Small Animal repro Flashcards
(41 cards)
Explain anatomy of the canine/feline reproductive tract
- Vagina Body: Made of longitudinal folds which increase under oestrus due rising E2 levels → can be used as a guide to stage the oestrus cycle
- Male Dog:
Testes: Orientated horizontally, epididymis is dorsal
Penis: Os penis
Accessory Glands: Large prostate that is palpable via rectum - Male Cat:
Testes: Orientated horizontally/diagonally, epididymis is cranio-ventral
Describe the canine oestrus cycle
Type: mono-oestrus 1-3 cycles/year. except Basenjis, wolves, Tibetan mastiffs cycle once a year.
Cycle duration: 7 months (range 4-12)
Ovulation: Lasts 3 days 2d post LH
Puberty: 7-12 month (6-24 month)
Fertilisation: 48-72 hours
Fertility: Decreases from 4 years, lowered sig. beyond age of 8
Gestation: 57+-1d post D1 OR 65+-2d post LH OR 58-72d from a single mating
What the phases of oestrus in canines?
- Pro-Oestrus: 5-9d (2-25d), Bitch has swollen vulva & blood, E2 ↑ and peaks prior to oestrus
- Oestrus: 6-12d (2-21d): Bitch allows mating, E2 decreases and P4 increases towards the end
- Dioestrus: P4 is the dominant hormone, last in pregnant 57d from D1, non-pregnant 2-3m
- Anoestrus: P4 levels are low causes reproductive quiescence, (resting) lasts 4m (3-10m)
What are the effects of hormones in the oestrus cycle?
- Oestrogen:
o Oedema of the vulva & vaginal mucosal folds
o Thickening vaginal epithelium
o Bleeding from endometrium o ↑ P4 receptors on the uterus
o Development of endometrial glands & mammary ducts
o Attracts males - Progesterone:
o Stimulate further endometrial gland development & secretion
o Suppress contractility of uterus
o Closes cervix
o Suppress leukocyte response in uterus
o Get mated & keep pregnant
What are some unique features of the oestrus cycle?
- P4 ↑ before oestrus
- Standing heat via ↓ E2 & ↑ P4 (increasing oestrogen and decreasing progesterone).
Progesterone levels start to increase BEFORE ovulation. - Ovulation of primary oocytes: Not fertilisable immediately, must undergo meiosis (48-72hrs), to ber eady for fertilisation
How to monitor the oestrus cycle?
- Vulvar turgidity/consistency
Pro-oestrus: Turgid
LH Surge: Sudden drop in turgidity
Oestrus: Doughy
*Vaginal cytology tells you that the bitch is in oestrus, and marks the day that she enters dioestrus
*Vaginoscopy helps to decide when to breed the bitch during oestrus (shrunken angular, pale, dry phase - late oestrus)
- Vaginoscopy/Speculum:
Method: NO lube (sperm toxic), gentle twisting motions whilst avoiding the clit & urethra
1. Pro-Oestrus: Swollen, pink, moist vagina folds
2. Late Pro-Oestrus to Early Oestrus: ‘Shrinking Rounded’ Folds large but shrinking, becoming drier & paler, 2nd transverse folds appear
3. Early Oestrus: ‘Shrinking-Rounded’ Folds large but shrinking as oedema decreases due to E2↓, becoming pale/dry, primary & secondary folds still round
4. Mid-Oestrus: ‘Shrunken Angular’ Oedema almost completely gone, folds are small & becoming angular, is pale-pink/pale & dry
5. Late-Oestrus: ‘Shrunken angular’ Small angular folds, pale & dry
6. Very Late Oestrus: Folds are sharply angular but some crests are becoming rounded & pale with increasing pinkness via epithelial sloughing, malodourous cell-rich opaque discharge
7. Early Dioestrus: Folds are small, pink, moist and round, foul smelling brown discharge (+- White/bloody) for 2-5d, bitch may still be attractive for a few days
8. Dioestrus: Folds are small, round, pink, moist and ‘rosette-shaped’
9. Anoestrus: Same as Dioestrus - Vaginal Cytology:
Method: Moisten sterile cotton bud with saline inserted dorsally in the vestibule to access the cranial vagina through a speculum → twirl 360→ roll on a microscope slide & stain with diff-quik
Superficial Cell Index (SCl): Proportion (%) of superficial cells present on a smear
–> Oestrogen increases the number of layers of cells within the epithelium. Increases distance between most superficial layers and blood supply.
