Twin-pregnancy increases susceptibility of ewes to hypoglycaemic stress and pregnancy toxaemia

Pregnancy toxaemia is a metabolic disorder with a high mortality rate and occurs in twin-bearing ewes in late gestation. Maternal hypoglycaemia is a characteristic symptom of the disease and has been attributed to an increase in glucose uptake by the twin-bearing uterus. The possibility that a reduced maternal glucose production rate might cause hypoglycaemia, has received little attention in the past. It was the aim of this study to investigate this explanation as a possible alternative. Six ewes were sequentially subjected to two types of hypoglycaemic stress, firstly by fasting for 14 h and secondly through induction of moderate hyperketonaemia. Glucose kinetics were assessed in each animal during the dry non-gestational period, during late gestation, and during early lactation. Application of these stress factors was associated with variation of plasma glucose concentration from 4.9 to 0.87 mmol L(-1). The plasma glucose concentration was always significantly related to the glucose production rate. The greatest stress-induced reductions in glucose concentration and glucose production rate were seen during late gestation in twin-bearing ewes. The decline in the glucose production rate after an overnight fast and during induced hyperketonaemia was greater in twin-bearing ewes than in single-bearing ewes (59% and 43%, respectively, p<0.05). The stress conditions resulted in the lowest levels of glucose concentration and glucose turnover rates in the stressed, hyperketonaemic, late gestation twin-bearing ewes. This illustrates that the glucose homoeostatic system of ewes bearing twins is significantly more susceptible to hypoglycaemic stress than that of ewes bearing single lambs. These findings also show that the primary cause of hypoglycaemia in late gestation twin-pregnant ewes is an increased susceptibility to a stress related reduction in glucose production rate. This metabolic condition leaves the twin-pregnant ewe predisposed for the development of pregnancy toxaemia.     

Real-time ultrasound pregnancy diagnosis in the bitch

A portable real-time ultrasound scanner was used for pregnancy diagnosis in eight bitches. Pregnancy was detected in seven; one bitch was not pregnant. The period between the 28th and 35th days of gestation seemed to be the most suitable time for counting the foetuses. Details of the foetal bodies were clearly visible after the 40th day of pregnancy. Most of the foetuses were detected. Real-time ultrasound can be used for the diagnosis of canine pregnancy as a safe, rapid and easy method, although some inaccuracy in foetal count exists.     

Pregnancy‐Associated Glycoprotein Secretion in North Moroccan Goats

The plasma profile of pregnancy‐associated glycoprotein (PAG) and its relationship with fetal number were studied in 14 North Moroccan goats using a semi‐heterologous radioimmunoassay (RIA). Peripheral blood was collected every day during the first month of pregnancy, afterward the blood samples were collected trice a week. The PAG were first detected at day 20 of pregnancy, their levels increase to week 8 of gestation then decrease slightly until parturition. Statistical differences between goats carrying one or two foetuses are observed from week 5 of pregnancy until parturition. Factorial Discriminant Analysis provides mathematical models for the discrimination between the litter size using the PAG level and the week of pregnancy. Using only one blood sample per week, high sensitivity, specificity and overall accuracy (74%, 88% and 81%) were obtained using these models. It is concluded that the PAG RIA is an effective tool for early diagnosis of pregnancy and for discrimination between the litter sizes in North Moroccan goats.     

Effect of protein level and flushing method on the reproductive performance of rabbits

Fifty‐five New Zealand white × California cross‐bred female rabbits were used to study the effect of protein level and flushing method on the reproductive performance of rabbits. The treatments consisted of three protein diets (18, 20 and 24% crude protein (CP)) and three flushing methods in a 3 × 3 factorial design. The flushing methods consisted of (i) flushing multiparous does and feeding a 16% CP diet during pregnancy; (ii) flushing multiparous does and feeding an 18% CP diet during pregnancy; and (iii) flushing nulliparous does and feeding an 18% CP diet during pregnancy. Flushing rabbits with different levels of protein did not significantly affect gestation length, litter size and mortality of kits. The trend showed an increase in litter weight with the increase in protein level from 18 to 24%. However, kits from does flushed with 24% CP had a higher individual kit weight gain than those on 20 and 18% CP. Gestation length, total litter size at birth, number of kits dead at birth and number of kits dead at 21 days post‐partum were not affected by flushing methods. There was, however, a significant effect of the flushing method on the number of kits alive at birth, and 7, 14 and 21 days post‐partum. Nulliparous does flushed and maintained on 18% CP during pregnancy had a significantly higher number of kits alive at birth, and 7, 14 and 21 days post‐partum. Litter weight was significantly higher for nulliparous does at 7, 14 and 21 days compared with that of multiparous does flushed and placed on a 16 or 18% CP diet during pregnancy. Protein intake during pregnancy had a significant effect on litter birthweight. Nulliparous and multiparous does flushed and placed on an 18% CP diet during pregnancy had a significantly higher litter birthweight than multiparous does flushed and placed on a 16% CP diet during pregnancy. The effect of protein level during pregnancy on the number of kits alive at birth was not significant. There was no interaction between protein level and flushing method on the reproductive performance of rabbits.     

