Reproduction Flashcards
Steroids
Made from cholesterol in adrenal cortex, testis, ovary, placenta
Mode of action:
- Freely enter target cells
- Interacts with specific receptor molecules inside cell
- Receptor hormone complex -> nucleus
Progestagens
Prepare uterus to receive embryo and maintains uterus during pregnancy
Stimulates mammary gland growth (suppresses milk secretion)
Regulates secretions of gonadotrophins (FSH, LH) produced by pituitary gland
Androgens
Differentiation of male tissue in embryo and secondary sexual characteristics
Supports spermatogenesis
Influences aggressive and sexual behaviour
Regulates secretions of gonadotrophins (FSH, LH)
Oestrogens
Secondary sexual characteristics
Prepare uterus for sperm transport
Stimulate growth and activity of mammary gland, gonads and endometrium
Regulates of gonadotrophins (FSH, LH)
Eicosanoids
Derived from arachidonic acid (AA) Local hormone (half life 10 mins) Leukotrienes and prostaglandins
Prostaglandins
Erection and ejaculation Luteal regression Ovulation Uterine contraction Uterine contraction Cervical softening Milk ejection
Protein and peptide hormones
Mode of action:
- Via plasma membrane receptors binding to receptors generate secondary messengers
- Activation of kinases
- Phosphorylates proteins -> physiological action
Glycoproteins: FSH, LH
Polypeptide: ACTH, prolactin (PRL)
Peptides: Gonadotrophin-releasing hormone (GnRH), oxytocin (OT)
Hypothalamic
Small part of brain - behavioural and stress responses
Neuroendocrine centre
Many pass to pituitary gland for processing
Cortico-release hormone (CRH)
Stimulates ACTH secretion (ACTH -> adrenal gland -> cortisol)
Growth hormone releasing hormone (GHRH)
Stimulates growth hormone release
Dopamine (DA)
Inhibit prolactin release
Gonadotrophin releasing hormone (GnRH)
Stimulates LH and FSH release
Half life 7 mins
Pulsatile secretion
- Neural control -> pulsatile release
- Non-neural control -> more sustained release
Synthesised by nerve cell bodies in hypothalamus -> arterial pituitary via blood -> anterior pituitary secrete LH, FSH
FSH (follicle stimulating hormone)
Growth and maturation of ovarian follicle
Acts mainly on granulosa (surrounds oocyte) cells of follicle
Artificially stimulate multiple ovulation for IVF
Affects spermatogenesis in testis - acts on Sertoli cells
Stimulates formation of oestradiol in ovary and testis (with LH)
Luteinising hormone
Pulsatile secretion - frequency and amplitude vary - control ovarian cycle
Pre-ovulation surge of LH -> follicle rupture and ovulation
Regulates progesterone synthesis after ovulation in CL
Stimulates formation of oestradiol in ovary with FSH
Regulate testosterone synthesis in testis - Leydig cells
Oxytocin-uterine contraction
Afferent sensory nerve impulse -> spinal cord -> midbrain -> produced in hypothalamus -> posterior pituitary -> myometrium to contract
Oxytocin - milk ejection reflex
Neural hormonal reflex
Afferent sensory nerve impulses -> spinal cord -> midbrain -> hypothalamus -> neurosecretory cells to discharge oxytocin form axons end in posterior pituitary -> bloodstream -> stimulates myoepithelial in ducts of lactating mammary glands to contract
Milk from alveoli to ducts to nipple to infant
Stimulate increased prolactin secretion - duct development and milk synthesis
Sertoli cells
Inside seminiferous tubules
Spermatocytes receive testicular proteins via Sertoli cell gap junction
Spermatocytes and spermatids physically attached to Sertoli cells
Removes material from elongating spermatid during cytoplasmic condensation - removal of excess cytoplasm
All linked by gap junctions - communication throughout tubule
Mediate actions of hormones on spermatogenesis
Spermatogenesis
Mitotic proliferation:
- Large numbers of spermatogonia (diploid) produced
- Basal compartment of tubule
Meiotic division:
- Spermatocytes -> spermatids
- Adluminal compartment of tubule
Cytodifferentiation:
- Packages genes for delivery to oocyte
- Elongating spermatid -> spermatozoa
Testosterone
Synthesised by Leydig cells - between seminiferous tubules
Passes into blood and seminiferous tubules
Sertoli cells convert testosterone -> dihydrotestosterone - passes into testicular fluid - stimulate male reproductive tract
LH stimulate Leydig cells to make testosterone
FSH stimulates production of androgen receptor proteins in Sertoli cells
Epipdidymal maturation
Sperm structure: loss of surplus cytoplasm, condenstaion of nuclear chromatin
Sperm membranes: surface glycoproteins added, membrane fluidity and lipid compisition change
Metabolism: Depressed - prolong life, increased dependence on external fructose
Motility: increase cAMP content of tail
Seminal plasma composition
(From prostrate, seminal vesicles, ampulla)
Glycoproteins - decapacitation factors
Fructose and sorbital - energy
Citric acid - stops cell coagulation
Acid phosphatase - phospholipid metabolism
Buffers
Ascorbic acid - protect sperm from oxidation
Prostaglandins - muscle contraction in female tract
Penis shaft
Corpus cavernosum - main body
Corpus spongiosum - urethra
Blood reservoirs during erection
Fibroelastic penis
Bull, boar, ram
Limited erectile tissue, sigmoid flexure
Sigmoid flexure
Retract penis inside body until erection
Help by retractor penis muscle
Contract - held in
Relax - protrusion
Musculovascualr penis
Stallion
Large corpus cavernosum - fills with blood
No sigmoid flexure
Retractor penis muscle
Erection and ejaculation
Stimulation of pelvic nerve, arterial dilation, increased blood flow to corpus cavernosum
Retractor penis muscle relaxes (sigmoid flexure straightens)
Muscles of vas deferens, smeinal vesicles and prostrate contract
Spermatozoa and seminal plasma expelled
May be fractions
Follicles
Females born with fixed number of primordial follicles
Contains granulosa and theca - hormone producing
And gamete - oocyte
Folliculogenesis
Primordial follicle:
- 1 primary oocyte, 1 layer of pre-granulosa
Primary follicle:
- Increased oocyte size
- 1 layer of cuboidal granulosa cells
- Zona pellucida separates oocyte from granulosa cells
