Ovine Perinatal Mortality

Question 1

Main determinants of fat lamb production.

Answer 1

Maximise conception rates.
Minimise embryonic and foetal losses.
Maximise neonatal lamb survival.
Maximise rate of growth of lambs.
Minimise losses from other causes.

Question 2

1. How many lambs lost in UK each year?
2. Neonatal loss target for well-managed lowland flocks.
3. % perinatal loss considered “normal”.

Answer 2

1. 3,000,000.
2. 5%.
3. <10%.

Question 3

1. Features of lamb that conclude been dead a long time.
2. Feature of lamb that conclude recently dead.
3. Features of lamb that conclude dystocia.

Answer 3

1. Mummification, autolysis, collapse of eyeball.
2. No thrombus in umbilical artery, square end to artery, lungs uninflated.
3. No thrombus in umbilical artery, tapered end to artery, lungs uninflated, localised oedema in prolonged dystocia.

Question 4

1. Feature that conclude death in first mins of life.
2. Features that conclude death in first hours of life.
3. Features that conclude death in first few days of life.

Answer 4

1. Thrombus in umbilical artery and lungs uninflated.
2. Lungs inflated, naval cord wet, hoof membranes still present.
3. Hooves hardened, naval cord shrivelled.

Question 5

How may prolonged second stage labour cause intrapartum death?

Answer 5

Prolonged second stage labour&raquo_space; subdural, subarachnoid and extradural haemorrhages around cranial and spinal meninges&raquo_space; which may cause death OR reduced mobility and sucking reflex which may cause death.

Question 6

1. Other reasons for intrapartum death?
2. Main cause of injury that can cause postpartum death of lamb.

Answer 6

1. • Oedema: “hung” lamb.
     - Ruptured liver (Vit E deficiency?).
     - Fractured ribs (posterior presentation).
     - Flail chest (all ribs broken at costo-chrondrial junction).
2. Fractures due to being trodden/laid on by ewe.

Question 7

Investigating perinatal mortality.

Answer 7

• History.
• Age group of ewes affected.
• BCS.
• Litter size and lamb weights.
• Hygiene of lambing pens.
• Peri-parturient management of ewes and lambs.
• Observe parturient ewes.
• Management/incidence of dystocia.
• Ewe-lamb bond.
• Colostrum/colostrum bank.
• Heat lamps.
• Navel treatment.
• Outdoor management.
• Records.

Question 8

What are most neonatal losses due to?

Answer 8

• Weakness at birth.
• Failure to suck (leads to hypothermia and lack of colostrum protection against neonatal diseases).
• Often due to disease or undernutrition in periparturient ewe, or if ewes in poor BC.
• Watery mouth.
• Diarrhoea.
• Navel/joint ill.
• Congenital disease.
• Haemolytic anaemia.
• Sub-capsular liver rupture.
• Predation.

Question 9

Hypothermia.

Answer 9

Cold alone cannot cause hypothermia.
Cold AND wet will – occurs soon after birth while lamb still wet.
Due to weakness and starvation.
Death 24-36hrs after birth – brown fat stores used up or lamb not sucked.
Death at >5hrs old – likely hypoglycaemia.

Question 10

Causes for weakness at birth.

Answer 10

• Small lambs from multiple births (born earlier).
• Placental insufficiency – placenta fully grown by 90 days, deficiency before this restricts growth and ability to transfer nutrients.
• Lamb growth – needs good nutrition in second half of pregnancy.
• Supervision at lambing (lack of).
• Congenital diseases: toxo, BD.
• Iodine deficiency.
• Subclinical copper deficiency.

Question 11

Treatment of hypothermia.

Answer 11

• Moderate = 37-39C.
  – Dry and feed colostrum by stomach tube.
• Severe = <37C.
  – If <5hrs old, unlikely to be hypoglycaemic.
  –> warm in warming box to 37C then feed w/ colostrum (50ml/kg).
  – If >5hrs old assume hypoglycaemic.
  –> Give energy first before warming otherwise may have hypoglycaemic fit.
  – If lamb very weak or unconscious, do NOT stomach tube.
  –> give intraperitoneal injection of glucose.
  –» 10ml/kg of 20% glucose.
  –» 2.5cm 19G needle.
  –» hold lamb vertically.
  –» 1.5cm lateral and 2.5cm caudal to umbilicus, then warm lamb.

