Bovine Top 20 Reproductive Diseases - Part 2 Flashcards
what cows are most often affected by milk fever?
high producing dairy cows, cows on their 3rd or more lactation, jersey cows, & multiparous mature dairy or beef cows
when does milk fever occur in cows?
occurs within 72 hours post-parturition
what are the three stages of milk fever & their associated clinical signs?
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
T/F: in milk fever cows, death can occur within hours if no intervention
TRUE
what are the three big things you must do when working up a cow for milk fever?
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
whey does hyperglycemia occur in cows with milk fever?
low extracellular calcium inhibits insulin secretion
how is milk fever in a cow diagnosed?
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
what are signs that you need to stop giving calcium IV to a cow with milk fever?
calcium is cardiotoxic - stop & wait if bradycardia, arrhythmia, weakened pulse, or cow begins to pant
what signs are seen in a cow being treated for milk fever with calcium that indicates the treatment is working?
decreased heart rate, strong pulses, eructation, able to rise, & urination/defecation
why correct lateral recumbency in a cow down with milk fever?
prevent regurgitation & aspiration
how is milk fever in cows prevented?
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
T/F: 75% of cows with milk fever will stand up with treatment within 2 hours & 30% of those will relapse
TRUE
why is completely milking a cow out to decrease calcium reabsorption to prevent milk fever no longer recommended?
it leads to mastitis
what is the prognosis for a cow with milk fever?
good to excellent if no concurrent diseases
what is the normal stage 1 of parturition in cows?
uterine contractions & cervical dilation, completion is marked by amnion & part of fetus eneter the vagina ‘water breaking’, & usually lasts 1-4 hours
what is the normal stage 2 of parturition in cows?
beginning is marked with abdominal contractions, completion marked with fetal expulsion, usually lasts 1-4 hours, in mature cows, under 3 hours
what is the normal stage 3 of parturition in cows?
fetal membranes are expelled, beginning of uterine involution, & usually occurs 12 hours after parturition
what indicates dystocia in the different stages of parturition?
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
what indicates dystocia in heifers? what about cows?
heifers: deliver within 60-90 minutes of seeing calf’s feet, & cows: should deliver within 30-60 minutes of seeing calf’s feet
what are risk factors for dystocia in cows?
weight loss in late pregnancy, pelvic canal width, male calves, & cold weather leads to longer gestation & higher birth weight
what are some underlying causes of dystocia in cows?
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
what is primary uterine inertia as a cause of dystocia? what about secondary uterine inertia?
primary: due to hypocalcemia, uterine overstretching, abnormal uterus, hormone levels, & contractions, secondary: exhaustion after prolonged attempts to expel fetus
how is dystocia prevented in cows?
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
how is dystocia treated in cows?
vaginal assistance, traction, c-section (standing or under general anesthesia), or fetotomy if dead calf
what are some common problems with calves after dystocia?
stillbirth, metabolic/respiratory acidosis, cool calf, & failure of passive transfer
what causes 30% of all dystocias in cows & 50-90% of beef cow dystocias?
fetopelvic disproportions!!
what are some examples of non-infectious causes of abortion in cattle?
genetic malformations, fever, stress, twin pregnancy, toxins (ponderosa pine, locoweed, broomweed, nitrates, & prostaglandins)
why are definitive causes of abortion on made in 30% of cases?
difficult due to fetal autolysis, disappearance of toxins, self-correction of physical causes, & abortion occurs long after infection
how are abortions in cattle prevented?
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
what is the normal abortion rate in cows? at what rate should you investigate?
1%, investigate if 3-5%
what are two major causes of abortion in cattle that are reportable?
brucellosis & tritrichomoniasis
what is the classic case of campylobacteriosis in cows?
early embryonic death, prolonged luteal phases, irregular estrous cycles, repeated breeding, unusually long calving intervals, & endometritis
T/F: testing cows is more reliable than testing bulls for campylobacteriosis
TRUE
what is the etiology of campylobacteriosis?
campylobacter fetus venerealis or c. fetus fetus
what is the best way to diagnose campylobacteriosis? what are some other options?
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
what is the treatment for campylobacteriosis?
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)
how is campylobacteriosis prevented?
artificial insemination & purchase only very young bulls
how is campylobacteriosis transmitted?
contaminated semen - rarely by fomites
T/F: with campylobacteriosis, some animals may have a transient infection while others may become a chronic carrier
TRUE
why are bulls tested over cows for tritrichomoniasis?
bulls are the carriers!!!!
what is the classic case presentation of tritrichomoniasis in cows?
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
what is the etiology of tritrichomoniasis?
tritrichomonas foetus - a pyriform or pleomorphic protozoan
how is tritrichomoniasis diagnosed?
preputial douche or aspirate - darkfield contrast microscopy, culture with diamond medium for over 48 hours, & more than 90% of cases are cultured successfully
how is tritrichomoniasis treated in cows?
imidazoles - treating bulls with pronidazole is most effective but can cause sterile abscesses at the treatment site, & semen can be treated with dimetridazole
how is tritrichomonoasis controlled in cows?
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
how is tritrichomoniasis transmitted?
between cows by bulls
T/F: tritrichomoniasis is usually self-limiting in cows
TRUE
T/F: tritrichomoniasis is reportable in many states
TRUE
T/F: reinfection of bulls after treatment for tritrichomoniaisis after treatment is possible as is treatment resistance
TRUE
