Canine Pregnancy & Female Reproductive Disease

Question 1

Where does fertilization of oocytes occur in bitches? How long do sperm cells last?

Answer 1

uterine tube (oviducts)

5-7 days if fresh

Question 2

What are 3 ways of determining whelping date? When does this not apply?

Answer 2

1. 65 days from LH surge
2. 63 days from ovulation (happens 2 days after LH surge!)
3. 57 days from first day of cytological diestrus (vaginal epithelium is rounded and neutrophils are present in response to stud contamination)

singleton pregnancy - only one fetus = no overcrowding to induce fetal cortisol spike, technically gestation can be indefinite and pup can get large enough to induce dystocia)

Question 3

What breed can go into whelping early?

Answer 3

CKCS —> early by 1-2 days

Question 4

What causes the huge range of whelping date estimation when only using one date?

Answer 4

(58 days if bred late - 71 days if bred early)

variability of estrus in the bitch and longevity of sperm in the uterus

Question 5

What kind of placentation do canines have? What unique structure does it have?

Answer 5

zonary endotheliochorial —> 4 layers: maternal endothenium + fetal endothelium, connective tissue, and epithelium

green pigmentation (uteroverdin) = marginal hematoma acting as an iron storage for the fetus

Question 6

What is occurring if the uteroverdin is seen without the pup?

Answer 6

placental detachment = dystocia

Question 7

What is progesterone responsible for in canine pregnancy? What is it not used for?

Answer 7

luteal dependence of pregnancy maintenance —> requires 2.6 ng/mL (typically gets >10-15 ng/mL)

pregnancy diagnosis (no maternal recognition of pregnancy)

Question 8

How do progesterone levels change as whelping approaches?

Answer 8

drops, resulting in a temperature drop

Question 9

When do prolactin levels increase with pregnancy? How is this related to progesterone?

Answer 9

lutetropic —> second half of gestation

concentration inversely related to progesterone - acts as a dopamine agonist

Question 10

What is the most pregnancy-specific hormone used for pregnancy diagnosis in dogs? When do levels increase?

Answer 10

relaxin - produced by the placenta

day 21 of gestation

Question 11

What induces pseudopregnancy? What clinical signs are seen?

Answer 11

decreased progesterone as prolactin increases in late diestrus, post-ovariectomy

• mammary gland enlargement with or without milk production
• nesting behaviors

Question 12

When can abdominal palpation be used to diagnose canine pregnancy? What is felt?

Answer 12

21-28 days —> gets difficult by day 35 , but can feel fetal bodies and movement after 50 days

string of pearls

Question 13

When can radiography be used to diagnose canine pregnancy? What is it used for?

Answer 13

day 43 —> fetal calcification

gold standard for counting pups

Question 14

How is ultrasound used for diagnosing canine pregnancy? When can it be used?

Answer 14

confirms pregnancy and fetal viability —> CAN’T be used for counting pups

• day 17 - can see vesicle
• day 25 - can see heart flutter

Question 15

What can ultrasound be used to estimate in canine pregnancies?

Answer 15

C-section/whelping date

Question 16

What 3 features on ultrasounds are used to determine if a bitch is prepared for C-section? When are each seen?

Answer 16

1. high kidney definition with visible cortex and medulla - 57-63 days after LH surge
2. intestines - 57-63 days after LH surge
3. intestine peristalsis - 62-64 days after LH surge

(determines pups’ maturity)

Question 17

What 3 ways of estrous cycle monitoring are used to estimate whelping date? How is ultrasound used?

Answer 17

1. progesterone profile
2. LH assay
3. cytology

fetal biometry measurements - inner chorionic cavity and biparietal diameter measurements based on size

Question 18

What 8 structures are seen on radiography when determining fetal maturity? When are they seen?

Answer 18

1. spine
2. skull
3. ribs
4. caudal vertebrae
5. fibula
6. calcaneus
7. paws
8. teeth

all present at 3-8 days before whelping

Question 19

What is the best way to assess canine fetal viability?

Answer 19

measuring fetal HR

• 220-240 bpm = normal HR before term
• 180-200 bpm = normal HR on whelping day (Stage II)
• 160-180 bpm = stress, mild hypoxia
• <140-160 bpm = decreased postnatal survival

Question 20

Fetal intestinal ultrasonographic definition:

Answer 20

• needs to be completely functional for colostrum digestion
• 5 days before parturition = spaghetti-like, prominent development, when a C-section can occur

Question 21

Fetal renal corticomedullary definition:

Answer 21

medullar and cortex are better differentiated by ~5 days before parturition

Question 22

What causes diestrual diabetes mellitus?

Answer 22

increased progesterone from the CL causes GH to be secreted from the mammary glands and IGF1 secretion from the liver —> decreased insulin sensitivity

Question 23

When is pregnancy toxemia most common? What occurs?

Answer 23

late-term pregnancy with large livers

anorexic mothers with increased energy demand causes the metabolism of large amounts of fat, resulting in ketonemia, ketonuria, and hepatic lipidosis

Question 24

How is pregnancy toxemia treated? What can happen in severe cases?

Answer 24

enteral and/or parenteral glucose supplementation

pregnancy termination

Question 25

What are 5 possible signs of impending canine labor?

Answer 25

1. decreased appetite 2. restless, panting, anxiousness 3. declining levels of progesterone 48 hours prior causes body temp to decrease by 1-2 degrees (~98 F) usually 12-24 hours before 4. presence of colostrum 1-7 days prior (unreliable) 5. nesting behavior 12-24 hours prior

Question 26

What is a recessed vulva? What 2 things is it associated with?

