Bovine Abortion (Galvao)

Question 1

Abortion: def in cows

Answer 1

• loss of fetus between 42-260 days of gestation
  
  • earlier than 42 days is embryonic loss
  • after 260 days calves can usually survive: born dead: still born
• normal gestation length: 280 days

Question 2

Incidence of abortion in cattle

Answer 2

• 10-15 % => dairy cattle
  
  • high incidence of dz
• 2.5-5 % => beef cattle

Question 3

Etiology non-infection abortion in cattle

Answer 3

• Drugs
• VItamin, macro or micronutrient deficiency
• Toxic plants or substances
• Elevated temperature

Question 4

2 main virus causes abortion in cattle

Answer 4

1. Infectious bovine rhinotracheitis virus (IBR)
   
   • aka: herpesvirus-1 (BHV-1)
2. Bovine viral diarrhea virus (BVD)

Question 5

IBR

about

Answer 5

• incidence has decreased: vaccination
• manifestations
  
  • respiratory, abortion, vaginitis/balanophosthititis, neonat septicemia
• abortions after 4 months gestation
• fetuses retained 48-72 h - autolyzed

Question 6

IBR

Diagnosis

Answer 6

• Microscopic
  
  • focal necrosis in liver
  • intranuclear inclusion bodies
• serology - paired samples 2-3 weeks apart
  
  • 4-fold increase in titers suggest infection
• virus isolation from placenta
• virust identification - FAT

Question 7

Vaccination IBR

Answer 7

• As calves: 4-6 months of age
• 3-4 weeks prior to breeding
• types
  
  • modified live
    
    • vaccine can cause abortion w/o prev vacc w/in past 12 months
    • revaccinate every year
  • Killed
    
    • safe in pregnant cows
    • require booster

Question 8

BVD

Answer 8

• Pest virus
  
  • More imp for beef cattle…
  • Two genotypes: type 1 and 2 (make sure vaccine has both)
    
    • ​two biotypes:
      
      • cytopathic = death
      • non-cytopathic = persistently infected calves
  • Disease
    
    • GI: mucosal
    • Repro: infertility, mummification, abortion, stillbirth, weak calves
    • Congenital: brain, eyes, skin, joints

Question 9

BVD

diagnosis

Answer 9

• Persistently virus proteins recognized as self (1:25:04)
• Dx
  
  • Virus isolation from whole blood
  • Immunohistochemistry, ELISA, PCR
    
    • snip of the ear

Question 10

BVD control

Answer 10

• ID and eliminate PI calves
• Vaccinate 4-6 months old and 3-4 weeks prior to breeding
  
  • modified live
    
    • revaccinate every year
    • not in preggos that haven’t had vaccine w/in last 12 months
  • killed
    
    • safe in pregnant cows
    • Requires booster

Question 11

Common Bacterial causes bovine abortion

Answer 11

1. Leptospira spp
   
   • main cause dairy
2. Campylobacter spp
   
   • main cause beef (or dairy that uses natural breeding)
3. Brucella abortus = eliminated from

Question 12

Leptospirosis

Answer 12

• Spirochete (zoonotic)
• Leptospira spp.
  
  • Interrogans
  • Borgpetersenii
  • Kirschneri
• ​TX: urine, products of abortion
• Invasive via mucous membranes
  
  • Incubation of 4-10 days
  • Bacteremia 2-6 weeks
  • Leptospiruria 2-6 months

Question 13

Leptospirosis species and serovars

Answer 13

• interrogans
  
  • Pomona; common incidental
  • Hardjo (maintenance)
  • bratislava
  • canicola
  • icterohaemorrhagiae
• Borgpetersenii
  
  • Hardjo (maintenance) - subtypes hardjo-bovis (US)
• Kirschneri
  
  • grippotyphosa

Question 14

Maintenance vs Incidental Serovars

Answer 14

• maintenance
  
  • infected with a host adapted serovar - endemic infection
  • persistent / carrier
  • asymptomatic
  • high susceptibility
• Incidental
  
  • high doses for infection
  • Acute form of disease
  • have leptospiruria for short time

