Ovaries and uterus

Question 1

In a study by Adams 2022 in Vet Surg, were puppies delivered by emergency or elective caesarian more likely to survive?

Answer 1

Elective caesarian. No difference in survival between brachycephalic and non-brachycephalic breeds.

Question 2

In a study by Pailler 2022 in JAVMA, what were 3 factors associated with a higher risk of uterine rupture in queens with pyometra? What was overall survival to discharge?

Answer 2

Increased rectal temperature, closed pyometra, or heart murmur.

100% survival to discharge was reported in this study.

Question 3

According to Benka 2023 in JAVMA, did gonadectomy increase the risk of developing an overweight or obese body condition score in dogs? Was the risk greater for males or females?

Answer 3

Yes an increased risk was observed. This risk was greater for males, and tended to be increased in patients sterilized after 1 year of age.

Question 4

In a study by Guest 2023 in JAVMA, was concurrent ovariohysterectomy at the time of caesarian associated with an increased risk of mortality, intra- or post-operative complications, or decreased mothering ability?

Answer 4

No - concurrent OVH was not associated with any of these issues. Only difference was an increased perception of post-operative pain as per the owners.

Question 5

In a study by Owen 2023 in JAVMA, was laparoscopic assisted ovary sparing hysterectomy associated with an increased risk of stump pyometra compared to OVE?

Answer 5

No - there was no increased risk observed.

Question 6

In a study by Bruckner 2024 in JAVMA, were there any benefits to lap-assisted OVH compared to open OVH for treatment of pyometra?

Answer 6

No benefits observed, although LapOVH took longer.

Question 7

In a study by Pegram 2019 in JSAP, what 3 factors increased the incidence of urinary incontinence in bitches? What factor was not correlated with urinary incontinence?

In a second study by the same author, what 4 risk factors were identified as risk factors for early onset urinary incontinence (<8 years)?

Answer 7

Spaying and increasing age and bodyweight.

Age of spay was not associated with an increased risk of incontinence.

In a second study spey, age at spay (<6 months), increasing age and bodyweight were all associated with increased risk of early onset incontinence.

Question 8

In a study by Demeli 2023 in JSAP, what 5 CBC/biochem parameters were increased with pyometra, what 3 parameters were reduced?

Answer 8

Increased: leukocytes, monocytes, AST, ALP, BUN.

Decreased: HCT, hemoglobin, albumin.

Question 9

In a study by Nilsson 2023 in VRU, what percentage of dogs had free peritoneal fluid on post-operative ultrasound at 1, 4-6, and 10-15 days post-surgery for pyometra?

Answer 9

45%, 41%, and 9%.
Presence of pneumoperitoneum was detected in 95%, 82%, and 14% of dogs at the same time points.

Question 10

In a study by Fudge 2021 in JFMS, did pregnant or non-pregnant cats have higher blood loss during OHE?

Answer 10

Pregnant cats had higher blood loss. They were also relatively hypercoaguable and had an increased rate of clot lysis, although no clinically relevant bleeding conditions occurred.

Question 11

In a study by Maniaki 2021 in JFMS, did neutering/spaying cats before 6 months of age result in an increase of owner reported mobility changes at 6 years of age? What 3 other risk factors for decreased mobility were identified?

Answer 11

No neutering/spaying before 6 months of age actually reduced the risk of mobility changes.

Outdoor, overweight cats with a history of trauma were at an increased risk of mobility issues.

Question 12

In a study by Bailin 2022 in JFMS, in what percentage of cats presenting to an emergency service was dystocia related to maternal v. fetal factors? In what percentage of cats was medical management of dystocia successful? What percentage of queens and neonates survived to discharge?

Answer 12

Maternal factors were responsible for 69% of dystocias, and fetal factors were responsible for 31%. No queens were hypoglycemic or hypocalcemic.

Medical management was successful in 29% of cases.

Maternal survival was 94%. Neonatal survival was 66%. Surgically delivered neonates had the lowest survival rates (50%, compared to 64% for medical management).

Question 13

In a study by Flock 2022 in JFMS, was anti-mullerian hormone a useful tool for detection of ovarian remnant syndrome in queens?

