Exam 3- Cooowwwssss Flashcards
T/F normal uterine tubes are palpable in a cow
False, unless there is pathology
What parts (stages) of follicles are palpable in a cow’s ovary
Tertiary follicles, corpus hemorrhagicum, corpus luteum
Explain the hormones involved in the positive feedback system between the ovaries and the hypothalamus and anterior pituitary
The ovaries release estradiol which stimulates the hypothalamus to release GnRH which acts on the anterior pituitary to release FSH and LH which act on the ovary to stimulate follicular genesis
Which hormone comes from the ovary and results in negative feedback on the hypothalamus (and thus the release of GnRH)
Progesterone from the CL (Also when progesterone is high estradiol will act as inhibitory)
At what phase of the estrus cycle is estradiol released from the ovary
Later proestrus (advanced follicular stage)
At what stage of the estrus cycle is progesterone released by the corpus luteum
Luteal phase (metestrus and diestrus)
How long is the average bovine estrus cycle and how many phases does it have
21 days- follicular phase (2-3 days) and luteal phase
What hormones are increasing/ high during the follicular phase and which hormone is decreasing
Estradiol, LH, and FSH are increasing and progesterone is decreasing (luteolysis)
What causes estradiol to increase in proestrus in the follicular phase
Developing follicles (create positive feedback to cause a GnRH surge in the hypothalamus)
The dominant follicle is producing estradiol with other follicles but what hormone is the dominant follicle also producing
Inhibit to suppress FSH and suppress the formation of other follicles
At what specific phase does estradiol peak
Estrus
What are secondary signs of estrus
Clear vaginal discharge, vulvar edema, vaginal hyperemia, increased physical activity
What induces ovulation and when does ovulation occur
The high levels of LH and ovulation occurs 12 hours after the end of estrus
What converts the corpus hemorrhagicum to a corpus luteum
Pulses of LH
What signals the start of metestrus and what hormone is increasing during this time, how long is metestrus
Ovulation and progesterone begins to increase, metestrus is 3-5 days
During diestrus progesterone is high, but what other hormones are released in low frequency pulses
FSH and LH to stimulate follicular development
What action does progesterone have on the myometrium
Relaxation to create a quiescent uterus
Along with progesterone, what other hormone is released by the corpus luteum
Oxytocin
What does oxytocin stimulate the release of
PGF2 alpha from the endometrium
What does PGF2 alpha do
Causes luteolysis (destruction of CL) which results in a decrease in progesterone
T/F many follicles may develop but only one becomes the dominant ovulatory follicle which the rest undergo atresia
True
T/F follicles are developing throughout the estrus cycle but the one that becomes the dominant follicle can fully develop to ovulation because progesterone is high
False progesterone must be low for the follicle to develop fully
T/F using the observation method of pregnancy diagnosis is cost-effective in the long run
False, it is not as reliable. It doesn’t require much training but it lacks in sensitivity and specificity which increases costs in the long run. Also if you are looking for a non-return to estrus, there are lots of things that can cause that, not just pregnancy (ovarian cysts, hydrometra, metritis, poor nutrition, etc.) Also, some pregnant females can show behavioral estrus
What is the most common and accurate method of pregnancy detection in cows
Trans-rectal palpation
What are the 4 cardinal signs of pregnancy in a cow when doing trans-rectal palpation
Membrane slip, amniotic vesicle, placentomes, presence of a fetus
In the gravid uterine horn, how early can you feel the chorioallantoic membrane slip on palpation
35 days
Approximately when can you first feel an amniotic vesicle in a heifer vs. a cow
At day 28 in a heifer and day 32 in a cow
At what point does the amniotic vesicle lose its turgidity and elongates to become the fetus
60-65 days
When are fetal placentomes able to be palpated
75-80 Days
Will placentomes be larger at the beginning or later on in gestation
They increase in size as gestation advances (and with location, they are more consistent in size cranial to the cervix)
What should you do to ensure you are not getting a false positive when palpating for placentomes
Always count more than 3 of them present
The fetus is resting on the abdominal floor at how many months
5th-6th month
T/F the uterine horns will be symmetric during pregnancy
False, one is larger
At what day does the pregnant cow’s cervix fix and the uterus is difficult to retract
90 d
What can you palpate to tell if there is increased blood flow to the pregnant cow’s uterus (secondary sign of pregnancy)
The fremitus of the middle uterine artery
At what day can you tell if there is a heartbeat detectable on ultrasound of an embryo
24-26 days
What is a good test for the earliest detection of pregnancy
Trans-rectal ultrasonography (day 24-26)
Is progesterone testing practical for pregnancy testing of cattle
Its better in non-pregnant cows so it isn’t the most practical (progesterone is produced throughout pregnancy)
What is a good early pregnancy blood test
Testing for Bovine Pregnancy-Specific Protein B (bPSBP test)
What are the 3 stages of parturition
- Cervix Dilation (6-12 hours) and eventually rupture of chorioallantois
- Fetal expulsion (2-4 hours)
