Ch 109 - Ovaries and uterus

Question 1

Where do the ovarian arteries arise from the aorta?

Answer 1

Caudal to renal arteries and cranial to deep circumflex iliac arteries

Question 2

Where do the ovarian vein drain into?

Answer 2

• Right ovarian vein drains into the caudal vena cava
• Left ovarian vein drains into the renal vein

Question 3

What are the layers of the uterus?

Answer 3

• Serosa
• Muscularis
• Mucosa (endometrium)

Endometrium is the thickest layer

Question 4

What are the 4 phases of the oestrus cycle?
How does the oestrus cycle differ in cats from dogs?

Answer 4

• Proestrus
• Oestrus
• Diestrus
• Anestrus

Cats:
- proestrus is much shorter and is not externally visible (feline vulva is not responsive to oestrogen)
- Formation of corpus lutea requires induction of ovulation, in non-pregnant cats will remain functional for 37d
- Dogs ovulate spontaneously, progesterone dominance seen for 60-100d in non pregnant bitches

Question 5

How can parturition be predicted in a dog?

Answer 5

• 64-66 d after LH peak
• Preovulatory progesterone rise to 1.5ng/ml - 65 +/- 3d
• Skeletons detectable by d42 (20-21d to parturition), pelvises by day 57
• Progesterone drop to 2-3ng/ml 18-30hr
• Body temp drops 10-14hr after progesterone drop, parturition imminent

Question 6

List the three stages of parturition

Answer 6

• Stage 1: Externally non-visible uterine contractions, behavioural changes. Lasts up to 24hr
• Stage 2: Expulsion of a foetus
• Stage 3: Expulsion of placenta

Stage 2 and 3 alternate and lasts up to 36hr. Active straining should not exceed 30 mins without expulsion of a pup and there should not be more than 4 hr between each puppy

Question 7

How does pregnancy and parturition differ in cats?

Answer 7

• Placental secretion of progesterone independant of the ovaries occurs in cats after day 40
• In less than 1% of litters, parturition may be interrupted for up to 48hr

Question 8

What % of intact bitches are reported to get pyometra?

Answer 8

24%

Question 9

What are some consequences of OVH?

Answer 9

• Increases risk of TCC, OSA, cardiac tumours, HSA
• OSA more commin in Rottweilers spayed under 1yr
• Viszlas increased risk of HSA and MCT
• Increased risk of diabetes in cats
• Increased risk of hypothyroidism in dogs
• Spayed dogs 2x risk of obesity
• USMI in up to 20% spayed bitches as compared to 0.2-0.3% of the intact population. Larger dogs 7x more likely than dogs under 15kg

Question 10

What sized vessels and uterine bodies can be sealed with a Ligasure?
What sized vessels can be sealed with an ultrasonic sealing device?

Answer 10

Ligasure:
- 7mm vessels
- 9mm uterine body

Ultrasonic:
5mm vessels

Question 11

What is the incidence of periop complications after OVH?

Answer 11

• 7.5-19% dogs
• 12% cats

Question 12

How does aminocaproic acid work?

Answer 12

Inhibitory effects of plasminogen activators and plasmin, thererby inhibiting fibrinolysis

Question 13

List the basic concepts of a laparoscopic spay

Answer 13

• 15-degree Trendelenberg position
• Pneumoperitoneum of 10-12mmHg
• 3 post technique (30mm caudal to umbilicus, 30-50mm cranial to umbilicus and 30-50mm cranial to pubis)
• Uterine bodies less than 9mm sealed with Ligasure have a median bursting strength of 237mmHg
• Low complication rate approx 2%

Question 14

What is a NOTES approach?

Answer 14

Natural Orifice Transluminal Endoscopic Surgery
- Has been describes experimentally for ovariectomy in 20 bitches

Question 15

WHat is the reported incidence of ovarian remnant syndrome with lap ovariectomy?

Answer 15

0.5%

Question 16

Can you FNA an ovarian mass?

Answer 16

Not recommended - high rate of seeding

Question 17

What are the most common ovarian tumours?