Answer 13

Yes, could be used to differentiate between spayed and cats with ovarian remnant syndrome. This was regardless of the hormonal activity of the remnant ovarian tissue.

Question 14

What is the capsule of the ovary called?

Answer 14

Tunica albuginea

Question 15

What structures constitute the broad ligament?

Answer 15

Mesovarium and mesometrium.

Question 16

What is the arterial supply to the ovaries?

Answer 16

The paired ovarian arteries, arise from the aorta cranial to the deep circumflex iliac arteries and caudal to the renal arteries.

Question 17

What is the venous drainage of the ovaries?

Answer 17

Right ovarian vein: caudal vena cava.
Left ovarian vein: left renal vein.

Both veins anastomose with the uterine veins.

Question 18

What is the lymphatic drainage of the ovaries?

Answer 18

Lumbar lymph nodes.

Question 19

What is the opening of the uterine tube into the uterine horn called?

Answer 19

Uterine ostium.

Question 20

What is located at the ovarian end of the uterine tube?

Answer 20

Infundibulum fringed with fimbriae.

Question 21

What are the three layers of the uterus?

Answer 21

Serosa, muscularis (myometrium), mucosa (endometrium). Endometrium is the thickest of the three.

The myometrium has a thick inner circular layer and thin outer longitudinal layer.

Question 22

What is the difference in cervical position between dogs and cats?

Answer 22

Dogs: diagonally positioned with the external orifice positioned toward the vaginal floor.

Cat: relatively horizontal.

Question 23

What is the vascular supply to the uterus?

Answer 23

Anastomosing blood supply from the ovarian and uterine arteries. The uterine artery is a branch of the vaginal artery.

Uterine veins follow the arteries.

Question 24

What is the lymphatic drainage of the uterus?

Answer 24

Hypogastric and lumbar lymph nodes.

Question 25

What are the four phases of the estrus cycle?

Answer 25

Proestrus, estrus, diestrus, anestrus. The feline cycle has a fifth 'nonestrus' phase during non-cycling periods.

Question 26

What are the main differences in ovulation between the dog and cat?

Answer 26

Cats are induced ovulators. Following ovulation they have progesterone dominance (functional corpus luteum) for 37 days. Dogs ovulate spontaneously and have progesterone dominance for 60-100 days.

Question 27

What is the gestational length of dogs and cats?

Answer 27

Dogs: 64 days Cats: 66 days

Question 28

What are methods to measure gestational length/stage in the dog?

Answer 28

1. Accurate when measured from progesterone elevation >1.5 ng/mL. 2. Ultrasound (before day 39 of pregnancy). 3. Measured from luteinizing hormone peak.

Question 29

When do canine fetal skeletons become visible on radiographs?

Answer 29

42 days, fetal pelvises by day 57.

Question 30

When are canine fetal heartbeats detectable on ultrasound?

Answer 30

1-2 days after implantation of blastocysts on the uterine wall (day 21-22).

Question 31

What are some bloodwork changes seen in the pregnant bitch?

Answer 31

CBC: normocytic normochromic anemia due to hemodilution (PCV <40% @ day 35, <35% at term). Biochem: leukocytosis, hypercholesterolemia, hyperproteinemia, increased protein C and fibrinogen +/- hyperglycemia (insulin resistance).

Question 32

What progresterone changes are observed in the bitch just prior to parturition?

Answer 32

Sudden drop in progesterone (<2-3 ng/mL) occurs 18-30 hours prior to parturition. This is typically followed by a fall in body temperature (<37.2-37.8 degrees) 10-14 hours later.

Question 33

What are the three stages of parturition in the bitch?

Answer 33

Stage 1: externally nonvisible uterine contractions (can last up to 24 hours). Bitch appears restless, exhibits nesting behaviours. Stage 2: expulsion of the fetus. Stage 3 (alternating with stage 2): expulsion of the placenta. Duration of stages 2 and 3 can last up to 36 hours, but active straining should not exceed 30 minutes, and time lag between puppies should not exceed 4 hours.

Question 34

What is lochia?