–> Can see which stage of the oestrus cycle
Cell Types:
Superficial Cells: Dead, dark-staining cells with a large angular cytoplasm & either no/pyknotic nucleus (Not vesicular cf. alive cells)
Intermediate Cells: Alive, vesicular living nucleus with clear outline, partly angular (Small) or angular (Large) cytoplasm
Parabasal Cells: Alive larger living nucleus, similar to intermediates but smaller & rounder
Basal Cells: Alive, largest vesicular nucleus, smaller & darker than parabasal cells
Phases:
Dioestrus & Anoestrus: SCI- Low <20%, RBC – No,
Neutrophils - +/- (Most in dioestrus), Debris - +++,
Bacteria - +++,
Thin layer of cells on slide
Pro-Oestrus: SCI – Rising 60-80%+,
RBC – Many sometimes but ↓ progressively,
Neutrophils – Some but progressively ↓, Debris – progressively ↓,
thin layer of cells on slide
Oestrus: SCI – 100% (All superficial), Debris – No (Clear),
RBC - +/-,
Neutrophils – NONE (Otherwise indicates infx/endometritis),
Cell layer progressively thickens with superficial cell rafts (Sheets of superficial cells) in the last 1-2d
(D1) First Day of Cytological Dioestrus: The first day where SCl drops by >20% with an ↑ of >10% intermediates/parabasal cells.
Marks the end of the fertile period
–> Stop further inseminations
- Behaviour Sx:
Tickle/rub the perirenal area between the anus and vulva
Reflexes (Tickle/Rub Perineal Region):
o Vulva reflex: Vulva lifts upwards
o Tail reflex: Deflects to one side
o Lordosis: Less useful, sometimes slight back arching - Hormonal Assays
1. LH: Snap test, not quantitative. Requires, 1-2 times daily, blood sampling to catch LH surge
2. Progesterone: Test every second day. LH surge coincides with a rise in progesterone above 6 nmol/L. Ovulation occurs around 16 nmol/L.
P4 rise above 30 nmol/L = confirms ovulation
*Aim to breed 4-7 day after LH surge using identified P4 (or LH)
*P4 value cannot indicate when it is too late to breed/D1
–> Only vaginal cytology can tell
Describe the Feline Oestrus Cycle
- Type: Seasonal polyoestrous (Summer) induced ovulation +- spontaneous, esp. in Orientals
- Puberty: 4-12m age
- Ovulation: 29-40hrs post coitus
- Oestrus: 7d
- Gestation: 66d (64-69d)
Phases
- Non-mating: E2 follicular phase for 1wk & interoestrus for 2wks (Low E2)
- Ovulation w/o Conception: LH surge in follicular phase → dioestrus (4-5wks) → ovarian inactivity (2wks)
Dx of Pregnancy
Diagnosis of pregnancy
- Abdominal Palpation: 15-30d
- US: >16d
- Radiographs: >40d
- Nipples Pinking: 2-4wks
How to approach breeding management?
- Ask owners to bring in bitch a few days after noticing vaginal bleeding
- Perform basic oestrus monitoring (OM), e.g, Reflexes, turgidity, vaginoscope, cytology
- Repeat OM every 2-4d initially; preferably 2d once LH surge until breeding/D1
- Add P4 (+-LH) as required
How to manage fresh semen via AI or natural breeding?
Fresh semen AI or natural breeding:
- Breed when enter the pale-dry-shrunken angular (100% SCI) phase, usually 4 days after LH surge
–> Oocytes 4-5 day prep for fertilisation + 2d ovulaion post LH = 4-5 window before D1 - 2-3 inseminations/matings done every second day, during the most fertile period (last 4 days of oestrus)
- Lifespan: 1 week
- Dose: > 150 million
Method for Fresh Semen AI:
- Check semen motility beforehand → carefully draw into warm pipette & syringe
- Insert pipette dorsally into vulva avoiding the clit/urethra to the fornix, as deep as possible
- Lift the bitches back legs and expel the semen → massage clit for 30s to encourage oxytocin
- Keep hindquarters elevated or 10m unless using TCI or Mavic catheter
What is a Mavic AI Catheter?
