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Biomedical subjects

Y Corrada

Publications and source records attributed to Y Corrada.

7 recordsLinked to original sources

Combination dopamine agonist and prostaglandin agonist treatment of cystic endometrial hyperplasia-pyometra complex in the bitch.

Cystic endometrial hyperplasia-pyometra (CEH-P) complex is a progesterone-dependent disease that requires medical treatment in bitches intended for breeding. To test the efficacy and safety of a combined protocol and to assess the effect of age, stage of cycle, previous steroid hormone administration and parity on treatment, 29 bitches diagnosed with CEH-P complex were treated daily with cabergoline 5 microg/kg PO and cloprostenol 1 microg/kg SC for 7-14 days, along with supportive antibiotic and hydration therapies. Before treatment, and on Days 3, 7 and 14, all bitches were evaluated clinically and uterine horn diameter measured during trans-abdominal ultrasonography. Twenty-four of 29 bitches were cured by either Day 7 or 14. Nine bitches had mild digestive side effects. Clinical signs related to pyometra began to improve markedly as early as Day 2 of treatment. Uterine diameters decreased (P < 0.05) by Day 3 of treatment, and continued to gradually decrease, reaching normal size by Day 14. Relapses occurred in 6 of 29 cases. Pregnancy was achieved in one of the two young bitches bred after treatment. No significant relationships were found between success rate and age, stage of the estrous cycle, previous hormone administration or parity. Although no variables affecting treatment results could be identified, this combination of compounds was found to be an efficient and safe for treatment of CEH-P.

Animals↗

Short-term progestin treatments prevent estrous induction by a GnRH agonist implant in anestrous bitches.

The objective of this study was to test the efficacy and safety of a short-term progestin treatment administered at two different times to prevent estrous induction in response to the administration of an implant releasing the GnRH agonist, deslorelin acetate (DA), in anestrous bitches. Interestrous intervals (IEI) observed prior to and post DA were compared. Forty-two anestrous bitches, with previous IEI history, were randomly allocated to one of the following treatments: PL: placebo sc (n = 12); MA: megestrol acetate 2mg/kg po for 8 days (n = 4); DA: 10mg sc (n = 8); MA&DA-1: MA beginning the day before DA (n = 8); and MA&DA-4: MA beginning 4 days before DA (n = 10). The dose of MA was identical for each treatment. All bitches were examined daily for 1 month and then every 3 months until the next spontaneous post-treatment estrous cycle. Post-GnRH estrous response occurred in 0, 0, 100, 50, and 10% of the PL, MA, DA, MA&DA-1, MA&DA-4, groups, respectively (<0.01). There was an interaction between the treatment and period for the duration of the IEI (< 0.01). Changes in IEI were different among treatments (p<0.01); the three DA-treated groups (147.5% +/- 10.3, 161.3% +/- 14.1, 148.6% +/- 19.2) differed from both the MA (12.9% +/- 17.6) and PL (8.1% +/- 7.8), but not among themselves. It is concluded that an 8 days megestrol protocol and DA on Day 4 was better than DA on Day 1 to prevent estrous response in anestrous bitches and that both protocols significantly increased the IEI.

Anestrus↗

Decrease of body temperature after aglepristone treatment in bitches.

Body temperature responses and the timing of abortions were evaluated in pregnant bitches with the anti-progestin aglepristone. Fifteen purebred and crossbred, 25-45 days pregnant, were included in this study and seven untreated bitches at the same stage of pregnancy served as controls. Treated bitches were administered two applications of aglepristone (10 mg/kg SC) 24 h apart for pregnancy termination. Pregnancy termination was confirmed by ultrasonographic assessment. Body temperature was rectally measured three times a day for 6 days beginning 24 h before treatment or pregnancy diagnosis in the treated and control bitches, respectively. Additionally, serum progesterone concentrations were assessed at time points during the study in the treated bitches. Pregnancy was terminated in 14 treated bitches in a mean+/-S.E.M. of 4.3+/-0.7 days after treatment. Control bitches remained pregnant. In the treated bitches, but not in the controls, body temperature significantly decreased 24 h after the beginning of the treatments (P < 0.01) and then gradually returned to pre-treatment values. Correlation between the day of mean minimum body temperature and the day of pregnancy termination was low (0.07; > 0.05). Progesterone did not show significant change throughout the study. Body temperature does not seem to be a suitable variable to clinically monitor the aborting effect of aglepristone. Decrease of body temperature after aglepristone treatment could represent further evidence of its hypothalamic effects.

Abortifacient Agents, Steroidal↗

Effect of tamoxifen citrate on reproductive parameters of male dogs.

