SA Repro

How long is the bitch oestrous cycle

6mth (longer in bigger dogs, shorter if smaller)

Stages of the bitch oestrous cycle

Pro-oestrus (7-9d)
Oestrus (7-9d)
Metoestrus (2-3m)
Anoestrus (2-4m)

What triggers the LH surge in the bitch

Spontaneous luteolysis of the follicles at the end of pro-oestrus = decreased oestradiol and increased progesterone = LH surge

Length of pro-oestrus in the bitch

7-9d

Signs of pro-oestrus in the bitch

Vulval swelling and hyperaemia
Serosanguinous (bloody) discharge (may just see licking)
Attractive to males but will not stand to be mounted

Endocrine changes in pro-oestrus in the bitch

Increased oestradiol until 2d prior to oestrus then it drops off
Low progesterone but rises towards the end

Vaginal cytology during pro-oestrus in the bitch

RBCs
Intermediate and basal cells

Length of oestrus in the bitch

7-9d

Signs of oestrus in the bitch

Enlarged vulva but oedema has decreased and vaginal folds wrinkled
Bloody or straw-coloured discharge
Attractive to males and will stand to be mated

Endocrine changes during oestrus in the bitch

LH peak at onset
Decreased oestradiol and increased progesterone due to follicle luteinisation
Ovulation 2d after LH surge
Oocytes mature to secondary oocytes 2-3d after ovulation

When is the bitch most fertile

4-5d after LH surge (2d to ovulate, 2-3d to form secondary oocytes)

Vaginal cytology during oestrus in the bitch

Cornified superficial epithelial cells (>90%)
Fewer RBCs
No neutrophils

Length of metoestrus in the bitch

2-3m (56-58d)

Signs of metoestrus in the bitch

Vulval swelling subsides
Will not stand for male
May see mammary development +/- abdominal distension (check for pregnancy)

Endocrine changes during metoestrus in the bitch

High progesterone (peaks 3w after LH surge)
Passive luteolysis (no PGF2a)
Increased prolactin in 2nd half

Vaginal cytology during metoestrus in the bitch

Neutrophils
Cornified epithelial cells (>80%)
Nucleated parabasal and intermediate cells
Sperm may be seen if mated

Length of anoestrus in the bitch

2-4m (up to 9)

Endocrine changes during anoestrus in the bitch

Low progesterone (and other hormones)

Vaginal cytology during anoestrus in the bitch

Few cells
No RBCs
Some parabasal/intermediate cells and neutrophils

Breeding season of the queen

January-July

Oestrous cycle in the queen

Seasonal
7d heat periods separated by 10d intervals
Long-life CLs = pseudopregnancy if mated and not pregnant

Oestrus behaviour in the queen

Vocalisation/calling
Rolling
Lordosis
No discharge

When should mating occur in the bitch

0-6d after the start of oestrus
(10-12d after start of pro-oestrus and again 1-2d later)

Timing of AI in the bitch

4-6d after LH surge

Progesterone levels in the bitch during oestrous cycle

Pro-oestrus = rises to 2ng/ml
At ovulation = 5-8ng/ml

How should the progesterone assay be used to monitor for ovulation in the bitch

Measure progesterone every 48h until it reaches 2ng/ml, then measure daily until it reaches 5ng/ml. Inseminate 2d later
Use in conjunction with vaginal cytology

What is the only hormone that can be used to differentiate pseudopregnancy from true pregnancy in the bitch

relaxin (from placenta)

When can you start to diagnose pregnancy in the bitch by palpation

28d

When can you start to diagnose pregnancy in the queen by palpation

17d

Timeline for ultrasound pregnancy monitoring in the bitch

28d = can see embryos and heart beats
35d = assess viability
42d = mineralisation

When can radiography be used to see pregnancies in the bitch

>42d

Disadvantage of using radiography to check pregnancy

Cannot check if viable

Signs of imminent whelping in the bitch

Decreased progesterone (

Physiology of whelping

Foetus produces cortisol = PGF2a release and myometrial contractions
Foetus in birth canal = oxytocin release (Ferguson reflex) = abdominal contractions

Stage 1 labour in the btich

6-24h
Uterine contractions and cervical dilation
Restlessness/hiding, vomiting/off food

