8. Feline Therio

Question 1

Feline estrous cycle general characteristics
-type
-timing

Answer 1

◦ Seasonal, polyestrous, induced ovulator
◦ Induced ovulators = require copulation to initiate the LH surge

◦ Estrus cycles occur at 4-30 day intervals in cats exposed to constant daylight (14 hrs)
◦ Prolonged anestrus > decreasing or short day lengths (autumn)
◦ Season begins Jan-Feb > peak is Feb-March

Question 2

when feline pubertal estrus? what influences this?

Answer 2

◦ Pubertal estrous = between 4 – 12mnts of age
◦ Influenced by time of year & body condition
◦ Usually when reaches 80% of adult body weight

Question 3

endocrinology underpinning the seasonality of the feline estrous cycle

Answer 3

> 14 hours of light (spring)
Hypothalamus releases lots of GnRH
pituitary gland releases gonadotropins
gonads release steroid hormones
steroid hormones act on hypothalamus causing release of even more GnRH
=> Positive feedback loop

<12 hours of sunlight (autumn)
pineal gland releases melatonin
>causes hypothalamus to release less GnRH
>pituitary gland releases less gonadotropins
>gonads release fewer steroid hormones
>less feedback to hypothalamus, releases less GnRH
=> Negative feedback loop

-melatonin decreases GnRH output

Question 4

based on the mechism behind feline seasonal breeding, what could melatonin be used for?

Answer 4

could be used to stop intact queens from cycling!

Question 5

feline estrous cycle phases

Answer 5

proestrus, estrus, interestrus interval, diestrus

Question 6

is proestrus observable in most queens?

Answer 6

no, most enter estrus directly

Question 7

how do males behave towards females during proestrus? how do females behave?

Answer 7

males are attracted but females non-responsive
◦ Continuous rubbing of head and neck

Question 8

how long does feline proestrus last?

Answer 8

◦ Short lived - if it occurs at all (0.5-2 days)

Question 9

hormone increased in feline proestrus

Answer 9

estrogen

Question 10

characteristics of feline estrus:
behaviour
hormone profile

Answer 10

◦ Behavioral stage of receptivity to mating

◦ Occurs during peak follicular activity & estradiol concentrations
◦ Behavioral estrus
◦ Crouching in the front with hind end elevated = lordosis
◦ Threading with hind legs, deviation of the tail = vulva exposed for mating
◦ Vocalize, more head rubbing, affectionate behavior

Question 11

how can we detect feline estrus?

Answer 11

◦ Estrus behavior
◦ Vulvar labia will only slightly increase in size compared to the bitch
◦ Mucoid discharge can be seen – won’t see bloody vaginal discharge
◦ Vaginal cytology > see cornification as in the bitch
> Not useful to tell you when to breed

Question 12

feline mating behaviour? how long does mating last?

Answer 12

◦ Nose to nose
◦ Investigate perineal area – Flehmen
◦ Grab neck – very important
◦ Mount
◦ Threading – slides down the female

◦ Pelvic thrusting > intromission > ejaculation > 20 seconds
◦ Pulls away quickly > avoid being struck by female

◦ Queen licks vulva, rubs on the floor, vocalizes = “after reaction”

Question 13

duration of feline estrus

Answer 13

Duration of estrus ◦ Variable
◦ Average: 5.8 days (Range: 2-19 days)

Question 14

what causes LH surge in feline?

Answer 14

copulation causes the LH surge
>NOT ovulation

Question 15

what does feline LH surge require for induction? what does magnitude depend on?

Answer 15

◦ Induced by copulation but requires hypothalamic/pituitary exposure to estrogen
> Needs to be in heat

◦ Magnitude of LH surge increases with number of copulations

Question 16

how soon after LH surge/coitus will ovulation occur in the feline?

Answer 16

◦ Induction of ovulation occurs 29-40hrs after LH surge
>ovulation occurs 24-48hrs post coitus

Question 17

when does diestrus occur in the queen?

Answer 17

◦ Follows estrus in the queen that has ovulated (induced or spontaneous ovulation)

Question 18

what hormone rises in diestrus? when, relative to ovulation?

Answer 18

◦ Progesterone dominated > CLs
◦ Progesterone starts to rise from baseline within 24 hrs post-ovulation

Question 19

how long does diestrus last in the queen?

Answer 19

◦ Lasts approx. 40 days in pseudopregnant queen

Question 20

is pseudopregnancy visible in queens?

Answer 20

pseudopregnancy is often not visible externally in comparison to bitches

Question 21

how does diestrus end in the queen? do they return to estrus?

Answer 21

◦ Ends with luteolysis (mechanism unknown in the cat)
◦ Return to estrus is variable

Question 22

what is the feline interestrus interval?
hormonal and behavioural characteristics
length

Answer 22

◦ Period that follows one estrus and precedes the next in queens that have not been induced to ovulate
◦ Estradiol drops
◦ No sexual behavior or receptivity is present
◦ Length is variable

Question 23

optimal breeding age for queen

Answer 23

◦ Between 1.5-7 years of age

Question 24

why is blood typing important for breeding cats?

