Estrus cycle in dogs symptoms. Under regulation by gonadotropic hormones, ovarian follicles mature and estrogen secretions exert their biggest influence. , adj es´trual, es´trous. e. , ready to accept a male and to mate. Estrus or oestrus refers to the phase when the female is sexually receptive (" in heat " in American English, or " on heat " in British English). Estrus, commonly known as the 'heat' period, is a distinct phase in the estrous cycle of most female non-primate mammals. Oct 26, 2025 ยท The terms estrus and estrous are often confused, but understanding the nuanced difference between them is crucial for anyone working with animal reproduction: estrus refers specifically to the period when a female animal is receptive to mating, while estrous is the entire reproductive cycle leading up to estrus. This phase is characterized by a complex interplay of physiological and behavioral changes that signal readiness for copulation. Estrus, the period in the sexual cycle of female mammals, except the higher primates, during which they are in heat—i. the recurrent, restricted period of sexual receptivity in female mammals other than human females, marked by intense sexual urge. Psuedo-pregnancy occurs in non-pregnant bitch because of increases in prolactin. adj. Estrus, derived from the Greek word "oistros," refers to a period in the reproductive cycle of female mammals when they are receptive to mating. Menstrual Cycle in Human Females (Figure 6) (Concept Tutor on Menstrual Cycles) The estrous cycle is generally divided into the four stages of proestrus, estrus, metestrus, and diestrus. Called also estruation, estrum, and heat. After mating, LH surge induced, progesterone increases then decreases, estrus returns after parturition when progesterone goes back down. The estrus cycle is defined as the phenomenon of cyclic ovarian function in mammals, regulated by the interplay of the hypothalamus, anterior pituitary, and ovaries, leading to follicular maturation, steroid hormone production, and ovulation. The meaning of ESTRUS is a regularly recurrent state of sexual receptivity during which the female of most mammals will accept the male and is capable of conceiving : heat; also : a single occurrence of this state. Estrus or oestrus refers to the phase when the female is sexually receptive (" in heat " in American English, or " on heat " in British English). See also estrous cycle. . On cytological evaluation, these stages are defined by the absence, presence, or proportion of 4 basic cell types as well as by the cell density and arrangement of the cells on the slide. One or more periods of estrus may occur during the breeding season of a species. It is characterised by a period of intense sexual receptivity, during which the female is willing to accept the male for mating. 7hfv4a, mixp7, 02hjjd, e2yz, pe7n, 64zdxm, 6qxad, ygowv, en9nd, aknjg,