- Placental expulsion (1-24 hours)
How much should the cervix be dilated 1 week prepartum vs. at parturition
1 week Pre-partum 2-4 fingers, at parturition 12 cm
What is the normal presentation of a fetus and which presentation may be normal
Cranial longitudinal and caudal longitudinal
What is the normal position and posture of the fetus
Dorso-sacral and limbs, head and neck extended
What is the number one cause of dystocia in cows
Fetal maternal disproportion
What is the difference between primary and secondary uterine inertia
Primary is the failure of the myometrium to normally contract due to like a hormonal defect or hypocalcemia
Secondary is the exhaustion of the myometrium after prolonged effort
Should an ebolic be one of the first things you grab in cases of dystocia
No! You should figure out the cause, these are drugs to cause uterine contractions (ex. Oxytocin) so you might cause damage
If you are trying to correct fetal head extension what should you use and not use
You can use a head snare or you fingers or eye hooks but don’t use a chain around the mandible
When is hock flexion a problem
When there is a caudal presentation of the fetus
What is proper chain placement on a calf to facilitate pulling it
First loop in the fetlock and second loop in the pastern
T/F you should rotate the fetus during traction (when pulling) to get the hips out
True
What are contraindications for a fetotomy
The fetus is still alive
Uterine torsion
Birth canal obstructed
Transverse dorsal presentation
You should do a C-section if you need more than how many cuts in a fetotomy
4
Which tool is used for a percutaneous vs. subcutaneous amputations in a fetotomy
What is a distinct difference in the methods
Percutaneous uses the fetotome and subcutaneous uses the hoe blade
Percutaneous can have sharp edges of bone that can cause uterine tears
T/F discharge that is bloody is abnormal in the post-partum period
False, discharge is normal during this time and can be dark brown to red to white
Unless the discharge smells gross or there are systemic signs
What are the 3 things that occur with uterine involution
Decrease in uterine size, increase in tone, abscesses of fluid in the uterus
Which cows, dairy or beef involute their uterus quicker and which ovulate quicker
Beef involute faster (21 days grossly vs. 30) but dairy cows ovulate faster (<21 days vs. 45-60)
FSH increases and the first follicular wave is typically how many days post-partum
10-14 days
Most cows expell the placenta by ___ hours and after ___ hours it is considered retained
6 hours and >24 hours
How does primary retention of fetal membranes differ from secondary
Primary- lack of detachment
Secondary- difficulty in expelling already detached fetal membranes
T/F retained fetal membranes are often spontaneously expulsed after a week by enzymatic proteolysis and necrosis of the caruncles and cotyledons
True (but you want to prevent the inflammation and other conditions this can cause in the cow)
What is the main reason for retention of fetal membranes
Deficiency of collagenase
Deficiency of what can cause retention of fetal membranes (4 correct answers technically)
Collagenase, Selenium/Vit E deficiency, Calcium, immunity (immunosuppressive)
What is contraindicated for getting rid of retained fetal membranes
Manual removal
Is oxytocin or prostaglandin F2 alpha practical for retention of fetal membranes
No
How is antibiotics helpful for treatment of retention of fetal membranes
To help reduce incidence of metritis
Should you put antiseptics in the uterus when there is retention of fetal membranes
NO! Also contraindicated
Are beef or diary cows more likely to have post-partum uterine infections
Diary
What organism is most likely to cause uterine infections
E. Coli (and then later trueperella pyogenes comes in)
What is a severe inflammation of all layers of the uterus and is usually within the first week of calving
Metritis
A cow had a calf about a week ago and has a very thick uterus with fetid discharge. She is running a fever and her milk production is down. What is your concern and how will you treat it
Metritis- treat with systemic antibiotics (Ceftiofur, excede) (if it was within the first 72 hours you could do oxytocin it after that not helpful), also fluids, NSAID (fluxamine/banamine), Ca, dextrose are all also possibilities
Do we treat metritis with intrauterine antibiotics
Not in the US but yes in other countries
How is endometritis different than metritis
It only impacts the endometrium and there aren’t systemic signs also endometritis can be later post-partum (>21 days)
How does clinical vs. subclinical endometritis differ
Clinical has vaginal discharge and Subclinical doesn’t have signs but you can see inflammatory cells on cytology
T/F if a cow has purulent vaginal discharge you can say she has endometritis
False, she might have cervicitis or vaginitis
What will you see in a cow with cytological endometritis
Increase in PMN (polymononuclear cells)
What is the most common organism to cause clinical endometritis
Truperella pyogenes (can get E.coli first with metritis to predispose to truperella too)
A farm is having issues with long post partum intervals. What are you concerned about and should be looking for
Endometritis, look for cows having purulent vaginal discharge or do cytologies of the uterus to look for cytologic/Subclinical endometritis
(Could also say campylobacter or tritrichomonas)
What bacteria causes Subclinical endometritis
Trick question- none!