Answer 24

◦ Important for prevention of neonatal isoerythrolysis

Question 25

purebred cats are more liekly to have what blood type?

Answer 25

B

Question 26

should the female go to the male cat or vice versa for breeding? then, when should we breed?

Answer 26

Bring the female into the tom’s territory ◦ Ideally don’t breed day 1 of estrus ◦ Then starting on day 2, breed 3-4x daily until end of estrus, if possible (at least over 2 day period)

Question 27

important hormone for feline pregnancy maintenance

Answer 27

progesterone, via CLs

Question 28

length of feline gestation

Answer 28

◦ 63-66 days, on average, from rise in P4 ◦ 56-69 days from mating

Question 29

when does feline prolactin increase?

Answer 29

Unlike in dogs – our prolactin only increases if pregnant – during the last 3rd of pregnancy and during lactation

Question 30

character of the feline placenta

Answer 30

◦ Endotheliochorial, zonary ◦ No obvious marginal hematomas

Question 31

do feline follicular waves stop during pregnancy? Consequences of this?

Answer 31

Cats can continue to have follicular waves during pregnancy ◦ Can display estrus behavior during pregnancy ◦ Superfetation is possible

Question 32

hormone changes upon queening? Temp changes?

Answer 32

Progesterone drops, but doesn’t necessarily have to >the drop isn’t a prerequisite for onset of parturition ◦ Don’t see a temperature drop like in bitches

Question 33

stages of feline parturition and signs

Answer 33

Stages very similar to dogs Stage 1: cervical dilation/uterine contractions ◦ Restlessness is the most common sign Stage 2: passage of fetuses ◦ Kitten should be delivered within 15 mins once noted at vulvar lips ◦ Can take a very long time (interruptions by 10-12 hours are possible) Stage 3: passage of fetal membranes

Question 34

stages of feline parturition and signs

Answer 34

Stages very similar to dogs Stage 1: cervical dilation/uterine contractions ◦ Restlessness is the most common sign Stage 2: passage of fetuses ◦ Kitten should be delivered within 15 mins once noted at vulvar lips ◦ Can take a very long time (interruptions by 10-12 hours are possible) => Should still ensure all is normal if there’s an interruption of more than 3-4hrs Stage 3: passage of fetal membranes

Question 35

is dystocia common for queens? causes? what cats are at increased risk?

Answer 35

no causes similar to dogs Purebred cats at increased risk ◦ Dolicocephalic and brachycephalic breeds > obstructive dystocia

Question 36

main cause of dystocia in queens

Answer 36

uterine torsion

Question 37

how do we treat dystocia in queens? when should we consider a c section? considerations?

Answer 37

Medical management >oxytocin & calcium gluconate ◦ Cannot do manipulations: too small ◦ Same “rules” apply as in dogs (no obstructive dystocias, FHRs, etc.) ◦ “Quiet” place, left alone No response to 2 oxytocin treatments = C section ◦ Pre-medicate queen at last minute >kittens hard to resuscitate

Question 38

if performing a feline c section when should we premedicate queens and why?

Answer 38

◦ Pre-medicate queen at last minute; kittens hard to resuscitate

Question 39

when will queens return to cycling post partum? what is the character of these cycles?

Answer 39

Within 2 weeks post-partum, begin cycling again Anovulatory cycles; at least @ start of lactation >become ovulatory as lactation decreases

Question 40

post partum conditions to be mindful of in queens

Answer 40

Very similar conditions to bitches Retained fetal membranes > metritis ◦ Usually queen is good at cleaning–don’t see much in terms of discharge ◦ If note discharge >7 days post-partum, investigate ◦ Mastitis ◦ Hypocalcemia Agalactia ◦ Sometimes can’t express milk – kittens are still gaining weight & healthy– not truly agalactia ◦ *Uterine prolapse; more common in cats* ◦ SIPS ◦ Poor mothering

Question 41

Specific disorders common in cats

Answer 41

◦ Benign mammary hypertrophy/hyperplasia ◦ Mammary neoplasia ◦ Cystic endometrial hyperplasia (CEH)/pyometra complex ◦ Ovarian cysts ◦ Ovarian remnant syndrome

Question 42

CASE: 7 month old female Sphinx Was in heat 3 weeks ago 5 days after her heat, this started Is doing well at home, eating/drinking, acting normal What could this be?

Answer 42

Benign mammary hypertrophy/hyperplasia

Question 43

hormone profile of Benign mammary hypertrophy/hyperplasia? when does it occur?

