Abnormalities & infertility in female small animals

Question 1

What is the common age of puberty in bitches?

Answer 1

• 6-24m
• small breeds earlier than larger breeds
• other effects, e.g. working dogs, administration of androgens to prevent oestrus

Question 2

What is the normal oestrus cycle length in bitches?

Answer 2

• normal proestrus and oestrus passes: 20d
• normal luteal phase: 65d
• normal anoestrus: 150d
• total cycle about 7m

Question 3

Which is the most reliable indication that a cycle has been missed in bitches?

Answer 3

• measuring progesterone
  – progesterone will be elevated for 70d

Question 4

What can result in failure of onset of puberty in bitches?

Answer 4

1. systemic dz (bitch ill and underweight for other reasons)
2. exogenous reproductive steroids have been given (e.g a performance animal)
3. chromosomal abnormality
4. ovaries are abnormal (usually associated with chromosomal dz)
5. hypothalamic or pituitary dz (rare, usually there are additional endocrinopathies)
6. no ovaries (v rare)

Question 5

What is primary anoestrus in the bitch?

Answer 5

• delayed puberty
• i.e. the bitch has never cycled

Question 6

Primary anoestrus in the bitch - workup

Answer 6

• on presentation collect relevant history (age, exogenous steroid use)
• CE for signs of systemic dz
• CE for signs of masculinisation (clitoral enlargement)
• consider tests to see if cycle has been missed (progesterone or CE)
• if bitch is less than 24m consider waiting until 24m
• at 24m consider establishing Karyotype
• at 24m consider attempting oestrus induction using cabergoline (Galastop): a response will tell you if there is ovarian tissue

Question 7

What is secondary anoestrus in the bitch?

Answer 7

• bitch has passed through puberty then fails to return to oestrus at expected interval

Question 8

What is secondary anoestrus commonly associated with in bitches?

Answer 8

• failure of observation

Occasionally related to:
- systemic dz
- drug-induced (corticosteroids, progestogens)

Question 9

What dog breed can cycling every 12m be normal?

Answer 9

• Basenji

Question 10

Secondary anoestrus tx in bitches

Answer 10

• if clinically well and >12m since last oestrus consider oestrus-induction e.g. with cabergoline (Galastop)

Question 11

When should 1st oestrus occur in queens? What is it influenced by?

Answer 11

• between 6-10m of age
• influenced by season of birth, body weight / condition
• puberty frequently occurs during the spring

Question 12

When to investigate primary anoestrus in the queen?

Answer 12

• if no oestrus behaviour after 10 months old and is spring
• investigate as for bitch

Question 13

What is secondary anoestrus most commonly associated with in queens?

Answer 13

• most commonly associated with inadequate lighting regimes in cattery housed queens (14h light abolishes anoestrus)
• may also occur as seen in the bitch with systemic dz or drug induced suppression (corticosteroids, progestogens)

Question 14

When are abnormal cycles especially common?

Answer 14

• at the first oestrus

Question 15

What are abnormal cycles often associated with?

Answer 15

• either inadequate LH release or too few LH receptors

Question 16

What is a common feature of abnormal cycles?

Answer 16

• failure of ovulation

Question 17

If there is ovulation failure what outcomes may occur?

Answer 17

• oestrus signs might persist as follicles wane away slowly
• there will be a more rapid return to oestrus as there is no luteal phase

Question 18

What is a common problem at puberty?

Answer 18

• persistent or prolonged oestrus

Question 19

What is common when there is no ovulation?

Answer 19

• a rapid return to oestrus

Question 20

What test can you do to rule out pyometra?

Answer 20

• vaginal cytology
• uterine US

Question 21

What is the most likely diagnosis in a bitch less than 1y/o, 6w after last oestrus, presenting with swollen vulva and zero-sanguinous vulval discharge, that is not a pyo?

