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S W Seager

Publications and source records attributed to S W Seager.

At least 37 records · Page 2Linked to original sources
PubMed1981

Behavioral, ovarian and endocrine relationships in the pubertal bitch.

Behavioral, ovarian and endocrine correlates were determined in seven bitches experiencing first estrus, and the results compared with previous data obtained on multiparous females. One or more atypical reproductive patterns were observed in certain bitches at the pubertal estrus. The ability of pubertal dogs to display normal reproductive relationships appeared to be related to age, because animals that exhibited normal sexual behavior and endocrine profiles tended to be older than females that produced aberrant patterns. For the latter group, atypical observations included lack of sexual receptivity and reduced or inconsistent patterns of circulating concentrations of estradiol-17 beta, luteinizing hormone (LH) or progesterone. Ovulation was confirmed in all four pubertal dogs subjected to laparoscopy, including two bitches that failed to demonstrate estrous behavior. In individual animals, it appeared that inadequate or sporadic elevations in titers of estradiol-17 beta during the preovulatory phase of the cycle were associated with reduced or abbreviated LH surge concentrations, and the latter were subsequently related to an absent or only minor preovulatory rise in serum progesterone. Reduced preovulatory estradiol-17 beta concentrations and a delayed increase in circulating progesterone were also associated with a lack of sexual receptivity. These results (1) suggest that hormonal insufficiencies or irregularities exist in certain bitches at the pubertal estrus and that such atypical activity appears more characteristic of the first than later adult estrous periods, and (2) are consistent with the theory that estrogen preconditioning and a decrease in the endogenous estrogen to progesterone ratio are important in the initiation of sexual receptivity in this species.

Animals↗
PubMed1980

Effect of copulatory stimuli on incidence of ovulation and on serum luteinizing hormone in the cat.

The relationship among the number of copulatory stimuli, the incidence of ovulation, and the pituitary release of LH was studied in the female cat (queen), an induced or reflex-ovulating species. Estrual queens were mated with a male either once during estrus (on day 1, 2, 3, or 4) or three times at 4-h intervals in a single day of estrus (on day 1, 2, or 3). Laparoscopy was used to examine the ovaries, initially to determine the numbers of preovulatory follicles and later to count corpora lutea. Blood samples were obtained serially from cats in each mating group, and sera were analyzed for LH. The day of estrus on which mating occurred, estrus duration, and follicle numbers had no effect on the proportion of animals ovulating. A single mating resulted in fewer queens ovulating per group (10 of 48 animals) than three matings on a single day (30 of 36). After copulation, LH was elevated only in animals later confirmed to ovulate. LH response in ovulating queens varied among individuals but, when averaged, appeared to be greater and more prolonged in multiple mated vs. single mated animals. These data indicate that the reflex-ovulating cate does not always ovulate after a single copulatory stimulus because of a failure of LH release. The frequency of coital stimulation apparently plays a major role in influencing the proportion of animals ovulating, with multiple copulation apparently enhancing the pituitary release of LH.

Animals↗
PubMed1979

Effect of prostaglandin F2 alpha on endocrine-ovarian function in the domestic cat.

The effect of prostaglandin F2 alpha (PGF2 alpha) on endocrine and ovarian function during the early luteal phase of the domestic cat was investigated. Queens were induced to ovulate and then injected subcutaneously with 0.5-5.0 mg PGF2 alpha/kg body weight. The greatest dose was found to approach toxicity. Concentrations of progesterone were similar in cats following treatment with PGF2 alpha compared to values of controls. Development and regression of corpora lutea as determined by serial laparoscopy were similar in all groups. These data indicate that PGF2 alpha at the tested dosages, given during the early luteal phase is not luteolytic in this species and suggest that these regimens would be ineffective for the premature termination of pseudopregnancy.

Animals↗
PubMed1979

Serum luteinizing hormone and ovulatory response to luteinizing hormone-releasing hormone in the estrous and anestrous domestic cat.

A heterologous double antibody radioimmunoassay was developed to measure changes in serum luteinizing hormone (LH) concentrations in estrous and anestrous queens (female domestic cats), following a single injection of varying doses (0--25 microgram) of luteinizing hormone-releasing hormone (LH-RH). No increase in serum LH was detected in any of the estrous or anestrous queens following a single saline injection. Treatment with LH-RH resulted in a sharp increase in serum LH concentration in both estrous and anestrous queens. Ovulations as observed by the presence of corpora lutea at laparoscopy occurred in none of four, one of four, two of four and four of four estrous queens receiving 0, 5, 10 or 25 microgram of LH-RH, respectively. Mean serum LH concentration of the ovulating queens was maintained at a higher level and did not return to basal level at the same time as that of nonovulating queens. The data show that: LH-RH can cause release of LH in both estrous and anestrous queens and induce ovulation in the estrous cat; the magnitude of LH response is influenced by the stage of the reproductive cycle; and the duration during which LH is maintained above basal level may play a significant role in ovulation induction in this coitus-induced ovulatory species.