Usefulness of clinical observations and blood chemistry values for predicting clinical outcomes in dairy goats with pregnancy toxaemia

Background

Pregnancy toxaemia (PT) is a disease that affects pregnant goats during their last month of gestation and is characterized by a high case fatality rate. This study involved 32 does maintained on a commercial dairy goat farm that were diagnosed with PT. A physical examination was performed on and haematology parameters obtained from each doe, at the time of diagnosis. The data from the 24 PT goats that died was compared with the corresponding data from the 8 PT goats that survived.

Results

Polypnea, swollen limbs, anorexia with absence of ruminal motility, recumbency, nervous signs and drooping ears were the most frequently observed clinical manifestations. Nineteen out of 21 recumbent goats died. Sixteen out of 17 goats with anorexia and absence of ruminal motility died. Mean beta-hydroxybutyric acid (BHBA) values in the goats that died were not significantly different from those in goats that survived. The blood values for pH and pCO₂ (p?<?0.005) as well as for HCO₃ ^?, BE and K⁺ (p?<?0.001) were significantly lower in the goats that died than in those that survived.

Conclusions

The clinical signs most indicative of a poor prognosis are anorexia with absence of ruminal motility and recumbency. Among the blood parameters to be considered, hypokalaemia and metabolic acidosis are the most relevant. Goats with PT have a high mortality and their condition can deteriorate very fast. Based on the authors’s experience, a good strategy to minimize the economic losses caused by PT is to focus on the offspring survival rate since an early decision (induction of kidding or caesarian surgery) can increase the number of alive kids.

     

Acid-base and electrolyte status during early induced pregnancy toxaemia in goats

Eleven Murciano-Granadina goats in late pregnancy were separated into two groups (1) control (n=6) and (2) fasting for 72 h to induce pregnancy toxaemia (n=5). Venous blood was taken daily to determine acid-base and electrolyte parameters. Significant decreases in blood pH, bicarbonate concentration and base excess, and a significant increase in anion gap were observed after 24h of fasting. These changes were significantly correlated with non-esterified fatty acid concentration. No significant changes were observed in pCO(2), and electrolyte or lactate concentrations. Clinical signs of pregnancy toxaemia in fasted goats appeared by 72h post-fasting. These signs and the changes in acid-base balance disappeared once feed was reintroduced. Blood pH, bicarbonate concentration, base excess and anion gap could be indicators of early pregnancy toxaemia in goats.     

Influence of gestation on the pharmacokinetics of four sulphonamides in goats

The influence of gestation on the pharmacokinetics of four sulphonamides was studied in goats before, during and after pregnancy. Similar doses were given as intravenous boluses of 50 mg kg-1 each. Results were compared with those of non-pregnant goats to eliminate seasonal effects. With sulphadimidine elimination was mainly apparently first-order. In gestating goats the mean residence times decreased and mean plasma clearance rates increased with sulphadimidine during pregnancy, but this effect was continued after kidding at least until the end of May. The same happened with sulphadimethoxine, but sulphisomidine was not affected. In contrast to the other sulphonamides the mean residence time of sulphadoxine showed a maximum in February in gestating goats, while mean plasma clearance remained constant during and after pregnancy, at a lower level than in September. The mean plasma clearance of sulphadoxine decreased significantly from September to February in the non-pregnant control goats. In May five of six control goats and two of six goats which had kidded showed capacity-limited elimination against only two control goats in the foregoing experiments. With sulphadoxine one animal in the gestation group, but not the same one in each experiment, showed capacity-limited elimination against one, four and three in the control group in December, February and May, respectively. Distribution volumes increased significantly during and after pregnancy with sulphisomidine and sulphadimethoxine. A decrease in distribution volumes was seen in control goats with sulphadimidine, sulphisomidine and sulphadoxine, but was only significant for sulphadoxine. The pregnant uterus could not be recognised as an extra compartment, either in distribution volume nor in the pharmacokinetic model.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cortisol in pregnancy toxaemia of sheep

Of 31 pregnant ewes with clinical signs of pregnancy toxaemia, 24 had hypoglycaemia and hyperketonaemia at the time that a single blood sample was obtained. Twenty-five of these had a plasma cortisol concentration in excess of 10 ng/ml and six had a value below this. All the seven animals which did not show both hypoglycaemia and hyperketonaemia had a plasma cortisol concentration in excess of 10 ng/ml. Taking all the sheep together, 80% had a high plasma cortisol concentration. This could be the consequence of increased adrenal output or reduced excretion by the liver.     