Answer 21

• split oestrus (essentially ovulation failure)
• tx is not required, she will likely ovulate at this 2nd cycle

Question 22

Ovulation in queens

Answer 22

• induced ovulators
• each copulation uses a release of LH, but:
  – <50% queens ovulate following a single mating
  – >90% queens ovulate if mated 3x at 4h intervals
• queens that don’t ovulate return to oestrus after 2-3w whereas those which ovulate have a 45d luteal phase

Question 23

Inducing/ensuring ovulation in the queen

Answer 23

• ensure multiple mating occur on day 2 or 3 of oestrus
• or consider induction of ovulation with a single injection of 500IU/cat hCG on day 1 of oestrus

Question 24

Causes of signs of persistent oestrus & how to differentiate

Answer 24

• failure to ovulate (pubertal animal)
• follicular cysts (rare in bitch)
• follicular neoplasia (rare in bitch)
• adrenal neoplasia (rare in bitch)
• exogenous oestrogen exposure
  – often exposure to HRT creams or patches
  – common in younger (smaller) dogs
  – sometimes seen in smaller neutered animals

How to differentiate:
- clinical hx (age and 1st oestrus common in ovulation failure)
- ovarian US
- adrenal US

Sometimes there are signs that result in male attractiveness but the female is not in oestrus (e.g. vaginitis) - here the male is attracted to the smell.

Question 25

Bursal cysts

Answer 25

- very common to find cyst-like structures at spay - these are usually para-burial in origin and not significant for cyclicality or fertility

Question 26

True ('functional') ovarian cysts - prevalence

Answer 26

- true follicular and luteal cysts are rare

Question 27

True ('functional') ovarian cysts - signs

Answer 27

Follicular cysts produce oestrogen - thus signs of persistent oestrus Luteal cysts produce progesterone - thus signs of acyclicity and occasionally pyometra

Question 28

Ddx for cysts (as cysts are uncommon)

Answer 28

Bitch with persistent oestrus - prolonged oestrus (young) - ovarian neoplasia (old) Bitch with persistent anoestrus - delated puberty (young) - prolonged anoestrus - ovarian neoplasia (old)

Question 29

Functional ovarian cysts - diagnosis & tx

Answer 29

Follicle cysts - may respond to hCG administration (ovulate and dog goes into luteal phase) - or may need suppression with progestogens Luteal cysts - usually only diagnosed with OVH because of pyometra - no tx reported

Question 30

Ovarian tumours - prevalence

Answer 30

- very rare

Question 31

Ovarian tumours - most frequent type

Answer 31

- granuloma cell tumour

Question 32

Ovarian tumours - CS

Answer 32

Often endocrinological inactive If produce oestrogen: - persistent oestrus & bone marrow suppression If produce progesterone - failure to cycle - occasionally pyometra

Question 33

Ovarian tumours - diagnosis

Answer 33

- US or radiograph

Question 34

Ovarian tumours - tx

Answer 34

- don't commonly mets - tx is OVH - can spread by trans-coelomic seeding therefore care when remove ovaries

Question 35

Diagnostic approach to pain at intromission

Answer 35

- digital examination of the vulva, vestibule and vagina -- allows appreciation of diameter, narrowing, fibrous bands, previous trauma

Question 36

What is the anatomical site of the fusion of the Mullerian Ducts with the urogenital sinus? What is the relevance of this?

Answer 36

- vagina / vestibule - the vestibule-vaginal junction is the site of the majority of abnormalities causing failure to mate

Question 37

Pain at coitus: vestibulo-vaginal remnants - where does this occur?

Answer 37

Remnant tissue at the junction between the vestibule & vagina. May be: - circumferential narrowing - sagittal bands

Question 38

Pain at coitus: vestibulo-vaginal remnants - CS

Answer 38

- pain at attempted coitus - chronic vaginitis in some cases

Question 39

Pain at coitus: vestibulo-vaginal remnants - tx

Answer 39

- transection (via episiotomy)

Question 40

Pain at coitus: vaginal hyperplasia - pathophysiology

Answer 40

Exaggerated response of the vaginal wall to normal oestrogen concentrations during oestrus - ventral vaginal wall thickens - may prolapse - occasionally is circumferential