Stage 2 labour in the bitch

3-6h
Green-black discharge
Visible abdominal contractions
Rapid expulsion of puppies (30-60mins between puppies)

Stage 3 labour in the bitch

Expulsion of placenta

Length of time between kittens being born

5-60mins (queen can take a break of 12-24h)

Most common cause of 'infertility' in the bitch

Mistimed breeding

Causes of primary anoestrus in the bitch

Husbandry
Previous OVH
Silent heats
Hermaphroditism
Hypothyroidism
Systemic disease

Causes of persistent oestrus in the bitch

Ovarian cysts
Granulosa cell tumour

Causes of failure to maintain pregnancy in the bitch

Canine herpes virus
Canine brucellosis
Subclinical uterine infection
Hypoluteoidism (inadequate progesterone)

Split oestrus in the bitch

Bitch shows pro-oestrus but doesn't ovulate and then returns to anoestrus
Returns to oestrus 2-4w later and ovulates

2 main types of ovarian tumours

Granulosa cell tumours
Epithelial cell tumours

Cause of cystic endometrial hypoplasia in the bitch

Long luteal phase = alternating oestrogen/progesterone influence = uterine wall becomes hyperplastic and cystic

Causes of infertility in the dog (male)

Poor breeding behaviour
Poor libido
Musculoskeletal problems (esp. if old)
Azoospermia
Poor semen quality

3 types of azoospermia

Pre-testicular
Testicular
Post-testicular

Retrograde ejaculation

Sperm goes into bladder during ejaculation
Diagnosis on cystocentesis

Causes of spermatic abnormalities

Retrograde ejaculation
Hypothyroidism
Prostatic disease
Testicular disease

Signs of benign prostatic hyperplasia

Blood from penis
Tenesmus

Treatment of benign prostatic hyperplasia

Castration (surgical or chemical)
Osterone (preserves fertility)

2 methods of canine AI

intravaginal
transcervical

When does pyometra usually occur in the bitch

4-8w after a season or after treatment with exogenous reproductive hormones

Signs of pyometra in the bitch

PUPD
Vomiting
Anorexia
Depression
Pyrexia
+/- vulval discharge
+/- abdominal distension

Diagnosis of pyometra in the bitch

Clinical signs
Haematology/biochemistry
U/S or radiography

Haematology/biochemistry findings with pyometra in the bitch

Neutrophilia and left shift
Leukopaenia and thrombocytopaenia
Mild/moderate normocytic normochromic anaemia
Hyperglobinaemia
Increased urea and creatinine
Hypoglycaemia

Treatment of pyometra in the bitch

IVFT
Abs (1st line = potentiated amoxycillin)
OVH
Medical management possible

Options for medical management of pyometra in the bitch

Prostaglandins (cloprostenol) and Alizin or Cabergoline
Antibiotics
Uterine lavage

When is it classed as dystocia in the bitch

Prolonged gestation (>72d from mating)
No pup after 2-3h of mild/intermittent stage 2 labour
No pup after 30min of hard stage 2 labour
>4h between pups
Evidence of foetal compromise (green/black/bloody discharge and no pup, foetal heartbeat

Management of prolonged gestation in the bitch

If

Main 2 causative agents of mastitis in the bitch

E. coli
Staph.

Treatment of mastitis in the bitch

Drain
Hot/cold compress
Analgesia
IVFT
Abs
Wean pups early (can still suckle based on Ab choice)

Signs of metritis in the bitch

Depression
Shock
Purulent vaginal discharge

Treatment of metritis in the bitch

IVFT
Abs
OVH when stable
PGF2a
Care for pups

What is eclampsia in the bitch

PP hypocalcaemia

When does eclampsia occur in the bitch

1-4w post partum

Signs of eclampsia in the bitch

Restlessness, panting
Muscle tremors
Hyperthermia
Dilated pupils
Seizures

Treatment of eclampsia in the bitch

IV Ca
Oral Ca and Vit D to go home with once stable
Care for pups

Class of drugs used to suppress oestrus in the bitch

Progestagens

Action of progestagens to prevent oestrus in the bitch

-ve feedback on the hypothalamus = decreased GnRH pulsatility = decreased LH pulsatility

