Small animal breeding Flashcards
Where do we deposit semen in dog AI
In the fornix
What route do we take into the vagina into the dog
In a small bit then directly up then continue forwards
NB: be aware of the clitoral fossa; can get pipette stuck there and mistakenly inseminate there
Bitch repro tract basics
2 ovaries; 2 uterine horns; 1 uterine body; cervix, vagina, vestibule
Why is it normal to see cavitation on some CLs
Because multiple follicles ovulating over course of a few hours; will see CLs at various stages of the luteal phase
- Have fluid in them early one
Two important features in dog sexual anatomy
Os penis = bone in penis; keeps rigid even when not erect; must be careful not to damage
Bulbus glandis = vascularised structure that wraps around base of penis; creates ‘copulatory lock’ to stop semen getting out
What can we use to tell if a cat has been castrated/ still has active androgen production
Look for spikes on penis; need activate maintenance do disappear within weeks without
What is different about male cat anatomy vs dog
Penis faces backwards
Spikes on penis for stimulation to induce ovulation
What age do female dogs reach puberty
Small dogs: 6-8 months
Large dogs: 12 months
Giant breeds (+ greyhounds, wolf hounds): 18-20 months
When do spermatozoa first appear in dog ejaculate
7-9 months
What age do male dogs reach puberty
Small: 6 months
Large: 12 months
Process of testes descending in male dogs
Born with them intra-abdominally
Move through inguinal canal by 3-4 days after birth
Descend by 2 weeks after birth
Final position in scrotum at 35 days
BUT can take longer
Puberty in queens
VERY weight dependent
See at 6-9 months
How is puberty onset in cats altered by being long day breeders
By photoperiod; may reach right AGE for puberty in winter BUT won’t achieve it until SPRING
Specific breed exceptions to normal puberty times in cats
Oriental breeds: reach puberty very early
Long haired and manx breeds reach it later (11-21 months)
Which breed of dog has retained seasonality in breeding
Bassen G
What is the oestrus cycle in the bitch like
Non-seasonally mono-oestrus
> Inter-oestrus interval variable; around 6-7 months
Exceptions in inter-oestrus interval in dog breeds
German shepherds and rottweilers: inter-oestrus interval just 4-5 months
Tibetin mastiff: cycles once per year
Reproductive cycle in the bitch; brief summary
Anoestrus: get small peaks of FSH but not enough to stimulate growth
- THEN: start to get LH in circulation which allows follicles to mature
Enter proestrus: follicles are producing oestrogens; get blood discharge from vagina and vulva enlargement (NOT RECEPTIVE)
- Then discharge gets paler and vulva less oedematous
Estrus: standing heat; will put tail to side to expose genitalia
After ovulation: enter luteal phase (dioestrus) = sexual quiescence
Which breeds have lots of vulval swelling; and what is normal
Normal is 2-3 x dioestrus size
Boxers show lots of swelling
What is significant about progesterone production in the bitch
Granulosa cells lining follicle start to produce progesterone before ovulation; so can use this to predict the timing of ovulation
WHy does fertilisation in the bitch not happen until 48-72 hours after ovulation
Because the oocyte that ovulates is IMMATURE; still in meiosis 2 i.e a primary oocyte
Takes time to complete this to be competent for fertilisation
How long is the luteal phase is a non-pregnant bitch
Almost identical to in a pregnant bitch i.e 45-70 days (~2 months)
How long is the follicular phase in dogs
18 days;
Proestrus ~ 9 days
Oestrus ~ 9 days
When does a bitch ovulate in relation to oestrus
On day 2 of oestrus; i.e 11 days after start of proestrus (blood)
What is a practical approach to when to breed a bitch in relation to start of proestrus (first blood)
Day 9, 11 and 13
What vaginal exfoliate cytology do we see in proestrus
RBCs
Non-cornified epithelial cells; large with lots of cytoplasm and visible nucleus
What vaginal exfoliate cytology do we see in oestrus
Epithelial cells starting to die and be shed = cornified epithelial cells which look like fish scales
> Bitch in ‘oestrus’ when 50% of cells are cornified