Answer 17

Dogs:
- Granulosa cell tumour - 50%
- Epithelial cell tumours (papillary adenoma/adenocarcinoma, cystadenoma, undifferentiated carcinoma) - 40-50%
- Dysgerminoma, teratoma, teratocarcinoma 6-12%
- Rhabdomyosarcoma

Cats:
- Granulose cell tumour - 50%
- Dysgerminoma
- Epithelial cell tumour - rare

Question 18

Which ovarian tumour:
- Produces oestrogen and/or progesterone
- May be bilateral
- May be calcified
- May cause bone marrow aplasia and irreversible pancytopaenia
- Arise from rete ovarii

Answer 18

• Oestrogen/progesterone - granulosa cell tumour
• Bilateral - papillary tumours
• Calcified - teratoma
• Bone Marrow aplasia - granulosa cell tumour
• Rete ovarii - cystadenomas

Question 19

List the types of functional ovarian cysts
What are the treatment options?

Answer 19

• Follicular cysts - lines with granulosa cells and produce oestrogen and prolong proestrus
• Luteinised cysts - produce progesterone - prolonged diestrus

Tx options:
- May spontaneously resolve - nothing!
- GnRH or hCG
- Ovariectomy

Normal preovulatory follciles 4-9mm, functional cysts 10-15mm

Question 20

How can you diagnose ovarian remnant syndrome?

Answer 20

• Serum estradiol over 15pg/ml and progesterone over 2ng/ml - likely
• Single low LH concentration indicates functioning ovarian tissue
• Anti-Mullerian hormone - benefit of being independant of the ovarian cycle

Ovarian neoplasia has been diagnosed in 5/21 and 2/7 animals with ovarian remnant - submit for histo

Question 21

How does an entire status increase the risk of pyometra?

Answer 21

• Progesterone leads to cystic endometrial hyperplasia which predisposes to secondary infection
• Oestrogen enhances endometrial response to progesterone
• Progesteron stimulates glandular secretions and inhibits uterine contractions
• Progesterone decreases the ability for proliferative mononuclear response in the uterus

Question 22

What is the most common bacteria isolated from pyometra?
What virulence factors are associated with canine pyometra?

Answer 22

E.Coli
- alphs-haemolysin
- P-fimbriae
- cytotoxic necrotising factor

Concurrent cystitis in up to 70% with identical E.Coli

Question 23

What % of dogs with pyometra also have SIRS?
What needs to be monitored in patients with SIRS?

Answer 23

• 47%

Question 24

What causes anaemia of chronic disease (in this case during pyometra)?

Answer 24

• Lactoferrin and other acute phase reactants mediate an iron sequestration within the myeloid cells in the bone marrow, withdrawing iron from normal erythropoiesis

Question 25

What are the acute phase proteins in bitches with pyometra?

Answer 25

• CRP
• Serum amyloid A
• Haptoglobins

Question 26

List the mainstays of medical management of pyometra

Answer 26

• ABx for atleast 14d
• PGF-2a - causes contraction of myometrium and relaxation of cervix. 48-hr lag time
• Dopamine agonists (cabergoline)
• GnRH antagonists (Acyline)
• Progesterone receptor antagonists (aglepristone)

Question 27

What is the mortality rate of pyometra?
What are some negative prognostic indicators?

Answer 27

Mortality rate 0-5% dogs, 8% cats
Negative prognostic indicators:
- Septic abdomen from uterine rupture
- Febrile dogs and high CRP - increased morbidity

Question 28

List DDx for pyometra

Answer 28

• Cystic endometrial hyperplasia
• Mucometra
• Hydrometra
• Haematometra
• Metritis (postpartum rather than dioestrus)
• Uterine torsion

Question 29

List the indications for a C-section

Answer 29

• 4 hours between puppies
• Contractions for 30 min
• Lochia without foetal delivery
• Obstructed birth canal
• Abnormal foetal presentation
• Lack of Ferguson reflex
• Foetal HR 150-180 or less
• Absent foetal movements or presence of bowel motion
• Failed medical management of primary uterine inertian (30-40% successful)

Question 30

By what time should the foetus’ be removed after en-bloc OVH?

Answer 30

WIthin 60s of clamping uterine blood supply

Question 31

What are the most common uterine tumours of dogs and cats?

Answer 31

Dogs:
- 90% benign leiomyomas
- 10% leiomyosarcoma

Cats:
- Most commonly malignant adenocarcinoma
- More likely to have mets, prognosis guarded