Real-time ultrasonography for pregnancy diagnosis and foetal ageing in fallow deer

SUMMARY Three groups of 15 to 17 adult fallow does with some additional yearling does in 2 of the groups were treated to synchronise oestrous cycles, and mated. All does were scanned by ultrasound at 4 weeks of gestation and at weekly intervals from week 7 to week 14 of gestation. Growth rates of 13 foetal and uterine characters, which have been used for ageing foetuses of red deer, were similar for adult and yearling does and among the 3 groups. Transrectal ultrasound scanning was a reliable and accurate means of detecting pregnancy and of ageing foetuses of fallow deer during weeks 7 to 17 of pregnancy.     

Transplacental BVD virus transmission after experimental inoculation of goats in different pregnancy stages

Eight groups of altogether 25 goats without neutralizing antibodies against BVD virus, were inoculated either intranasally or intranasally and subcutaneously with two different BVD virus isolates during different stages of gestation. In all 18 goats inoculated within the first 78 days of gestation an abortion and foetal death rate of approximately 100% occurred. Only one goat gave birth to a clinically healthy kid. The other seven goats which were inoculated after the 78th day of gestation showed also a high foetal death rate. Only two of them gave birth to clinically healthy kids. Neutralizing antibodies against BVD virus could be detected in blood samples drawn from 14 kids born at normal term including stillborn and non-viable offsprings. BVD virus was reisolated from different organs taken from seven foetuses. It was not possible to isolate BVD virus from any of the normal offsprings.     

A preliminary study of pregnancy termination in the bitch with slow-release formulations of prostaglandin analogues

Forty-two beagle bitches at gestational ages from 4 to 35 days were treated with various formulations of the prostaglandin analogues fluprostenol and cloprostenol at doses from 10–40 μg/kg in an attempt to terminate pregnancy. Pregnancy was confirmed and the effect of treatment assessed by euthanasia and post-mortem examination to detect viable foetuses or resorbing implants twenty-one days after prostaglandin administration. Five of the bitches treated with an aqueous solution of cloprostenol by subcutaneous injection showed unacceptable side effects but both compounds in a slow release injectable formulation or impregnated into intravaginal devices had a luteolytic effect with only mild side effects in occasional bitches. Successful response to treatment in terms of sustained depression of plasma progesterone concentrations and pregnancy termination was 80 per cent at gestation stages of 25 days or over but only 27 per cent when given earlier in pregnancy. Mature follicles developed in two bitches which aborted following treatment at 14 days and returned to oestrus 10–14 days later. These preliminary findings show that slow-release formulations of fluprostenol and cloprostenol can cause complete luteolysis in the bitch.     

Pathology in the ovine foetus caused by an ovine pestivirus

Homogenised tissues or tissue culture supernatant fluid containing a noncytopathic pestivirus obtained from a lamb with a neurologic form of border disease, were inoculated into ewes at different stages of pregnancy. Foetal death occurred in 9 ewes of those inoculated between 19 and 47 days of pregnancy while 3 ewes did not lamb. Eight of the foetuses were aborted between 77 and 132 days of pregnancy; of these 6 were autolysed or mummified and one had arthrogryposis. The one full-term dead lamb had a hairy birth coat and lissencephalic micrencephaly. Foetal death occurred in only 7 of 14 ewes inoculated between 57 and 72 days of pregnancy. Four of these ewes aborted between 77 and 108 days of pregnancy and 3 gave birth to full-term, dead, hairy lambs. The remaining 7 ewes gave birth to live hairy lambs with severe inco-ordination. All lambs carried to term and aborted foetuses or lambs that could be examined had a range of intracranial malformations including focal leucomalacia, micrencephaly, hydranencephaly, porencephaly, lissencephaly and cerebellar hypoplasia. Some lambs also had skeletal abnormalities including arthrogryposis, scoliosis and brachygnathia inferior. The pestivirus isolate used in these trials produced more severe effects on the ovine foetus than previously observed in similar inoculation trials using pestivirus isolates from border disease lambs without nervous signs.     

