Bovine Flash Notes - Abortion

Question 1

what causes infectious bovine rhinotracheitis?

Answer 1

bovine herpes virus 1

Question 2

T/F: clinical signs are seldom seen in dams with abortions due to IBR

Answer 2

TRUE

Question 3

what does an aborted fetus due to IBR look like?

Answer 3

focal necrotizing lesions of tissue

Question 4

how is IBR causing abortions prevented?

Answer 4

intranasal MLV for breeding cows (won’t cause abortions), can use IM MLV in feedlot young & open females without risk of causing abortion

Question 5

what is the presumed cause of abortion due to actinomyces pyogenes?

Answer 5

maternal bacteremia

Question 6

when does actinomyces pyogenes cause abortion in cattle?

Answer 6

can occur at any stage but most often in late gestation plus or minus a retained placenta

Question 7

how is actinomyces pyogenes diagnosed as a cause of abortion?

Answer 7

isolate in nearly pure culture from abomasal contents from fetus, rule out other causes

Question 8

what are the most common lesions seen with an abortion from actinomyces pyogenes?

Answer 8

placentitis & bronchopneumonia

Question 9

what is the etiology of bovine campylobacteriosis?

Answer 9

campylobacter foetus venerealis - obligate parasite of the bovine genital tract that doesn’t affect other species, gram negative curved or spiral rod that is motile

Question 10

how is campylobacteriosis transmitted?

Answer 10

coitus

Question 11

what are the carriers of campylobacteriosis?

Answer 11

subclinical carrier bulls - crypts of the prepuce

Question 12

when does campylobacteriosis cause abortions?

Answer 12

sporadic abortions at 5-6 months

Question 13

what is the pathophysiology of campylobacteriosis?

Answer 13

vaginal infection that persists for 2-3 months that will prevent conception or cause early embryonic death with irregular returns to estrus - problem in replacement heifers, less common abortion in cows up to 8 months gestation

Question 14

what are the big clinical signs associated with bovine campylobacteriosis?

Answer 14

infertility, early embronic death, carrier bulls, causing repeat breeders, & a low % abortion

Question 15

how is campylobacteriosis prevented?

Answer 15

vaccinate heifers with killed bacterin 1 month before breeding & booster 2 weeks later, vaccinate bulls with 2.5x dose of cows repeatedly to prevent carrier state, revaccinate bulls & cows annually, AI from non-infected bulls or treat semen with streptomycin

Question 16

T/F: AI exclusively controls disease by prevention

Answer 16

TRUE

Question 17

how is campylobacteriosis treated?

Answer 17

animals will recover spontaneously within 5 months, so isolate - will resist reinfection after this

Question 18

how is trichomoniasis diagnosed in cattle?

Answer 18

diamond’s media - culture of preputial smegma from fornix of bulls, cervicovaginal mucus, uterine exudate, placental fluids, or fetal abomasal contents

Question 19

how are bulls with tritrichomoniasis treated?

Answer 19

imidazole, dimetridazole, or metronidazole

Question 20

how are cows with tritrichomoniasis treated?

Answer 20

either cull or give them 3 months of sexual rest

Question 21

how is tritrichomoniasis prevented?

Answer 21

AI reduces but doesn’t eliminate the chance of infection, young bulls in natural breeding helps to reduce incidence

Question 22

T/F: young bulls are resistant to infection from tritrichomoniasis

Answer 22

TRUE

Question 23

what are the main clinical signs caused by tritrichomoniasis?

Answer 23

early embryonic death, high non-pregnancy rate, increased calving intervals up to 100 days, & early occasional abortion around 3-4 months

Question 24

what is the number one mycotic cause of abortions in mares & cows?

Answer 24

aspergillus fumigatus

Question 25

when do mycotic infections cause abortion?

Answer 25

3rd trimester - often near term

Question 26

what is a possible sequelae of mycotic abortion?

Answer 26

retained placenta

Question 27

how is mycotic abortion diagnosed?

Answer 27

last trimester abortion with a retained placenta, leathery placentitis, & culture

Question 28

is fertility affected by mycotic causes of abortion?

Answer 28

nope

Question 29

how is mycotic abortion prevented?

Answer 29

reduce exposure to fungus

Question 30

when does brucellosis cause cattle to abort?

Answer 30

after 5 months gestation

Question 31

what are some sequelae of brucellosis?

Answer 31

retained placentitis, mastitis, & lameness

Question 32

how is brucellosis diagnosed as a cause of abortion?

Answer 32

culture of brucella abortus from fetal lung, fetal abomasal contents, placenta, uterine, or mammary secretions, titer of 1:100 for unvaccinated animals & 1:200 for vaccinated animals

Question 33

how is brucellosis prevented?

Answer 33

b. abortus strain 19 given to calves 4-12 months old to increase resistance to infection with a USDA tattoo in the right ear of vaccinated animals. replacement animals (vaccinated calves or non-pregnant heifers), pregnant/fresh cows kept in brucellosis free areas, & isolating replacement animals for more than 30 days & retesting before adding them to the heard

Question 34

what screening tests are used for brucellosis in dairy herds?

Answer 34

brucella milk ring test every 3 to 4 months to ID infected dairy herds - if positive, individual blood tested on all with reactors slaughtered

Question 35

what screening tests are used for brucellosis in non-dairy herds?

Answer 35

market cattle testing - serum is collected from cattle for slughter at market, reactors are traced to herd of origin & all animals tested, & reactors are slaughtered

Question 36

what classifies a herd as being brucella free?

Answer 36

herds maintained by BRT/MCT & slaughter with 2-3 successive negative tests given at regular intervals

Question 37

when does foothill abortion cause cattle to abort?

Answer 37

late in gestation - around 6-7 months, or they will have very weak calves

Question 38

T/F: cows with epizootic abortion don't show clinical signs

Answer 38

TRUE

Question 39

what transmits epizootic bovine abortion?

Answer 39

soft ticks

Question 40

how is foothill abortion diagnosed?

Answer 40

enlarged spleen in the fetus seen postmortem, increase in IgG in fetal blood, but no serologic test because agent is unknown

Question 41

what drug reduces the rate of abortion due to foothill abortion?

Answer 41

chlortetracycline

Question 42

how is foothill abortion prevented/controlled?

Answer 42

seldom abort in subsequent pregnancies & no vaccine - so, expose heifers to ticks before breeding & change from spring to fall calving to reduce exposure to ticks only during the last trimester

Question 43

neosporosis causing abortion in cattle is a major problem in what state?

Answer 43

california

Question 44

what is the only clinical sign associated with neosporosis in cattle?

Answer 44

sporadic/multiple, or storms of abortions - year round abortions!!!!