Question 41

Pain at coitus: vaginal hyperplasia - CS

Answer 41

- a mass at the vulval within the bitch at oestrus - pain at attempted coitus

Question 42

Pain at coitus: vaginal hyperplasia - tx

Answer 42

- conservative (disappears end of oestrus) - surgical resection - OVH for prevention

Question 43

Causes of failure to mate - female

Answer 43

- not presented at correct time - inexperience / too shy - normal oestrus behaviour is not allowed to be displayed (inadequate time) - size differences - female pain at coitus - previous bad experience

Question 44

Causes of failure to mate - male

Answer 44

- inexperience / too shy - inadequate libido - MSK pain - previous bad experience - penile/preputial abnormality - erection failure

Question 45

Commonest cause of infertility in the bitch and queen

Answer 45

Bitch: mating an incorrect time Queen: insufficient number of times or mating on incorrect day

Question 46

Optimal mating time in the bitch

Answer 46

- ovulation can vary between d5-32 - poor relation between behaviour and endocrinology - physical changes: onset of vulval softening occurs 1d after LH surgery - vaginal cytology - vaginal endoscopy - measurement of plasma progesterone (surge in plasma progesterone)

Question 47

Causes of failure to get/stay pregnant in the bitch (in order of most common)

Answer 47

- inappropriate mating time - male factor infertility - abnormal uterine environment - infectious causes of pregnancy failure

Question 48

Cause of abnormal uterine environment

Answer 48

- cystic endometrial hyperplasia (CEH)

Question 49

CEH - pathophysiology & link to pyo

Answer 49

Hyperplasia occurs during each luteal phase in prep for supporting the pregnancy - commonly the uterus doesn't return to the same histological appearance at the end of the luteal phase. There appears to be an age-related change where areas of the endometrium are hyperplastic - uterine clearance of commensal bacteria impaired - ? sperm transport / oocyte affected - ? inability to form normal placenta US documentation of CEH is common in bitches that fail to get pregnant. May lead to accumulation of sterile (?) fluid within the uterus. The uterine environment is hostile and pregnancy doesn't establish or fails. CEH occurs with or without mating (it is associated with exposure to progesterone). May progress ultimately after a number of cycles to clinical pyometra Pyo may be seen in mated and non-mated bitches. Pyometra is normally only seen in mated queens - if the queen is not mated she normally doesn't ovulate and so there is no progesterone to drive the pyo

Question 50

Pyometra - pathophysiology

Answer 50

- bacterial contamination may occur during oestrus (cervix is open) -> pyometra in the luteal phase - most common in middle aged and elderly bitches (as there is CEH at this age) - may also be induced by: -- therapeutic administration of oestrogens for tx of unwanted pregnancy -- therapeutic administration of progestogens for prevention of oestrus

Question 51

Example of less common abnormalities causing failure of pregnancy

Answer 51

- intersexuality

Question 52

What is intersexuality?

Answer 52

- abnormalities of chromosomal, gonadal or phenotypic sex

Question 53

Intersexuality - phenotypic female CS/presentation

Answer 53

- clitoris enlarges at puberty - odd shaped vulva (often positioned more cranially) - male behaviour - some cases have minor clitoral enlargement, but have other detectable abnormalities of the external genitalia including small diameter vestibule - most cases don't cycle and thus is a ddx for primary anoestrus

Question 54

Intersexuality - phenotypic male CS/presentation

Answer 54

- small penis with slit-like prepuce that may be more caudal - commonly have tubular abnormalities so no ejaculation and if any abnormal sperm - may have penile bleeding (oestrus - may have uterus and if there are ova-testes may come into oestrus) - may have other lesions (e.g. hypospadias) - may develop pyo (if ovulation occurs and there is a uterus)

Question 55

Recognition of chromosomal abnormalities

Answer 55

- requires karyotyping

Question 56

Intersexuality - tx

Answer 56

Removal of repro tract including gonads is necessary: - female: clitoris may reduce in size after gonadectomy and may then no longer protrude, but later clitoridectomy may be necessary - male: mainly reducing the risk of pyo is important