A goat mortality study in the southern North Island

A study was undertaken to indicate the importance of different causes of death in goats and to investigate the management factors which influence these problems. Over a 15 month period, 324 dead goats were received from 67 farms in the Horowhenua, Wairarapa, Wanganui and Wellington regions. Although a wide range of diseases was encountered in the study, the major causes of mortality could be divided into 4 groups: problems directly related to management, microbial diseases, nematode parasitism, and trace element related deficiencies and toxicities. The highest proportion of deaths related directly to management problems and included deaths from hypothermia, mismothering, premature birth, ruminal acidosis, pregnancy toxaemia, trauma, and plant and chemical toxicities. In larger flocks, microbial diseases including Pasteurella pneumonia and yersiniosis were major problems. Deaths from nematode parasitism were predominantly observed in goats 12 months of age and older. White muscle disease (selenium/vitamin E deficiency) was the major trace element deficiency causing death in goats. The influence of factors including age of goat, flock size and management practices on the major causes of death are discussed.     

Evaluation of a fibrate,specific stimulant of PPARα, as a therapeutic alternative to the treatment of clinical ovine pregnancy toxaemia

Ovine pregnancy toxaemia is a metabolic disorder affecting sheep in their last 6 weeks of pregnancy as a result of their inability to maintain adequate energy homoeostasis. Different alternative treatments are available with variable results. The aim of this research was to evaluate a peroxisome proliferator‐activated receptor alpha (PPARα) stimulant as an alternative to treat clinical pregnancy toxaemia. Thirty‐three adult sheep, with known gestation date and carrying a single foetus, were fasted from day 130 of gestation until animals showed clinical disease. From that moment onwards, sheep were treated during 6 days with three different therapeutic alternatives: 10 mg/kg of 2‐methyl‐2‐phenoxy‐propionic acid; 10 mg/kg of 2‐methyl‐2‐phenoxy‐propionic acid + 100 mL of propylene glycol oral; or 100 mL of propylene glycol oral. Glycaemia and serum β‐hydroxybutyrate (BHOB) were determined daily. Liver biopsies were taken at day 130 of gestation, at the beginning and end of treatments and at 5 days postpartum, evaluating the extent and degree of the steatosis lesion. Even though in sheep treated with 2‐methyl‐2‐phenoxy‐propionic acid, serum concentrations of glucose and BHOB recovered more slowly, we conclude that 2‐methyl‐2‐phenoxy‐propionic acid alone or combined with propylene glycol can be used as an alternative to effectively treat fatty liver, and therefore pregnancy toxaemia.     

A goat mortality study in the southern North Island

A study was undertaken to indicate the importance of different causes of death in goats and to investigate the management factors which influence these problems. Over a 15 month period, 324 dead goats were received from 67 farms in the Horowhenua, Wairarapa, Wanganui and Wellington regions. Although a wide range of diseases was encountered in the study, the major causes of mortality could be divided into 4 groups: problems directly related to management, microbial diseases, nematode parasitism, and trace element related deficiencies and toxicities. The highest proportion of deaths related directly to management problems and included deaths from hypothermia, mismothering, premature birth, ruminal acidosis, pregnancy toxaemia, trauma, and plant and chemical toxicities. In larger flocks, microbial diseases including Pasteurella pneumonia and yersiniosis were major problems. Deaths from nematode parasitism were predominantly observed in goats 12 months of age and older. White muscle disease (selenium/vitamin E deficiency) was the major trace element deficiency causing death in goats.

The influence of factors including age of goat, flock size and management practices on the major causes of death are discussed.     

Metabolic profiles in goat does in late pregnancy with and without subclinical pregnancy toxemia

Background: Pregnant goat does can develop various metabolic diseases during late pregnancy that may have profound effects on their health and productivity, including subclinical pregnancy toxemia. Objectives: This study was performed to evaluate serum biochemical findings in goats in late pregnancy with and without subclinical pregnancy toxemia. Methods: Serum samples were obtained from 153 clinically healthy goats in the last trimester of pregnancy from 14 herds in central and northern Jordan. Serum was analyzed for the following constituents: 3‐hydroxybutyrate (3‐HB), glucose, total protein, albumin, urea, creatinine, aspartate aminotransferase, alkaline phosphatase, cholesterol, triglycerides, cortisol, T3, T4, total calcium, magnesium, and phosphorus, using commercially available kits. Goats were classified as having subclinical pregnancy toxemia or as controls on the basis of 3‐HB results. Biochemical results were compared between the 2 groups using nonparametric statistical tests. Results: Fifty‐three does had subclinical pregnancy toxemia (3‐HB>0.86 mmol/L) and 100 were pregnant control does (3‐HB≤0.86 mmol/L). Does with subclinical pregnancy toxemia had significantly lower glucose concentrations (P<.001) and significantly higher urea (P=.042) and total protein (P=.048) concentrations compared with pregnant control does. 3‐HB concentration was significantly correlated with glucose (r=0.290, P=.035), phosphorus (r=0.351, P=.01), and cortisol (r=0.394, P=.004) concentrations in goats with subclinical toxemia. Conclusions: Results of this study indicate that the biochemical profile of does with subclinical pregnancy toxemia differs from that of other pregnant goats. 3‐HB should be measured in pregnant does in late stages of gestation with hypoglycemia or with elevated urea and total protein concentrations.     