Question 15

Clinical Signs maintenance vs incidental

Answer 15

• Chronic: Maintenance Serovars
  
  • Infertility
  • Abortion
  • Agalactae
  • Mastitis
• Acute: Incidental Serovars
  
  • Hemoglobinuria
  • Fever
  • Hemolytic anemia
  • Jaundice Nephrosis
  • Agalactea
  • Mastitis

Question 16

Abortion in Cattle

Answer 16

• L. borgpetersenii - hardjo - bovis

Question 17

Leptospirosis DX

Answer 17

• Serology
  
  • MAT: specific but not sensitive
• FAT in urin - specific and sensitive
• Culture
• PCR
• Silver staining

Question 18

Leptospirosis Control

Answer 18

• Vaccination
  
  • start with calves 4-6 mo
  • then 2 x a year
  • commercial vaccines: serovar hardjo-prajitno and/or hardjo-bovis
• Environmental Management
• Wildlife: skunks, opposum
• Treat heifers with OTC before breeding and cows at dry-off

Question 19

Campylobacteriosis (vibriosis)

Answer 19

• Insideous venereal dz of cattle
  
  • infertility
  • occasionally abortion
• Species
  
  • campylobactor fetus ssp fetus
  • campylobactor fetus ssp venerealis

Question 20

Campylobacteriosis (vibriosis)

Clinical signs

Answer 20

• Cows: prolonged estrous cycle
• Herd: low preg rates
• Transmitted during coitus
  
  • causes endometritis incompatible with embryo development (EED)
  • extended estrous cycle
• Abortion 5% due to placentitis
  
  • 4-6 months

Question 21

Campylobacteriosis (vibriosis)

DX

Answer 21

• Herd history
• Antibodies in cervical mucus
• Direct culture
  
  • Clark’s media for transport
  • Skirrow’s for culture

Question 22

Campylobacteriosis (vibriosis)

Control

Answer 22

• Vaccination
  
  • effective for 4 months
• Changes in breeding management
  
  • use young bulls
  • check during BSE
    
    • usually scrape for: tritichomonus and campy
  • Change to AI

Question 23

Protozoa

Answer 23

• Tritrichomonas foetus
  
  • beef cattle
• Neospora caninun
• Sarcosystis spp
• Toxoplasma gondii

Question 24

Trichomoniasis

Clinical Signs

DX

Answer 24

• Clinical signs
  
  • similar to vibriosis
  • post coital pyometra
  • abortion first half of gestation
• Diagnosis
  
  • swab from bull prepuce
  • pyometra fluid
  • modified diamonds media

Question 25

Trichomoniasis Control

Answer 25

* Changes in breeding managment * use young bulls * check bulls during BSE - **eliminate positives** * Change to AI * **no vaccine**

Question 26

Neosporosis

Answer 26

* Major cause of abortion in dairy cows * Dogs/coyotes definitiv host * Abortion in early second trimester * Vertical transmission from dam to fetus (70%) * Specific lesions (cysts) in heart and brain of fetus * Vaccine with questionable efficacy

Question 27

Mycotic abortions

Answer 27

* Thickened and leathery cotyledon * Fetal skin lesions (20% of cases) * Non infectious * chromosomal abnormalities * Drugs * Nutritional * Endotoxin * Heat stress

Question 28

Toxic plants Other toxins

Answer 28

* Toxic plants * Ponderosa pine * Locoweed * Broomweed/snakeweed * Moldy sweet clover * Other toxins * Coumarin =\> rat poison * Mycotoxins * Nitrates

Question 29

Investigation of abortion problems

Answer 29

* Complete history - vaccination * Percentage of animal abortion * Stage of gestation * Categories of animals * Collect fetuses and placentas for necropsy * submit samples to good lab * contact lab for advice

Question 30

Study key

Answer 30

1. know epidemiology, clinical signs and diagnosis for 1. IBR 2. BVD 3. Lepto 4. Vibrio 5. Trich 6. Neospora 2. Be familiar with non-infectious causes of abortion