Question 12

Control of hypothermia in lambs.

Answer 12

Avoid weak lambs.
- Use appropriate breed for environment.
- Adequate ewe nutrition.
- Adequate iodine.
- Good supervision at lambing.
- Control toxo and BD.
- Give weak lambs 60-100ml colostrum and provide heat lamps.
Avoid cold wet environment.
- Access to shelter/housing.
- Emergency shelters from straw bales.
- Lamb macs (also confuses foxes!)
Ensure lambs suck.
- Good supervision and extra supervision of ewe lambs.
- Check ewe has milk for lambs.
- Choose breed w/ good mothering ability.
- Make provision for orphan lambs.

Question 13

Navel ill/joint ill.

Answer 13

• V common.
• Bacteria enter through cord.
• Haematogenous spread.
• Swelling of navel.
• Meningitis.
• Joint ill.

Question 14

Bacteria that can cause navel/joint ill.

Answer 14

Fusobacterium necrophorum.
Streptococcus dysgalactiae.
Staphylococcal spp.
Actinomyces pseudotuberculosis.
Haemophilus agni.
Mannheimia haemolytica.
E. coli.

Question 15

1. Bacteria most commonly isolated from joints w/ joint ill.
2. Pain?
3. Age group of lambs affected by joint ill.
4. Sign?
5. Acute stages.

Answer 15

1. Streptococcus dysgalactiae.
2. V painful as bone affected: osteoarthritis.
3. <4wks old.
4. Often recumbent, few w/ omphalitis.
5. Joint not swollen.

Question 16

Joint ill treatment.

Answer 16

• ABX that perfuse joint cavity i.e. penicillin G, oxytetracycline (some streps resistant).
  10 days treatment to eliminate infection.
• Joint flushes – sterile saline and perfuse w/ ABX.
• Pain relief.

Question 17

Navel ill treatment.

Answer 17

• Lance and irrigate abscesses w/ sterile saline and perfuse w/ ABX.
• Liver abscesses occur in hopeless cases.
• Meningitis – early treatment w/ high doses ABX.
  – Ensure lamb does not damage itself.

Question 18

Joint/navel ill control.

Answer 18

Dress navels w/ tincture of iodine asap after birth.
Provide dry and well-bedded pens.

Question 19

1. How to best maximise lambs/ resistance to disease.
2. Congenital diseases of lambs.

Answer 19

1. Colostrum intake.
2. • BD.
     - Daft lamb disease.
     - Swayback.
     - Entropian.
     - Red foot.

Question 20

1. Daft lamb disease.
2. Swayback.
3. Red foot.

Answer 20

1. Hereditary abnormal cerebellar development.
   Seen in border Leicesters.
   Lambs appear stupid, ataxic, intention tremor.
2. Weak, ataxia, particularly hindlimbs, die w/in 3-4d.
3. Scottish black face lambs, loose hoof cases: cull.

Question 21

Entropian treatment.

Answer 21

Clips.
Suture.
Sterile paraffin.
Antibiotic injection.

Question 22

Haemolytic anaemia.

Answer 22

Cow colostrum fed to lambs or kids.
May contain antibodies to sheep blood group antigens.
Absorbed bovine IgG attaches to sheep RBCs and to their precursors in bone marrow – recognised as foreign and destroyed.

Question 23

Diagnosis of haemolytic anaemia.

Answer 23

• Seen 5-12 days of age.
• Dull and lethargic.
• Anaemia and jaundice.
• Anaemia evident when PCV <0.1 l/l.
• (n= 0.27-0.35).

Question 24

Treatment for haemolytic anaemia.

Answer 24

• IV blood transfusion (expensive).
• Intraperitoneal blood.
• Blood collected and mixed w/ 10% of 3.8% sodium citrate.
• Given as for glucose (~60ml).
• Antibiotic cover.
• Iron dextran.

Question 25

Controlling haemolytic anaemia.

Answer 25

• Pool colostrum as will dilute out any anti-sheep IgG from a single cow.
• Record identity of donor cows for future.

Question 26

Subcapsular liver rupture.

Answer 26

• Found dead w/ no evidence of trauma.
• Occurs in lambs up to 3wks old.
• Associated with low vit E status.
• Check blood and/or liver vit E.