other causes eg. septaicaemia
What % embreyonic death can be considered normal in most species?
15-30%
What happens to an embreyo lost early? What does this mean clinically?
Reabsorbed or expelled (may be small so dont see it)
- no diagnositc material available
- infections rare (ureaplsa, tritrichomonas foetus,campylocater) endometritis
WHat are the 3 forms of foetal retention?
- mummification
- maceration
- emphysema
What is SMEDI?
- Stillbirth, mummification, early death adn infertility
- Retention of some dead foetuses with others still being bron alive - especiall seen in pigs with parvo as one foetus is infected after another
What is mummification? Commonly seen with which sp? causes?
- NO bacterial infection
- mostly multiparous animals esp sow
- foetal skin developed enough to withstand autolysis so now odour
- absortion of placental and foetal fluids
- clsoed cervix
- time point of expulsion varies
- genetic, twinning mare,viral (BVD, Parvo sow, CHV) protozoan (toxoplasma) uterine torsion queen, placental insufficiencies
Is dx of a mummified foetus usually possible?
no
Does mummification usually have an effect of subsequent breeding?
NO
What is maceration?
- foetus becomes liquified
- bacterial uterine infection necessary
- reabsorption or expulsioin with purulent exudate
- foetal bones and teeth may remain
- foetid odour
- common with venereal infections (campylobacter foetus venerealis, tritrichomonas foetus, non-specific endometrial infections) -> pyo or endometritis
- uterine perforation possible
What is foetal emphysema?
- putrefactive organsims ascending from vagina (gas producing eg. clostridia)
- petnet cervix
- mostly seen with dystocia/near term incomplete abortion
- putrifactive foetus, dsitends with putrefactive gas, crepitates
- advanced uterine lesions and often fatal to dam due to toxaemia
What is the most common route of infection causing abortion?
- haematogenous
- except mare (bacterial and fungal usually ASCENDING)
Give egs. of veneral infections causing abortion
- tritrichomonas foetus
- camyplobacter foetus venerealis
How many abortions are caused by non-infectious causes in cattle, sheep, pigs and horses?
- cattle: 50%
- sheep: 40%
- pigs: 60-70%
- horses: 60-70%
How may non-infectious causes be detected?
Difficult to detect (mostly chromosomal or environmental abnormalities)
WHat does the pathology report tell you about aboriton causes?
Rules out some diseases but rarely gives definitive diagnosis
Which species have highest diagnostic success of abortions? How does this affect which abortions are recommended for path investigation?
Sheep (cattle and pigs less successful)
- only recommend investigation when abortion >3-5% cows or cluster of abortions
- pigs only investigate outbreaks otherwise dx unlikely
WHat are the top 3 infectious casues of ovine abortion?
- chlamydophila
- campylobacter foetus foetus
- toxoplasma