Secondary follicle:
- Multiple layers of granulosa cells - oocytes fully grown
- Theca - interna, externa
- Vascularisation of theca layer
- Theca calls produce antigens - substrate for oestrogen synthesis (granulosa cells)
Tetiary (antral) follicle:
- Granulosa secrete fluid
- Antrum formed (fluid filled)
- Theca internal cells become steroidogenic
Follicle maturation
Antral follicles reposnd to FSH Dominant follicle selected - Graafian follicle - Dependent on LH - Granulosa cells acquire LH receptors - Ovulation caused by LH surge
Corpus luteum
After ovulation, follicle collapses and remaining granulosa and luteal cells form the corpus luteum
Numbers of CL - number of ovulations and release oocytes
Remains for duration of luteal phases, rapidly invaded by blood vessels
Synthesise progesterone to maintain pregnancy
Formation regulated by LH
Seasonal breeders
Sheep, goat, horse, deer
+/- cat
Wild pig
Hamster, rabbit
Non-seasonal breeders
Dog
Cow, pig
Guinea pig
Rodents
Physiological basis of seasonal breeding
Neuroendocrine pathway
Light -> pineal gland produces melatonin -> hypothalamus produces GnRH -> pituitary produces LH pulses -> oestrous cycle -> ovulation of oocytes
Sperm motility
Moving through uterine tract: uterine cilia, uterine contractions
Sperm tail: energy production, propulsive apparetus
Axenome: similar to flagella
Sperm structure
Tail:
- Mitochondrial helix - energy
- Axenome - 2 central microtubules surrounded by 9 microtubule doublets
Head: Apical ridge, acrosome, plasma membrane, equatorial segment, almost no cytoplasm
Sperm transport
Rapid transport phase:
- Reaches oviducts within minutes
- No time to mature, unable to fertilise
Sustained transport phase:
- Capacitation and hyperactivation in female tract
- Storage reservoirs - cervix and oviducts
Sperm storage
Extends window for fertilisation
Cervical storage: cervical crypts - blind ending tunnels get rid of bad swimming sperm, absence of progesterone - sperm released
Oviduct sperm storage: uncapacitated sperm bind to epithelial cells in the isthmus, at ovulation number of sperm in the oviduct increase
Fertilisation
Acrosomal enzyme -> small hole in zona pellucida (rapid process)
Sperm move into perivitelline space between zona pellucida and oocyte plasma membrane
Oocyte plasma membrane fuses with sperm equatorial segment - sperm engulfed
Cortical granules from oocyte move into perivitelline space to cause zona pellucida to block polyspermy
Pregnancy - progesterone
Corpus luteum:
- Maintains progesterone production
- 2 weeks in non fertile cycle (lysed by PGF2a)
- Continues if pregnant (until placenta takes over- primates, horses)
- Implanting foetus must signal its presence to prevent removal of progesterone
PMSG
Pregnant mare serum gonadotrophin
AKA equine chorionic gonadotrophin - luteotrophics
Secreted by trophoblasts cells on day 40-120
LH-like activity - promotes follicular growth, ovulation and production/maintenance of CL
Placenta takes over from CL around day 140
Maternal support of pregnancy
Adequate metabolism of O2, salts and organic pre-cursors
Conceptus induces formation of placenta
Development and hypertrophy of the uterine musculature
Development and maintenance of mammary glands
Take over motherās metabolism with pregnancy hormones (progesterone, oestrogen, CG, placental lactogen, PL)
Labour - stage 1
Regular uterine contractions Cervical mucous plug Cervical shortening and dilation occurs Latent phase: cervix slowly dilates to 3cm Active phase: rapid dilation of cervix
Labour - stage 2
Complete delivery of foetus
Rupture of membrane and abdominal contractions
Labour - stage 3
Delivery of placenta
dogs and cats: occurs with stage 2
Myometrial contractions
Co-ordinated uterine contraction requires the simultaneous activation of all smooth muscle cells in the uterus
Brachystasis
Contractions lead to retraction of the lower uterine segment and cervix upwards
Creates a birth canal
Myometrial cells undergo brachystasis - muscles contract and shorten but do not regain their original length at relaxation
Contraction hormones
Oxytocin: lowers the excitation threshold of muscle cells
Prostaglandins: stimulate liberation of Ca2+ from intracellular stores
Cervical softening
High connective tissue content Resist stretch, allowing distension of the body of the uterus whilst maintaining the cervix in a closed state Softening - 2 changes: - Reduction of collagen fibres - Increase in proteoglycan matrix fibres
Regulated by prostglandins
White vaginal discharge
Vaginitis
Early metoestrous
Open pyometra
Cystitis
Red vaginal discharge
Proestrous Oestrous Persistant ovarian follicle Ovarian tumour (oestrogen secreting) Vaginal trauma/FB Cystitis Urethral neoplasia Coagulopathy Placental separation Subinvolution Post partum Vascular malformation
Vaginal discharge - other colours
Clear: normal Clear watery: amnotic/allontic fluid Greeny/black: normal parturition/dystocia Brown/red-black: metritis Yellow: incontinence
Vaginitis
Usually purulent discharge in a bitch
Age at onset important to determine:
- Juvenile: secondary to bacterial contamination and excess vaginal secretion, usually resolves spontaneously with 1st season, avoid Abs
- Adult: less common, ID and treat specific causes, may respond to exogenous oestrogens
Pyometra
Uterus filled with pus - usually within 8 weeks of last oestrous
Open: mucopurulent vaginal discharge and mild-moderataly enlarged uterus
Closed: no discharge, grossly enlarged uterus, systemic illness
Depression, lethargy, mucopurulent discharge, pyrexia, PU/PD, V, collapse, shock, neutrophils with a left shift, possible azotaemia, acidosis, endotoxaemia, hypoglycaemia, anaemia, coagulation abnormalities
Vaginal/vestibulo neoplasia
Smooth muscle tumour of the vagina/vestibule - most common
Typically slow growing smooth muscle tumours
- Leiomyoma, leiomyosarcoma
- Usually elderly entire bitches
- May present with visible mass, bulging perineum or dysuria/dyschezia
Treat: surgical excision and spay, chemotherapy?