What is the indicator cell for metostrus on vaginal cytology
neutrophils
= too late for breeding
How does vaginal mucosa look (via vaginoscopy) through different phases of the cycle
Early proestrus: pale pink, no oedema
Late protestus: very pale; LOTS OF SWELLING
Oestrus: very pale and wrinkled, no swelling = like funnel with completely flat mucosa and can see to cervix
Dioestrus: vortex; pink, no swelling
Using hormonal tests to work out when ovulation is
Measure progesterone levels daily from 1 week after blood discharge starts
Take ovulation to be when there is a sudden rise of 3-5ng/ml in P
Or measure LH; from 5 days after bleeding; until you measure the surge
When should we breed bitch in relation to ovulation timing
2 days after ovulation
What kind of oestrus cycle does the domestic queen have
Seasonally poly-oestrus
Starts cycling around jan/feb
(may not be seasonal if indoors the whole time)
What is different about ovulation in domestric queen c/f bitch
INDUCED OVULATOR; ovulates after mating
And usually needs >1 mating to stimulate ovulation
What is meant by term ‘pseudopregnancy’ in the domestic queen
When queens that ovulate don’t conceive enter shorter luteal phase than if pregnancy
Luteal phase is ~40 days in non-pregnant
Gestation period in a dog
57-72 days post breeding
- Variation because we don’t know at what point ovulation and fertilisation occurred
Counting from LH surge; 65 days
Gestation period in a cat
57-72 days
- Variation due to multiple matings being involved in inducing ovulation
How does multiple affect LH surge
MUCH greater c/f single mating
Only 50% would ovulate from single mating
What are some influences on the duration of pregnancy in dogs
Number of fetuses; fewer means longer duration
Body weight; heavier bitches pregnancy for longer
What is single pup syndrome
Getting an oversized single pup because gestation longer with just a single pup
What type of placenta do dogs and cats have
Endotheliochorial
Zonary placenta
What proportion of antibody transfer happens in utero vs from colostrum
Just 5% in utero
Rest from colostrum
Why can’t we use progesterone levels to detect pregnancy in cats and dogs
BEcause very similar whether pregnant on not
- In cats; we only get a significant difference later on in pregnancy at which point you can palpate the fetuses
When are we able to palpate a pregnancy in dogs vs cats
Dogs: 4 weeks post mating
Cats: 3 weeks post mating
When can we detect pregnancy via X ray
After skeletal mineralisation
In dogs: 45 days
In cats: 40 days
When can we use ultrasound to detect a pregnancy
From ~18-20 days in dogs
~16 days in cats
What is a test we can use for pregnancy in dogs but not cats
Relaxin test from day 20
What is the max interval between pups being born
1 hour
What colour are placentas in dogs vs cats
Dogs: green/black
Cats: brown
Stages of labour and timings in the bitch
Stage 1 = cervical dilatation + uterine contractions; 4-36 hours
Stage 2 = expulsion of foetuses; pups normally born every 30-60 mins
Stage 3 = expulsion of placentas; may be after each pup or at end
Stages of labour and timings in the queen
Stage 1 takes 24 hours
Stage 2; HUGE VARIATION IN TIME
> Kittens born every 5-60 mins
Stage 3: brown placentas
Labour can take 36 hours
When do we worry during parturition
If no labour by 68-70 days post-mating
If strong abdominal straining but don’t get first pup/kitten within 30-40 mins
If more than 2 hours between first and second pup/kitten
Green discharge and no pup within 30 mins of this; placental separation so stress
Lots of bloody discharge 1
What drug can we give to neonates to stimulate and breathing and what must we be aware of
1-2 drops doxapram
BUT be careful of overdose as risk of hyperventilation and cerebral hypoxia
What level of daily weight gain do we want in newborns
10% MINIMUM
Eyelid and ear canals opening
Takes 2 weeks in dogs
9 days in cats
How long does uterine involution take in bitches
4-5 weeks
Uterine involution in the queen
INfluenced by lactation
Can be cycling again by 4 weeks post-partum if not lactating
Post birth discharge in bitches vs queens
Bitches: green/red –> brown
Queens: not much
