The uterine motility in cattle during late pregnancy, labor and puerperium. II. Drug modification

The uterine effects of oxytocin, the prostaglandins dinoprost and cloprostenol as well as clenbuterol, ergometrin, xylazine and Utrorale were investigated in 8 cows during late pregnancy, parturition and early puerperium (until 4th day p. p.). Uterine motility was measured by means of pressure microsensors and electrodes which were surgically implanted 3 to 4 weeks before parturition. Hysterograms were characterized by means of pressure amplitude, frequency and duration of uterine contractions and also by electromyography. Oxytocin (2-5 IE) given intravenously always provoked strong uterine contractions until the 4th day p.p. From the prostaglandins examined during early puerperium only dinoprost (15 mg i.v.) produced uterotonic effects, while the synthetic analogue cloprostenol (0.25 mg i.v.) had a weak stimulatory activity only on day 1 p.p. Both prostaglandins were ineffective when injected intramuscularly. Clenbuterol (0.3 mg i.v.) a beta 2-mimetic compound effectively induced long lasting tocolysis during parturition, which could be abolished by oxytocin. Xylazine (10 mg i.v.) was able to significantly increase uterine motility during late gestation. Following intravenous administration of ergometrin (1 and 10 mg), bunitrolol (1-16 mg) and Utrorale (0.1-4 ml) including its compounds oleum sabinae, oleum terebinthinae, balsamum copaivale and Styrax no uterokinetic activity was recorded at any time.     

Fluid therapy in the neonate: not your mother's fluid space.

Fluid therapy is a universally used therapeutic modality in critical care patients. To effectively deliver fluids to neonates., an understanding of their fluid physiology is necessary. Neonates, as they make the transition from fetal physiology, have increased capillary filtration and a compliant interstitium producing a large ISF reserve. This reserve helps the neonate to adapt to fluid challenges, serving as a ready source of fluids in times of need, but it also frustrates therapeutic fluid administration by damping the effect of intravenous fluid therapy when treating hypovolemia. Additionally,it explains the difficulty neonates have in handling fluid overload. Successful treatment of hypovolemia requires aggressive volume repletion using 20-mL/kg fluid boluses. Once euvolemia is restored and ongoing losses are replaced, maintenance fluid rates should be conservative so as to avoid fluid overload. The neonate's unique sodium handling must also be recognized.Many critical neonates benefit from sodium restriction, whereas others may have high ongoing losses and require careful sodium replacement therapy.Careful attention to fluid therapy formulation ensures positive fluid support without adding to the physiologic stress of the critical neonate.     

Oestrus during pregnancy in the cow

Forty-three oestruses were observed in 35 pregnant cows in one beef suckler herd and 17 dairy herds; at each oestrus the pregnant cow stood willingly to be mounted by another cow or bull. Such oestruses were observed at all stages of pregnancy, although more often between 121 and 240 days, occurred more than once per pregnancy and were also seen in successive pregnancies. On one farm where the dairy cows were observed for four 30 minute periods daily, oestrus was recorded in 5.7 per cent of pregnant cows. The behavioural signs associated with oestrus during pregnancy were indistinguishable from those of true oestrus in non-pregnant animals and although its duration was shorter (mean 5.6 hours), its intensity was comparable to that of the true oestrus. Pregnant cows showing oestrus were usually seen interacting with other oestrous cows in the sexually active group. Pregnant cows showing oestrus had a higher mean condition score (3.9 +/- 0.64) than control pregnant cows (3.0 +/- 0.36). Physiological changes in the genital tract normally associated with true oestrus were not observed in pregnant cows showing oestrus. There was no ovulation or metoestrous bleeding. The characteristics of cervical mucus, including ferning patterns, were similar to those of pregnant cows at the same stage of pregnancy. Hormonal changes associated with oestrus in non-pregnant cows were not observed in the pregnant cows exhibiting oestrus. Seven of nine pregnant cows at oestrus stood willingly to be mounted by a bull. On seven occasions, bulls exposed only to cervical mucus from pregnant cows showing oestrus did not display flehmen.(ABSTRACT TRUNCATED AT 250 WORDS)     

