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Female (2) (Ovarian Disease (Cystic Ovarian Disease in Cows (Dx (Per…

- - - - follicles grown in waves
      - persist at pre-ov. size for 5-6d
      - Ovulate at 13-19mm after LH surge
    - - LH problem (need for final maturation and ov)= failure of GnRH surge (no oestradiol)= follicle cant respond/ no LH= One/ more follicles dont ovulate
      - Failure of complete dev./ partial luteinisation- large fluid filled with luteal tissue/ no ov.
    - - Follicular (no prog. thin wall)
      - Luteal (prod. prog, thick wall)
    - - Behaviour
      - Anoestrus (70-80%)
      - Nymphomania, irregular and prolonge cycles (20-30%)
      - Per Rectum exam
        
        Follicular-like structure >20mm, one/both ovaries
        
        no CL
        
        Uterus enlarged
        
        Oedematous
        
        US to check
      - CS= oestrogens, swollen vulva, mucous discharge, relaxed pelvic lig, elevated tail, masculinisation
    - - BUT delays preg. $$$ loss.
      - WANT: complete lutealisation, then get rid of CL
      - Produce full lutealisation (form active CL)
        
        GnRH
        
        LH
      - PG: luteolysis of formed CL/ lysis of luteal cysts
      - IF NOTHING RESPONDS= Prog for 7d, stop-LH surge, form CL that will respond to PG
  - - - long day breeders
      - Anoestrus over winter, decreased GnRH, FSH and LH,
      - Transition= 60d
      - Increased daylight= more GnRH and FSH= follicle dev.= increased oestradiol, LH starts to increase, 3-4 transition follicles= LH gene activated= surge in LH= Ov
    - - Early Spring= Prolonged oestrus (large ovaries)
      - Stand for breeding, dotn ovulate, dont get preg, return to oestrus
    - - Lots of little follicles
    - - Progesterone
        
        shut down trickle of LH release
        
        10d
        
        Only works if in spring heat- wont advance season
      - LH/GnRH injections
        
        advance fertile ovulations
  - - - "Autumn follicles"
      - no oestrus behaviour- ddx from spring heat
      - Follicle doesnt rupture, fills with blood
        May reach up to 10cm diameter
      - Dx
        
        US= contain echogenic spots- coalesce into fibrinous bands, outer walls thick
      - Regress over 1-2mnths
    - - What= XS haemorrhage into follicular lumen at ovulation
      - Pain= CAN BE HUGE
      - Not hormonally active- doesnt alter cycles
      - Dx: US (one ovary enlarged with echogenic fluid in follicles)
      - Regresses over weeks
    - - Common in mares (occasionally cows and bitches)
      - What= benign tumours, produce hormones
      - CS= barren/ anoestrus, continuous oestrus, nymphomania/ stallion-like behaviour
      - Hx: irregular/ abnormal cycles
      - Dx
        
        Palpation: one enlarged ovary, other small and inactive
        
        US: affected ovary larger, filled with cyst-like structures (honey comb like)
        
        Hormonal: elevated testosterone, elevated inhibin, elevated plasma AMH
  - - - anoestrus or irregular cycles
      - Nymphomania
  - - - usually Follicular
        
        Oestrogen produced: signs like proestrus but doesnt progress
        
        LH failure
      - Occationally Luteal cysts: prolonged anoestrus
- - - - no oestrus cycling, no behavioural oestrus
        Hormonal env: nothing happening (true) OR progesterone negative feedback (Dioestrus)
    - - Silent/ unobserved heat, pregnancy
    - - i) Normal part of cycle (bitch)
        
        bitch has anoestrus= 4 mnths, prog with CL for 2 mnths, then with no indication and cycle restarts
      - ii) Seasonal (mare-long day, ewe-short)
        
        INfluenced by photoperiod, change in GnRH secretion, change in tonic LH, FSH released to start follicles forming BUT DONT DEVELOp or mature until season suitable
      - iii) Nutritional
        
        poor diet, young growing?
        
        Lots of molecular mechanisms
      - iv) Lactational
        
        preg. steroids inhibit hypothalamus and suckling inhibits tonic GnRH and LH secretion
        
        Regular milking= less inhibitory than suckling and nursing
      - vi) Stress
      - Vii) Abnormalities of uterus, ovaries
        
        Ovarian hypoplasia, dysgenesis, freemartinism
      - viii) BEHAVIOURAL: persistent production of prog.
        
        Cystic ovaries, uterine disease (no PG= no luteolysis= retained CL), Preg/ pseudo/ lost preg/ still have CL, prolonged dioestrus
      - v) Aging
    - - Why do they cycle: need active ovaries (time of year, nutrition e.g. need no prog- origins of prog (why persisting?)
  - - - Length of cycles?
      - Consider= ovarian structures, uterine health, time of yr
      - E.g. " My cows dont seem to be cycling regularly. What's wrong and how are you going to fix it?"
    - - Stage= early regression of CL
      - Common Cause
        
        Endogenous PG release
        
        First cycle of season
    - - Transition phase in mare- not enough LH for ovulation
      - Follicular cysts in cows
      - Cats not induced to ovulate- return to oestrus quickly
    - - prolonged dioestrus- damage? early embryo loss? early embryonic death
    - - Early oestrus mare
    - - production animals- need a priming period
      - First cycle of season in sheep- no priming prog.
      - Young, shy animals, low in hierarchy
  - - - mares early in season- insufficient LH
      - cows with cystic ovaries, especially first cycle post-partum, insufficient LH
    - - abnormal or aged gametes
      - abnormal female tract- infection, defects of tract, oestrogenic clover
    - - mating but no preg- is male ok? mated at right time? did she ovulate- how will you tell?
  - - - Embryonic Cause
        
        Chromosomal abnormalities, infections (BVDV), twinning/ multiples
      - Maternal Cause
        
        Uterine infections, hormonal imbalance (prog def), undernutrition, heat, stress, maternal disease, toxins= NEEDS TO BE SERIOUS
      - 25-40% early embryos lost in farm sp. (HEAPS!!)
        
        early loss, absorbed by uterus +/- discharge
        
        later loss= delayed return to service
    - - Resorption, mummification, maceration .
      - Abortion= termination of preg with expulsion of a fetus before it is viable. (many causes- infections, toxins etc)
    - - Did she definitely get pregnant? how will you know? (difficult with early embryonic death)
      - INfectious causes- how will you diagnose these?
      - Mx factors: nutrition, stress?