Canine Flashcards
Describe the canine oestrus cycle type
Monoestrus and non-seasonal (3 cycles in 2 years)
When is the first pubertal heat?
6-10 months of age
What is the inter-oestrus interval?
4-12 months
What is the angle of the vestibule?
80 degrees
Where is a vaginal swab taken?
Cranial vagina
Where is the fornix located?
Ventral side only
Describe the shape of the vagina
Narrow cranially and wider caudally
Name the 4 stages of the oestrus cycle and their length
Proestrus - 9 days average
Oestrus - 9 days average
Dioestrus - 60 days average
Anoestrus - 5 months
Describe Proestrus signs
vulvar swelling, serosanginous vulvar discharge, vaginal epithelium cornified with 30 layers at end of this stage
First drop of blood - follicle begins growing
Describe the hormones during proestrus
Oestrogen peaks - LH surge then follows in oestrus
Progesterone low until late proestrus
LH pulses
FSH low
Describe oestrus symptoms
Softening of vulva, vaginal epithelium completely cornified, female allows copulation
Describe oestrus hormones
Oestrogen drops to basal
Progesterone increasing rapidly
LH surge - ovulation within 2 days
Ovulation
Describe signs of dioestrus
Return to non-cornified vaginal epithelium
CL presence for entire 60 days
Progesterone drops in second half
How long does the LH surge last?
24 hours (entire up and down spike)
When after LH surge does ovulation occur?
48 hours
What type of oocyte is ovulated? How long after LH surge can fertilisation occur?
A primary oocyte not capable of fertilisation- takes 48 hours for a final division for this
So 4 days after LH surge fertilisation can occur
How long is gestation?
65 +/- 1 day
What is examined for general health in a pre-breeding exam?
Physical exam
vaccination status
Genetic defect screening
What is examined on a reproductive exam?
vulvar confirmation
Vaginal exam - blockage
Mammary glands
Serology if required
what is the lifespan of a secondary oocyte?
4-5 days
How many follicles are polyovular?
20-30%
List 5 ways to predict ovulation
- Progesterone assay
- LH assay (expensive)
- Vaginal cytology
- Vaginal mucosal changes
- Ultrasound of ovaries (difficult)
Describe the cycle of progesterone
During anoestrus and proestrus is <1ng/ml
Increases 2-3 days before ovulation
Increases to >1ng/ml before and during LH surge
Peak = 10-15 days after ovulation
1ng = 3.18nmol/L
What will serum P4 be 2 days before ovulation?
1-2ng/ml -> breed 4 days after this
What will serum P4 be on the day of ovulation?
4-10ng/ml -> breed 2 days from this
How many superficial cells means she is in oestrus?
> 90%
What types of cells are seen in anoestrus?
parabasal + small intermediate
What types of cells are seen in proestrus?
early -> RBC, epithelial cells, may be neutrophils
late -> % superficial cells and large intermediate cells increases
What types of cells are present during oestrus?
> 90% superficial epithelial cells
No neutrophils
Bacteria seen
RBC may be seen
What cells are present during dioestrus?
Increase in parabasal and small intermediate cells
Neutrophils may reappear
Explain the changes in vaginal mucosa between stages of the cycle
early proestrus -> oedematous
Late proestrus -> folds shrink, less oedematous
Oestrus -> shrinkage intensifies
Dioestrus - smoothing out of vaginal mucosa
What is crenulation?
Vaginal mucosa becomes oedematous in response to LH surge (as oestrogen starts to decrease)
Causes wrinkling at fertile period
What stage has no crenulation?
Anoestrus
How many times should a bitch be bred in natural mating?
2-3 times every 48 hours
What are the 3 methods for AI?
- Vaginal insemination
- Surgical intra-uterine insemination (frozen)
- Trans-cervical insemination
List 4 reasons for vaginal insemination
- Bitch and stud not compatible behaviour
- Shipped semen
- Prevent disease
- Bitch has problems that prevent mating
Why would we use trans-cervical insemination and what dose for fresh or frozen semen?
Frozen or fresh semen
Poor quality semen from valuable dog
Fresh semen -> 200 million PMS
Frozen -> 100 million PMS
Advantages of TCI over surgical AI
No need for anaesthesia
Less invasive
Repeat inseminations are possible
Example schedule for TCI (spotting noticed on 13/2, ovulation on 26/2) -> when is her fertile period?
P4 was 13 at ovulation
Fertile period -> 28th-3rd
How long is whelping from LH surge?
64-66 days
How long is whelping from ovulation?
62-64 days (63+- 1)
How long is whelping from cytological dioestrus?
56-58 days
57 +/- 1 day
What type of placentation do dogs have?
Endothelialchorial - zonary
Explain haemodilution
haematocrit decreases by 30% 7-9 weeks of gestation
How is pregnancy maintained?