Question 57

Infectious infertility

Answer 57

Bacterial commensals are common and normal screening is pointless (except in some countries for Brucella canis) - currently there are major issues with screening for B.canis in the UK, due to the low prevalence of the dz, there is a v significant false positive result. Most dz is caused by opportunistic commensals, esp Uropathogenic E.coli (e.g. in cases of pyometra). Some viruses are venereal pathogens e.g. Canine Herpes Virus (can be spread venereally and via the resp route). Some viral dz are associated with resorption/abortion but aren't necessarily spread venereally (e.g. Distemper).

Question 58

BSE in the male

Answer 58

- clinical hx - general CE - observation of libido - examination of the scrotum - examination of the testes - examination of the sheath - examination of the penis - examination of the accessory glands - collection of the ejaculate - ? endocrine testing

Question 59

BSE in males - Hx & CE

Answer 59

- breed effects: semen quality & IWH - genetic dz (cryptorchidism in parents) - nutrition: is there a real impact? General CE may indicate: - maturity (body size and masculinised appearance = has he reached puberty yet?) - concurrent illness that may impact on fertility (e.g. emaciated) Specifics that may impact on breeding: - obesity - hindlimb lameness - spinal or lumbar pain Temperament and suitability for breeding

Question 60

Bacteriology/virological screening

Answer 60

Dog - no routine screening for venereal pathogens (issues with B.canis screening bc of high false positive rate) - lesions on penis/prepuce mucosa might be viewed suspiciously for canine herpes virus Tom cat - may be screened for FeLV prior to mating since this can be transmitted via close contact

Question 61

Observation of libido

Answer 61

- sniffing, jumping and playing - 1st fraction ejaculated - bitch stands and deviates tail - rapid thrusting movements - penis partially eject but os penis maintains rigidity - erection starts after intromission - 2nd fraction ejaculated - sweeping of bulbus glands inside vagina - dog turns to face caudally - penis twists 180 degrees - 3rd fraction is ejaculated

Question 62

Testicular size - good correlations of testicular size with...

Answer 62

- total sperm output - onset of puberty - testicular degeneration - advanced testicular pathology

Question 63

Examination of the scrotum, tests & epididymides

Answer 63

- freely movable? - some conditions may be suggestive of repro dz: scrotal dermatitis - tests have firm texture - testicular parenchyma and size best appreciated with US

Question 64

Testicular US

Answer 64

- normal tests have moderately hypoechoic parenchyma with echogenic stippling - linear mediastinum in sagittal plane - circular mediastinum testis in transverse plane

Question 65

Testicular lesions - examples

Answer 65

Focal testicular lesions - testicular cysts (US: focal anechoic lesion) - testicular tumours (US of Sertoli cell tumour: focal mixed echogenicity lesion) generalised testicular lesions - orchitis (US: hypoechoic parenchyma)

Question 66

Examination of the sheath & penis

Answer 66

- freely mobile, normal discharge - discharge can be significant in volume - spines and caudally-directed tom-cat penis

Question 67

Examination of the urethra and perineum

Answer 67

- normally via flexible endoscope or positive contrast urethrocystography - CE of perineum & anus

Question 68

Collection of ejaculate

Answer 68

1st fraction ejaculated during foreplay - 0.5-2ml - prostatic fluid - contains no sperm - flushes urethra clear or urine 2nd fraction ejaculated during intromission - 0.5-2ml - sperm rich - deposited into cranial vagina 2rd fraction ejaculate during the tie - 15-20ml - prostatic fluid - no sperm - washes sperm into the uterus

Question 69

Mating problems

Answer 69

Poor libido - frequently results from inexperience or poor breeding management - no evidence that it is caused by low plasma testosterone - don't give androgens Mating difficulty - inexperienced stud dog - psychological problems - abnormal prepuce or penis - (inexperienced bitch) - (incorrect mating time) - (abnormal vulva, vagina) - (male-female size difference)