Cats

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Cats

Age of puberty can vary from 4 - 18 months.  The main factor influencing onset of puberty is day length, with puberty usually starting when the hours of daylight increase i.e. in the spring.  This seasonal control is under the influence of the hormone melatonin, produced by the pineal gland.  Higher levels of melatonin are produced during darker periods.  Breed may also have some effect on the onset of puberty, with long haired breeds, e.g. Persians, tending to come into season later than short-haired breeds, e.g. Siamese and Burmese

When cats come on heat, the main hormone responsible for the clinical signs is oestrogena steroid hormone produced primarily by the ovaries that stimulates changes in the female reproductive organs during the oestrous cycle and promotes the development of secondary sexual characteristics..  This is produced by follicles on the ovaries.  Follicle development is stimulated by a Follicle Stimulating Hormone (FSHFollicle stimulating hormone; produced by the anterior pituitary gland and stimulates maturation of the ovary prior to ovulation) produced from the pituitary gland.

Pro-oestrus:

  • lasts 1 - 4 days
  • no significant external signs visible and no discharge
  • associated with calling but non-acceptance of male.

Clinical signs of pro-oestrus calling include rubbing against objects, rolling around, increased affection and increased vocalisation/ howling.  If stroked across the back, the cat will adopt the mating posture, i.e. forelegs crouched, hind end raised and tail deflected with paddling movements of the limbs.  Male cats will be attracted to her.

Oestrus:

  • follows pro-oestrus and lasts 2-6 days
  • associated with calling, attempts to escape and acceptance of male

What follows oestrus depends on whether a successful mating, ovulationthe release of an egg cell (ovum) from the ovary in female animals and/or fertilisation occur as follows:

Ovulation:

Metoestrus:

This phase of the reproductive cycle is associated with high levels of progesteronea steroid hormone secreted by the corpus luteum of the ovary that maintains pregnancy and promotes the development of the mammary glands., produced from the corpus luteumLiterally means “yellow body” and is responsible for progesterone production within the ovary.  In the Queen, the length of this phase depends on whether fertilisation occurs as follows

Fertilisation occurs

Fertilisation does not occur

Unsuccessful Mating:

Interoestrus:

Interoestrous refers to the phase during the breeding season, either between seasons or following pseudopregnancy/ pregnancy.  It is associated with no physical or behavioural signs.

Anoestrus:

  • this is a time of little ovarian activity and occurs from late Autumn/ Early Winter until Spring time, during which time the queen will not come into season
  • this may be absent in cats submitted to constant long light days, e.g. cats kept indoors.

At the end of interoestrous or anoestrus, oestrogena steroid hormone produced primarily by the ovaries that stimulates changes in the female reproductive organs during the oestrous cycle and promotes the development of secondary sexual characteristics. levels start to increase and increases in FSHFollicle stimulating hormone; produced by the anterior pituitary gland and stimulates maturation of the ovary prior to ovulation are once again responsible for the induction of follicular growth and return to oestrus.