The CL -> prolactin and LH required for CL maintenance
Explain what “zonary” placentation means (transfer, pigmented and transparent zone)
Band like zone of chorionic villi -> transfer zone
Pigmented zone -> either end of central zone for iron transport
Transparent zone -> distal ends of chorion with poor vascularity - absorbing materials from uterine lumen
List 5 methods for pregnancy diagnosis
- Serum relaxin - 28 days after LH
- Acute phase proteins - C reactive protein, haptoglobin used 28 days after LH
- Abdominal palpation (28-30 days after ovulation)
- Transabdominal ultrasonography
- Radiography 45 days after LH surge
What is serum relaxin produced by?
Placenta
What accessory glands do dogs have?
Prostate
When does puberty occur in studs?
6-10 months
How long is spermatogenesis?
60-70 days
How long does copulatory lock occur for?
5-30 minutes
Name the 3 sperm fractions and their mls
- Pre-sperm 0.25-3ml
- Sperm rich - 0.4-3ml
- Prostatic - 1-30ml
How many sperm are in the ejaculate?
200 million
How many sperm are motile?
60-90%
How many sperm should be normal?
75%
What should seminal alkaline phosphatase be?
5000IU/L
More than this -> sperm production low
Less than this -> normal sperm but blockage present
How long is first stage coitus?
1-2 minutes
How long is second stage coitus?
5-45 minutes
3rd fraction ejaculated
List the 6 types of abnormal oestrus cycles
- Failure of first oestrus
- Failure of oestrus cycles
- Prolonged oestrus
- Split proestrus
- Split oestrus
- Hypothyroidism
When should a bitch have her first oestrus and when should she be in puberty?
By 2 years
6-10 months should be in puberty
What are some differential diagnosis for failure of first oestrus?
failure to see it
Silent first oestrus
Intersex
Gonadal agenesis
How do we diagnose failure of first oestrus?
Examine teats and vulva for enlargement -> if it is then do cytology Expose bitch to teaser Serum progesterone (CL or not) Gonadotrophin stimulation test - using hCG
How do we treat failure of first oestrus? (2 things)
Stimulation of ovaries with eCG 3 times a day to determine effect
Cabergoline (dopamine agonist) - lowers prolactin to lyse CL
What are differential diagnosis for sudden failure to cycle?
Ovarian problems
Issue with hypothalamus or pituitary
Poor body condition/disease
How do we diagnose failure to cycle?
Physical exam
Thyroid work up - low thyroxine affects cyclicity
Serial progesterone assay (every 10-14 days to see if she goes above baseline meaning she has cycled)
Ultrasound/abdominal radiograph
What are 3 treatments for failure of oestrus?
Cabergoline -> increase GnRH
eCG -> LH action
GnRH agonist -> Deslorelin implant - 7-10 days see proestral bleeding
What defines prolonged oestrus?
more than 3-4 weeks
What are differential diagnosis for prolonged oestrus?
Failure to ovulate
Steroid producing cystic follicle
False oestrus - inflamed caudal tract and swollen vulva
Granulosa cell tumour producing oestrogen
How do we treat prolonged oestrus?
Monitor progesterone and breed if she is normal
Use progestins
Induce ovulation (GnRH or hCG)
Ovarioectomy
Name oestrus suppression drugs for prolonged oestrus
- Progestins
- GnRH agonists -> ovuplant suppress for 6-12 months
- GnRH antagonists
- Androgens - negative feedback on hypothalamus
What is split prooestrus?
Normal signs of proestrus but doesnt enter oestrus - then proestus occurs again followed by oestrus
Reason -> failure of follicular maturation
What is split oestrus?
Normal proestrus, enters oestrus, refuses male for 3-7 days and resumes receptivity
Progesterone assay useful
May rebreed during second part of oestrus
How does hypothyroidism cause oestrus irregularity?
Low thyroxine -> less neg feedback on hypothalamus -> increased TRH and TSH -> elevated prolactin -> less GnRH and failure of ovulation
How do we treat hypothyroidism?
Thyroxine replacement therapy
Infertility due to anomalies/diseases - causes
Urogenital sinus or mullerian duct or junction of both ducts
List 5 anomalies of reproductive tract
- Hymen remnant
- Vulvovestibular strictures
- Vestibulovaginal strictures
- Complete vaginal septum
- Annular structure
What 3 things can vaginal anomalies cause at breeding?
Pain
Block intromission
Block sperm transport
How do we diagnose vaginal anomalies?
Digital exam per vaginum
Vaginoscopic exam
What age are vaginal tumours seen?
5-6 years old
How do we diagnose vaginal tumours?
Vaginoscopic exam
Digital exam
Vaginal cytology
What is vaginal prolapse?
A sequel to elevated oestrogen during proestrus that persists through oestrus
Vaginal tissues enlarge with oedema
Where does vaginal hyperplasia start (as part of vaginal prolapse)
Starts on vaginal floor cranial to urethral opening and progresses circumferentially - affects urination
What are 2 differential diagnosis for vaginal prolapse/hyperplasia?
Uterine prolapse
Vaginal polyp or tumour
How do we treat vaginal prolapse?
Topically Induce ovulation Surgical removal of tissue Progesterone treatment Spay
What are signs of vaginitis?