Answer 26

juvenile/hooded vulva due to excessive skin folds covering the dorsal aspect 1. early OVH 2. ascending bacterial infections - perivulvar dermatitis, UTI, incontinence due to urine pooling

Question 27

What are 2 treatment options for recessed vulvas?

Answer 27

1. topical cleansing* 2. valvuloplasty/episioplasty

Question 28

What is clitoral hypertrophy? What are the 2 most common causes?

Answer 28

enlarged tissue in the ventral clitoral fossa +/- development of os clitoris 1. progestogens/androgens during pregnancy 2. DSD - inherited in GSP, Beagles, English Cocker Spaniels

Question 29

What treatment is recommended for clitoral hypertrophy?

Answer 29

milberone (androgen) - suppresses estrus

Question 30

When is vaginal fold hyperplasia (prolapse) most commonly seen? What causes it?

Answer 30

proestrus, estrus, late pregnancy ---> tissue from ventral vaginal floow becomes extremely edematous (not true prolapse) hypersensitivity to estrogen with recurrence in next cycle - normalizes with estrogen decrease as progesterone rises

Question 31

What are the 3 stages of vaginal fold hyperplasia? What can it cause?

Answer 31

1. swollen internally 2. ventral floor becomes edematous, commonly in a pear shape 3. dorsal portion of vagina becomes involved, becomes more of a dome shape impaired breeding, dysuria

Question 32

What are the 3 most common causes of vulvar discharge?

Answer 32

1. vaginitis 2. CEH-pyometra complex 3. SIPS

Question 33

In what individuals is vaginitis most commonly seen? What are 2 predisposing factors?

Answer 33

spayed females, due to decreased estrogen (decreased mucosa development) 1. congenital anomaly 2. neoplasia - TVT, leiomyoma

Question 34

How are adult and juvenile vaginitis treated?

Answer 34

ADULT - systemic antimicrobials, probiotics JUVENILE - typically resolves after first estrous cycle without antibiotics - mucosa will become thicker with development

Question 35

What is the most common cause of cystic endometrial hyperplasia (CEH) in canines? In what bitches is it most common?

Answer 35

repeated exposure to steroidal hormones, where progesterone predominates over estrogen (multiple rounds of estrus) with aggravation as estrogen also increases intact bitches >9 y/o

Question 36

When does pyometra occur in canines? What causes it? What is the most common bacterial etiology?

Answer 36

diestrus ---> high progesterone progesterone causes cervical closure, decreased myometrial contractions, and leukocyte inhibition E. coli

Question 37

What is pyometra commonly confused with on ultrasound/radiographs?

Answer 37

- hydrometra - mucometra - hematometra

Question 38

What clinical signs are associated with open and closed pyometra?

Answer 38

OPEN - mucoid/purulent vulvar discharge CLOSED - abdominal distension, more severe systemic signs of endotoxemia (LPS endotoxin) and PU/PD

Question 39

What diagnostics are used for pyometra?

Answer 39

- radiographs - ultrasound - bloodwork - leukocytosis with neutrophilia and a left shift

Question 40

What treatment is recommended in non-breeding and breeding females with pyometra?

Answer 40

surgical removal of uterus and ovaries - PGF2a - luteolysis + uterine contraction, cervix MUST be open - *cabergoline* - dopamine agonist decreases luteotrophic prolactin - aglepristone - progesterone antagonist - antibiotics

Question 41

What are uterine serosal inclusion cysts?

Answer 41

common incidental finding in older bitches believed to arise when mesothelial cells becomes trapped in the serosa ---> continue to secrete and become hyperplastic - C-section adhesion traps mesothelial cells - usually does not affect fertility

Question 42

What is subinvolution of placental sites (SIPS)? In what bitches is it most common?

Answer 42

delay in the involution of placental sites characterized by fresh blood discharged from the vulva > 6 weeks post-partum (remaining fetal debris is passed before) ---> varying degree of hemorrhage can be fatal primiparous bitches <3 y/o

Question 43

What is seen on vaginal cytology in cases of SIPS? Is treatment commonly necessary?

Answer 43

trophoblast-like cells invade endometrium spontaneous remission is common, monitor for heavy bleeding and perform OVH if needed

Question 44

What do follicular and luteal cysts secrete?

Answer 44

estrogen progesterone

Question 45

What 2 types of tumors are most common in the female canine reproductive tract?

Answer 45

1. ovarian epithelial tumors - subepithelial structure origin, causes ascites and abdominal distention 2. granulosa cell tumors - often functional and result in elevations in estrogen and persistent/erratic estrus

Question 46

What is the most common cause of ovarian remnant syndrome? What are 3 options for diagnosis?

Answer 46

iatrogenic - remnant left behind after surgery, resulting in revascularization and estrogen secretion 1. AMH - ovarian granulosa cell source, will be positive with remnants 2. progesterone - increases with presence of follicles and ovulation, will be high with remnants 3. LH - high levels in spayed individuals due to loss of negative feedback, will be low in remnant cases

Question 47

What are the predisposing causes of mastitis? What 2 time periods are most common?

Answer 47

teat trauma and milk retention 1. 1-3 weeks after parturition - maximal milk production 2. after weaning - mammary glands become distended

Question 48

How do affected glands appear with mastitis? What other signs are seen?

Answer 48

swollen, warm to the touch, discolored or painful + discolored milk (red/brown) - *offspring fail to gain weight* - fever - anorexia - tachycardia - SEVERE CASES: abscessation, gangrene, septic shock