An inactivated, oil-emulsion vaccine for the prevention of porcine parvovirus-induced reproductive failure

Pig fetuses inoculated at 45 days gestation with virulent porcine parvovirus (PPV) were harvested 10 days later. Virus was extracted, inactivated with binary ethylenimine and the antigen suspension emulsified with mineral oil adjuvant. One dose of this vaccine, or two doses with a 14 day interval, stimulated high and long lasting serum antibody titres in gilts. Vaccination caused no clinical reactions and lesions at injection sites were minor. Vaccination of seronegative gilts at 40 days gestation caused no adverse effects on fetuses. Six gilts which had been vaccinated five to nine weeks before mating were challenged intravenously with live, virulent PPV at 40 days gestation. At 98 days gestation 78 out of 84 (93 per cent) fetuses were alive and normal and no evidence of PPV infection was found in the six dead (mummified) fetuses. In four unvaccinated gilts similarly challenged with PPV at 40 days gestation only five out of 51 (10 per cent) fetuses survived to 98 days gestation and the virus was detected in 41 of the 46 dead (mummified) fetuses. This vaccine appears to be safe and effective for prevention of PPV-induced fetal loss in gilts.     

Prevention of Toxoplasma gondii abortion in goats by vaccination with oocysts of Hammondia hammondi

Nineteen does (female goats) were dosed with 500,000 oocytes of Hammondia hammondi prior to breeding. At about 90 days of gestation these, and 18 uninoculated does were challenged with 25,000 Toxoplasma gondii oocysts. The 19 H. hammondi--inoculated does produced 26 live and one dead kid (newborn goat). The 18 does not given H. hammondi produced 12 live and 19 dead kids. However, examination of all of the kids by isolation of T. gondii in mice, serology and histology revealed that they were all infected with T. gondii. Thus, while H. hammondi "vaccination" is protective against the deleterious effects of T. gondii on pregnant does, perhaps by reducing the severity of placental lesions, it does not prevent foetal infection.     

Influence of general anaesthesia (thiopental sodium) on progesterone and cortisol levels in pregnant goat serum

6 pregnant Baladi goats underwent general anaesthesia, using thiopental sodium. Intravenous application of 10-15 mg/kg body weight of thiopental sodium in 2.5% solution produced light anaesthesia for about 20 minutes. The effect of general anaesthesia on progesterone and cortisol levels was studied before and during the application of anaesthesia as well as 1/2, 1, 4, and 24 hours after anaesthesia. Progesterone was determined by RIA and cortisol by competitive protein binding reaction. Decrease in progesterone and rise in cortisol were noticed during and after anaesthesia. 4 of 13 foetuses were aborted 1-2 weeks after the application of anaesthesia. 6 were born dead. 2 died few hours after birth, and 1 stayed alive.     

Effect of number of corpora lutea and fetuses on concentrations of progesterone in blood of goats

The objectives of this study were to assess relationships between 1) number of corpora lutea (CL) and concentrations of progesterone (P) in plasma of goats from onset of estrus (d 0) to d 45 of pregnancy and 2) concentration of P and number of fetuses on d 45. Blood from 79 pregnant goats was obtained on d 0 and 1 and at 48-h intervals thereafter to d 25 of gestation. Additional samples were collected every 5 d from d 25 to d 45. Plasma samples were analyzed for P by RIA. Fetuses and CL were counted at laparotomy on d 45 +/- 3. Six does had one CL, 47 had two and 26 had three or four. Concentrations of P were compared for 1) animals with different numbers of CL and 2) animals with the same number of CL but different numbers of fetuses on d 45. Concentration of P increased in all animals from d 3 to a maximum of 8.5 +/- .3 ng/ml on d 13, then P declined to 5 +/- .3 ng/ml by d 35. Goats with multiple CL had higher P than goats with one CL (P less than .01) from d 7 to d 30. Of goats with two CL, those with two fetuses at d 45 had higher P on d 13 than those with one fetus (P less than .01). The number of CL or fetuses did not influence the concentration of P after d 30.