Vaginal hyperplasia and vaginal prolapse
Excessive response of vaginal mucosa to oestrogen during follicular phase of oestrous cycle - vaginal oedema/prolapse
Brachycephalic breeds are predisposed, may interefer with mating, exposed tissues may get traumatised
Treat: Conservative measures - moist, vulvar sutures, surgical excision, usually via episiotomy, spay/control oestrous
Ambiguous genitalia
Indication of presence of androgens and therefore testicular material +/- ovarian tissue
Investigate: evaluate pelvic anatomy, remove gonads + histopath, karotyping
Treat: remove gonads, possible partial penile amputation possible via an episiotomy
Recognise dystocia in the bitch (and queen)
Foetal fluid passed more than 2-3h but no birth
Vigorous, regular straining for 20-30min but no birth
Greenish/reddish brown vulval discharge apparent but no birth
>2-4h since last pup/kitten (def more coming)
Second stage of labour >12h
Sickness of dam
Maternal causes of dystocia
Narrow birth canal Disturbed labour: uterine inertia (most common), uterine spasm/tetany, inadequate abdominal forces Uterine abnormalities Prolonged pregnancy Pyschogenic status Extra uterine problems Premature birth Prolonged parturition Idiopathic
Foetal causes of dystocia
Increased foetal size/litter size, gestational length, genetic/breed factors
Foetal malpresentation (most common)
Abnormal foetal development - hydrocephalus, other congenital abnormalities, foetal death
Uterine inertia
Primary: more common, uterus fails to response to foetal signs, complete or partial
Secondary: exhaustion of the myometrium, secondary to an obstruction
Medical management of dystocia
Dog/Cat
No evidence of obstruction
Exercise dam, feathering the roof of vaginal floor, treat hypocalcaemia/hypoglycaemia, tocospasmolytic drugs sometimes
Oxytocin:
Repeat small doses - 0.2-0.4 IU/kg every 30-40 min
Then consider caesarean
Vulval/vaginal abnormalities
Congenital: vulval stenosis, anovulvar cleft, rectovaginal fistula, vestibulovaginal stricture/band
Acquired: Vulval hypertrophy, recessed vulva, trauma, neoplasia
Ovarian neoplasia
Relatively uncommon in cats/dogs Granulosa cell tumour Cystadenoma Adenocarcinoma Teratoma
Large mass +/- ascites
May be endocrinologicall active
Surgical excision
Hydrometria
Sterile accumulations of fluid within uterus
Large fluid filled viscous within abdomen
Rare, may be incidental
Cryptorchidism
Most common congenital defect in male dog (occasionally cat)
May be abdominal/inguinal/prescrotal
More common in pedigrees
More susceptible to torsion and neoplasia - castrate
Anorchism/monorchism very rare
Testicular neoplasia
2nd most common site in male dogs (rare in cats)
Three types of roughly equal incidence:
- Seminoma (may rarely be assocated with feminisation)
- Interstitial cell tumour aka Leydog tumours (functional - produce testosterone)
- Sertoli cell tumour (functioning produce oestrogen)
Usually benign if scrotal (not retained)
Can cause infertility
Orchitis/epidiymitis
Usually together
Signs: epididymal enlargement, testicular pain, tenesmus and scrotal oedema, may abscessate via scrotum, systemic illness
Chronic: small, firm testes with epididymal enlargement, adhesions between tunics and scrotum may reduce testicular motility
Infection may originate from urinary tract, via direct penetrations or via haematogenous spread
Castrate
Protruding penis
Social problem for owner, low grade irritation, pain, bleeding, trauma
Paraphimosis: Non-erect penis protrudes from prepuce and cannot be retracted or retained in its normal position - narrowed preputial orifice, penile enlargment
Priapism, trauma
Failure of penis to stay in prepuce:
- Abnormally short prepuce
- Weak preputal muscles
- Wear retractor penis muscle
- Contracture following wound
Treat: Symptomatic, surgical enlargement of preputial opening, phalloplexy, preputial lengthening/reconstructive procedures, partial penile amputation
Priapism
Persistent erection of >4h without sexual excitement
Uncommon in cats/dogs
- Trauma, perineal abscess, neuro disease
-Non ischaemic vs ischaemic (emergency!)