Answer 43

Progesterone dependent condition ◦ Occurs following ovulation (pregnant or not) Common in young cats (13 weeks- 2 years)

Question 44

clinical signs of benign mammary hypertrophy/hyperplasia in queens

Answer 44

See asymmetrical, firm, rapidly growing mammary tissue ◦ Can become bruised & ulcerated as they enlarge Histologically, there is no evidence of inflammation other than at the level of the surface epithelium

Question 45

diagnosis of benign mammary hypertrophy/hyperplasia

Answer 45

◦ Signalment ◦ Clinical signs ◦ Progesterone assay ◦ Biopsy in older cats to rule out neoplasia

Question 46

treatment of benign mammary hypertrophy/hyperplasia

Answer 46

◦ Removal of progesterone source ◦ OHE, aglepristone, luteolysis or abortion(spontaneous)

Question 47

how common is mammary neoplasia in cats relative to other types? what increases risk?

Answer 47

3rd most common tumor in cats ◦ Still overall rarely seen Intact = 7x greater chance of developing mammary neoplasia

Question 48

main concern regarding mammary neoplasia in cats

Answer 48

High rates of metastasis ◦ Malignant adenocarcinoma > Occurs in 50-90% of cases

Question 49

clinical signs of mammary neoplasia in cats:

Answer 49

◦ Older cats ◦ 1 or more masses (can have L and R mammary chain involvement) ◦ Are firm, can be well or poorly demarcated nodules (several mm to 10cm) ◦ Swollen nipples +/- exudate ◦ Ropy lymphatics

Question 50

how do we diagnose mammary neoplasia in cats

Answer 50

◦ Tumor histology (FNA, biopsy)

Question 51

how can we treat mammary neoplasia in cats? what is an important differential

Answer 51

◦ Surgery ◦ Chemotherapy ◦ Radiation ◦ **Important to do metastasis check**

Question 52

Cystic endometrial hyperplasia/pyometra in cats is associated with what hormone?

Answer 52

high progesterone

Question 53

Cystic endometrial hyperplasia/pyometra signs

Answer 53

Often see infertility signs prior to pyometra ◦ Due to endometrial changes noted (cystic hyperplasia) Clinical signs of pyometra: ◦ Not cycling ◦ Depression, lethargy ◦ PU/PD ◦ Distended abdomen, vomiting ◦ +/- vaginal discharge

Question 54

are ovarian cysts common in cats?

Answer 54

yes

Question 55

signs of ovarian cysts in cats

Answer 55

If cyst cells are secreting estrogen: ◦ Persistent estrus Or can have no clinical signs (no estrogen secretion) True persistent estrus – like those caused by ovarian cysts – can be hard to distinguish from a normal cat (overlapping follicular growth)

Question 56

how to diagnose ovarian cysts in cats?

Answer 56

◦ Ultrasound

Question 57

how to treat ovarian cysts in cats?

Answer 57

◦ Luteinization with hCG (induce ovulation) ◦ Surgical drainage ◦ OHE

Question 58

how to treat ovarian cysts in cats?

Answer 58

◦ Luteinization with hCG (induce ovulation) ◦ Surgical drainage ◦ OHE

Question 59

Causes of EED/abortion in cats:

Answer 59

* FIP * Feline Herpes Virus * FeLV * Panleukopenia * Toxoplasma * Salmonella * Chlamydophila * Mycoplasma

Question 60

4 categories of infertility in queens

Answer 60

◦ Persistent anestrus ◦ Persistent estrus ◦ Cycling queens that refuse copulation with the male ◦ Cycling queens that fail to conceive after copulation with a fertile male > 1st step is to determine if they ovulated

Question 61

in a case of queen infertility, where should we look first for solutions?

Answer 61

look at management 1st ◦ Including breeding behavior ◦ Season? Photoperiod? ◦ Recent change in environment ◦ Partner discrimination ◦ Husbandry – vaccine status, deworming, etc.

Question 62

What is the most common cause of infertility/subfertility in the bitch?

Answer 62

Poor bitch breeding management/ovulation timing

Question 63

Pyometra most commonly occurs when? What hormone causes this disease?

Answer 63

progesterone; diestrus

Question 64

What happens if a queen does not ovulate? What stage of the estrous cycle does she go into?

Answer 64

She goes into the interestrous interval

Question 65

The induction of estrus is most effective when: a) < 120 days have passed since the last proestrus b) GnRH agonists are used c) >120 days have passed since the last proestrus

Answer 65

c) >120 days have passed since the last proestrus

Question 66

Select the most correct answer: a) Ovulation is induced by copulation in cats b) The LH surge is induced by copulation in cats c) Cats can be induced to ovulate at any time during their estrous cycle

Answer 66

b) The LH surge is induced by copulation in cats

Question 67

Benign Mammary Hyperplasia/Hypertrophy is most common in what type of signalment? What is an important part of the history that could lead you to believe that a cat was affected by Benign Mammary Hyperplasia/Hypertrophy?

Answer 67

Young Cats Was recently in heat