Bovine Top 20 Reproductive Diseases - Part 2

Question 1

what cows are most often affected by milk fever?

Answer 1

high producing dairy cows, cows on their 3rd or more lactation, jersey cows, & multiparous mature dairy or beef cows

Question 2

when does milk fever occur in cows?

Answer 2

occurs within 72 hours post-parturition

Question 3

what are the three stages of milk fever & their associated clinical signs?

Answer 3

stage I: ambulatory/weak/ataxia/down with normal head posture, hypersensitive/excitable/restless/aggressive, fine muscle tremors starting in flanks/triceps, & bellowing, stage II: sternal recumbency, obtunded, cool extremities/low temp, anorexic, increased heart rate & decreased heart sounds with weak pulses, neck in ‘s-curve’, & smooth muscle paralysis which can lead to bloat/failure to defecate/loss of anal sphincter tone/inability to urinate, & stage III: comatose, opisthonus, flaccid muscles, increased heart rate & no pulses

Question 4

T/F: in milk fever cows, death can occur within hours if no intervention

Answer 4

TRUE

Question 5

what are the three big things you must do when working up a cow for milk fever?

Answer 5

rule out sepsis in any down cow who calved recently, check the uterus for a possible dead twin, & check udder/quarters for milk for possible septic mastitis

Question 6

whey does hyperglycemia occur in cows with milk fever?

Answer 6

low extracellular calcium inhibits insulin secretion

Question 7

how is milk fever in a cow diagnosed?

Answer 7

history & physical (weak cow that recently calved or is about to), total blood calcium under 8.0 mg/dl, & ionized blood calcium under 4.5 mg/dl

Question 8

what are signs that you need to stop giving calcium IV to a cow with milk fever?

Answer 8

calcium is cardiotoxic - stop & wait if bradycardia, arrhythmia, weakened pulse, or cow begins to pant

Question 9

what signs are seen in a cow being treated for milk fever with calcium that indicates the treatment is working?

Answer 9

decreased heart rate, strong pulses, eructation, able to rise, & urination/defecation

Question 10

why correct lateral recumbency in a cow down with milk fever?

Answer 10

prevent regurgitation & aspiration

Question 11

how is milk fever in cows prevented?

Answer 11

low calcium diet during dry periods, dietary cation difference during late dry & early milking period to decrease blood pH, feed vitamin D3 late dry period, administer PTH right before parturition, & avoid diets high in potassium & low in anionic ions

Question 12

T/F: 75% of cows with milk fever will stand up with treatment within 2 hours & 30% of those will relapse

Answer 12

TRUE

Question 13

why is completely milking a cow out to decrease calcium reabsorption to prevent milk fever no longer recommended?

Answer 13

it leads to mastitis

Question 14

what is the prognosis for a cow with milk fever?

Answer 14

good to excellent if no concurrent diseases

Question 15

what is the normal stage 1 of parturition in cows?

Answer 15

uterine contractions & cervical dilation, completion is marked by amnion & part of fetus eneter the vagina ‘water breaking’, & usually lasts 1-4 hours

Question 16

what is the normal stage 2 of parturition in cows?

Answer 16

beginning is marked with abdominal contractions, completion marked with fetal expulsion, usually lasts 1-4 hours, in mature cows, under 3 hours

Question 17

what is the normal stage 3 of parturition in cows?

Answer 17

fetal membranes are expelled, beginning of uterine involution, & usually occurs 12 hours after parturition

Question 18

what indicates dystocia in the different stages of parturition?

Answer 18

in stage 1 longer than 6 hours, in stage 2 amniotic sac is visible for 2 hours & cow isn’t trying, in stage 2 & cow is trying more than 30 minutes without progress, in stage 2 & cow not trying for over 20 minutes after initial progress

Question 19

what indicates dystocia in heifers? what about cows?

Answer 19

heifers: deliver within 60-90 minutes of seeing calf’s feet, & cows: should deliver within 30-60 minutes of seeing calf’s feet

Question 20

what are risk factors for dystocia in cows?

Answer 20

weight loss in late pregnancy, pelvic canal width, male calves, & cold weather leads to longer gestation & higher birth weight

Question 21

what are some underlying causes of dystocia in cows?

Answer 21

fetopelvic disproportion (dam factors: genetics, age, parity, nutrition, & calf factors: size, genetics/environment, gender, gestational length, & genotype) malpresentation, over-conditioned dam, uterine torsion, milk fever, & uterine inertia

Question 22

what is primary uterine inertia as a cause of dystocia? what about secondary uterine inertia?

