Control of Repro= DOG
Control of Repro= CAT
Oestrus Cycle
When= every 6mnths or so
Proestrus= 9d
Oestrus= 9d
Dioestrus (CL acvite, producing prog)= 56-60d if preg or not
Anoestrus= 4mnths
- Induction of Oestrus
Need have have 3-4mnths to repair
Puberty= 24mnths (breed variation)
eCg/hCG, oestrogens
Monitor vaginal cytology
Some Recipes
20-40 IU eCG/kg daily for 10d, 25-50 IU/ hCG/kg at 10d
GnRH agonists (deslorelin- 4.7mg immplant)
Cabergoline (antiprolactin) 0.005 mg/kg SID PO until 3-8d onset proestrus/ 40d
- Suppression of Oestrus
Why
"I want her to have one cycle before she is sterilised." uncertain benefits
" I cant show/race her in season." need to prove themselves before breeding
" I want her to get a bit older before she has pups." Does hormonal suppression interfere with subsequent breeding?
A Progesterone
maintains anoestrus- no Gn secretion
Contraindications
i) Suppress a pro-oesturs that has started
Need to ID proestrus= bloody vulval discharge, Vaginal Cytoloty
ii) Prevent an expected oestrus
Methods
Long acting Progestagen: E.g. proligestone EARLY in proestrus, next cycle 3-9mnths
Oral progestagen: e.g. megasterol acetate, start in frst 3d of proestrus.
Too EARLY= can return to oestrus
Too LATE= can still have fertile oestrus
Start in anoestrus (2mnths after last), 1-2wks before oestrus
Methods
Long acting proligestone
Oral megestrel acetate, low dose
Too EARLY= effect wears off before oestrus affected
Too LATE= enter proestrus, could then change to suppression dose
CAUTION
Stimulate endometrium
Predispose to CEH (Cystic endometrial hyperplasia), pyometra
If using on breeding bitches/ for long periods
Proligestone= unreliable time period in return to oestrus
Side Effects= increases apetitie, decreases activity
B. Testosterone/ Androgens
Given in anoestrus (>30 before next proestrus) prevents cycle
Doesnt mimic luteal phase= RAPID RETURN to cyclical activity after Tx
Methyl/ testosterone
Mibolerone
Reduces worry of CEH
Ehyloesteronol
Anabolic steroid, used in greyhound racing to prevent return to oestrus
Compounding pharmacists
Nitrotain paste (reg for horses)- anecdotal dose for greyh. bitch= 0.33g/d
C. GnRH Agonist
D. Immunological Methods
Suprelorin- deslorelin
What= down-regulation of GnRH receptors in AP= decrease LH and FSH
Males
6/12mnths implant
REVERSIBLE- after drug wears off
Males= no stimulation of testes, no prod of sperm/ test.
Females
Initial stimulatory effect can bring into Oestrus
PREVENT= prog (e.g. initial 7d megestral acetate 2mg/kg)
OR give: <4mnths old, <60d after ovulation, <7d after parturition
Vacc against relevant antigens
Zona Pellucida
GnRH (coupled to larger protein)
- Treatment of Mismating (misalliance)
no perfect solution- many have undesirable side effects
OVH= GET BITCH STERILISED
best solution
Step 1: Assess the mismatched bitch
Has she been seen mating/tied?
When is the most fertile time to mate?
Vaginal cytology- may see sperm (though not always)
Assess stage of oestrus
Asses plasma prog
Step 2. Decide on Method
Medical
Prog required to maintain preg
Prog from CL for 2 mnths (preg/not)
PG- doesnt have role in bringing back into oestrus but is luteolytic at end of dioestrus
Prolactin= main luteotrophic support
Drugs Used
Oestrogens
potentially fatal
PG
luteolytic, after 25d,
Uterine contractions
not reg for small animals
Antiprolactin drugs (cabergoline)
terminate luteal phase
Glucocorticoids
PU/PD
Antiprog.
Bind to prog receptor
E.g. Mifepristone (RU 486), Aglepristone
Effective in many sp.
Aglepristone (Alizin)
Reg for dogs in Aust
Binds to prog receptor (BETTER AFFINITY THAN PROG)
Used up to 45d of preg
Can Tx Pyometra
BEST DRUG CHOICE FOR MISALLIANCE
1-22d post mating: 100% effective (resorption of embryo
Very early Tx (still in oestrus)= could still get preg again
23-45d= 95% effective (US confirmation, expulsion of foestuses)
Abortion 3-4d after Tx (up to 7d)
early loss= onyl sign vulval discharge
No increase in metritis post Tx
Side Effects
local swelling at injection site
Parturition signs are bitch aborts
- Induction of Parturition
not commonly done
Oxytocin (assist in expulsion once labour started)
- Induction of Oestrus
Increase amount of light
Group therapy
Drugs
Oestrogen
FSH
PMSG
- Induction of Ovulation
Induced ovulators= required mating= LH release
Methods
hCG
Manual stimulation of vagina and cervix
Study= several mating normally necessary to induce ovulation
General
No mating=
Mating
Permanent Oestrus
Pineal gland producing melatonin
Hypothalamus producing GnRH
AP producing FSH and LH
Ovary producing follicles
Producing oestrogens
Positive feedback on Ap and hypothalamus to continue
Pineal Gland producing melatonin
Hypothalamus producing GnRH
AP with EXOGENOUS STIMULIS producing FSH and SURGE of LH
Ovary forms CL= Prog
= negative feedback on AP and hypothalamus
- Suppression/ Postponement of Oestrus Cycle
Progesterone= during anoestrus/ early post-partum
adverse side effects
Megastrol acetate PO/ long acting injection
Delmadinone acetate- antiadrogenic effect
Superlorin- 6mg implant, stimulated then suppressed oesturs (50% need 2nd implant), 11mnth effect
- Tx of Mismatching
OVH
Oestrogens (ECP)
Side effects, there are better options
Megastrol Acetate
Androgens
Aglepristone: 10-15mg/kg 2SC injections 24hrs apart
Alizin
PG
Dinoprost (Lutalyse): multiple injections after preg Dx (not >50d), soem side effects (less than in dogs)
PG/ Prolactin agonist
Cloprostenol low ose + Oral Tx every day with Cabergoline.
few side effects
<40d preg= resorbed