- Mimics the bulbus glandis of the dog penis
- Balloon is inflated following placement of catheter into vagina
- Sperm is passed through the catheter, followed by post-sperm fraction/semen extender. Injected slowly over 10 minutes
How to manage fresh chilled semen/frozen semen?
Fresh chilled Semen
Timing: 4-5d post LH surge
Frozen Semen
Lifespan: 24hrs once inseminated Timing: 5.5d post LH surge
Dose: Small dose 100 mil
Method:
- Using either a Norwegian pipette, surgical or using an endoscope to catheterise cervix (TCI)
- Inseminate directly into uterus instead of cranial vagina
What are important hormones in pregnancy?
- Progesterone – not specific for pregnancy
- Prolactin – increases throughout dioestrus, not specific
–? luteotrophe (maintains the CLs)
–> preparing for, and maintaining, lactation - Oestrogen – small rise during second half of gestation
- Relaxin – pregnancy specific – detectable from D21, rises through second half of gestation
Diagnosis:
- Abdominal palpation
- Radiography
- Ultrasound
- Hormone assays: Relaxin
How do you estimate gestation length?
Indications:
- When dealing with dystocia
- Managing a C-section or pregnancy termination
Whelping:
- 58 to 72 says from a single mating
- 63-67 days after the LH peak
- 56-58 days post D1
- Long fertile period due to longevity of sperm in the reproductive tract (7 days of fresh semen)
- ALSO 4 day fertilisation period at the end of oestrus
*11 days prior to D1 during which mating result in pregnancy
–> Range of when birth will be due to this
Estimating Gestation date:
- Number of days from mating to today
- Gestation length range from D1
- Further mating dates: Widens the window
Also use progesterone levels to predict:
- If p4 lower than 8.7 nmol/L: 48 hours
- If P4 < 3.18 nmol/L: 24 hours
- If P4 low, likely to be close to whelping
- If P4 high, unlikely to whelp within 12 hours
Other methods:
- Ultrasound measurements of amniotic sac, embryo/foetus
- Radiography
- Auscultation of foetal heartbeats: last 5 days gestation
- Relaxation of abdomen, preineal area and paracervical area
–> Abdomen changes from barrel shape to pear shape
–> Cervix becomes visible when paracervical area relaxes
- Mucoid discharge: Liquifaction of mucous plus: 4 weeks to 1 day prior to whelping
- Lactation: 2 weeks prior to whelping
- Rectal temperature may fall one degree witihin 24 hours to 36 hours of parturition. Not reliable
What are the stages of parturition?
- Stage I: onset of uterine contractions, relaxation of the cervix, ~ 6 – 12 hrs
- Stage II: full dilation of cervix to expulsion of final foetus (hrs)
- Stage III: expulsion of foetal membranes (usually follows each pup)
What is Dystocia?
- Maternal vs foetal causes
- Primary inertia: Failure to push
- Obstructive dystocia: Pushing is futile
Signs:
- Strong tenesmus (painful defecation) for 20-30 min without pup
- Weak intermittent tenesmus for more than 2-3 hours
- More than 4 hours between pups
- Green discharge before the birth of first pup
–> Placental separation: Oxygen supply may be compromised
- Abdominal discharges e.g. black, bloody, purulent, stinking
How to diagnose Dystocia
Abdominal radiographs:
- Number of foetuses present/left
- Gestation length
Ab US:
- Normal foetal heart rate: >220 beats per minute
- HR < 180 bpm: Getting nervous
- HR <150 bpm: Proceed to C-Section
Digital palpation
Vaginoscopy
- Identify foetal membranes = cervix dilated
- If dilated: C-section safe
What is primary inertia?
Is the inability of a dam to deliver normal sized foetus through a sufficient birth canal
Cause: Excess myometrium stretch, weak myometrium, HypoCa, Hypoglycaemia, anxiety
Treatment:
- C-section: After 3x oxytocin or prior
- Glucose supplement
- Oxytocin:
Timing: Wait 30-60m between doses, give only a max 3 doses before C-section
Contraindicated: High foetus no. as it may cause uterine tetany → foetal hypoxia or premature separation
–> Obstructive dystocia or if cervix still close it is also contraindicated - Ca supplement:
Total Ca may be normal but Ionised is low
Admin: Slow IV given to effect
Sings of Success (saturation): Stop if bradycardia, calm, nausea, vomiting, licking lips & uterine contractions
What is Obstructive Dystocia?