3 progestagens used to suppress oestrus in the bitch

Medroxyprogesterone Acetate (MPA)
Megestrol Acetate (MA)
Proligestone

Use of MPA to suppress oestrus in the bitch

S/c depot injection = very long acting
Only use in bitches in anoestrus
Lots of side effects

Use of MA to suppress oestrus in the bitch

Oral (daily)
Can give to bitches in pro-oestrus or anoestrus
Lots of side effects

Use of proligestone to suppress oestrus in the bitch

S/c injection
Injection - 3mth - injection - 4mth - injection - 5mth injection (repeat every 5mth)
Give to bitches in pro-oestrus or anoestrus
Less side effects

Side effects of progestagens in SA

Increased appetite and weight gain
Mammary hyperplasia and tumours
Diabetes mellitus
Adrenal suppression
Cystic endometrial hyperplasia
Pyometra
Coat and behaviour changes

When are progestagens contraindicated in SA

Diabetes mellitus
Liver disease
Mammary tumours

What can be used to suppress the oestrus cycle in queens

Progestagens - same as in dog, but at a much lower levels as more prone to side-effects

3 options for suppressing fertility in the male dog

Progestagens (e.g. Delmadinone Acetate, MA)
GnRH agonists (e.g. Deslorelin)
Androgen receptor agonists (e.g. Osaterone)

What can be used to suppress fertility in the tom cat

GnRH agonist (Deslorelin)
Not progestagens

When do male dogs become infertile after hormonal fertility management

6-8w (although rapid decrease in sexual behaviour)

Physiology of pseudopregnancy in the bitch

Long luteal phase = long period of progesterone = mammary gland development
Lactation triggered by decreased progesterone and increased prolactin at the end of the luteal phase

Is pseudopregnancy repeatable

Yes - if had it once, more likely to have it again (and this will increase the risk of mammary tumours)

What can happen if a bitch is spayed during the luteal phase

Pseudopregnancy 6-8w later

Signs of pseudopregnancy

Similar to pregnancy
Weight gain
Mammary gland development and lactation
Vomiting
PUPD
Behaviour changes

Diagnosis of pseudopregnancy in the bitch

Relaxin
U/S or radiography

Treatment of pseudopregnancy in the bitch

Mild = conservative treatment = distraction and exercise
Dopamine agonists (anti-prolactin) - cabergoline or bromocryptine

Options for termination of a pregnancy in the bitch

Aglepristone (Alizin)
OVH
Cabergoline +/- prostaglandins

When can aglepristone be used to abort in the bitch

Up to 45d

Class of drugs used to suppress oestrus in the bitch

Progestagens

Action of progestagens to prevent oestrus in the bitch

-ve feedback on the hypothalamus = decreased GnRH pulsatility = decreased LH pulsatility

3 progestagens used to suppress oestrus in the bitch

Medroxyprogesterone Acetate (MPA)
Megestrol Acetate (MA)
Proligestone

Use of MPA to suppress oestrus in the bitch

S/c depot injection = very long acting
Only use in bitches in anoestrus
Lots of side effects

Use of MA to suppress oestrus in the bitch

Oral (daily)
Can give to bitches in pro-oestrus or anoestrus
Lots of side effects

Use of proligestone to suppress oestrus in the bitch

S/c injection
Injection - 3mth - injection - 4mth - injection - 5mth injection (repeat every 5mth)
Give to bitches in pro-oestrus or anoestrus
Less side effects

Side effects of progestagens in SA

Increased appetite and weight gain
Mammary hyperplasia and tumours
Diabetes mellitus
Adrenal suppression
Cystic endometrial hyperplasia
Pyometra
Coat and behaviour changes

When are progestagens contraindicated in SA

Diabetes mellitus
Liver disease
Mammary tumours

What can be used to suppress the oestrus cycle in queens

Progestagens - same as in dog, but at a much lower levels as more prone to side-effects

3 options for suppressing fertility in the male dog

Progestagens (e.g. Delmadinone Acetate, MA)
GnRH agonists (e.g. Deslorelin)
Androgen receptor agonists (e.g. Osaterone)

What can be used to suppress fertility in the tom cat

GnRH agonist (Deslorelin)
Not progestagens

When do male dogs become infertile after hormonal fertility management

6-8w (although rapid decrease in sexual behaviour)