Large Animal Clinical Reproduction 2

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Large Animal Clinical Reproduction 2 by Mind Map: Large Animal Clinical Reproduction 2

1. Dystocia

1.1. Pre-parturient stage - Parturition - Puerperium - Postpartum period

1.1.1. Allantochorion - cervix and vagina relax, birth canal - allantoamnion from bursting - lubricant

1.2. Mare: 1-2% ponies, 10% draught breeds Cow: 3-4% dairy, higher beef Ewe: 2-3%; Doe: 1-2%; Sow: <1% Bitch 100% in some brachycephalic/achodroplastic breeds Queen: <1% in feral animals, high in brachycephalics

1.2.1. Main problem = foeta-maternal disproportion Foetal monsters

1.2.2. Uterine intertia

1.2.3. Hypoaclcaemia - straining not enough

1.2.4. Disposition

1.2.5. Ring womb/birth canal not ready hormonally

1.2.6. Uterine torsion

1.3. Dystocia = emergency

1.3.1. History - full term/overdue/early? primigravida/multigravida Pregnancy problems? How long has it been straining? Water bag? Foetal fluids? Foetus? What has been done so far? Exam - general, exhaustion, milk fever, ill? Adequate restraint, floor grip Specific exam - keep clean, reduce change of endometritis, dam position, feel cervical ring, injuries previous and new, foetus, more than one? live or dead (pinch)? Vulva, vagina, cervix check Calf is secondary - make sure the cow will live! Equipment - Lubrication important, disinfectant, cotton wool Local anaesthetic, calcium, antibiotics Head/leg snares

1.3.2. Correction Manipulation - lube, reposition, traction Manual dilation of vagina and vulva Chain or rope - proper placement, above and below fetlock joint, or on head Hip lock - head snares, rotate once head out Head out, shoulders and hips obstacles Hip also an obstacle - pelvis oval shape Caudal presentation - dilate vulva and vagina, check umbilical cord, hock joint, deliver ASAP, pull Dorsally Consider uterospamolytic - Phenbutyryl Foetotomy, or C-section (not monsters) Anaesthesia - Epidural, Paravertebral, Inverted L, Line block Sedation or GA Presentation = longitudinal axis of foetus and dam and portion of foetus entering birth canal: Longitudinal (normal) anterior, Longitudinal posterior, or transverse Position - relationship of dorsal surface of foetus and surface of maternal birth canal: Dorsal (normal), Ventral, Lateral (unilateral/bilateral) Disposition - occurs due to: weak contractions, delayed foetal reflexes development, weak foetal movements, competition of uterine space, oversized, ankylosis (cant stretch)

1.3.3. After care Mother: Trauma, antibiotics, oxytocin, NSAIDs Neonate - navel dip, colostrum

2. Pregnancy Complications

2.1. Pregnancy Failure

2.1.1. Fertilisation

2.1.2. Embryonic loss 43% Calving rate in UK 33% US Most mortality by day 42 Physiological factors Pathological factors (genetic, environmental) Early/late embryonic mortality Foetal loss after day 42 - irregular returns Maceration, mummification (CL persists), abortion, stillbirth

3. Puerperium Disorders

3.1. Repro tract back to non-preg state - want short duration so can get preg again

3.1.1. Involution, endometrium regeneration, elimination of contaminants, resumption of ovarian cyclical activity Involution Check for pathology/infection (fluid discharge, should be clear by fourth week of Lochia) Involution of uterus - palpable by 8-10 days, completed 26-50 days Vasculature compression, discharge fluids/tissue, myometrial contractions Atrophy, myofibril size reduction Controlled by prostaglandins/oxytocin - can use exogenous acceleration 2-3 days pp Endometrium regeneration - caruncles degenerative change (vasoconstriction and ischaemia), slough off into Lochia, with bloods and foetal fluids - 2-9 days pp, yellow/reddish brown colour No fetid colour Systemic response (acute phase proteins) Bacterial contamination E.coli, streptococci, staphylococci, arcanobacterium pyogenes, Fusobacterium necrophorum, Prevotella spp. - growth in Lochia Ovarian cycle PP pituitary refractory 7-10 day FSH increase, then PP follicular wave, (silent) ovulatoin

3.1.2. Disorders affecting it: Dystocia, uterine prolapse, RFM, uterine disease Dystocia C-section - retained foetal membranes, contractility problems Breakage of physical host barriers, tissue damage, contamination, uterine inertia Prolapse Invaginated, more in pluriparous cows vs heifers Retained Foetal Membranes (RFM) Common in bovine, uterine infection and infertility contribution, 25-40% incidence with dystocia When dehiscence and expulsion fails e.g. hypocalcaemia Uterine Disease Depends on elimination during involution Impairs fertiltiy Physical barriers + immune defences