Anestrus↗
PubMed1978

Semen collection by electroejaculation in the domestic cat.

A procedure for electroejaculation of domestic cats was developed. The method involved anesthetization of adult male cats with ketamine HC1 (33 mg/kg) or CI 744 (5.5 mg/kg). Optimal results were obtained with a 120-V ac electric stimulator capable of a continuous range of 0 to 60 V and 0 to 1 A. Using a 1- by 12-cm rectal probe constructed of teflon and stainless steel electrodes, ejaculation was obtained with an electrical stimulus over a range of 2 to 8 V and 5 to 220 mA. Voltage and amperage were increased at specific intervals in order to compensate for refractory ejaculatory response due to continued nerve and muscle stimulation. The procedure provided a means of obtaining ejaculates from domestic cats for purposes of semen evaluation and artificial insemination.

Animals↗
PubMed1978

Laparoscopy in zoological medicine.

The technique of laparoscopy was adapted and utilized in zoological medicine for various mammals, birds, and reptiles for reproductive and diagnostic studies as well as clinically related research. It was concluded that since anesthesia was routinely required for most manipulative procedures in zoo animals, and since laparoscopy adds little additional risk, the use of this technique provides an additional diagnostic aid when indicated. Laparoscopy was found to be effective for evaluating reproductive status, particularly ovarian anatomy and function, direct visual biopsy of internal organs, sex determination in selected birds, and as a surgical means of fertility control.

Animals↗
PubMed1978

Ovarian response in the estrual cat receiving varying dosages of HCG.

Laparoscopy was utilized to determine the ovulatory response of the domestic cat to various dosages of human chorionic gonadotropin (HCG) administered intramuscularly at one or two time periods during estrus. A linear HCG dose-ovulatory response was observed in queens receiving 0--500 IU HCG as a single injection on day 1 or as injections given on days 1 and 2 of estrus. Animals treated with 500 IU HCG on day 1 or days 1 and 2 of estrus produced the maximum percent ovulation rates based on pre- and post-HCG ovarian morphology observation by laparoscopy (100.0, 95.9%, respectively). A single injection of 500 IU HCG produced a significant increase (p less than 0.05) in mean percent ovulation rate in comparison to the 0, 50 and 100 IU HCG single injections. Administration of 500 and 250 IU HCG for 2 days of estrus resulted in a greater percent ovulation rate than the 2-day injection of 50 IU (p less than 0.05). These results indicate that the proportion of mature follicles ovulating in an induced ovulator, such as the cat, is an increasing function of graded dosages of exogenous hormone.

Animals↗
PubMed1978

Pregnancy in the domestic cat after artificial insemination with previously frozen spermatozoa.

Methods for collection, freeze preservation and artificial insemination of domestic cat semen were developed. Total sperm count and pre-freeze and post-thaw percent motility were significantly greater (P is less than 0.05) for samples collected by an artificial vagina method than for those collected by electroejaculation. Although conception rate was low (10.6%), 6 pregnancies were achieved, 2 after hormonal induction of oestrus.

Animals↗
PubMed1978

Gonadotropin induced reproductive cyclicity in the domestic cat.

Adult queens were treated with one of two sources of follicle stimulating gonodotropin (follicle stimulating hormone or pregnant mares' serum gonodotropin) to induce ovarian follicle development and estrus. Treatment involving single injections of follicle stimulating hormone stimulated mature follicle development but resulted in inconsistent display of sexual receptivity and variable ovulation rates. Single or multiple injections of pregnant mares' serum gonadotropin induced follicel growth, but follicle rupture often occurred prior to estrus and the mating stimulus. When compared to results obtained from queens mated while in natural estrus, cats receiving a series of injections of follicle stimulating hormone or pregnant mares' serum gonadotropin demonstrated ovarian hypersensitivity and produced follicular cysts which failed to rupture. The most effective hormone regimen for inducing follicle growth and estrus consisted of 2.0 mg follicle stimulating hormone injected daily intramuscularly until estrus. Queens receiving this treatment were capable of ovulating following mating or human chorionic gonodotropin administration and were capable of conceiving if mated.

Animals↗