Answer 34

An odorlous green, dark red-brown or hemorrhagic vaginal discharge associated with uterine involution. Can last for 4-6 weeks.

Question 35

How can gestation length of queens be determined?

Answer 35

1. Measured from the rise in progesterone >2.5 ng/mL. 2. Ultrasound

Question 36

When is mineralization of feline fetuses observed?

Answer 36

Day 25-29 post parturition (1 week earlier than dogs).

Question 37

When does trophoblastic attachment occur in the queen?

Answer 37

Day 15

Question 38

What are some bloodwork changes typically seen in pregnant queens?

Answer 38

Anemia (20% reduction in hematocrit).

Question 39

Is temperature drop an accurate indicator of impending parturition in cats?

Answer 39

No

Question 40

What is the typical time taken between the first and last kitten in queens?

Answer 40

6 hours, although some queens will act as though parturition has finished for up to 48 hours before recommencement (<1% litters).

Question 41

What are some health problems related to ovariohysterectomy?

Answer 41

Neoplasia: osteosarcoma more common in Rottweilers spayed < 1 year of age, spayed Vizslas have an increased risk of mast cell or hemangiosarcoma. Endocrine: increased risk of diabetes mellitus in cats and hypothryoidism in dogs. Weight: obesity is 2 x more likely in spayed female dogs. Urinary: urethral sphincter mechanism incontinence reported in up to 20% of spayed bitches. Larger dogs (15 kg) 7 x as likely to develop this condition.

Question 42

What are some physiologic considerations when performing prepubertal OHE?

Answer 42

Pediatric animals have an immature hepatic and renal function, increased risk of hypothermia and hypoglycemia, and greater reliance on heart rate for cardiac output. Fasting should be limited to <4 hours, glucose supplementation may be required, active warming is essential. Judicious use of drugs required and at lower doses (underdeveloped microsomal P-450 enzyme activity prior to 4.5 months and lower plasma protein concentrations = higher fraction of unbound drugs). RAAS does not become functional before 6 weeks and therefore renal bloodflow is entirely dependent on arterial blood pressure. Care with fluid administration required. Anticholinergics may be required to maintain cardiac output. If nonresponsive may be due to hypoxemia and O2 supplementation should be administered.

Question 43

Is prepubertal OHE associated with an increased risk of complications?

Answer 43

No - dogs older than 2 years of age, with increasing body weight and surgical time associated with higher short-term complications.

Question 44

What size uterine body can vessel sealing devices safely ligate?

Answer 44

9mm (low mean bursting pressure observed for uterine bodies sealed >9mm).

Question 45

What is the incidence rate of post-operative complications following OHE?

Answer 45

Dogs: 7.5-19% Cats: 12%

Question 46

What are the most common complications associated with OHE?

Answer 46

Wound inflammation, hemorrhage (increased risk in dogs >25kg), GI upset. Less common complications include ureteral damage, sponge foreign body, granuloma formation, and intestinal or urethral obstruction.

Question 47

What is thought to increase the risk of granuloma formation with OHE?

Answer 47

Use of braided nonabsorbable suture and nylon cable. Has been reported in up to 28% of cases in some instances.

Question 48

What are greyhounds at increased risk for post-operative bleeding?

Answer 48

Hyperfibrinolysis.

Question 49

What is the mechanism of action of aminocaproic acid?

Answer 49

Inhibitory effects on plasminogen activator substances and plasmin, therefore limiting fibrinolysis.

Question 50

What are some proposed advantages of laparoscopic OHE over open surgery?

Answer 50

Less post-operative pain, faster recovery, minimal wound inflammation, fewer wound infections, superior visualization.

Question 51

How can hemostasis of the ovarian vessels be achieved in patients undergoing laparoscopic OHE?

Answer 51

Pretied ligature loop, extracorporeal suture, hemoclips, electrocautery, vessel sealing device. Use of a sealing device associated with a faster surgery and less hemorrhage.

Question 52

What are some reported complications associated with lap-OHE?

Answer 52

Seroma, omental herniation, subcutaneous accumulation of CO2, minor splenic or pedicle hemorrhage. Overall complication rate low (<2%).

Question 53

What are some laparoscopic techniques for OVE?