We think it is immunodeficiency from negative energy balance, oxidative stress, or alterations in the Microbiome
What is the recommended diagnostic for diagnosing endometritis
Endometrial Cytology
T/F as you get farther from post-partum the cut-off window for endometritis and acceptable percentage of PMNs on cytology gets larger
False it gets smaller (18% 21-35 days, 10% 35-45 days, 5% >45 days)
What is the treatment for endometritis
Antibiotics and prostaglandin F2 alpha (yet no strong evidence for any treatments)
What is the treatment for Subclinical endometritis
Intrauterine tx with cephapirin and PGF2 alpha
What must be present for there to be a pyometra
A corpus luteum (progesterone)
What is the treatment for a pyometra
2 doses of PGF2 alpha- luteolysis and estrus
What is the difference between chromosomal, gonadal, and phenotypic sex
Chromosomal is determined at fertilization
Gonadal depends on the chromosomal sex- its what the germ cells develop (testes or ovaries)
Phenotypic is what we see- the external genitalia
What factors and hormones are secreted to make a male
Testis determining factor form the Y chormosome—> SRY and SOX9 produced—> testes develop and serotonin cells secrete anti-mullarian hormone—> development of phenotypic sex
What factors or hormones are (or are not) secreted to make a female
No Y chromosome so no TDF—> Wnt 4 and FoxL 2–> ovaries develop —> no AMH—> female repro tract forms
What duct regresses if AMH is present
The paramesonephric duct
Why do freemartins occur
Twins sharing blood supply which exposes both to AMH and other cellular elements
A freemartin is a blood cell chimera meaning an individual has two cell types from 2 separate zygotes
A prominent tuft of hair at the vulva, and increased ano-genital area of a calf may indicate this calf is what
A freemartin
What lab test can you do to detect freemartinism
PCR on the blood looking for XX and XY in same animal
What disease is known as White Heifers disease and can cause the absence of a uterine horn or imperforate hymen
Segmental aplasia of the Müllerian ducts
What can segmental aplasia of the Mullerian ducts predispose a cow to
Hydrometra, hydrosalpinx, mucovagina (basically the malformations can cause accumulation of fluid or mucus depending on the location)
Should you breed a cow with segmental aplasia of the Müllerian ducts
No, it is an autosomal recessive gene so she shoudl be culled
Incomplete fusion of the Müllerian ducts is also known as what and can cause what
Uterus didelphys, can result in a double external cervical os (can cause dystocias)
What is a differential diagnosis for ovarian hypoplasia
Atrophy by nutritional deficiency (ovarian hypoplasia is an inherited condition)
The lack of what hormone will cause acyclicity (anestrus)
Lack of LH surge
What is it called when there is a lack of GnRH and LH surge
Anestrus (no estrus, ovulation, or CL and inhibition of GnRH and LH)
Name the 9 causes of anestrus
- High milk yield
- Under nutrition
- Negative energy balance
- Metabolic diseases (ketosis, mastitis)
- Uterine issues- retained fetal membranes, Dystocia, puerperal metritis, pyometra
- Mastitis
- Presence of a calf
- Heat Stress
- Poor heat detection
What drug implant is used to synchronize cows to end anestrus and be able to be bred together
Progestagen controlled internal drug release
What is it called when there is a follicle without any active luteal tissue that has a diameter of at least 20mm and is interfering with cyclicity
Cystic ovarian follicle
Lack of LH surge causes what 2 acquired conditions of infertility
Anestrus and ovarian cysts
If you have loss of negative feedback by Progesterone (P4) or decreased sensitivity of hypothalamus and anterior pituitary to estradiol (E2) what can result
Formation of ovarian cyst
Which type of cyst is thin walled vs. thick walled
Follicular cysts are thin walled and luteal cysts are thick walled
Ovarian cysts can cause cows to do what
Not exhibit estrus or Nymphomania (frequent and prolonged estrus- less common)
In cows with cysts do they produce LH? If so how
Yes its just produced in small pulses in high frequency (why the cyst just keeps growing and doesn’t ovulate like a normal follicle)
The lack of an LH surge for a follicular cysts can be because of a lack of negative feedback from what
Low progesterone levels so there isn’t sufficient negative feedback on LH
Follicular cysts vs. luteal cysts secrete what
Follicular cysts secrete estradiol and luteal cysts secrete progesterone
What are the three mainstays of treatment for ovarian cysts
