Problems during bovine pregnancy

Question 1

Steps needed for a cow to conceive and stay pregnant.

Answer 1

• 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.

Question 2

Suitable uterine conditions for maintenance of pregnancy.

Answer 2

• Normal uterus.
• Appropriate hormonal status.
• Freedom from uterine infection.

Question 3

1. % fertilisation failure.
2. % early embryonic death.
3. % late embryonic death.
4. % abortion.
5. % total repro wastage.

Answer 3

1. 10%.
2. 25%.
3. 5%.
4. 5%.
5. 45%.

Question 4

Early embryonic death.

Answer 4

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’.

Question 5

Late embryonic death.

Answer 5

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.

Question 6

Causes of embryonic death.

Answer 6

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.

Question 7

Specific infectious agents responsible for embryonic death.

Answer 7

• 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.

Question 8

Foetal death.

Answer 8

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.

Question 9

1. What happens in foetal mummification?
2. What does foetal mummification feel like on rectal palpation?
3. Treatment of foetal mummification.

Answer 9

1. Foetus dies and becomes dehydrated. CL persists. Cow fails to calve at expected time. No udder development.
2. Hard mass in uterus. No placentomes, fluid or fremitus, CL maintained and cervix closed.
3. PGF2a.
   NB corticosteroid not effective.

Question 10

Types of mummification.

Answer 10

Papyraceous (dry), haematic.

Question 11

1. Breeds where papyraceous mummification occurs.
2. What happens in this mummification?
3. Causes.

Answer 11

1. Any.
2. All foetal fluids slowly resorbed.
3. Infections.
   BVD, LEPTO, NEOSPORA, GENETICS.

Question 12

1. Breeds where haematic mummification occurs.
2. Cause?
3. What happens?

Answer 12

1. Channel Island breeds.
2. Autosomal recessive gene.
3. Placental haemorrhage and subsequent fluid reabsorption, leaving thick, sticky, ‘chocolate’ coating.

Question 13

What is foetal maceration and what happens?

Answer 13

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.

Question 14

Treatment of foetal maceration.

Answer 14

Rarely attempted as rarely effective.
However, some suggestion of successful surgical approach via gluteal muscles.

Question 15

Abnormalities of foetal fluids and intra-foetal fluids.

Answer 15

Hydrops = excessive accumulation of foetal fluids.
Hydramnios, hydrallantois.
Hydrocephalus, foetal anasarca, foetal ascites.

Question 16

Hydramnios.
Clinical signs.

Answer 16

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.

Question 17

Hydrallantois

Answer 17

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.

Question 18

1. Clinical signs of hydrallantois.
2. Prognosis of hydrallantois.

Answer 18

1. Abdo distension.
   Per rectum – huge fluid filled mass palpable plus bilateral fremitus.
   Placentomes and foetus often impalpable.
   Animal may become recumbent and die.
2. Guarded.

Question 19

Treatment of hydrallamtois.

Answer 19

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.

Question 20

Breed affected most by anasarca?

Answer 20

Ayrshire breed.

Question 21

1. When does uterine rupture occur mostly?
2. Clinical signs of uterine rupture.
3. Treatment of uterine rupture.

Answer 21

1. Parturition due to mismanagement of dystocia.
2. Cessation of labour.
   Shock, pain and external haemorrhage.
3. Cull.
   Perform exploratory laparotomy.
   Remove foetus.
   Repair uterus.

Question 22

1. When does vaginal prolapse usually occur?
2. Aetiology of post-calving prolapse?

Answer 22

1. after 7th month of pregnancy.
   Can occur post-calving.
2. Multifactorial, breed (Hereford), Parity, Overfeeding, Lack of exercise, Sloping surface to stand on, previous prolapse.

Question 23

Treatment of vaginal prolapse.

Answer 23

Epidural and clean and repair any damage.
Retain prolapse w/ either trusses and harnessed or sutures (purse-string (Buhner’s using TAPE) (Mattress sutures)).