Altrenogest and progesterone therapy during pregnancy in bottlenose dolphins (Tursiops truncatus) with progesterone insufficiency

Progesterone production is essential for growth and development of the conceptus during pregnancy. Abnormal development of the corpus luteum (CL) after conception can result in early embryonic loss or fetal abortion. Routine monitoring of bottlenose dolphin (Tursiops truncatus) pregnancy after artificial insemination or natural conception with ultrasonography and serum progesterone determination has allowed for the establishment of expected fetal growth rates and hormone concentrations. Using these monitoring techniques, we revealed four pregnant dolphins (12-24 yr old) with abnormally low progesterone production indicative of luteal insufficiency. Once diagnosed, animals were placed on altrenogest (0.044-0.088 mg/kg once daily) alone or with oral progesterone (50-200 mg twice daily). Doses of hormone were increased or decreased in each animal based on how fetal skull biparietal and thoracic growth rates compared with published normal values. Hormones were withdrawn starting from day 358 of gestation in animals 1 and 2, with labor occurring 6 and 7 days after withdrawal and at 376 and 373 days of gestation, respectively. Both deliveries were dystocic, with each calf requiring manual extraction and fetotomy for calf 1. The fetuses in animals 3 and 4 died at 348 and 390 days of gestation, respectively. Induction of labor was attempted in both animals, after fetal death, by using a combination of rapid progesterone withdrawal and steroid and prostaglandin F2alpha administration. The calf of animal 4 had to be removed with manual cervical dilation and fetotomy All adult females survived the procedures. These data provide the first in vivo evidence that the CL is the primary source of progesterone throughout pregnancy in the bottlenose dolphin. Until further characterization of hormones required during pregnancy and at parturition has been accomplished, the exogenous progestagen supplementation protocol described here cannot be recommended for treatment of progesterone insufficiency in bottlenose dolphins.     

Drug therapy of respiratory disorders

The emphasis of this article is on the clinical application of drugs in therapy for treatment of disorders of the lower respiratory tract. Medications discussed include those used to enhance clearance of secretions and those employed to prevent and/or alleviate bronchoconstriction. Antimicrobial agents and respiratory stimulants are briefly mentioned.     

Unusual phenomena during pregnancy in the cat and cow.

Unusual situations were observed during examination of pregnant uteri from a cat and a cow. The feline specimen revealed three corpora lutea at the surface of each ovary with three fetuses developing normally in the left and two in the right uterine horn. The right horn had been ruptured between two of the locular enlargements but the damage was sealed by the omentum. Three conceptuses were present in the cow's uterus. Two of these embryos, each with its individual allantois, were developing within a single chorion within one uterine horn. The adjacent tips of these allantoic vesicles were entangled into a complex knot which could provide opportunity for vascular anastomosis.     

Steroid receptors in the myometrium during pregnancy in the ewe

Three studies were conducted to investigate concentrations of estrogen and progestin receptors in ewe myometrium during gestation. In the first two studies, concentrations were found to be similar in pregnant and nonpregnant ewes on d 5, 9, 12 and 14 postestrus. The receptor concentrations were relatively high on d 5 and were lowest on d 14. Apparently concentrations of myometrial steroid receptors during the luteal phase are commensurate with the successful establishment of pregnancy. The concentration of both types of receptors increased from d 14 to 35 in pregnant ewes. This change was associated with a concomitant increase in the amount of DNA and protein in cells. In Exp. 3, it was found that the concentrations of the estrogen receptor remained fairly constant after d 45 until late gestation, while the concentration of cytoplasmic progestin receptor increased after d 65. The ratio of RNA to DNA appeared to increase throughout pregnancy. Progestin receptor increases may be involved in the continued growth and quiescence of the uterine myometrium.     