Treat:
- Buster collar, analgesia, topical treatment
- Therapeutic aspiration via surgical excisions and flushing of the corpus cavernosum +/- intra-cavernosal injection of phenylephrine
- If all else fails: amputation with perineal urethrostomy (cat) or scrotal urethrostomy (dog)
Penile tumours
Uncommon, dog>cat
Soft tissues: transmissable venereal tumour, squamous cell carcinoma, papilloma, lymphoma, adenocarcinoma, mast cell tumour
Os penis: osteosarcoma, ossifying fibroma, chondrosarcoma
Hypospadias
Developmental abnormality of male external genitalia
Failure of fusion of the urogenital folds and incomplete formation of penile urethra
Can occur anywhere along ventral aspect of penis
Persistent frenulum
Usually immature dogs
Penis and prepuce should be fully separated after puberty
Treatment: sectioning under short GA
Phimosis
Inability to protrude the penis beyond preputial orifice
Congenital/acquired
Treat: surgical enlargement, underlying conditions
Preputial discharge
Slight creamy discharge normal in mature dog
Severe/blood-tinged discharge should be investigated
Originating from external urethral orifice, from prepuce
Treat underlying cause
Difficulty defecating/systemic illness
Dyschezia: usually indicates prostatic enlargement
May be in combo with other disorders e.g. perineal rupture
Causes: benign prostatic hypertrophy (BPH), prostatic cysts, prostatitis/abscessation, neoplasia
Benign prostatic hypertrophy (BPH)
Entire male dogs
Normal aging change that may be associated with clinical disease
Testosterone dependent, results in uniform prostatic enlargement -> dychezia and sometimes dysuria
May be associated with haematuria/urethral bleeding
Surgical: castration - permanent involution 3-12w
Medical:
- Anti-androgen - oestrogen acetate - 7d PO repeat every 5m
- Synthetic progestagen - delmaldinee acetate - monthly injection
- GnRH - deslorelin implant, 6m, not licensed
- Oestrogens - may get squamous metaplasia
- Faecal softeners
Prostatitis/prostatic abscessation
Common in dog, rare in cat
Usually from UTI (or haematogenous spread)
More likely in entire dogs
Maybe: Purulent urethral discharge, systemically ill, dysuric, painful, V/D, PU/PD
May present with collapse and septic shock
Prostatic/paraprostatic cysts
Two types:
- Prostatic/parenchymal cysts
- Paraprostatic/periprostatic cysts
Can be secondary to possible squamous metaplasia, uterus masculinous remnant, neoplasia, resolved abscess
Treat: rarely medical, surgical (castration, omentalisation/other drainage procedure, biopsy cyst wall)
Prostatic neoplasia
Rare but most common prostatic disease in castrated animals
Adenocarcinoma/transitional cell carcinoma
Tends to be locally invasive and metastasise
Signs: weight loss, pain, hL lameness, dychezia/dysuria, may get HL oedema, prostate not always enlarged may be irregular in contour and firm on palpation
Palliative treatment
Castration
Opne vs closed
Open: Vaginal tunic out and not repaired
May reduce post-op swelling and reduce the risk of ligature slippage
Closed:
Vaginal tunic left intact
Reduced risk of intestinal herniation
Varicose haemangioma
Dog and boar
Benign proliferation of blood vessels that may ulcerate or become traumatised
Testicular atrophy/degeneration
Reduces in size after puberty
Causes: increased scrotal temp, decreased testicular blood supply, vit A or Zn deficiency, drug reactions, radiation damage, obstruction and hyperoestrogenism
Hypoplasia +/- fibrosis and granuloma formation
Infectious epididymitis - ram
Haematogenous e.g. Brucella ovis - notifiable
Ascending e.g. Actinobacillus seminus, Histophilus somni, E.coli
Swelling and spermatic granuloma formation especially in tail of epididymus
Funiculitis
Inflammation of the spermatic cord
After open castration, common in pigs, generally acute and necrotising
Horses: āScirrhous cordā after open castration, exuberant granulation tissue in the affected cord often with weeping fistulation to the exterior staph and strep
Prostate metaplasia
Glandular epithelium -> squamous type dogs with Sertoli cell tumours and predisposes to infection
Cattle/sheep associated with oestrogenic implants and ingestion of phytoestrogens e.g. red clover
Squamous metaplasia also occurs in bulbourethral lands of wethers exposed to oestrogenic effects of high clover pastures
Trichomonus foetus
Sheath washings
Infertility/early embryonic death/abortion and metritis/pyometra in female cow
Campylobacter foetus spp. venerealis
Sheath washings and FAT/culture
Infertility/early embryonic death/abortion in female cow
PIzzle rot
Sheep, ulcerative posthitis
Mainly castrated male sheep (wethers)
Caused by Corynebacterium renale
Predisposed by hypoplasia of the penis or prepuce, urinary soiling and high planes of nutrition Yellowish discoloration (necrosis) and ulceration on the anterodorsal aspect of the prepuce
If severe, that portion of the prepuce may slough
Secondary infection is common
Summer sores