Tamoxifen is a synthetic, nonsteroidal Type I antiestrogenic compound that competitively blocks estrogen receptors with a mixed antagonist-agonist effect. The manifestation of these different actions depends on each species, organ, tissue and cell type considered. Very little is known about the effect of antiestrogens in dogs. The objectives of this study were to determine the effects of tamoxifen citrate on some testis, prostate, hormone, and semen parameters in seven Beagle dogs with uncomplicated spontaneous benign prostatic hyperplasia. Two dogs were normospermic, four were oligozoospermic, and one was azoospermic. The dogs were allocated to a control pre-treatment period, followed by a treatment period, and five post-treatment periods (the duration of each period was 4 weeks). During the treatment period, 2.5mg tamoxifen citrate was given p.o. daily for 28 days to all the dogs. Maximum scrotal width, testicular consistency, libido semen parameters, prostatic volume, serum testosterone concentrations, and side effects were assessed. Tamoxifen negatively affected testis size and libido (P<0.01), and decreased prostatic volume (P<0.01) and testosterone concentrations during treatment. Semen quality deteriorated to nadir values (P<0.01) approximately one spermatic cycle after treatment and returned to pre-treatment values on the second cycle after treatment in all the dogs, except one young oligoazoospermic dog, in which the sperm count was higher ( P<0.01 ) at that time. No side effects were observed and fertility was conserved at the end of the study. Tamoxifen acted more like an agonist than antagonist on the gonadal axis and, therefore, upon both the prostate and testis. Therefore, tamoxifen may have therapeutic applications in dogs.

Animals↗

Secretory patterns of prolactin in dogs: circannual and ultradian rhythms.

The objectives of the present study were to characterize in dogs circannual and ultradian prolactin (PRL) secretory patterns and also to compare gender differences in the ultradian period of study in the Southern hemisphere. Blood samples were collected at 15-min intervals for 2.5 h from seven male and seven female dogs and a single monthly sampling, over a 1-year time span, from six male dogs for the ultradian and circannual studies, respectively. Plasma PRL was measured by a homologous enzyme immunometric assay. The ultradian study evidenced PRL elevations suggesting pulsatile secretion in both genders. Significantly higher mean smoothed baseline (ng / ml [7.02 +/- 1.2 vs 1.23 +/- 1.0, p < 0.01]) and AUC (ng/ml * 2.5 h [25.2 +/- 3.8 vs 4.4 +/- 3.8, p < 0.01]) were found in females when compared with males. In the circannual study, plasma PRL concentrations did not statistically differ among the months of the year. When grouped together the 3 months with a longer daylight had significantly higher PRL concentrations than the 3 months with the shortest (2.31 +/- 0.37 vs 0.96 +/- 0.37, p < 0.01). The correlation between length of daylight and PRL concentrations was 0.24, p < 0.05. It is concluded that PRL does have a circannual rhythmicity and that there are ultradian gender-related differences in the period under study in these groups of dogs. This study also demonstrates plasma PRL elevations suggesting pulsatile secretion in male dogs.

Animals↗

Coat colour changes associated with cabergoline administration in bitches.

Cabergoline or bromocriptine were administered orally to 60 bitches at doses of 5 microg/kg and 15 microg/kg daily, respectively, for two to 45 days for the treatment of pseudopregnancy or for oestrus induction. Seven of the dogs which received cabergoline for more than 14 days developed coat colour changes from the second week of administration to the next coat shedding. Of these, fawn-coloured bitches developed a yellowish coat colour while Argentine boar hounds became black spotted, mainly on their extremities. In previous untreated oestrous periods, these bitches had shown no coat colour changes. It is concluded that a colour shift in certain haircoats of particular breeds could be mediated through the inhibition of the secretion of melanocyte-stimulating hormone by the administration of the dopaminergic agonist cabergoline for more than two weeks. Transient coat colour changes should be considered a possible side effect when planning long-term treatment with dopaminergic agonists in dogs.

Animals↗

Effects of vincristine treatment on semen quality in a dog with a transmissible venereal tumour.

The effect of vincristine treatment on semen parameters in a male boxer with a genital transmissible venereal tumour are described. The dog was treated with vincristine intravenously at 0.5 to 0.7 mg/m2 body surface area per week for six weeks until complete regression of the tumour occurred. Semen samples were collected before each application and then at weeks 10, 12, 17, 21 and 23 after the start of therapy. There were no alterations in libido or in testicular size and consistency either during or after treatment. Total sperm count decreased to abnormally low values during weeks 4 and 5, and then began to increase up to pretreatment values. No significant alterations in the other semen parameters were found during the study period.

Animals↗