Neuroendocrine-immune interactions in the neonate

Cytokine responses to lipopolysaccharides in neuroendocrine tissues are age- and tissue-dependent in neonatal pigs. Developmental differences in serum and tissue-specific responses are not necessarily equivalent. Lower levels of cytokine gene expression in neuroendocrine tissues of early neonates potentially could influence neuroendocrine and immune responses to infection. The limited information on neuroendocrine-immune responses and interactions in neonatal farm animals presents significant challenges, as well as opportunities for new discoveries and improvements of livestock production.     

Drug therapy in cats: a systems approach

In the second part of this 4-part series, drug therapy in cats is discussed by use of a systems approach. Specifically, drugs that can be used safely for treatment of disorders affecting the feline gastrointestinal, central nervous, respiratory, cardiovascular, and urogenital systems are described. Many drugs that are used in dogs can be safely used in cats according to the same or similar dosing regimens. Several drugs that have traditionally been considered inappropriate (eg, morphine derivatives, primidone) can probably also be used, if cautiously, in cats. In contrast, use of several drugs that are safely used in other species should be avoided in cats (eg, selected emetics and antiemetics, phosphate salt enemas, and selected urinary antiseptics). Cats are more sensitive than dogs to the adverse side effects of a variety of drugs (eg, aspirin, digoxin, selected antiarrhythmics), and extra precautions must be taken when these drugs are used in cats. Finally, several drugs are used for the treatment of illnesses that tend to be unique to cats (eg, taurine and calcium-channel blockers in selected feline cardiovascular disorders).     

Myometrial electrical activity during pregnancy and parturition in the pygmy goat

To quantify the pattern of myometrial activity during gestation and parturition, one bipolar electrode was implanted on each uterine horn of four bilaterally pregnant pygmy goats between days 102 and 120 of gestation. After a recovery period, electromyographic recordings were made for at least six hours per day and continuously when parturition was judged to be imminent. During late gestation myometrial activity occurred as discrete episodes of myometrial electrical activity (EMEA) with a mean duration ranging from 6.2 +/- 2.07 to 8.3 +/- 1.60 minutes. The mean interval between two successive EMEAs ranged from 45.8 +/- 19.95 to 74.7 +/- 42.27 minutes. In three of the four goats these characteristics were not significantly different from the two uterine horns. Parturition was preceded by a prolonged period (eight to 12 hours) of myometrial quiescence. It was only from 19 to 15 hours before expulsion of the first kid that total duration of EMG activity increased. This finally resulted in the regular occurrence of bursts which occupied 25 to 30 per cent of the recording time. The results demonstrate that, as in the sheep, cow and pig, the myometrium is active during late pregnancy. It is postulated that luteolysis coincides with the prolonged period of myometrial quiescence which precedes the onset of the parturient pattern of uterine activity.     

Hemostasis development in the lamb fetus and neonate

Fetal and neonatal lamb hemostasis were studied from the 60th day of pregnancy to birth. Platelet counts and blood coagulation, as assessed by tests such as recalcification time and thromboelastography, were similar in fetuses, neonates, and adult sheep. The values of coagulation factors were low, ie, vitamin K-dependent Factors II, VII, IX, and X remained unchanged (30 and 40% of adult reference values) until the last 10 days of gestation, and then increased until birth (40 to 60%). Values of fibrinogen and Factor V followed a similar pattern, although their activities became identical to adult values at birth. Also, we measured values of protein C and antithrombin III, which are synthesized by the liver. The importance of hepatic failure and fetal vitamin K deficiency were discussed. Factors VIII and XII activities increased gradually during pregnancy to reach adult values at birth. Fetal fibrinolytic activity increased. This could not be explained by the values of tissue-type plasminogen activator (it was not detectable) or by the presence of its fast-acting inhibitor, whose concentration did not decrease.