Large Animal Lab Exam

Question 1

BCS in Bulls

Answer 1

Beef
 Scale 1-9
 Ideal 6-7

Dairy
 Scale 1-5

Question 2

Using Oxytocin & PGF2 Alpha for Bulls During Electroejaculation

Answer 2

Oxytocin
 Increases contractility of epididemus
 Increased sperm output
 Decrease time to penile protrusion
 Decrease amount of stimulation needed

PGF2 Alpha
 Increased sperm output in buffalo but not bull

Question 3

Cranial (anterior) Presentation of Fetus

Answer 3

o Head & feet facing vaginal opening
o Fetlocks & carpal joints bending same direction

Question 4

Caudal (Posterior) Presentation of Fetus

Answer 4

o Head facing away from vaginal opening
o Feet facing vaginal opening
o Fetlocks & carpal joints bend opposite directions

Question 5

Transverse Ventral or Dorsal Position of Fetus

Answer 5

o Calf folded in half
o Feet and head face away from vaginal opening

Ventral
 Head and chest more ventral than legs

Dorsal
 Head and chest more dorsal than legs

Question 6

Dorsosacral Vs Dorso-ilial Vs Dorsopubic

Answer 6

Dorsosacral
 Normal

Dorso-ilial
 To the left or right

Dorsopubic
 Upside down

Question 7

When is Vaginal Delivery Possible in Anterior or Posterior Dorsosacral Presentation in Cows

Answer 7

Anterior dorsosacral position
 if one person can pull the fetlocks 10 to 15 cm beyond the vulva
 Point of the shoulders at the level of the ilial shafts

Posterior dorsosacral position
 If the hock can be exteriorized

Question 8

When is Vaginal Delivery Impossible in Cows

Answer 8

o The head has not moved spontaneously into the pelvis
o Fetus is positioned in the birth canal and the forelimbs are crossed (fetus too wide at the shoulder)
o Hooves are rotated with volar surfaces facing medially (i.e. elbows are forced together)
o Fetus is lodged and does not move when abdominal press occurs

Question 9

Repulsion; Technique, Requirements

Answer 9

o “Pushing” the fetus away from the pelvis to make room for manipulations

Requirements
 Relaxed uterus w/ Clenbuterol or Epinephrine
 Eliminate abdominal expulsive efforts w/ Caudal epidural
 Lubrication (pump water soluble lubricant)
 Can be done manually or use of the Kuhn’s crutch

Question 10

Rotation

Answer 10

o Turning the fetus on its longitudinal axis
o Partial to take advantage of the largest diameter of the pelvis
o Complete to bring fetus from dorsoilial or dorsopubic to dorsosacral
o Can be done manually using the fetal limbs
o Use of a detorsion rod

Question 11

Version

Answer 11

o Applied in transverse presentation
o Usually not possible in ventral transverses

Question 12

Extraction of Calf Fetus w/ Chains

Answer 12

o Loop chains above fetlock
o Half hitch around pastern
o Maximum 2 / 3 persons or 600-800 lpi of force
o one foot at the time
o Pull in arc direction
o Traction on head to avoid neck flexion
o Calf pullers aren’t great

Question 13

Calf Extraction Technique for Posterior Presentation

Answer 13

o Rotate the fetus 45 to 90 degrees
o Check if there is risk of hip lock by extending the hock outside the vulva

Question 14

BCS of Dairy Cows

Answer 14

Tuber coxae -> hip joint -> tuber ischii
 V shape <3
 Curve >3.25

Hooks & pins from behind
 Rounded = 3
 Angular <3

Question 15

Indirect Uterine Retraction in Cows

Answer 15

o Grasp cervix and pin to opposite side of palpating arm ->
o Reach for the broad ligament on side of palpating arm ->
o Hook the VENTRAL intercornual ligament ->
o Flip the uterus dorsally

Question 16

Palpating Cow During Estrus & Immediately After Ovulation

Answer 16

Palpating During Estrus
o Ovary is round and smooth
o Dominant follicle present - Blister-like, fluid filled, continuous with ovarian stroma (12-25 mm)
o High estradiol
o Uterus is toned
o LSRF20UTone

