Problems during bovine pregnancy Flashcards
Steps needed for a cow to conceive and stay pregnant.
- Synchronisation of ovulation and the introduction of fertile sperm into the female genital tract.
- Transport of sperm to site of fertilisation.
- Transport of egg to site of fertilisation.
- Suitable conditions in oviduct for fertilisation.
- Suitable environment in uterus for embryo growth.
Suitable uterine conditions for maintenance of pregnancy.
- Normal uterus.
- Appropriate hormonal status.
- Freedom from uterine infection.
- % fertilisation failure.
- % early embryonic death.
- % late embryonic death.
- % abortion.
- % total repro wastage.
- 10%.
- 25%.
- 5%.
- 5%.
- 45%.
Early embryonic death.
Dies before day 15 of pregnancy.
Cow returns to oestrus at normal interval and it is impossible to differentiate from fertilisation failure. Animals present as ‘repeat breeders’.
Late embryonic death.
Embryo dies between 15 days and 42 days of pregnancy.
Cow returns to oestrus after a prolonged and irregular interval.
There may be a slight vulval discharge.
Causes of embryonic death.
Genetic factors.
Stress (incl. heat stress).
Infection resulting in pyrexia.
Fatty liver disease.
Nutritional deficiencies and excesses.
Endocrine deficiencies, asynchrony and imbalance.
Non-specific infectious agents.
Small embryo.
Specific infectious agents responsible for embryonic death.
- Leptospira hardjo.
- Campylobacter foetus venerealis.
- Bovine viral diarrhoea virus.
- Bovine Herpes Virus-1 (BHV-1) (IBR) (IPV) (IBP).
- Granular vulvo-vaginitis (Ureaplasma diversum).
- Histophilus somni.
- Tritrichomonas foetus (not UK).
*all can be venereal.
Foetal death.
Occurs between day 43 of pregnancy and term.
Can be followed by expulsion of foetal fluids, autolysis of foetal tissue and membranes which are voided and are sometimes not detected.
Can also be followed by reabsorption, abortion, mummification, foetal maceration, stillbirth.
- What happens in foetal mummification?
- What does foetal mummification feel like on rectal palpation?
- Treatment of foetal mummification.
- Foetus dies and becomes dehydrated. CL persists. Cow fails to calve at expected time. No udder development.
- Hard mass in uterus. No placentomes, fluid or fremitus, CL maintained and cervix closed.
- PGF2a.
NB corticosteroid not effective.
Types of mummification.
Papyraceous (dry), haematic.
- Breeds where papyraceous mummification occurs.
- What happens in this mummification?
- Causes.
- Any.
- All foetal fluids slowly resorbed.
- Infections.
BVD, LEPTO, NEOSPORA, GENETICS.
- Breeds where haematic mummification occurs.
- Cause?
- What happens?
- Channel Island breeds.
- Autosomal recessive gene.
- Placental haemorrhage and subsequent fluid reabsorption, leaving thick, sticky, ‘chocolate’ coating.
What is foetal maceration and what happens?
Sequel to foetal death.
Occurs in cows after third month of gestation and occurs after incomplete process of abortion.
CL regresses, parturition process begins but not completed.
Partial dilation of cervix.
Vaginal discharge.
Bony remnants palpable per rectum and confirmed by ultrasound.
Cow usually remains well.
Treatment of foetal maceration.
Rarely attempted as rarely effective.
However, some suggestion of successful surgical approach via gluteal muscles.
Abnormalities of foetal fluids and intra-foetal fluids.
Hydrops = excessive accumulation of foetal fluids.
Hydramnios, hydrallantois.
Hydrocephalus, foetal anasarca, foetal ascites.
Hydramnios.
Clinical signs.
Due to failure of swallowing by foetus.
Usually co-exists w/ foetal abnormality e.g. Bulldog calf of Dexter, Hydrocephalus in Hereford.
Often no external signs in cow.
Exam per rectum.
- Excessive uterine enlargement.
- Placentomes usually palpable.
Hydrallantois
Not usually associated w/ foetal abnormality.
Foetal/maternal incompatibility is basic cause.
Due to failure of selective reabsorption of electrolytes (Na pump) from the allantois.
- Clinical signs of hydrallantois.
- Prognosis of hydrallantois.
- Abdo distension.
Per rectum – huge fluid filled mass palpable plus bilateral fremitus.
Placentomes and foetus often impalpable.
Animal may become recumbent and die. - Guarded.
Treatment of hydrallamtois.
Medical preferred – induce abortion w/ PGF2a. Dexamethasone. May be dystocia, so need to assist.
Surgical – ‘2-stage’. Drainage of allanto-chorion using large gauge needle inserted low in right flank or via catheterisation of cervix.
30L fluid removed followed by C section or drug induced abortion.
Breed affected most by anasarca?
Ayrshire breed.
- When does uterine rupture occur mostly?
- Clinical signs of uterine rupture.
- Treatment of uterine rupture.
- Parturition due to mismanagement of dystocia.
- Cessation of labour.
Shock, pain and external haemorrhage. - Cull.
Perform exploratory laparotomy.
Remove foetus.
Repair uterus.
- When does vaginal prolapse usually occur?
- Aetiology of post-calving prolapse?
- after 7th month of pregnancy.
Can occur post-calving. - Multifactorial, breed (Hereford), Parity, Overfeeding, Lack of exercise, Sloping surface to stand on, previous prolapse.
Treatment of vaginal prolapse.
Epidural and clean and repair any damage.
Retain prolapse w/ either trusses and harnessed or sutures (purse-string (Buhner’s using TAPE) (Mattress sutures)).