Cutaneous habronemiasis in horses
Exuberant granulation following the deposition of larvae in this region
Squamous cell carcinoma - horses
Geldings and stallions and occasionally other species
Novel papillomavirus, cauliflower-like of variable size and occurs principally on Glans penis
Fibropapilloma of the penis
Bovine papillomavirus type 1
Occurs on the Glans penis of 1-2y bulls - regresses with age
Benign but may be large or multiple
Complications: secondary infections or penile obstruction
Transmissable veneral tumour
Rare in UK
Caudal portion of penis principally
Also on the skin at site of wounds
Variable size, cauliflower like, prone to ulceration and secondary infection
Relaxin
Elevated after LH surge
Undetectable in non-pregnant animals
Relaxin enzyme assay - pregnancy diagnosis
Control of oestrous in the bitch
Spay
Synthetic progestagens:
- First generation progestagens potentially induce GH secretion leading to acromegly, DM, mammary tumours
- Proligestone (PRG) prevents oestrous in queen and bitches - strongly antigonadotrophic, weakly progestagenic, antioestrogenic
Pseudopregnancy
Non-pregnant bitch showing signs (weight gain, mammary development, lactation) from 45 days after the end of oestrous
Treat:
- Synthetic progestagens
- Oestrogens and androgens in combo
- Dopamine agonists (can induce vomiting)
Control of oestrous in the queen
Spay
hCG: induce ovulation and delaying subsequent calling because queen goes through phase of false pregnancy
Androgens: used to postpone calling, oral doses - 30d before anticipated oestrous (induces masculinisation)
Progesterone:
- Prevention - as soon as calling starts, suppress call and prevent conception
- Temporary postponement - given during anoestrous
- Permanent postponement - repeat doses given anoestrous
Reinstating reproductive activity in normal healthy animals
Treatment of anovulatory anoestous/acyclicity in cows:
- Correct underlying factors first
- PRID OR CIDR first and 500 iu eCG on day of removal
Manipulate photoperiod/melatonin:
- 16h dark, 8h light, regulin implants
Ram/boar effect:
- Isolate: sight, sounds and smell
- Perception of male by females: visual or physical contact or pheremones
Induction of puberty in gilts
Prepubertal gilts:
- Induction of puberty/prevention of delayed puberty
- At 6-7 m of age/100kg bw/>8m of age
1st litter sows:
- Pevention of anoestrous
- Day of weaning
Multiparous and 1st litter sows:
- Treatment of anoestrous
- 8-10d after weaning
Multiparous and 1st litter sows (seasonal anoestrous):
- Prevention of anoestrous due to seasonal influence
- On day of weaning
Increasing the number of gametes
Increase in follicular recruitment or decrease in atresia - FSH, LH and P4 profiles during follicles waves
Super-ovulation of donor - recombinant FSH, pFSH, oFSH, eCG (PMSG), porcine pituitary extract (purified)
Manipulation of nutrition:
- Increase in follicular recruitment
- Flushing: rising plane of nutrition before mating
- Mechanism: higher energy intake lower estradiol concentrations and promotes FSH release
Synchronisation of oestrous/ovulation
Controlled breeding without oestrous detection:
- Fixed time AI
- High pregnancy rates
- Control of luteal phase and/or follicular growth
Luteolysis in the cow:
- PGF2a produced after day 15 in cow - causes CL lysis
- Ovsynch: follicular wave synchrony and prostaglandin; follicular wave synchrony wit GnRH and control (shortening of luteal phase
- Exogenous progesterone (PRID/CIDR) with PGF2a
Enhancement of embryo survival
Establishment of pregnancy - maternal recognition: compromised by insufficient rise in post-ovulatory progesterone - defective CL?
Luteal deficiency/poor maternal recognition of pregnancy:
- Progesterone supplementation of GnRH day 11 (cows)/9 (ewes)
- Works bets in herd with low conception rates
Control of parturition
Synchonize calving with seasonal grazing
Foetus initiates paturition - stops progesterone production by CL or placenta
Immunological control of reproduction
Immunisation against androstenedione:
- Single injection in ewe (Fecundin)
- Androvax, Ovastim
Immunisation against GnRH:
- Inhibits production of gonadotrophins and gonadal steroids
- Reduces testicular size and function
- Control aggression and reduce male-associated odours
- Vaxstrate (cattle), Equity (horses), Gonacon (White tailed deer), Improvac (improve boar taint)
Treatment of reproductive diseases
Cystic ovarian disease:
- Defect in the ovulatory mechanism due to failure of the pre-ovulatory LH surge
- Contributory factors: stress, lower oestradiol concentrations, lower hypothalamic sensitivity to oestradiol, uterine infection, negative energy balance
Luteal cysts: prostaglandins, in heat after 3/4d
Follicular cysts: no manual rupture, GnRH or hCG
Pyometra, pseudopregnancy (goats)
Oestrous detectiong aids
Pedometers Beacon Estroheat Tail paint Closed circuit TV
Ostreous synchronisation + single/double fixed AI?
Natural service?