4. Reproductive surgery in Farm animals

4.1. Castration

4.1.1. Prevent indiscriminate mating, aggression, easier management, safety, reduces meat taint, improve carcass quality (more fat)

4.1.2. Reduced growth rate, less food conversion efficiency, pain, more fatty carcasses, can't breed

4.1.3. Anaesthetic - >2 mo (bull, goat) >3 mo (ram) Elastrator ring for <1 week Calves - usually castrated, except bull beef done up to 18 months, better if young Lambs - usually, old lambs = severe set back Pigs normally not castrated Elastrator ring - simple, low failure, cheap Only 1 week of age, painful, necrotic tissue Lambs and calves - ensure both testis within crotum, otherwise inguinal cryptorchid Burdizzo/bloodless castrator - calves and lambs No wound, but painful, high failure rate, scrotal ischaemia, may crush sigmoid flexure Restraint important, sedation? Safety Position spermatic cord on lateral sides of scrotum, 4cm above testis, second clamp 1cm distal to first Repeat for left, but stagger Open castration Bottom of scrotum to allow drainage Only touch tissues to be removed LA, cleanliness, swab scrotum J-shaped incision through skin, dartos, vaginal tunic - pull and twist off testis Could crush and cut spermatic cord

4.2. Caesarean section

4.2.1. Routine obstetric procedure in cattle, prompt decision, faster and safer than foetotomy Heifer or cow? >5 days expected calving date? Long period of unproductive straining? Valuable calf? BCS > 3.5? Big calf? Young dam (<18 mnths)? Gross abnormalities? concurrent disease? Cattle - mostly disproportion - head and elbows/stifles cannot be pulled into pelvic canal Success depends on: duration of dystocia, concurrent disease, skill and speed, skilled assistance, environment, live calf?

4.2.2. Standing surgery Halter, LHS, bulldogs in nose, rope on right hind, tie tail to right leg, Clenbuterol, Epidural, Xylazine IV (probably not as dopy calf) Clip, shave, prep, drape, test anaesthesia, incise abdomen, look out for air rush, avoid rumen, take leg out of uterus, stretch and pull out, check for second calf

4.2.3. Recumbent Cast, or xylazine Clenbuterol Tie tail, hobble legs, semi-lateral recum.

4.2.4. Anaesthesia Proximal Paraverterbral (T13, L1, L2, L3 Local block inverted L or line Epidiral if straining

4.2.5. Complications - straining, incised rumen, uterine tear, haemorrhage, recumbency, contamination, wound infection, endo/metritis, peritonitis, sepsis/emphysema, adhesions, infertility/sub-production, death

4.3. Small ruminants - single large sized lamb/kid Multiple foetuses (ketotic? Uterus very thin, horn torsion, vaginal prolapse, thin body wall - be careful not to tear

5. Pig Reproduction

5.1. £/kg = Cost of production + p/s/y + mortality UK target = 26 p/s/y, Denmark 30 - more efficient

5.1.1. No. of litters = 2.2 - 4.4 Litter = 12-14 pigs Pre-wean mortality <10%

5.2. Puberty (8 mnths, 120kg for mating) Mated on oestrous (3rd) Gestation 115 days, lactate 4 weeks, reutrn to oestrous 5 days later ,culled per parity (can be up to 6-8)

5.2.1. Pregnancy - range of litter sizes, oestradiol for maternal recog., embryo nutrients, prepare uterus, inhibit PG production Early embryo initiate change in uterus, secrete oestradiol PD - non oestrous return, US, A mode, Doppler (see convoluted uterus with fluid), hormones, visual

5.2.2. Lactation = 3 weeks, WOI = 6 days, then oestrous (48 hours, ovulation at about 2/3 through i.e. 32 hours) increaesd lactation, shorter weaning, longer oestrous - can be variable, problems with insemination

5.3. Farrowing - induction - costly, risk of dates, easier management, fostering

5.4. Parity

5.4.1. Nutrition, management Optimal = 4-6, lose money after 6/7

5.5. Gilts

5.5.1. Disease free animals more expensive - no point if farm diseased already Culled sows - act as sentinels for incoming gilts - vaccinate during quarantine