Pushing is futile → may cause 2nd inertia (Exhaustion)
Causes:
- Maternal: Small pelvic canal, Abnormal expulsion, abnormal uterus, or caudal repro tract
- Foetal: Increased size, abnormal presentation, abnormal development
Tx: C-section, resolve cause, e.g., correct malposition but is difficult due to small opening (Raising forequarters may help)
– hygiene is important
C-section:
- Short gestation length so do not cut until cervix is dilated on vaginoscopy
PPC < 6nmol/L considered safe
Estimated date for LH surge or D1 is major advantage
How to manage neonate resuscitation and care?
- Stretch the umbilical cord to encourage blood vessel closure → then cut 2cm away from ab wall
- Clear airways, assess heartbeat & rub vigorously with towel to stimulate RR
- If slow to breathe + HR present: Doxopram (1-2 drops sublingual/IM) & O2 or acupuncture philtrum/nasal philtrum to stimulate respiration
- Once breathing warm the pup (Do NOT do before as ↑ acidosis)
- Check for congenital abnormalities & weigh
Describe causes of Pregnancy Loss
Non-Infectious
Cause: Severe malnutrition, trauma, endocrinopathy, uterine insufficiency, exogenous drugs, genetic
Infectious
Bacterial:
- Brucella Canis:
–> Transmission: Ingestion, inhalation, venereal
–> CS: Often subclinical
Pathogenesis:
- Entry through the mucosa → regional LN → bacteraemia into the following areas
- Male genital tract: Infertility, epididymitis, testicular atrophy, orchitis
- Pregnant female: 3rd trimester abortion, infertility
- Reticuloendothelial System: Splenomegaly, lymphadenopathy, hepatitis
- Filters: Discospondylitis, paresis, uveitis, meningoencephalitis, arthritis, glomerulopathy
Diagnosis:
- Bacteria Culture: Difficult, done on chilled tissues
- Blood Culture
- Rose Bengal Test (RBT): More sensitive (Not species specific)
- Complement Fixation (CFT): More specific (Not species specific)
- Slide Agglutination: High sensitivity, low specificity → follow with AGID
Treatment:
- Not recommended due to potential relapse and human susceptibility
- Castration + Ab therapy (Minocycline, Aminoglycoside)
Control (Endemic): Ensure kennels disease-free, test animals prior to external breeding, quarantine
Brucella Suis
Incidence: Widespread in feral pig populations (QLD & NSW)
Transmission: Pig hunting or ingesting raw pig meat Zoonosis: Careful w/ Sx on hunting dogs
Dx & TX: Same as B. Canis
VIral
Canine alphaherpes virus-1
CS:
- Adults: Tracheobronchitis, vesicular lesions on vestibulum/vagina/prepuce
- Bitches: Late abortion, mummified foetus, still-birth, ↓ litter size
- Neonates (<2wks): Anorexia, ab pain, crying, mucosal haemorrhage, death <48rs
Pathology:
- Scattered haemorrhage in kidney
- Necrosis of liver & lungs
- Enlargement of spleen & LN’s
- Intranuclear inclusion bodies
Dx: No readily available tests in Aus
Tx: No effective Tx, experiments on temp >37 degrees suppressed replication
Control: Minimise stress! Isolate pregnant & lactating bitches, vaccination during oestrus & final week of gestation
What is the CEHMEP Complex?
Cystic endometrial hyperplasia, mucometra, endometritis, pyometra (CEHMEP)
CS: Infertility (CEHME)
Pathogenesis:
1. Oestrus: Oestridial causes development of endometrial glands & P4 receptors
2. Progesterone:
o Further secretion from endometrial glands → cystic changes
o Suppress motility of endometrium
o Closure of cervix
o ↓ Immune funct.
What are other conditions of pregnancy and the puerperium?
