Feline reproduction

Feline Reproduction

Parturition

• Milk may be obsereved just prior to parturition - uncommon
• Prepartum rectal temperature drop - is not obsreved

• Posterior presentation is common, does not predispose to dystochia

Pregnancy

• Ovulation follows coitus by 24-30 h
• Fertilisation in oviduct
• as morulae pass into the uterine horn by day 4-5 postcoitus
• superfecundation

• Transuterine - intercornual migration
• Implantation - 12-13 (14-16) days after ovulation
• Endotheliochorial (4 layer) placenta zonaria

E2

• remains low during the first 35–40 days of pseudo-pregnancy similar secretion pattern, with higher values, is observed during pregnancy
• in the second half of gestation E2 concentrations start to vary, commencing with decreasing P4 concentrations, and increase toward parturition > Estrus behavior

Feline placenta is capable of producing both P4 and E2

Intraplacentally produced P4 has a supplemental role with mostly local effects

Relaxin becomes detectable at about day 20–25 of gestation

PRL is elevated during the last one third of pregnancy

During pseudo-pregnancy, PRL remains generally at basal levels

ICC in queens: DBP = (mm – 62.03)/1.1

BP in queens: DBP = (mm – 23.39)/0.47

• Short partial anorexia, vomiting
• First 3-4 weeks > minimal weight gain - Queens should be fed a normal prebreeding ration
• 4-6 weeks - Caloric intake should be increased gradually about 50%
• Final weeks -70%, maintain the optimal body condition

underweight - maintaining lactation

obesity - dystochia

Proestrus

Estrus

1-3 days

7 (3-16) days

• Begins - the queen allows to mount and breed
• Behavioral stage of receptivity to mating
• Occurs during peak follicular activity and E2 secretion
• Lordosis, tail deviation, head rubbing, vocalization

• Observed only a minority of queens
• Rubbing of the head and neck against of any convenient object
• Vocalizing and rolling on the ground
• Not permit breeding, nonreceptive - Attracts the toms but refuses

• Rising serum estradiol (granulosa cells of the ovarian follicles)
• Effect on vaginal epithelium >
• increased number of epithelial cell layers
• vaginal cornification > the proportion of anuclear superficial cells increases (10%)
• Vulvar labia are nonresponsive to E > remain small
• Not observed - vaginal bleeding

Peak vaginal cornification occurs at time of peak E2 concentration

Anuclear squames 10% >> 40% (by the 4. day)

Mating

5-50 sec - Mounting and grasping of the neck by male

0,3-8 min - Positioning

1-30 sec - Intromission, ejaculation, queen's coital cry

0-1 sec - Dismounting

1-7 min - Queen's after-reaction > disoriented rolling, stretching, genital licking

21 days

Anestrus

3 months

Interestrous

10-14 days

Puberty

• The puberal estrous occurs 6-9 months of age
• incfluenced by
• Time of year/photoperiod
• Body condition - at least 80% of adult body weight (2,3-3,2 kg)

• Oriental breeds (Siamese, Burmase) - very young age
• Longhaired and Manx - later onset of puberty (11-21 months)

• in queens that have not been induced to ovulate, Ø CL
• low E2, P4
• no sexual behavior or receptivity

Occasionally, queens appear to miss an interestrous

• estrous behavior persist during two or more follicular than interestrous phases
• cyclic E fluctuations -but the lowest E conc. remained above the 20 pg/ml

((Metestrus))

Pseudopregnancy

1-3 days

30-35 days

• During estrus
• Morphologic evidence of CL development

Reesthabilishment of ovarian activity can begin 7-10 days following luteolysis in both pregnant and pseudopregnant queens

Lactation and suckling of kittens may cause lactatioanal anestrus > 2-3 weeks after weaning

• Diestrus - time of functional corpora lutea
• P4 dominance
• Ovulation, Ø fertilization
• Luteal phase of nonpregnant queen is one-half the duration of the normal gestation period

• Spontaneous ovulation - without male contact
• Infertile copulation
• Artificial stimulation of the vagina by probing with cotton swab > induce ovulation

No clinical signs

40-45 days "rest period"

P4

is similar in pregnant and pseudo-pregnant cats until days 10–12 of g., when implantation takes place in pregnant

• increase dynamically, reaching peak values (~30–40 ng/ml) at day 21.
• thereafter, gradual decrease toward parturition

in pseudo-pregnancy

• similar initial P4 secretion - peak levels > lower than during pregnancy, followed by a gradual decline (dropping to <1 ng/ml) by days 36–46
• the luteal phase in pseudo-pregnant cats lasts about half of its length in pregnant queens

Luteal regression/luteolysis during pseudo-pregnancy appears to be a passive degenerative process in the absence of a luteolytic principle of uterine origin

Prepartum luteolytic mechanism > signifi cant increase in fecal and serum PGF2α

This placental signal is missing in pseudopregnant queens

Mariusz P. Kowalewski (2017)

Pregnancy

63-65 days

meaning that they can go into heat several times during a season,

repeatedly exhibits estrus behavior in a given season

Seasonally polyestrous

• Cycles repeatedly throughout a breeding season
• Northern hemisphere -January/February with gradual frequency decline until September/October
• Anestrus from November until end of January
• Hot summer, stress - interrupts
• Hours of daylight - major impact on the onset and the duration of ovarian activity

Long-day breeders, are sexually active in spring and summer.

Prolonged anestrus results from decreasing or short day length (< 8h/day)

Senger, 2012.

When the photoperiod is shortened, melatonin and PRL secretion are enhanced > reducing ovarian function

14h/day

~16 day

12h/day+

interrupted darkness

~16 day

12h/day +

social stimuli

~21 day

Induced ovulator - by coitus

• Vaginal stimulation is transmitted via spinal afferent nervous pathway to HT> increased neural activity > GnRH release > LH peak
• LH correlated with the number of copulation, max LH - 4h after 8-12 copulations
• about 50 % of queens ovulating after a single copulation
• Most queens do ovulate following 4 (or more) copulation
• Ovulation occurs 24h after the LH peak
• number of matings does not influence the number of ovulated follicles

Spontaneous ovulation - with incidence ranging from 35% up to 87%

dr. Linda Müller

clinical veterinarian

Department and Clinic of Reproduction

University of Veterinary Medicine