Increase the secretion of progesterone or give progesterone, decrease the pulses of LH, sensitize the hypothalamus to estradiol
What do you give to treat ovarian cysts
Give GnRH or exogenous progesterone—> lutenization of dominant cyst and ovulation—>form a corpus luteum to produce progesterone to reduce pulses of LH and sensitize hypothalamus to PGF2alpha—> cysts regresses
OR you can place a CIDR (progesterone implant)
How long is gestation in the cow
283 days +/- 14 days
At what day of gestation is there the switch between calling it an embryo then fetus
At day 42
What is defined as a stillbirth vs. abortion
A fetus that is natured fully in utero and is born dead
An abortion is termination of pregnancy resulting in fetal death and expulsion of the fetus
Which type of fetal death will result in CL persistence but causes chronic endometrial damage and poor prognosis
Fetal maceration
What does brucellosis cause in pregnant cattle
Abortion after 5 months, weak calves, retained fetal membranes, metritis
In bulls what does brucellosis cause
Orchitis and Epididymitis
Why does Brucella persist so well and what does this mean for treatment
It is a facultative intracellular bacteria so the infection persists indefinitely in phagocytes and lymphoid tissue so there is no treatment, cow much be killed
What is the transmission of Brucella
Ingestion of the placenta, uterine or fetal fluids, or fomites
A cow in a herd in Montana has had an abortion and the placenta has a dry necrosis that could be described as Moroccan leather. What disease might this cow have and how would you diagnose it
Brucellosis, isolate the bacteria from the fetus (abomasum content or lung), placenta, or uterine fluids
T/F there is a vaccine for brucellosis but it is not given because it interferes with the serological test
False, the vaccine does not interfere with the serological test
What is the most widespread zoonotic disease and can cause septicemia, nephritis which result in non-reproductive losses in cattle
Leptospirosis
What is the host-adapted Leptospira serovar for cattle and what does it do in cows
Leptospira borgpetersenii hardjo-bovis it causes persistent infections but less clinical disease
What leptospira can cause worse disease and abortion storms in cattle
Other Leptospira serovars from other animals
Where does leptospira colonize once its infected a host to cause leptospiruria (long infection)
The kidneys and genital tract
Cattle that live with pigs in a pen that has a pond for them to enjoy are having issues with needing repeat breeding and having prolonged interval to conception, and sporatic abortions and weak calves. What might be the problem
Infection with leptospira serovar Hardjo
Is there a vaccine for lepto?
Yes but if the prevalence is high you may need multiple vaccinations a year
Which disease can cause encephalitis, placentitis and thus sporadic abortions in the last trimester, neonatal septicemia, and metritis and septicemia
Listeriosis
How does an animal contract listeria
Ingestion of contaminated feed, often rotten hay or silage
What 2 diseases can cause foci of necrosis in the liver and spleen
Listeria and Infectious Bovine Rhinotracheitis (herpesvirus)
Is there a vaccine for listeria
No
Why is Campylobacter really good at growing and living in preputial folds and what does this mean for bulls
It is microaerophilic so bulls are asymptomatic carriers
What are 2 diseases that can cause early abortions (that aren’t viral causes)
Campylobacter and tritrichomonas
Which campylobacter strain causes infertility, endometritis, sporadic abortion, salpingitis
Campylobacter fetus venerealis
If a herd breaks out with campylobacter what recommendations can you make
Break from breeding for this year or switch to AI
If you see that a cow is having an interestrus interval of 35 days (or is slightly increased) what must this mean , and what bacteria could be causing this
That there is embryonic death, campylobacter
How do you diagnose Campylobacter
Isolation in microaerophilic media in Clark’s media from preputial scrapings, fetal tissue, vaginal mucus or PCR
Is there a vaccine for campylobacter
Yes
Do bulls infected with tritrichomonas have any clinical signs
Not usually
What are the herd signs that tritrichomonas may be present
Early abortions (3-5 mon.), poor pregnancy rate and repeat breeders, pyometra (similar to campylobacter)
What is the treatment for tritrichomonas
Unfortunately slaughter, there isn’t an approved treatment for bulls
Cows- sexual rest for 3 cycles and they will clear the infection and can give vaccine to shorted recovery
What causes abortions around 5-6 mon in cattle or stillborn or weak calves and encephalomyelitis and myositis in dogs
