Basic informations about infertility in bitch

1. INFERTILITY IN
BITCH
Anna Karolina Goc

2. Structural abnormalities of the reproductive
tract
◦ Congenital abnormalities
◦ Acquired abnormalities
◦ Neoplasia

3. Congenital abnormalities
◦ Agenesis of an ovary – rare doesn’t cause infertility unless both ovaries are affected
◦ Ovarian dysplasia – in bitch with abnormal nr of chromosomes
◦ Uterine tube/ uterine horn agenesis – if the bitch has normal ovaries it can exibit typical estrus behaviour
but fail to get pregnant or have low nr of offspring

4. Congenital abnormalities
◦ Segmental aplasia of Mullerian duct system – may be caused by inadvertent administration of exogenous
hormones during pregnancy
◦ Complete aplasia of vagina – resultis in infertility and accumulation of uterine fluid producing signs similar
to those of pyometra; treatment is ovariohysterectomy
◦ Strictures of the caudal reproductive tract – common, may produce clinical signs associated with vulval
pruritis or chronic vaginitis

5. Congenital abnormalities
◦ Vulval hypoplasia – rare, associated with perivulval dermatitis
◦ Abnormally shaped vulva – in masculinised female pups

6. Intersex
◦ Ambiguous genitalia
◦ Bitch - usually recognised because of an abnormal phenotypic sex appearance; externally appears female but
when it reaches puberty the clitoris enlarges and male-like behavior may develop
◦ Intersex animals may be classified as those with abnormalities of chromosomal, gonadal or phenotypic sex.

7. Abnormalities of chromosomal number
◦ phenotypic females (X0 or XXX) which have underdeveloped genitalia
◦ chimeras and mosaics that arise from two cell populations with different chromosome constituents
◦ Chimeras and mosaics - there may be both ovarian and testicular tissue (true hermaphrodite)

8. Abnormalities of gonadal sex
◦ Sex-reversed individuals
◦ Chromosomal and gonadal sex are dissimilar
◦ Affected animals may conform to one of three categories:
◦ true hermaphrodites with one ovotestis, bilateral uterine tubes and normal external female genitalia
◦ true hermaphrodites with ovotestes and/or epididymides and masculinised external male genitalia
◦ XX males

9. Abnormalities of phenotypic sex
◦ Chromosomal and gonadal sex are the same, but internal or external genitalia are ambiguous
◦ Female pseudohermaphrodites
◦ occur as the result of androgen or progestogen administration during pregnancy
◦ masculinisation of the external or internal genitalia but with two ovaries
◦ Clinical appearance vary from simple clitoral enlargement to almost male-like external genitalia
◦ Male pseudohermaphrodites
◦ have testes, but the internal or external genitalia are feminised

10. Acquired abnormalities
◦ Acquired atrophy of the genitalia has been seen with neoplasia of the hypothalamus or pituitary - Fröhlich’s
syndrome
◦ Endometrial hyperplasia and pyometra
◦ Vaginal hyperplasia
◦ vaginal mucosa cranial to the urethral orifice becomes hyperplastic during pro-oestrus and oestrus and may protrude
from the vulva and prevent mating

11. Bitch with hyperplasia of the vagina during oestrus. The entire
circumference of the vaginal mucosa is hyperplastic and protrudes from
the vulva. Top is the dorsal commissure.

12. Neoplasia
◦ Ovarian tumours - uncommon in the bitch, approx 1% of all neoplasms
◦ Increased incidence of ovarian neoplasia in older dogs (> 8 years)
◦ Granulosa cell tumours
◦ May become very large and produce clinical signs related to a mass effect or ascites
◦ May secrete progesterone and produce cystic endometrial hyperplasia and pyometra
◦ May secrete oestrogen and produce signs of persistent oestrus or possibly bone marrow suppression
◦ Transmissible venereal tumour (TVT)
◦ Affects the vagina and external genitalia of the bitch and the penis of the dog
◦ Transmission of the tumour occurs at coitus

13. TVT

14. Functional abnormalities of the reproductive
tract
◦ Delayed puberty and prolonged anoestrus
◦ Silent oestrus
◦ Unpredictable ovulation time
◦ Prolonged pro-oestrus/oestrus
◦ Split oestrus (false oestrus)
◦ Ovulation failure
◦ Ovarian cysts
◦ Premature ovarian failure
◦ Habitual abortion

15. Delayed puberty and prolonged anoestrus
◦ Age of puberty – between 5 and 24 months; influenced by the breed, body weight and environmental
conditions
◦ Bitches that do not reach puberty by 2 years of age - delayed puberty
◦ Prolonged anoestrus - difficult to define, as the duration of anestrus vary between breeds and particular
individuals (26-36 weeks)
◦ Clinical investigation
◦ Ensure that the estrus hasn’t been missed
◦ Ensure animal’s body weight and nutritional plane are normal
◦ Look for underlying diseases
◦ Ovarian cysts

16. Silent oestrus
◦ Normal cyclical endocrine changes occur without obvious external signs of pro-oestrus or oestrus
◦ 25% of greyhound bitches at the first cycle after puberty
◦ Ovulation can be confirmed by the measurement of peripheral plasma progesterone concentration or by the
weekly examination of vaginal cytology

17. Split oestrus (false oestrus)
◦ At first oestrus
◦ Bitches develop vulval swelling and a serosangineous vulval discharge of a short duration
◦ Ovulation does not occur
◦ Follicles regress and the signs of pro-oestrus disappear
◦ A normal oestrus follows several weeks later
◦ Recognition is important to ensure that mating is achieved at the correct time

18. Unpredictable ovulation time
◦ Most bitches ovulate between 10 and 14 days after the onset of pro-oestrus but may occur as early as day 5,
or as late as day 30, after the first signs of proestrus
◦ Bitches are also not necessarily consistent between cycles
◦ Infertility results because of attempted matings at inappropriate times