- Pregnancy Toxaemia
Incidence: Uncommon Cause: Inadequate nutrition, large litter
Dx: Ketonuria w/o glucosuria, hypoglycaemia, CS of depression & recumbency
Tx: IV dextrose, improved nutrition, severe cases may warrant OVH/induction/abortion - Metritis
Is inflammation of the endometrium and myometrium usually <1wk post whelping
PF: retained placenta/foetus, traumatic/unhygienic obstetrics, unhygienic environment
CS: Fever, malodourous red-brown discharge +- leukocytosis/leukopenia, shock, dehydration
Dx: No P4 present post-whelping (Ddx pyometra cf. has P4), Vagina cytology (Degenerate N, bacteria), Ab US & radiographs (Uterine size & presence of foetus)
Tx: Fluid therapy, broad spectrum Ab, ecbolic +- OVH (foetal remnants), dextrose supplement (Hypoglycaemia) but AVOID IU infusion
Uterine Prolapse
Incidence: Rare
Tx: Replace via laparotomy, OVH if traumatised/no longer breeding
–> Ovariohysterectomy
Px: Recurrence is uncommon
- Subinvolution of Placental Sites (SIPS)
Is bloody vulvar discharge lasting for >6 week after parturition but otherwise healthy
Incidence: Common, especially in young primiparous bitches
Pathogenesis: Abnormal persistence & invasion of endometrium by foetal trophoblasts causing erosion of maternal BV’s
Tx: None if healthy, resolve spontaneously at pro-oestrus, monitor anaemia/metritis (OVH)
Ddx: Oestrogenisation, vaginitis, metritis, neoplasia, haemorrhagic tendency
Px: Doesn’t recur, doesn’t affect future fertility - Hypocalcaemia AKA Milk Fever
Host: Usually small breed with a large litter of ~3wk pups
Cause: Pre-partum or during parturition as a cause of primary intertia
CS: ↑ Muscle tone, tremors, clonic spasms, dilated pupils, seizures, dry nose
Dx: Total Ca <7mg (Normal 9-11), ionised Ca <0.8mmol or <2.4mg
Tx: Calcium gluconate – admin slowly IV to effect, manage diet, ↓ suckling
PX: If results not dramatic post Ca rethink Dx
Ddx: Epilepsy, meningoencephalitis, poisoning (Coffee, 1080)
What is a pyometra?
Causes: E. Coli!!! Strep, Staph, Klebsiella, Proteus, Actinomyces, Pasteurella, etc.
PF: Repeated non-pregnant cycles, oestrogens, progesterone
Timing: Dioestrus!! 1-12wks post-oestrus
Cause: NOT from the male → from bitches’ poo
Hosts: Middle-age/old unspayed nulliparous/low parous, history of exogenous steroids
CS: Purulent vulvar discharge, non-specific signs of illness (ALWAYS think Pyo in non-specific signs in intact bitch)
Diagnosis:
- Vaginoscopy
- Cytology +- Culture
- Ab US
- Haematology: Severe leucocytosis w/ left shift (+- normal), Normocytic/chromic anaemia
- Serum: Hyperglobulinaemic, hypoalbuminaemia, pre-renal azotaemia, liver dysfunction
- Urinalysis: Low USG (ADH interference via endotoxin), renal casts +- Proteinuria/glucosuria
- Contra-indicated: Do NOT palpate abdomen (Uterine rupture)
Tx:
- Stabilise & OVH: Lavage after, take care w/ ligatures, tie off arteries early, open large
- Medical Tx:
Indication: <4yo, valuable breeder, systemically healthy
Methods: Similar to abortion induction, e.g., PGF2a, Aglepristone, Cabergoline +- Misoprostol (Cervix dilation), Oxytocin (Helps evacuate – only if cervix open & P4 at baseline)
Adjuvant: Combine with Broad spectrum Ab (Amoxycillin + Metronidazole)
Timing: Continue until uterus is normal on US, vagina discharge stops +- P4 reaches baseline
Post-op: Advise breeding on subsequent oestrus
What is Transmissible Venereal Tumour?
Transmission: During sex or sniffing/licking genitals, metastasis
Cause: ?Viral
Envi: Many free-roaming dogs in warm humid climates (NA)
Prevention: Strict biosecurity
CS: Tumours around penis/vagina/oral/nasal mucosa, pink/grey friable ‘cauliflower heads’ & discharge
Dx: Impression smear (Round cells), biopsy, response to vincristine
Tx:
- Chemotherapy: Vincristine (Doxorubicin), Treat weekly for 1-2 treatments post resolution of lesion
- Surgical resection
- Radiation: Small lesions
- Sterilise ASAP