5.6. Increase productivity

5.6.1. Low p/s/y = breeding herd improvement Number of litters and pre-weaning mortality can be influenced WOI should be short - not coming into oestrous early enough WOI - oestrous detection, duration of oestrous, insemination/mating time, body weight loss, empty days Weaning to farrowing: return rates (regular/irregular), abortions Longevity - culling rates, age of culling Target p/s/y = 24-26, litter size 11.5, regular returns 8%, irregular <3%, abortions <1%, farrowing rate 87% of herd, culling rate 35%, WOI 5 days

5.7. Disease of reproduction

5.7.1. Gestation: SMEDI, abortion, vaginal prolapse 30-40% abortions infectious small litter size = losses pre-ossification One size mummified/still births = uterine environment Differing sizes = prolonged damaged to foetuses Infectious i.e parvovirus, PRRS Non-infectious = husbandry, management, stockmanhip, hygiene, environment, season, heat stress Genetics - parental/progeny Nutrition - micronutrients (Vt E, A due to poor feed storage - rancid) Toxic agents - misuse hormonal drugs, chemicals (teratogens), mycotoxins (Zearalenone in feed) Sequential death = viral <35 day most absorbed, 35-40 days ossification, >35 days = mummified or stillborn 70d incompetant Full term = 112-116 SMEDI Majority = porcine parvovirus (NOT abortion) Full term litter with smedi or live weakly piglets Stillbirth - when death occured? Vaginal prolapse pre-farrowing, replae, purse string suture or Buhner Antibiotics, NSAIDs

5.7.2. Neonatal loss Meconium - stomach or somewhere else = in-utero stress Normally accumulates in rectum - should not be expelled with membrane around it Lungs float - prepartum vs post partum death Worn cartilaginous tips/slippers? - post partum if worn

5.7.3. Piglet: mortality, chilling, crushing, starvation, hypothermia, bleed into umbilicus, congenital abnormalities Lack of colostrum, non-viable, diseased, fostering, management, sow factors Mostly by crushing Crushing = sow factors, environment, piglet factors Starvation - very common - should suck every couple of hours Sow factors and piglet factors Chilling - farrowing house should be 30 degree, or heat lamps - take long time to regain normal temp after chilling - lethargic, fail to suck, lie close to sow and crushed Umbilicus - 1/5 broken before birth - bleeding from umbilical stub - take longer to suckle, blood loss, infections CO poisoning - faulty heaters - not as common anymore Also electrocution, fires etc. Congenital : Splay leg, atresia ani, epitheliogensis imperfecta

5.7.4. Sow: uterine prolapse, lactation, agalactia, mastitis Swollen/damaged vulva - vulval biting, trauma from dystocia, farrowing crate injuries, zearelenone toxicity

5.7.5. Lab investigations Sample 3 foetuses, and placenta Stomach contents and/or liver Consider opportunistic infections if taken aspectically Antibodies in foetal fluid (pleural or abdmonal) - in-utero challenge Antigen detection (parvo, lapto, PCV2) Sow sampling - positive titres, disease within herd, rise in titre = recent infection APHA abortion kit - swine influ, Erysipelas, Parvo, PRRS, Lepto

5.7.6. Parturition Primary uterine inertia - no straining, lack of uterine contractility/tone Absence of straining, cervix dilated, no obstruction, lack of tone Secondary uterine intertia Assist farrowing, oxytocin IM at 30 min internals Toxaemia/infection - antibiotics and/or NSAIDs Acclimatisation to farrowing house and staff Uterine prlapse post-farrowing Euthanase or immediate slaughter and cross foster Marigold glove? catheterise prolapsed bladder?

5.7.7. Sow problems Downer sow Lactation osteoporosis, fractured pelvis/femur, muscle weakness, apophysiolysis, rupture of lesser trochanter Hypocalcaemia post farrowing Recumbency, coma, death, convulsions Non-functioning teats NEcrosis, trauma, inverted, poor mammary development, ergot poisoning, poor water supply, poor energy, chronic mastitis Protect teats using copydex/rubber glue Agalactia Water deprivation - empty dried glands, vulva chalky dry deposits Urinary tract disease Sudden death 3 weeks post mating, mid pregnancy, post partum Haematuria, pyrexia, bloody vulval discharge, fibrin, pus, inappetance, depression death Pyelonephritis/cystitis ineffective ttx once signs seen, otherwise potentiated sulphonamides in v. early cases Cystitis, Ureteritis, nephritis

5.8. Investigations

5.8.1. Farm records, underperformance areas, plan for visit, sampling, abbatoir visit (repro tract, disease outbreak investigation)