19. Prolonged pro-oestrus/oestrus
◦ Normal interval between the onset of proestrus and ovulation varies from 5 to 30 days
◦ Most bitches ovulate by day 14 after the onset of pro-oestrus – those that ovulate later than this are
considered to have prolonged oestrus
◦ Animals do not require treatment but require careful assessment of the optimal mating time
◦ If pro-oestrus or oestrus persists longer than 30 days may require treatment
◦ Causes
◦ Oestrogen-secreting follicular cysts
◦ Oestrogen-secreting ovarian tumours

20. Ovarian cysts
◦ Cystic follicles and corpora lutea
◦ Very rare in the bitch; most are of parabursal origin and have no clinical significance
◦ Oestrogen-secreting follicular cysts may produce persistent oestrus with vulval discharge, flank alopecia and
hyperkeratosis
◦ Luteal cysts
◦ Their significance is unknown.
◦ It was suggested that they may secrete progesterone and produce prolonged anoestrus and cystic endometrial
hyperplasia

21. An ovary of a labrador bitch demonstrating
multiple follicular cysts.
Multiple parabursal
cysts adjacent to the
ovary and proximal
uterine horn

22. Infectious agents
◦ There are three categories of organism that exert an influence upon fertility:
◦ agents that are known to have a specific pathogenic effect upon the reproductive tract
◦ organisms that are present in the normal environment and under certain circumstances can
become opportunistic pathogens
◦ agents that cause systemic disease and exert their effect upon reproduction indirectly

23. Normal vaginal bacterial flora
◦ Vaginitis and fading puppy syndrome are caused by bacteria that inhabit the reproductive tract
◦ Streptococci, especially β-haemolytic types G and L
◦ Many aerobic and anaerobic bacteria
◦ Escherichia coli, staphylococci and streptococci
◦ Bacteroides spp. and Peptostreptococcus spp.
◦ Mycoplasmas

24. Opportunist pathogens
◦ The bacterial species found in bitches with reproductive disease do not differ significantly from those found
in healthy bitches
◦ Disease may result if the uterine or vaginal defence mechanisms are depressed
◦ Bacteria may enter the uterus during oestrus when the cervix is relaxed
◦ Bacteria may persist within the uterus and be associated with the development of pyometra during the
progesteronedominant phase of the cycle
◦ Pseudomonas spp., Proteus spp., some streptococci
◦ Mycoplasmas and ureaplasmas

25. Specific infections
◦ Brucella canis
◦ Toxoplasma gondii
◦ Canine herpesvirus
◦ Canine adenovirus
◦ Canine distemper virus
◦ Canine parvovirus

26. Brucella canis
◦ G+ bacteria that may produce infertility and abortion
◦ Transmission
◦ Contact with aborted fetal or placental tissue
◦ Contact with the vaginal discharge of infected bitches
◦ Venereal transmission and congenital infection
◦ Abortion occurs most commonly between days 45 and 55 of pregnancy
◦ Diagnosis
◦ Isolation of the bacterium from blood or aborted tissue - there may be prolonged periods when the bitch is not
bacteraemic, negative blood culture does not rule out infection
◦ Late agglutination test for screening and tube agglutination for confirmation

28. Toxoplasma gondii
◦ Causes abortion, premature birth, stillbirth and neonatal death
◦ Surviving infected pups may carry the infection

29. Canine herpesvirus
◦ Produces a few mild signs limited to the respiratory or genital tract
◦ Virus may cause genital lesions in the bitch - infertility, abortion and stillbirths
◦ Infection of the pregnant bitch results in the production of placental lesions and the infection of the fetuses
◦ Infected placentae - underdeveloped, and possess small greyish white foci characterised by focal
degeneration, necrosis and the presence of eosinophilic intranuclear inclusion bodies
◦ Pups may become infected at birth, during passage through the vagina, and subsequently die with
characteristic widespread histological necrotising lesions

31. Cystic endometrial hyperplasia and
pyometra

32. Etiology
◦ Etiology is uncertain
◦ Infectious cause of infertility even though the role of the endocrine environment is significant
◦ Condition may be recognised by ultrasound examination of the uterus during the luteal phase
◦ Multiple small, focal, fluid-filled cystic regions within the endometrium
◦ It was suggested that pyometra was the result of excessive and/or prolonged stimulation of the uterus by
progesterone from ‘retained’ or ‘cystic’ corpora lutea
◦ Predisposing factors
◦ Middle-aged or old bitches
◦ Bitches with abnormal oestrus cycles

33. Clinical signs
◦ 5-80 days after the end of oestrus
◦ Lethargy, reduced appetite
◦ Increased thirst and vomiting
◦ May or may not have vulval discharge of pus
◦ Distended abdomen
◦ Death to toxemia or peritonitis

34. Diagnostic features
◦ Abdominal palpation – thickened horns with irregular structures
◦ Ultrasonography – uterus is filled with fluid and enlarged
◦ Radiography – opacity mass in caudal abdomen, displaced abdomen
◦ Haematology – elevated nr of leukocytes
◦ Rectal examination – may be possible to palpate uterus per rectum

35. Treatment
◦ Ovariohysterectomy is the treatment of choice
◦ Intravenous fluid therapy is essential to ensure minimum renal toxic effects
◦ Intravenous broad-spectrum antimicrobial agents and fluid therapy
◦ 0.25 mg/kg of dinoprost daily by subcutaneous injection - combined with appropriate broadspectrum
antimicrobial agents and intravenous fluid administration
◦ Combined use of the prolactin inhibitor cabergoline (5.0 μg/kg/day) and cloprostenol (5.0 μg/kg every
other day) for up to 10 days