Answer 53

Single port, two- or three-port. Two port had shorter surgical times and decreased post-operative pain compared to the single port technique.

Question 54

Why should exogenous progestins not be administered in dogs after OVE or OVH?

Answer 54

Can lead to cystic endometrial hyperplasia and pyometra of the residual uterus.

Question 55

What is NOTES?

Answer 55

Natural orifice transluminal endoscopic surgery. A transgastric approach has been described for OVE.

Question 56

What are the health consequences of ovary sparing spay?

Answer 56

Mammary neoplasia, vaginal hyperplasia, maintained signs of heat, behavioural effects. Uterus must be transected caudal to the cervix to remove the risk of stump pyometra.

Question 57

Why is fine needle aspiration of suspected ovarian tumours not recommended?

Answer 57

Risk of tumour seeding to the abdomen.

Question 58

What are the three classifications of ovarian tumours?

Answer 58

Epithelial: adenomas and adenocarcinomas, cystadenomas. Sex cord stromal: granulosa cell tumours. Germ cell: dysgerminomas, teratomas, teratocarcinomas. Epithelial and sex cord stromal are the most common (50/50).

Question 59

What hormonal changes might be observed with granulosa cell tumour in the bitch?

Answer 59

High levels of estrogen and/or progesterone with signs of persistent proestrus, estrus, cystic endometrial hyperplasia, or pyometra. Will have a subnormal response to GnRH stimulation as compared to spayed or anestrus bitches. 20% rate of metastatic disease.

Question 60

What might occur secondary to persistently high estrogen levels in dogs with granulosa cell tumours?

Answer 60

Bone marrow aplasia with irreversible pancytopenia.

Question 61

What is the metastatic rate of canine dysgerminomas?

Answer 61

10-30%

Question 62

What is the prognosis for ovarian neoplasia in the bitch?

Answer 62

Good if the tumours are single and nonmetastazied and there is no evidence of bone marrow aplasia.

Question 63

What is the most common ovarian tumour in cats?

Answer 63

Sex cord stromal. More than 50% of granulosa cell tumours are malignant in cats.

Question 64

What are the clinical signs of functional ovarian cysts?

Answer 64

Prolonged proestrus (due to elevated estrogen levels), or estrus (elevated estrogen and progesterone) If the cyst is luteinized they produce signs of prolonged diestrus (elevated progesterone only). Most common in dogs <3 years, and cats <5 years of age.

Question 65

What cytologic and bloodwork changes are observed with follicular cysts?

Answer 65

Cytology (dogs only): 80% superficial cells on vaginal smear consistent with estrus. Bloodwork: Dogs - progesterone >2 ng/mL, estrogen > 20 pg/mL. Cats - estrogen > 20 pg/mL. Ultrasound can be used to confirm the diagnosis.

Question 66

What are treatment options for functional ovarian cysts?

Answer 66

Breeding bitches: 1. Estrogen producing cysts = GnRH administration. 2. Surgical resection of the cyst from the ovary 3. Luteinized cysts = prostaglandins. Partial response or recurrence is common. Non-breeding bitches: OVE or OVH.

Question 67

What are some tests that can be used to confirm ovarian remnant syndrome in the dog?

Answer 67

1. Vaginal cytology. 2. Estrogen concentrations > 15 pg/mL 3. Progesterone concentrations > 2ng/mL 4. Low LH. 5. Anti-Mullerian hormone.

Question 68

What are some tests that can be used to confirm ovarian remnant syndrome in the cat?

Answer 68

1. Vaginal cytology (although changes are more subtle than the dog). 2. Estrogen concentrations. 3. Progesterone concentration > 2.5 ng/mL 5 -7 days after luteinization with GnRH.

Question 69

On which side are ovarian remnants more likely to be diagnosed?

Answer 69

Right side (62%), left side (29%), bilateral (10%).

Question 70

What is the risk of an intact bitch developing pyometra before 10 years of age?

Answer 70

23-24%

Question 71

What is the role of progesterone in the development of pyometra?