Palpating Immediately After Ovulation
o dominant follicle is replaced by an ovulation depression (OVD)
o Uterus still has some tone or edematous
o Vaginal discharge may be bloody
o LS RFOVD U Tone/edema

Question 17

Palpating a Cow at Days 0, 1, & 2-3 of her Cycle

Answer 17

Palpating Day 0 of Cow Cycle
o 15-25mm follicle
o Toned uterus
o Estrus
o High estrogen

Palpating Day 1 of Cow Cycle
o OVD
o Toned uterus
o Ovulation
o LH surge

Palpating Day 2-3 of Cow Cycle
o CH1 (Corpus Hemorrhagicum), soft, <1cm diemeter
o Edema
o Metaestrus
o Not responsive to PGF 2 alpha

Question 18

Palpating a Cow at Days 3-5, 5-6, & 7-17 of her Cycle

Answer 18

Palpating Day 3-5 of Cow Cycle
o CH2, soft, 1-2cm diameter
o some edema or relaxed uterus
o Not responsive to PGF 2 alpha

Palpating Day 5-6 of Cow Cycle
o CH3, 2-3cm diameter
o Relaxed uterus
o Early luteal phase
o Progesterone >2
o Will respond to PGF2 alpha

Palpating Day 7-17 of Cow Cycle
o CL 3, > 2 cm diameter
o Relaxed uterus
o Mid cycle
o Progesterone plateau
o Will respond to PGF2 alpha

Question 19

Palpating a Cow at Days 17-19 & 20-21 of her Cycle

Answer 19

Day 17-19 of Cow Cycle
o CL 2, 1-2cm diameter
o Uterus beginning to tone
o Proestrus
o PGF2 alpha release

Day 20-21 of Cow Cycle
o CL 1 or no CL, <1cm diameter
o Follicle present
o Toned uterus
o Estrus
o High estrogen

Question 20

Indications of Pregnant Cow on Palpation

Answer 20

o Amniotic vesicle: palpable 28-60 days
o Fetal membrane slip: 30d to term (MOST IMPORTANT)
o Placentomes: 70d to term
o Fetus: 60d days to term

Question 21

Pregnancy Diagnosis in Cow on Palpation at 35 Days, 42-45 days, 50 days, & 60 days

Answer 21

35 Days
o Membrane slip - thread
o Amniotic vesicle – 1 finger

42-45 Days
o Membrane slip – string
o Amniotic vesicle – 2 fingers

50 Days
o Membrane slip – both uterine horns
o Amniotic vesicle – 3 fingers

60 Days
o Membrane slip – both uterine horns
o Amniotic vesicle – palm
o Fetus the size of a mouse
o Can sex fetus w/ ultrasound

Question 22

Pregnancy Diagnosis on Palpation at 75+ days

Answer 22

Placentomes (caruncle + cotyledon)
 90 days = dime size
 110 days = nickel
 120 days = quarter
 150 days = half dollar

Fetus
 90 days = rat size
 120 days = kitten
 150 days = cat
 180 days = medium dog

Question 23

Fremitus

Answer 23

o turbulence of blood in the middle uterine artery located in the broad ligament of the pregnant horn.
o NOT a positive sign of pregnancy

Question 24

When to Inseminate a Cow

Answer 24

o 12hrs after first sign of standing estrus

Question 25

Proper Bull Semen Handling for Insemination

Answer 25

o LN Tank should not be in contact with floor
o Maintain straw in liquid nitrogen until use ->
o Thaw straw at 95°F (35°C) for 45 seconds ->
o Dry straw and load in a clean warm AI gun ->
o Use plastic protector of cannula to avoid contamination ->
o AI should be performed within 10 minutes of thawing

Question 26

Cow Insemination Method

Answer 26

o ID cervix ->
o Hold cervix longitudinally & cranially to stretch vaginal tissue ->
o ID external cervical os ->
o Advance gun through cervical rings ->
o Deposit semen in uterine body
o May also be deposited in uterine horn if inseminator is very experienced

Question 27

Normal Conformation of Equine Vulva & Perineum

Answer 27

o dorsal commissure should not incline more than 10 degrees from vertical
o 2/3 or more of the vulva should be below the horizontal plane of the ischial arch
o Minimal dorsal displacement when pushed