Answer 22

primary: due to hypocalcemia, uterine overstretching, abnormal uterus, hormone levels, & contractions, secondary: exhaustion after prolonged attempts to expel fetus

Question 23

how is dystocia prevented in cows?

Answer 23

if small pelvic canal width, either cull or breed to a small bull & watch calving closely, choose sires that have low weight calves by using expected progeny differences calculation for determining calf size

Question 24

how is dystocia treated in cows?

Answer 24

vaginal assistance, traction, c-section (standing or under general anesthesia), or fetotomy if dead calf

Question 25

what are some common problems with calves after dystocia?

Answer 25

stillbirth, metabolic/respiratory acidosis, cool calf, & failure of passive transfer

Question 26

what causes 30% of all dystocias in cows & 50-90% of beef cow dystocias?

Answer 26

fetopelvic disproportions!!

Question 27

what are some examples of non-infectious causes of abortion in cattle?

Answer 27

genetic malformations, fever, stress, twin pregnancy, toxins (ponderosa pine, locoweed, broomweed, nitrates, & prostaglandins)

Question 28

why are definitive causes of abortion on made in 30% of cases?

Answer 28

difficult due to fetal autolysis, disappearance of toxins, self-correction of physical causes, & abortion occurs long after infection

Question 29

how are abortions in cattle prevented?

Answer 29

vaccinate dams against leptospirosis, IBR, BVDV, brucellosis, campylobacter fetus, test bulls for trich, check feed for nitrates, keep dogs off pasture to prevent neosporosis, & wait until 3rd trimester before allowing dams on foothill agent infected pastures

Question 30

what is the normal abortion rate in cows? at what rate should you investigate?

Answer 30

1%, investigate if 3-5%

Question 31

what are two major causes of abortion in cattle that are reportable?

Answer 31

brucellosis & tritrichomoniasis

Question 32

what is the classic case of campylobacteriosis in cows?

Answer 32

early embryonic death, prolonged luteal phases, irregular estrous cycles, repeated breeding, unusually long calving intervals, & endometritis

Question 33

T/F: testing cows is more reliable than testing bulls for campylobacteriosis

Answer 33

TRUE

Question 34

what is the etiology of campylobacteriosis?

Answer 34

campylobacter fetus venerealis or c. fetus fetus

Question 35

what is the best way to diagnose campylobacteriosis? what are some other options?

Answer 35

test breed heifers & check for infection, vaginal mucus agglutination test (sample at least 10 cows), ELISA on vaginal mucus, & sheath wash on bulls for fluorescent antibody test/culture

Question 36

what is the treatment for campylobacteriosis?

Answer 36

vaccination once diagnosed to help eliminate bacteria, improve fertility, & a double dose is given to bulls - bulls may be treated systemically with streptomycin & topically to penis (cows not practical to treat)

Question 37

how is campylobacteriosis prevented?

Answer 37

artificial insemination & purchase only very young bulls

Question 38

how is campylobacteriosis transmitted?

Answer 38

contaminated semen - rarely by fomites

Question 39

T/F: with campylobacteriosis, some animals may have a transient infection while others may become a chronic carrier

Answer 39

TRUE

Question 40

why are bulls tested over cows for tritrichomoniasis?

Answer 40

bulls are the carriers!!!!

Question 41

what is the classic case presentation of tritrichomoniasis in cows?

Answer 41

embryonic or early fetal death is the most common, repeated breeding, increase in number of non-pregnant normal cows & late bred cows, pyometra, & later fetal death or abortion

Question 42

what is the etiology of tritrichomoniasis?

Answer 42

tritrichomonas foetus - a pyriform or pleomorphic protozoan

Question 43

how is tritrichomoniasis diagnosed?

Answer 43

preputial douche or aspirate - darkfield contrast microscopy, culture with diamond medium for over 48 hours, & more than 90% of cases are cultured successfully

Question 44

how is tritrichomoniasis treated in cows?

Answer 44

imidazoles - treating bulls with pronidazole is most effective but can cause sterile abscesses at the treatment site, & semen can be treated with dimetridazole

Question 45

how is tritrichomonoasis controlled in cows?

Answer 45

test & cull positive bulls, cull all bulls & replace with virgin bulls, cows with calves & virgin heifers are presumed to be uninfected, & vaccination may improve breeding in heifers but not in bulls

Question 46

how is tritrichomoniasis transmitted?

Answer 46

between cows by bulls

Question 47

T/F: tritrichomoniasis is usually self-limiting in cows

Answer 47

TRUE

Question 48

T/F: tritrichomoniasis is reportable in many states

Answer 48

TRUE

Question 49

T/F: reinfection of bulls after treatment for tritrichomoniaisis after treatment is possible as is treatment resistance

Answer 49

TRUE