Answer 71

Plays a role in the development of cystic endometrial hyperplasia (estrogen appears to play a supporting rather than primary role). Progesterone also increases glandular secretions and suppresses contractions of the uterus, creating an environment for bacterial growth. May suppress the local immune response.

Question 72

What bacteria is most frequently implicated in pyometra?

Answer 72

E. coli. Suspected to originate from ascending perineal flora. Secondary infection of the bladder with genetically identical bacteria occurs in 70% of cases.

Question 73

In what percentage of bitches with pyometra is SIRS observed?

Answer 73

57%

Question 74

Should the uterine stump be oversewn in cases of pyometra?

Answer 74

No - will leave compromised tissue and foreign material in an infected site.

Question 75

What are some common bloodwork findings with pyometra?

Answer 75

CBC: normochromic normocytic anemia, leukocytosis with a left shift. Biochem: decreased albumin, increased globulins, bilirubin, cholesterol, ALP and AST. Increased protein C. Decreased ALT. Azotemia (6-31%). Urinalysis: proteinuria.

Question 76

What are medical management options for pyometra?

Answer 76

Are only recommended if the bitch has high breeding value and will be bred on a subsequent heat. Treatment involves a combination of the following: 1. Antimicrobials 2. Prostaglandin (IV or intravaginal). Synthetic prostaglandins (cloprostenol) has fewer side effects than natural compounds but cause less uterine contractions. 3. Dopamine agonists (cabergoline). 4. GnRH antagonists (acyline). 5. Progesterone receptor antagonists (aglepristone). Combination therapy resulted in 60-88% successful treatment in one study. Uterine drainage has been reported for refractory cases.

Question 77

What is the mortality rate for dogs and cats undergoing surgery for pyometra?

Answer 77

Dogs: 0-5% Cats: 8% Low central venous oxygen saturation and high base deficits have been associated with increased mortality in dogs.

Question 78

What are the most common complications reported with OVH for pyometra?

Answer 78

Peritonitis (13%), urinary tract infection (6%), wound infection (3%), uveitis (2%), and cardiac arrhythmias (2%). Preoperative leukopenia was associated with an 18-fold increased risk for peritonitis

Question 79

Aside from pyometra, what other conditions of the canine uterus can cystic endometrial hyperplasia cause?

Answer 79

Mucometra, hydrometra, hematometra.

Question 80

How many of the following clinical signs do patients with cystic endometrial hyperplasia in the absence of pyometra typically display: vaginal discharge (67%), polyuria and polydipsia (22%), lethargy (22%), and inappetence (11%)?

Answer 80

Typically only display one sign, whereas patients with pyometra often display three or more.

Question 81

What is the difference between metritis and pyometra?

Answer 81

Metritis occurs in the post-partum period (fever occurs 12-hours after delivery and lasts for 24-48 hours).

Question 82

Are vaginal smears diagnostic for metritis?

Answer 82

No - because degenerative neutrophils and phagocytized bacteria are frequently seen postpartum.

Question 83

What antimicrobials are safe for administration in instances of metritis post-partum?

Answer 83

Penicillins, clindamycin, erythromycin, cephalosporins.

Question 84

What are surgical options for the treatment of metritis?

Answer 84

1. Hysterotomy, removal of uterine contents, lavage +/- intrauterine antimicrobials. 2. OVH.

Question 85

What is the treatment for uterine torsion?

Answer 85

OVH (uterus should not be detorsed). Caesarian can be performed if gestation is at term.

Question 86

What is the treatment for uterine rupture?

Answer 86

OVH, or for valuable breeding animals unilateral removal of the affected horn. Surgical repair may predispose to re-rupture.

Question 87

What are the potential causes of dystocia?

Answer 87

Fetal causes (uncommon): malposition (most frequent), fetal malformation, oversize and death. Maternal causes (common; 75% of bitches, 65% of queens): uterine inertia (most frequent), small pelvic canal or pelvic malunion fracture, uterine torsion, uterine stricture, vaginal stricture.

Question 88

What are the two types of uterine interia?

Answer 88

Primary (most common): can be partial (partial birth of litter) or complete (birth of no kittens/puppies. Cause unknown (small or large litters? Inability to secrete adequate PGF2?). Secondary: myometrial fatigue due to fetal obstruction or other fetal or maternal causes.