Ovsynch
Embryopathic organisms (cows)
Campylobacter foetus Tritrichomonas foetus Chlamydophila psittaci Mycoplasma, ureoplasma, acholeplasma BVDV Infectious bovine rhinotracheitis (IBR) Bluetongue virus
Endometritis (cows)
Frequent causes
Trueperella (Arcanobacterium) Progenes Prevetella sp. E. coli Fusobacterium necrophorum Fusobacterium nucleatum
Treat:
CL present - PGF2a
No CL - metricure
Abortion and still birth (cows)
Infectious causes
Brucella abortis: 6-9m Leptospira spp: 6-9m Listeria monocytogenes: 6-9m Campylobacter foetus: 5-7m Tritrichomenas foetus: 5m Salmonella spp: variable, 7m Trueperella (Arcanobacter) progenes: sporadic and variable Mycobacterium tuberculosis: anytime Fungi: Aspergillus, Absidia, Mortiella spp., Mucoralis group - 4m to term Bacillus licheniformis: sporadic late abortion Neospora caninum: late abortions IBR - IPV virus: 4-7m BVDV: any stage
Poor conception rate in sheep (sheep)
Season: late/early in breeding season Reproductive tract abnormalities: relatively uncommon, freemartinism, hyperplastic ovaries, cysts Fertilisation failure Phytooestrogens - red clover Stress Male infertility
Early embryonic death (sheep)
Asynchronicity between embryonic development and timing of P4 rise
Dietary intake
Age
Mineral deficiencies: Se, I
Infectious: toxoplasma, border disease virus
Late foetal death:
- Overfeeding in early pregnancy
- Underfeeding in late pregnancy
- Ovine/caprine abortion: Chlamydophila abortus, Toxoplasmosis, Campylobacter (Q-fever, Brucellosis, Leptospirosis, Salmonellosis, Listeriosis, Border disease)
Perinatal mortality (sheep)
Still birth, trauma, mineral deficiency
Disease: e.g. watery mouth, viral diarrhoea etc.
- Toxoplasma, Chlamydophila may result in the birth of weak lambs
Starvation/exposure
Equine reproductive infections
Taylorella equigenitalis (CEMO) Klebsiella pneumoniae (capsule 1, 2 and 3) Pseudomonas aeruginosa
Equine viral arteritis (EVA) - pink eye
Equine herpesvirus 1 (EHV-1) - abortion
Equine infectious anaemia (EIA) (not in UK)
Equine coital exanthema (EHV-3) pox like
Trypanos equiperdem - Dourine - not in UK, but in Italy
Strangles: Streptococcus equi equi - screen for carriers
Pre-season screening
Stallions and teasers
01/01 - 15/02
Bacterial swab: 2 sets - urethral, urethral fossa, prepucial smegma and pre-ejaculatory fluid swabs, 7 days apart
Viral swab: 1 serum sample for EVA titre, vaccinated stallion will be positive; 1 serum sample for EIA
Pre-season screening
Mares
01/01 - 15/02
Swab late foaling mares, 1m before due date
Additional clitoral swab for dystocia/treated mares - Klebsiella and Pseudomonas
Bacterial infections: 1 set clitorial sinus and fossa swabs
Viral infections: 1 serum sample for EVA titre; 1 serum sample EIA
Equine viral arteritis
Brick red conjunctivitis, fever, depression, filled legs, head, skin rash, abortion, early pregnancy failure
Blood sample for Abs, nasopharyngeal swabs and tissues for PCR and culture, stop mating/AI
Trace and notify, follow up blood sample (1m)
Stallions become permanent shedders - castrate/euthanase
Equine herpesvirus
EHV3: genital pustules but not abortion
EHV4: Resp disease, very rare, isolated abortions
EHV1: abortions, resp disease, paralysis, mutlifocal necrosis in liver, lungs and spleen
Weanlings, yearlings, horses out of training
Abortion: isolate (other pregnant mares), PM
Ataxia:
- Blood sample, nasopharyngeal swab
- Intensive care, movement restrictions (euthanasia)
Vaccinate:
- EHV-1,4 - against abortion
Equine coital exanthema
Pox like lesions -penile, preputial, vulval skin 5-9d after infection
10-14d recovery - cease mating
Symptomatic treatment, occasional systemic signs
Equine Infectious anaemia
Fever, anaemia, oedema, weight loss, death
Lentivirus spread by infected horseflies and stable flies
Strangles
Discharge, nasopharyngeal swabs, isolates
Respiratory infection: nasal discharge, submandibular abscess
Internal abscesses: pneumonia, colic, diarrhoea, weight loss
Carriers: Guttural pouch washes
1st stage labour (1-4h)
Horses
Variable duration
Usually late evening/night
Mare become restless and starts ānest-makingā, digging, re-arranging bedding
Abdominal pain, passing small quantities of urine and small droppings
2nd stage of labour (0.1-0.5h)
Horses
Breaking water, point of no return
Violent abdominal straining, unbroken, smooth, pale-coloured, amnion starts to protrude, allantoic fluid is expelled
Muzzle and front feet starts to emerge, amnion is still intact
Delivery
Horses
Abdomen and hind legs expelled
Mare rests
Placental blood flows through the unbroken umbilical cord into the foal
When cord breaks, should be dressed with antiseptic
Avoid foaling standing up but if it happens - support the foal during delivery
3rd stage labour (1-2h)
Horses
Tie amnion into a ball so it is not damaged if the mare stand up sudden
Placenta should be expelled within 1h - both horns intact
Red bag delivery
Horses
Waters do not break, placenta can be seen - thick, red and unbroken at vulval lips
If allowed to continue, placenta will be expelled - foal will asphyxiate - open manually
Epidural
Horses
Eases manipulation, prevents impaction
Copious lubrication, repel and reposition
6 inch spinal needle, 1st intercoccygeal space
- 7-10ml 2% lidocaine
- 7.5ml 1% xylazine
Pain after foaling
Immediately after: normal uterine cramps - usually resolve quickly
Soon after: uterine artery haemorrhage, uterine rupture, colonic/caecal rupture
24-48h/weeks/months: colon torsion
Retained placenta
Horses
Tie amnion up, gently pull
Oxytocin: 0.5 iu in 500 ml saline over 2h
Abs, analgesia - anti-endotoxic doses of flunixin
Pump in weak (
Obturator paralysis
Horses
āDoing the splitsā during foaling
