Bovine mammary glands were inoculated intracisternally with a streptomycin-resistant (SR) strain of Corynebacterium bovis to determine the number of colony-forming units (CFU) required to induce colonization and to maintain persistence of C bovis colonization throughout lactation and involution. Streptomycin resistance was used as a strain marker. Uninfected quarters in cows during midlactation were challenge exposed with successively higher numbers of SR C bovis until all quarters became colonized. Inoculum containing 790 CFU of SR C bovis established colonization in only 7 of 38 quarters. Colonization persisted in only 4 of these quarters by 23 days after inoculation. Eleven quarters were reinoculated with higher numbers of SR C bovis, and all became colonized by the time challenge-exposure inoculum contained 8 X 10(4) CFU. Colonization persisted throughout the 93-day experimental period. Somatic cell counts were significantly (P less than 0.01) higher in SR C bovis-colonized quarters after inoculation than before. Sixteen additional quarters were inoculated with a mean number of 8 X 10(4) CFU of SR C bovis 7 days before suppression of lactation. All quarters became colonized, and SR C bovis was shed during the experimental period; throughout the nonlactating and peripartum periods, high numbers of SR C bovis in pure culture were shed from 13 of 16 quarters.

A total of 301 Thoroughbred mares were investigated the characteristics of breeding in the local areas in Jeju during the period from February 2000 to July 2001. The pregnancy rate and foaling rate in 143 mares were 93.0%, 72.0%, respectively, and mean gestational length was 339.3 days in 2000. The pregnancy rate in 158 mares was 86.7% in 2001. Mature follicles were ovulated in right(46.0%), left(45.2%), and bilateral(7.8%) ovary. The incidence of multiple pregnancies in 158 mares between 15 days and 45 days after mating were 89.3%(single), 10.1%(twin), and 0.6%(triple). The incidence of EED was 13.3%.

To establish a prediction table of parturition day real-time B-mode ultrasonographic examinations were performed in 12 pregnant Shih-tzu bitches. Measurement of inner chorionic cavity diameter and fetal head diameter was performed from 15 days of gestation to parturition. These were converted retrospectively based on the day of parturition (Day 0). The data of inner chorionic cavity diameter obtained from Day -44 to Day -25 and fetal head diameter obtained from Day -25 to Day -1 were used to compile a prediction table of parturition day.

The aim of the present study was to test the efficiency of estrous induction in the premature, metestrous and anestrous bitches. The estrus was induced with prostaglandin F2 alpha, estradiol-17 beta, pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG) in the treatment A, and with PMSG and HCG in the treatment B. Day 0 was the first day of estrone injection in the treatment A and the day of PMSG injection in the treatment B. Twenty three of the twenty six bitches laparotomized under general anesthesia between 11 and 18 days after onset of behavioral estrus, whereas three bitches were not laparotomized and remained until parturition. Ovarian responses were evaluated with the total number of corpora lutea or ovulation sites. The uterine horns were flushed with phosphate-buffered saline added heat treated canine serum (10 %), the flushing media was collected into watch glass and the ova were examined under stereomicroscope. Standing estrus was observed on the day 17.7 +- 1.5 after injection of estrone in the treatment A, but ovarian responses were not detectable. Standing estrus was observed on the day 12.2 +- 0.2 after injection of PMSG in the treatment B and 14 of 17 bitches showed ovarian responses. Ova were recovered in 9 of the 14 bitches. Ovarian responses were observed in one of the three premature bitches, two of the three metestrous bitches and all of the 11 anestrous bitches. The average number of the ova collected from 9 bitchs were 12.2 +- 1.4. Three bitches in the treatment B exhibited behavioural estrus and all of them were mated with fertile male dog, resulting the pregnancy in only one bitch. The pregnant bitch gave the birth of two pups