Question 89

How is primary uterine inertia diagnosed?

Answer 89

Complete: prolonged gestation, lack of progression from stage 1 to stage 2 labor within 12 to 24 hours, failure to deliver pups within 36 hours of rectal temperature falling below 37.8°C (100°F), or signs of toxemia. Partial: prolonged interval between neonates (>4 hours).

Question 90

What signs during parturition might indicate fetal obstruction?

Answer 90

Strong contractions exceeding 30 minutes without expulsion of a fetus.

Question 91

What is the Ferguson reflex?

Answer 91

Abdominal contractions in response to vaginal stimulation. Absence can signify dystocia.

Question 92

What percentage of puppies and kittens present in the breech position with the hindlimbs presented?

Answer 92

40%

Question 93

What fetal heart rate on ultrasound is indicative of fetal distress?

Answer 93

<150-180 beats/min (should be >220 beats/min).

Question 94

What are some diagnostic criteria that indicate primary uterine inertia that may benefit from medical management?

Answer 94

Question 95

What are some diagnostic criteria for dystocia that indicate need for immediate caesarean section?

Answer 95

Question 96

What are some contraindications to medical management of dystocia?

Answer 96

30 minutes of strong abdominal contractions without fetal expulsion, rectal or vaginal palpation findings indicative of obstruction, or diagnostic imaging indicative of fetal malformation or malposition, ultrasonographic signs of severe fetal distress.

Question 97

After how many doses of oxytocin is surgical treatment of dystocia indicated?

Answer 97

If two doses of oxytocin (SQ or IM) has not resulted in expulsion of a fetus, then surgical intervention is indicated.

Question 98

What percentage of bitches with dystocia are successfully managed medically?

Answer 98

30-40% (with 60-65% requiring C-section).

Question 99

Administration of what drug during C-section is associated with increased fetal death?

Answer 99

Xylazine.

Question 100

Does glycopyrrolate cross the placental barrier?

Answer 100

No , therefore atropine should be used if fetal heart rates are low.

Question 101

What closure techniques are appropriate for the uterus?

Answer 101

Single layer continuous or two layer closure with a simple continuous appositional inner layer and continuous inverting outer layer. Suture should engage the submucosa but not penetrate the lumen.

Question 102

If the en bloc uterine removal technique is used for C-section, how long after clamping of the uterine blood supply should the fetuses be removed?

Answer 102

60 seconds

Question 103

Why is swinging of neonates no longer recommended?

Answer 103

Can lead to intracranial hemorrhage

Question 104

If bradycardia is present in a neonate following delivery what treatments are recommended?

Answer 104

Oxygen supplementation (as most frequently due to hypoxia). Atropine is not indicated as increases oxygen demand. Naloxone can be administered sublingually or IV if an opiate was administered in the pre-medication to the dam. Epinephrine via the umbilical vein can be used as a final attempt of resuscitation in neonates with asystole.

Question 105

Why is doxapram no longer recommended for use in neonates?

Answer 105

It increases myocardial oxygen consumption and is ineffective in states of hypoxia.

Question 106

What is the survival rate for bitches undergoing c-section?

Answer 106

99% (neonatal survival rate 88%).

Question 107

How long does normal uterine involution take?

Answer 107

12-15 weeks. Subinvolution of placental sites is thought to occur secondary to persistence of fetal trophoblasts, causing continued hemorrhage. Can be managed medically if the patient is clinically well or via OVH.

Question 108

What is the most common canine uterine tumour?

Answer 108

Leiomyoma (90%), leiomyosarcomas (10%). A hereditary mutation in the FLCN gene is associated with a syndrome of multiple uterine leiomyomas, bilateral renal cystadenocarcinomas, and nodular dermatofibrosis in German Shepherds

Question 109

What is the most common uterine tumour in cats?

Answer 109

Normally adenocarcinoma. More likely to have metastatic disease than dogs and prognosis is guarded.

Question 110

What commonly occurs in conjunction with congenital abnormalities of the uterus?

Answer 110

Renal agenesis (29% of cats and 50% of dogs).