Recent infection recurred
Vulval licking, attracting males, urinary incontinence
Clinical signs of vaginitis
Purulent vaginal discharge
Vulvar lip pyoderma
Hyperaemia on the vestibular mucosa
How do we diagnose vaginitis?
Examine perineal anatomy
Vaginal cytology/culture -> lots bacteria may be significant
Vaginal exam
Rule out UTI
How do we treat vaginitis?
Systemic antibiotics for 4-6 weeks
Correction of anatomical defects
Oestrogen for spayed bitches to improve vulva confirmation
What are 3 diseases and one factor causing infertility?
- Endometritis
- Cystic Endometrial hyperplasia
- Pyometra
Mismating
What will cytology show and how do we treat endometritis?
Lots of neutrophils in late proestrus + oestrus
Treat with antibiotics
No apparent clinical disease
What is cystic endometrial hyperplasia (CEH)?
Seen in nulliparous older bitches that havent been pregnant
Hyperplasia + cyst formation on uterine glands + fluid in uterus
Predisposes to uterine bacterial infection and infertility
How do we diagnose CEH?
Abdominal ultrasound
Endometrial biopsy
How do we treat CEH?
Ovariohysterectomy
What is a predisposing factor for pyometra?
Cystic endometrial hyperplasia
What are features of pyometra?
Uterine infection during dieostrus with accumulation of pus
CL present
What are clinical signs of pyometra?
Depressed, PU/PD, vomiting
with out without purulent discharge (cervix closed)
Can have heavy vaginal discharge and weight loss sometimes
How do we diagnose pyometra?
Vaginal cytology
Abdomen palpation
Ultrasound
Radiography
What are the 2 types of pyometra?
Open or closed cervix
Closed -> give low dose PG and increase slowly once it opens up and fluid releases
How do we treat pyometra?
Ovariohysterectomy after fluids and antibiotics
PG for uterine evaculation
Alizin -> 2 injections 24hrs apart progesterone blocker to open cervix and drain pus
Follow up tretament for pyometra
Measure serum PG to ensure luteolysis
3-6week antibiotics
Ultrasound to ensure no more pus
What breeding management is there for pyometra?
Use antibiotics during proestrus and oestrus
Breed on next cycle
How do we fix mismating?
at 25-30d confirm pregnancy and give mismate shot
PGF2a or cabergoline
What infectious disease causes infertility?
Canine herpes virus - respiratory and genital infection
What does canine herpes virus cause?
EED, abortion, stillbirth and neonatal death
How do we diagnose herpes?
Serology, histology and necroscopy of pups
What is benign prostatic hyperplasia?
Spontaneous enlargement of prostate in 80% of dogs over 5 years old
Glandular and stromal hyperplasia due to DHT
What are clinical signs of BPH?
Haemorrhagic urethral discharge
Haematuria
Haemospermia
Poor semen quality
How do we diagnose BPH?
Clinical signs Palpation Prostatic imaging Cytology and culture of semen Serum canine prostatic specific enterase will be increased
How do we treat BPH?
Castration
Flutamide - antiandrogen 5mg/kg/d
5-a-reductase inhibitors (finasteride) treatment of choice
Name 2 testicular tumours
Sertoli cell tumour
Interstitial cell tumour
Describe sertoli cell tumours
Most common tumour in retained testis
60% oestrogen producing
Personality change, enlarged nipples, hair loss, infertility, decreased libido, attractive to other males
Prepucial smear = stratified squamous epithelium
Describe interstitial cell tumours
Common - not in retained testis
Affects leydig cells
Surgically remove
What are 4 other conditions of males?
- Balanoposthitis
- Cryptorchidism
- Phimosis
- Paraphimosis
What is balanoposthitis?
Inflammation of penis and prepuce with purulent preputial discharge
Treated with systemic antibiotics
What is cryptorchidism?
Failure of testis to desend from genital ridge
Testis can be abdominal, inguinal or subcutaenous
Surgical treatment
Should descend by 1-3 months normally
What is phimosis?
Failure to protrude penis out of prepuce (congenital or acquired lesions)
What is paraphimosis
Failure to get penis back into prepuce - congenital or acquired
Can be due to neurologic disease, trauma, neoplasia
Surgery of prepuce of penile amputation
How do we test for testicular tissue?
hCG - 500 IU take bloods 1hr later and see if T increases
GnRH -> increase in testosterone = testicular tissue
How do we determine if functional ovarian tissue is left?
hCG stimulation -> induce ovulation and measure progesterone a week later
AMH test -> detect testicular or ovarian tissue - submit serum sample of blood
7 ways the canine reproductive cycle is unique
- Progesterone increases before ovulation
- Oestrus behaviour needs mix of progesterone and oestrogen
- Bitches ovulate primary oocyte - 2 more days to mature to secondary
- Mature oocytes viable for 4-5d
- Dioestrus similar duration to pregnancy
- Obligatory anoestrus (av 4 months)
- NO MRP