Dog's head dimentions show consistent variability for their dimentions, such as length, width (biparietal diameter) and height, according to anatomical classification in: braquicephalic, mesaticephalic and dolicocephalic. Since there are attempts to standardize values that characterize canine pregnancy, those architectonic features must be considered. The aim of this study is to use ultrasonography scanning examinations to correlate the fetal's head dimentions and gestational age in order to contribute to the intra uterine development comparative study of the dog' head. Serial ultrasonographic examinations were performed in 10 pregnant Boxers biches, 2 or 3 times per week from 18º day of gestation until the whelping, the used device was a portable GE®, Logic 100 MP, equipped with a sectorial transducer 5,0 MHz and another linear one of 7,5 MHz. Biparietal diameter (DBP), length (CC) and width (HC) of the fetal head had been measured since the opportunity that was possible to distinguish fetal head from fetal body, until the end of gestation. Such informations had been located in graphics of dispertion of the mensuration in function of the number of days before parturition. It was concluded that the mensurations of selected parameters were consistent among studied gestations and hightly correlated among them and with the parturition day. The parameter DBP was the most technically easier to be gauged. | A cabeça dos cães apresenta uma considerável variabilidade quanto suas dimensões, tais como comprimento, largura (diâmetro biparietal) e altura, segundo sua classificação anatômica em braquicefálicos, mesaticefálicos e dolicocefálicos. Tais aspectos arquitetônicos devem ser considerados ao tentar padronizar valores que caracterizem a gestação canina, em geral por meio de ultra-som. O objetivo deste estudo foi o de utilizar a ultra-sonografia para correlacionar as dimensões do crânio fetal e a idade gestacional com a finalidade de contribuir para o estudo comparativo do desenvolvimento intra-uterino do crânio dos cães. Examinou-se 10 cadelas da raça boxer com um aparelho portátil da marca GE®, modelo Logic á 100 MP, equipado com um transdutor convexo 5,0 MHz e outro linear de 7,5 MHz, de 2 a 3 vezes por semana a partir do 18º dia de gestação até o parto. As variáveis HC, CC e DBC foram aferidos a partir de quando foi possível distinguir a cabeça do corpo fetal, até o fim da gestação. As informações obtidas foram plotadas em gráficos de dispersão das mensurações em função do número de dias antes do parto. Concluiu-se que as variáveis estudadas são consistentes entre as gestações estudadas, apresentaram-se altamente correlacionadas entre si e com a idade gestacional e que a variável DBP é a mais tecnicamente fácil de ser aferida.

Apesar do crescente número de pesquisas na área de reprodução canina, ainda não foram desenvolvidos métodos que possibilitem datar a gestação e estimar a data do parto utilizando variáveis obtidas de mensurações por meio de ultra-som, como há muito tempo se faz e se aplica na espécie humana. A ultra-sonografia é o método mais adequado para a obtenção de tais valores por ser indolor, inócuo para a mãe e conceptos, não necessitando de sedação. O objetivo deste estudo foi o de utilizar a ultra-sonografia para mensurar as dimensões da placenta e verificar como estão relacionadas à idade gestacional em cadelas da raça Boxer. Examinou-se 10 cadelas da referida raça com um aparelho portátil da marca GE®, modelo Logic á 100 MP, equipado com um transdutor convexo 5,0 MHz e outro linear de 7,5 MHz, de 2 a 3 vezes por semana a partir do 18º dia de gestação até o parto. A placenta foi aferida desde o exame em que foi possível sua identificação até o fim da gestação, sendo assim, verificou-se o comprimento e a espessura da placenta. Tais informações foram plotadas em gráficos de dispersão das mensurações em função do número de dias antes do parto. Concluiu-se que a variável espessura da placenta (EP) foi consistente entre as gestações estudadas e altamente correlacionada com o dia do parto. | Despite increasing research on reproduction in dogs, methods have not been developed to allow dating the gestation and predict the parturition day under definitive measurable parameters, as it has been done for human gestation. Ultrasonography is the most suitable method to this propose because it is painless, harmless for the mother and conceptus and no need of sedation. The aim of this study is to use ultrasonographic scannings to measure Boxer placenta dimensions and then verify the correlation between them and gestational period. Serial ultrasonographic examinations were performed in 10 pregnant Boxers, 2 or 3 times per week from the 18th day of gestation until the whelping, the used device was a portable GE®, Logic 100 MP, equipped with a sectorial transducer 5,0 MHz and another linear one of 7,5 MHz. Thickness and width of the placenta had been measured since the opportunity of detection until the end of gestation. Such informations had been located in graphs of dispersion of the measurement in function of the number of days before parturition. It was concluded that the measurements of selected parameters were consistent between studied gestations and highly correlated to the parturition day.