Hind limb hobbles for merginal cases
Slings for those who cannot stand
Perineal lacerations
Horses
Minor: vulval splits, Cowslick tears, vaginal tears
1st degree: small tears of the mm of the vulva and vestibule
2nd degree: Involved deeper structures - perineal body, constrictor vulvae muscle, immediate surgical correction
3rd degree: tearing of the vestibulo and vaginal walls, perineal body, anal sphincter, rectal wall, immediate surgery
Ovarian neoplasms
Horses
Germ cell neoplasms - rare:
- Dysgerminoma: from primitive germ cells - smooth surface and commonly area of haemorrhage/necrosis
- Teratoma: from totipotent germ cells, mostly well-differentiated and benign
Gonadal stromal neoplasm/sex cord stromal tumours:
- Granulosa-theca cell tumour
- Thecoma, luteoma
Epithelial neoplasm:
- (Cyst)adenoma and (cyst)adenocarcinoma
Secondary tumours: lymphoma, mammary carcinomas (bitch), intestinal carcinomas (cow)
Endometritis
Pathology
Limited to uterine mucosa Inflammatory inflitrate (lymphocytes, plasma cells) into mucosa Severe cases can become chronic and fibrous Persistent CL in mare and cow in chronic endometritis
Common pathogens (Cows): Herpesvirus, Tritrichomonas foetus, Campylobacter foetus spp venerealis, others include pyogenic cocci and coliformes. T. pyogenes
Common pathogens (Mares): Alpha-haemolytic streptococci, Klebsiella pneumonia, E. coli. Taylorella equigenitalis (CEM), Pseudomonas aeruginosa
Pyometra (cow)
Endometritis/metritis predisposes
Early post-partum or at various times after breeding - venereal disease
Peristing CL and high progesterone levels
A few ml - several litres of thick, mucinous, cream/grey coloured pus
Rarely systemic
Common pathogens: Haemolytic streptococci, Staphyococcus, coliforms, Trueperella pyogenes, Pseudomonas sp, Tritrichomonas foetus
Sow: Trueperella pyogenes
Mare: Streptococcus zooepidemicusm, E. coli, Actinomyces spp., Pasteurella spp., Pseudomonas
Equine arteritis virus
Arterivirus
Notifiable
Enters via respiratory tract or semen
Infects macrophages and endothelial cells -> arteritis
Fever, depression, pink eye, abortion
Stallions become shedders
Bovine viral diarrhoea virus
Pestivirus
Shed in respiratory secretions and faeces
Haematogenous spread to foetus via placenta
1st trimester (0-110) prior to immuno competence:
- Embyonic/foetal death - resorption/abartion/mummification
- Persistent infection
2nd trimester (111-190):
- Abortions/mummifications, PIs (only until 140), congenital deformities (125-175)
3rd trimester:
- Occasional abortions/still births/weak calves but usually ānormalā calf
Vaccinate dam, ID and isolate PIs
Bovine herpesvirus-1
Venereal, contact, aerosol
IBR, IPV (infectious pustular vulvovaginitis), IBP (infectious balanoposthitis)
Abortions:
- Following respiratory infections
- May occur weeks after infection of dam
- 4-8m gestation, necrosis in foetal liver and lung
Schmallenberg virus
Orthobunyavirus, Arbovirus
Infection of dam during early pregnancy
Virus has neurotropism
Common findings in affected foetus/neonates: arthrogryposis, hydranencephaly, cerebellar/cerebral hypoplasia
Porcine reproductive and respiratory syndrome (PRRS)
Arteriviridae
Infection of respiratory tract via aerosol or genital tract via virus infection semen
Respiratory disease or oedema or subclinical
Immunosuppression
Abortions/mummification/premature piglets
Porcine parvovirus
Early embryonic death ( resorption (infertility)
Infection at later stages causes death of foetus with mummification
Death at late stages -> still births
If infected >70d, foetal death less frequent - immune response
Swine influenza
Type A influenza virus
Resp signs, pyrexia >41, abortions
Transplacental infection considered rare
Porcine circovirus 2
Abortions, mummification, still births, weak piglets, congenital tremor
Post-weaning multisystemic wasting syndrome (PWMS)
Porcine dermatitis and nephropathy syndrome (PDNS)
Aujeszkyās disease
Herpesvirus
Notifiable
Entry via respiratory tract
CNS signs and high mortality in piglets
In pregnant sows: haematogenous spread to foetus - abortions/still births
Classical swine fever
Pestivirus Notifiable High mortality Diarrhoea Haemorrahages in skin and other organs such as kidneys Abortions, mummifications, still birth
Canine herpesvirus
INfection of pups during or just after birth leading to systemic herpesvirus infection
Immature immune systems and poor regulation of body temp allows infection to establish
Organ necrosis and death
Vaccine available for pregnant bitch
Ewe gestation period
144d (20 weeks)
Pregnancy toxaemia/twin lamb disease
Negative energy balance in ewe
Recumbent, neuro signs, twins/triplets
Stress: cold weather, wet weather, moving, transport, change of feed, delay in feeding
IV glucose, oral propylene glycol, oral electrolyte carb source - liquid lactate
Less common in cows
Fat cow syndrome
Fatty liver
Fat mobilisation due to hormonal influences (last two weeks of pregnancy and early lactation)
Fatty liver: immunosuppression, endometritis, ketosis, retained foetal membranes, infertility, mastitis
Can be life threatening - recumbent, inappetent
Foetal stress - initiate parturition
Foetal stress Foetal glucocorticoid Placental oestrogen increase Myometrial oxytocin receptors increase and endometrial PGF2a Myometrial contraction, luteolysis, decreased progesterone Relaxin secretion Placental separation from endometrium Fresh non-autolysed foetus
Rapid foetal death -> loss of pregnancy by other mechanisms -> autolysed foetus
Embryonic death
15-30% considered normal
Expulsion/repulsion
Can return to oestrous at normal interval or delayed return to service
Infections rarer: Ureaplasma spp., Tritrichomonus foetus, Campylobacter spp.