Question 28

Non-Reproductive Organs Felt on Rectal Palpation of Mare

Answer 28

Left
 L kidney
 Edge of spleen
 Pelvic flexure of large colon
 Maybe small colon

Right
 Cecum

Question 29

Uterine Changes During Mare Cycle Felt on Transrectal Palpation

Answer 29

Anestrus
 Flaccid uterus

Estrus /follicular Phase
 Edematous & heavy uterus
 Estrogen dominance

Diestrus/ Luteal Phase
 Toned & tubular uterus
 Progesterone dominance

Question 30

Palpation of Mare Ovaries & follicle sizes

Answer 30

o Kidney shape w/ ovulation fossa
o 3x5cm
o Dominant follicle – 28mm
o Pre-ovulatory follicle – 40-60mm, soft, sensitive
o CL NOT palpable

Question 31

Early – Severe Small Intestinal Distention Felt on Transrectal Palpation of Mare

Answer 31

o Will feel loops of intestine in early
o Will feel firm hotdog shapes if severe
o Ileal impaction
o Ileocecal intussusception
o Strangulating lipoma
o Epiploic foramen entrapment
o Small intestinal volvulus

Question 32

Signs of Estrus on Ultrasound in Mare

Answer 32

o Uterine/endometrial edema
o Follicle >27mm
o Follicle grows by 5mm/day

Question 33

Signs of Pre-ovulation on Ultrasound in Mare

Answer 33

o Uterine edema begins to decrease
o Follicular wall develops edema
o Pear shaped follicle

Question 34

Pregnancy Diagnosis Timing W/ Transrectal Ultrasound or Palpation of a Mare

Answer 34

Ultrasound
 Commonly 14 days (may be diagnosed as early as 10 days)

Palpation
 Very skilled veterinarian: 18 days
 Good skills: 20-22 days
 Average skill: 25 – 30 days
 Day 1: 35 days

Question 35

What to Look For on Transrectal Ultrasound for Pregnancy Diagnosis on a Mare

Answer 35

o Over time allantois increase & yolk sac decrease

16-17 days
 Vesicle fixation at base of horn

20-21 days
 Loss of spherical shape & visible embryo

24-25d
 Heartbeat

35d
 Endometrial cups
 Accessory corpora lutea

42d
 Organogenesis
 Placentation

Question 36

Mare Vaginal Exam Tools

Answer 36

Vaginoscope
 Plastic or cardboard
 Single-use
 Visualize the cervix only

Polanski Speculum
 Stainless steel
 Multiple use
 Visualize the entire vaginal vault, cervix, and urethral opening
 Best speculum for complete vaginal & Postpartum examination

Question 37

Performing Uterine Culture or Cytology on a Mare

Answer 37

o Insert instrument halfway into cervix ->
o Remove safety & push 2nd guard in ->
o Push swab or brush gently until it contacts the endometrium ->
o Rotate in the same direction 10-15 revolutions ->
o Retrieve the system in reverse (inner guard, then outer guard, then come out)

Question 38

Mare Endometrial Biopsy; Basics, Method

Answer 38

o gold standard for fertility prognosis
o can also be used for culture
o Sample size 20x4x3mm
o Sample from the base of the horn, dorsal aspect

How To
 Closed biopsy instrument is carried sterilely into the vagina ->
 Into uterine cavity through cervix ->
 place the arm in the rectum and identify by palpation the jaws of the punch ->
 gently depress the uterus by transrectal palpation so an endometrial fold is trapped in the biopsy jaw ->
 remove piece of endometrial fold & place in 10% formalin

Question 39

Kenney-Doig Classification System of Mare Endometrial Biopsies

Answer 39

I
 >80% foaling rate
 No changes to tissue

IIA
 50-80% foaling rate
 Slight-moderate cellular infiltrate
 <2 fibrotic nests
 Can revert to I w/ treatment

IIB
 10-50% foaling rate
 widespread moderately severe inflammation
 2-4 fibrotic nests
 Infertility for > 2 seasons
 Can revert to IIA with treatment

III
 <10% foaling rate
 Widespread periglandular and perivascular fibrosis
 > 5 nests
 Hypoplastic endometrium
 Neoplastic endometrium
 poor prognosis