Neosporosis caninum (protozoa)
What are the three infectious stages of neospora and what do they do
Oocysts- infecting form
Tachyzoites- trans-placental infection
Bradyzoites- tissue cysts in nervous tissue (brain, spinal cord, nerves)
What are the definitive hosts for neospora caninum
Dogs (duh)- pass oocytes in feces
How do you diagnose neospora caninum
IHC for parasites in fetus and placenta or serological evidence (PCR)
A pregnant cow with Bovine Viral Diarrhea Virus can result in what
A persistently infected calf
T/F most BVDV cases are clinical showing fever depression, diarrhea, respiratory signs, thrombocytopenia, and lymphopenia, abortions, stillbirths, congenital defects (cerebellar hypoplasia), embryonic losses
False, most infections are Subclinical and severe clinical disease is usually from more virulent strains but those are some of the clinical signs you would see in those cases
T/F there is a vaccine for BVDV
Yes and it is recommended to use it
What causes abortion >4 months, pneumonia in young animals, encephalitis, and infectious pustular vulvovaginitis
Bovine herpes virus (Infectious Bovine Rhinotracheitis)
How is BHV-1 maintained in a herd
It can go into latency in the trigeminal neuron
Is there a vaccine for BHV-1
Yes good for prevention of EED and abortion
When should you vaccinate cows you will be breeding
60 days pre-partum and 30 days post-partum
When should you vaccinate heifers you will be breeding
At least twice (and 3-4 weeks) before breeding
What type of idenitfication should a bull have
A permanent one like a tattoo or brand
Why is it important to check things like the eyes and walking on a bull
The bull must be able to see the cows in the field and can’t be lame, must be able to walk to the cows and mount them also some foot and leg problems are hereditary
What amount of asymmetry between testis is acceptable
<25%
If the testis has some dermatitis is this okay?
No any source of inflammation can impact sperm development
If there is testicular degeneration what will the testis feel like
Smaller and softer
If a 2 year old bull has a persistent frenulum is this a problem
Yes, some immature bulls may have it before they fully mature but if it is retained that is a problem and this bull should not be bred
T/F you can palpate the bulbourethral glands, prostate, vesicular glands, and ampulla all on a rectal
False, you can’t palpate the bulbourethral glands
Vesiculitis causes enlargement and excessive firmness of the vesicular glands more commonly in what age of bull
Young (<2 years) or older bulls (>9 years)
T/F scrotal circumference is heritable
True
T/F scrotal circumference is correlated with testicular weight, sperm production, and semen quality
True
In a herd of yearling bulls, a few of the bulls have slightly smaller scrotal circumferences. Should you worry or will they likely catch up to the others?
They won’t likely catch up
What are acceptable sizes for scrotal circumference in yearling bulls (12-15 mo) and >24 mo and where do you take the measurement
Yearlings- >/=30cm
>24 mon >/= 34 cm
Measure around the greatest diameter
What are examples of very good sperm counts and semen color and poor
750 mill-1 bill/ml of sperm with creamy, grainy semen is very good
<250 mill/ml semen with translucent semen is poor
A sperm sample you are examining for motility has sperm swimming in slow swirls and eddies, what would you grade this sample
Good, if it was very good it would have rapid dark swirls but if there was no swirls or little cell movement it would be fair to poor
For individual motility sperm scores what would be a very good score and a poor for % of sperm moving linearly across the field
> 80% is very good, <40% is poor
Where is the origin of the abnormality if a sperm has head or mid-piece defects vs. tail defects
Head or mid-piece- testis (spermatogenesis)
Tail defects- Epididymis (maturation and storage)
What is the minimum % of normal morphology you should see when evaluating sperm
Want more than 70% normal
If a bull is a satisfactory potential breeder on its BSE this correlates to meaning the bull is fertile
No, but if the bull is an unsatisfactory potential breeder it would be expected that his use will result in poor fertility
What are 5 things that would mean a bull would get the classification of satisfactory potential breeder on a BSE
Optimum physical soundness, no physical hereditary defects, optimum scrotal circumference for age, >30% progressive motility, > 70% normal morphology
When should the BSE be completed
Every year on the bull 2 months before the breeding season