Mummification
Usually multiparous animals
Foetal skin is well-developed enough to withstand autolysis
Absorption of placental and foetal fluids
No odour, closed cervix, time point of expulsion varied
Genetic, viral, protozoan infections. placental insufficiencies, no putrefying bacteria
Maceration
Foetus becomes liquified - bacterial uterine infection required
Reabsorption (early cases) or expulsion with purulent exudate
Only incomplete if foetal bones are developed
Foetid odour
Common with venereal infections by Campylobacter foetus venerealis and Tritrichomonas foetus or non-specific endometrial infections
Often leads to pyometra or endometritis
Perforation of uterine wall by foetal bones possible
Emphysema
Putrefactive organisms ascending from the vagina
Patent cervix
Dystocia at or near tern and complete abortion
Putrefaction of foetus which distends with foul gas and crepitates
Advance uterine lesions often fatal to dam - toxaemia
Leptospira hardjo
Spirochaete
Major cause of bovine abortion, infertility and milk loss
Zoonotic
Reservoir: cattle and sheep co-grazing, water, introduced new animals/shared bull
Bacillus licheniformis
Oppurtunistic pathogen
Spore-forming, aerobic, Gram positive rod
Sporadic abortion from the environment
Chlamydophila abortus
Enzootic abortion, obligate intracellular pathogens, persistent infection, late pregnancy abortion in ewes
Subsequent fertility not affected
Uterine prolapse
Immediately postpartum Hypocalcaemia Emergency! Support when cow is standing Remove foetal membranes Epidural block
The puerperium
Period after parturition when repr tract returns to its non-pregnant state so pregnancy can re-occur
Involution
Greatest decrease in uterine size occurs in first few days
Completed after 26-50d
Regeneration of the endometrium
Uterine caruncles undergo degenerative changes probably due to vasoconstriction and ischaemia - necrosis and sloughing
Necrotic material, blood and foetal fluids constitutes the pp lochial discharge
Resumption of ovarian cyclical activity
7-10d pp, increase in plasma FSH concentrations associated with 1st pp follicular wave
Ovulation will only occur if the follicle produces enough oestradiol to stimulate adequate LH adequate secretion
Puerperal metritis
Systemic illness
Purulent fetid fluid in uterine lumen - distended fluid filled atonic uterus
Elevated rectal temperature 40-41
Dullness, depression, milk drop, inappetence, few day pp
Sore, swollen and inflamed vagina and vulva
Systemic toxaemia, pyaemia
Anaesthesia for C-section in cow
0.8-1ml IV Xylazone to sedate (if necessary)
Epidural if straining
Local block: line, inverted āLā
Paravertebral: T12, L1, L2, L3
Primary uterine inertia
Pigs
Early cessation of farrowing or failure to start farrowing
No straining
Causal factors: lack of uterine contractility/tone
Secondary uterine inertia
Pigs
2nd stage labour
Sow is staining but no effect - may have become exhausted
Oxytocin 2-5iu given IM at 30min intervals
Downer sow
Failure to rise in the periperturient period
Causes: lactation osteoporosis - fracture of pelvis/femur, muscle weakness, apophysiolysis, rupture of lesser trochanter
Support, cull if fractured, improve surfacing
Lactation problems
Pigs
Non-functioning teats
Agalactia: failure to let down milk, inject oxytocin (10iu)
Hot painful immature glands with normal milk
Ergot poisoning: poor mammary development and no response to oxytocin
Water deprivation
Coliform mastitis
Pigs
Anorexia, pyrexia, loss of milk production
Causal agents: Pseudomonas, Enterobacter, Circobacter and Morganella. Most commonly E.coli, Klebsiella, environment pathogens
Pyogenic mastitis
Pigs
Generally well
Usually single gland affected - hard and pendulous
End of lactation/soon after weaning
Staph, strep (also Actinomyces)
Urinary tract disease
Pyelonephritis/cystitis
Pigs
Sudden death, 3 weeks post mating, mid-pregnancy, post-partum
Haematuria, pyrexia, bloody vulval discharge, inappetence
Fibrin, pus and blood while urinating
Depression, death
Congenital abnormalities
Piglets
Splayleg: muscle weakness problem in adductor muscles in heavy, male piglets
Atresia ani: may be able to cut through layer of skin if bulge present - form an anus, Euthanasia
Epitheliogenesis imperfecta: may die or recover, differentiate from other wounds, may be inherited - new boar
Mammary tumour types
Benign: adenoma, mesenchymal tumour, mixed tumour
Malignant: Carcinoma (solid, tubular, papillary, inflammatory), sarcoma, carcinoma
