Pregnancy failure in ruminants

Question 1

How does NEBAL affect lactating cows?

Answer 1

• in early lactation - cant consume enough DMI to meet energy needs
• weight loss
• immunosuppressed - dont deal with uterine inflam as well
• lower quality oocytes
• alter change to cyclicity
• smaller hormonal flucuations - wont express oestrus as well

Question 2

What are the causes of failure of ovulation?

Answer 2

• Acyclicity
  
  • NEBAL
  • endocrinologies
  • systemic disease
• Asynchronicity
  
  • behavioural oestrus miss timed with ovulation
• Anatomical
  
  • uterine tube blockage
  • may have had chronic endometritis/ inflam before

Question 3

WHat is this?

Answer 3

• post-parturient uterine inflam disease

Question 4

What are the anatomical / physical factors in females causing failure of conception?

Answer 4

• Free maritinism - segmental aplasia
• salpingitis
• vaginal regression
  
  • faecal material
  • thinner cows

Question 5

what day does MRP and definite attachment occur in cows?

Answer 5

• MRP = 18-17 days
• Definite attachment - day 18-22

Question 6

WHat level of early pregnancy loss is normal?

Answer 6

• Day 28-70 - 5-10%
• rare after day 70
• if getting about 5% - should do something about it
• recheck preg at 70 days

Question 7

What are the DDX for preg loss?

Answer 7

• primary - infectious cause
• secondary - infectious cause
• nutritional
  
  • NEBAL
  • deficiencies - Vit E/ iodine
  • food spoilage
• toxic
  
  • plants (brassicas), chemical (myotoxins)
• iatrogenic
  
  • rectal palpation
• genetics - congenital

Question 8

Whats SMEDI?

Answer 8

• stillbirth
• mummification
• embryonic death
• infertility

Question 9

Clinical signs, diagnosis, prevention for infectious abortion?

Answer 9

• clinical signs
  
  • pyrexia
  • milk drop
  • aborted material
  • inappetance
• diagnosis
  
  • send off materials to APHA lab
• control
  
  • vaccination, vector control, feed pres

Question 10

What are the most common bacterial, viral and protozoal causes?

Answer 10

• bacterial - L.hardjo, Salmonella Dublin, Brucella abortus
• virus - BVD (5% losses), BHV-1
• protozoa - neospora caninum

Question 11

What is neospora caninum?

Answer 11

• parasite
• lifelong infections
• doesnt cause abortions every year
• dog = DH
• cow = IH
• dog - ingest aborted materials
• produce sporozoites - on pasture - ingested
• abortion at 5-7 months
• vertical transmission occurs
• PCR on brain stem and heart base
• cull/ dont breed

Question 12

Significance of L. hardjo?

Answer 12

• spread in urine
• rodents, cows, sheep
• zoonotic
• abortion
• infertility
• pyrexia
• milk drop
• vaccination

Question 13

Significance of BHV-1?

Answer 13

• severe upper resp disease
• latent infection
• sheds during stress
• cause abortion storms
• vulvovaginitis, balanoposthis
  
  • +ve dam serology
  • liver histopathy

Question 14

Significance of Salmonellosis?

Answer 14

• host adapted vs non-host adapted
• cattle - S.Dublin, S.typhimurium
• abortion - may also have diarrhoea, pyrexia
• calves - resp disease, diarrhoea, septicaemia polyarthritis
• fecal-oral route/ aborted materials, wildlife reservoirs, zoonotic
• culture from foetal stomach contents

Question 15

How can spoiled silage cause abortion?

Answer 15

• L.monocytes - spoiled silage - winter (aerobic conditions)
• L.lichenformis / L.cereus - mouldy cereals
  
  • +ve foetal stomach contents
• fungal - mouldy feed
  
  • use mycotoxins

Question 16

What other bacteria cause abortion?

Answer 16

• E.coli
• Campylobacter
  
  • venereal spread
  • preputial wash, vaginal wash
• trueperella
• culture from foetal stomach contents