Clinical relevance Flashcards
What parts of the male reproductive anatomy can be assessed using ultrasound?
- Testes (incl. epididymis)
- Prostate
What trasnducer should be used for ultrasonography of the male reproductive tract?
8MHz curvilinear array/microconvex
Describe the method for ultrasonography of the scrotum, testes and epididymis
- Sagitaal, transverse, frontal planes
- Apply lube to caudal asspect of scrotum
- Apply transducer to scrotal skin
- Image in all views
- can identify mediastinum testis, mostly in saggital plane
- Identify epididymis
Describe ultrasonography of the prostate in large animals
- Transrectal
- Can see all accessory glands
Where is the prostate located in the dog?
At neck of bladder encircling urethra
Describe ultrasonography of the prostate in dogs
- Topographical landmark is pubis
- Dog in RLR, transducer sagitall plane
- Parallel to prepuce just cranial to pubis
- Identify bladder
- Move transducer caudally to bladder neck, then continue until find prostate
- Fan transducer to identify whole structure
- return to centre of prostate, turn to get transverse plane image
Describe the appearance of the testicular parenchyma on ultrasonography
- Hypoechoic
- Regular diffuse echogenic stippling throughout organ
Describe the appearance of the mediastinum testis on ultrasonography
- Centrally within testis in dog
- In sagittal is echogenic line approx 2mm wide, from cranial to caudal pole
- In transverse appears echogenic circular structure
- Often see acoustic shadow distal to mediastinum
Describe the appearance of the testucular and vaginal tunic, cremaster and scrotal skin on ultrasonography
- Often summed together
- Well defined hyperechoic line surrounding the testicle
- Scrotal surface distal to transducer more readily imaged than that near to transducer
Describe the appearance of the epididymis on ultrasonography
- Hypoechoic compared to testicular parenchyma
- Close to testicular tunic
- Cannot apply line of separation
Describe the ultrasonographic appearance of the prostatic parenchyma
- Moderately echogenic
- Diffuse coarse stippling
- Well circumscribed
- Symmetrical bi-lobed outline, midline furrow dorsal to the prostatic urethra
- Urethra and capsule difficult to identify, vas deferens not possible to visualise
- Small and hypoechoic in castrated male
What is the main reason for veneral swabbing in stallions?
- Swabbing for contagious equine metritis (Taylorella equigenitalis)
- Also Kelbsiella
Describe the method for veneral swabbing in stallions
- Stallion erect, urethra lubricated
- First swab urethra, then urethral space, then shaft
- Different swab for each location
- Medium sized tip, charcoal transport medium
Why might a reproductive exam be performed in the cow?
- Abnormalitites before, during or after calving
- Non-bulling cows
- Failure to conceive
Outline the features of a reproductive clinical history in the cow
- Calving date
- Abnormalities observed around parturition
- Abnormalities in pre/post calving period
- Observed oestrus
- Service dates and history
- Previous repro treatment
- General health and milk production
- Milk progesterone profile (not routine)
What is the actioin of GnRH?
Stimulates FSH adn LH release
What are the potential pharmacological effects of GnRH administration in the follicular phase?
- Superovulation
- Treatment of follicular cysts
- Increases pregnancy rates
- Improved concption rates if at time of service
- Stimulates ovulation if dominant follicle present
What are the potential pharmocological effects of GnRH in the luteal phase?
- Induction of parturition, increased regression of CL
- Gonadal suppression if too much administered(negative feedback to reduce GnRH secretion)
- Speed up development of follicles, or formation of accessory follicles
What is the action of FSH in the female?
- Stimulation of E2 production
- Recruitment of small antral follicle
What are the potential pharmacological effects of FSH in the follicular phase?
Superovulation due to stimulation of multiple follicle growth
What are the potential pharmacological effects of FSH in the luteal phase?
- Stimulate new follicle wave
- Little effect
- May aid dominant follicle develop further
What is the action of LH in the female?
- Stimulates dominance and growth of large antral follicles
- Stimulates E2 and ovulation
- Luteal P4 production
What are the potential pharmacological effects of LH in the follicular phase?
- Stimulate ovulaton
- Improves conception
- Treatment of cystic ovaries
What are the potential pharmacological effects of LH in the luteal phase?
Maintain CL (2-3 days) if given 12 days after heat (useful to synchronise herd)
What are the primary actions of oestradiol in the female?
- Uterus proliferation, tone and blood flow
- Oestrus behaviour
- gnRH release (stimulatory at high conc, inhibitory at low)
- Suppresses FSH secretion
What are the potential pharmacological effects of oestradiol in the follicular phase?
- Oestrus behaviour increased
- GnRH/LH sruge
- Ovulation
What are the potential pharmacological effects of oestradiol in the luteal phase?
Luteolysis at high doses
What are the primary actions of progesterone in the female?
- Stimulates production of histotroph (branching/coiling of glands)
- Suppresses oestrus
- Suppresses GnRH/ovulation
What are the potential pharmacological effects of progesterone in the follicular phase?
Contraceptive by inhibiting ovulation
What are the potential pharmacological effects of progesterone in the follicular phase?
- Maintains luteal phase
- Drop in progesterone on removal causes expression of oxytocin receptors and so can lead to ovulation
- Can be used for pregnancy termination
What are the actions of oxytocin in the female?
- PGF2a production if OXTR present
- Milk ejection
- Myometrial contractions
What are the potential pharmacological actions of oxytocin in the follicular phase?
None
What are the potential pharmacological actions of oxytocin at parturition?
- Stimulation of contractions during parturition to remove uterine debris
- Induce premature parturition
- Improves post-partum involution and stimulation of milk secretion
What are the potential pharmacological actions of oxytocin in the luteal phase?
No effect on cycle
What are the actions of PGF2a in the female?
Luteolysis
What are the potential pharmacological actions of PGF2a in the follicular phase?
None (does not alter follicular growth)
What are the potential pharmacological effects of PGF2a in the luteal phase?
- Luteolysis
- Induction and synchronisation of calving
- Regress persistent Cl
- Abortion
- Treatment of open pyometra
- Treatment of pseudoanoestrus and silent heat
Describe synchronisation of oestrus in cows using 2 doses of PGF2a
- PG at day 0 of protocol
- Will lyse CL if present, or no effect if in follicular phase or very early luteal where CL non-responsive to PGF2a
- PG again 11 days later - all will be in luteal phase so PGF2a will have an effect
- Will bring all cows back to oestrus at same time
Describe herd cycle synchronisation using the OvSynch protocol
- GnRH day 0
- Causes ovulation of any dominant follicles if one present, no effect if in luteal phase
- CL will pregress with time or PG injection
- PG administered day 7 of protocol: Leads to CL regression of one that was either already present before GnRH, or one that was formed from ovulation due to GnRH = all in follicular phase
- GnRH on day 9 then stimulates ovulation of the follicles at the same time
Outline how pancytopaenia occurs in ferrets
- If not mated, remain in heat (induced ovulators)
- High oestrogen maintained for rest of breeding season (6 months)
- Causes severe bone marrow suppression leading to anaemia
Why is neutering not a common option for prevention of pancytopaenia in ferrets?
Can lead to hyperadrenocorticism
Give options for preventing oestrogen aplastic anaemia in ferrets
- Induce ovulation using sterile (vasectomised) male or manual stimulation
- Mate and have a litter
- hCG administration
- Progesterone administration
- GnRH analogues
Describe treatment of oestrogen induced aplastic anaemia in ferrets
- Mating with sterile mate
- Blood transfusion (difficult in ferrets)
- Hormone therapy e.g. gonadotrophins (hCG) to stimulate ovulation
- Primary concern is to stimulate ovulation then deal with anaemia
In order of susceptibility (most to least) what species are susceptible to oestrogen toxicity
- Cats
- Ferrets
- Rats
- Mice
- Dogs
In what situations does oestrogen toxicity occur in dogs?
- Only when therapeutic administration
- When sued to treat pyometra can cause myelotoxicity
