Cerebrospinal fluid and plasma glucose concentrations of ovine pregnancy toxaemia cases, inappetant ewes and normal ewes during late gestation

Pregnancy Toxemia in Sheep and Goats

Pregnancy toxemia is a common metabolic disease of late pregnant ewes and does, which potentially has devastating impacts on health and performance. This metabolic syndrome is not only one of over conditioned animals but is more typically associated with inadequate energy intake to support pregnancy requirements leading to body protein and fat mobilization. Blood chemistries provide insight into diagnosis and possibly may predict responsiveness to treatment and outcome. Early recognition of the disease with appropriate intervention is the best approach to minimizing the impact of this disease in the sheep flock or goat herd.

The distinctive short-term response of late-pregnant prolific ewes to propylene glycol or glycerol drenching

Pregnancy toxemia is the most frequent metabolic disorder of ewes in late pregnancy. Although propylene glycol (PG) and glycerol (GLY) are common glucogenic supplements for treating pregnancy toxemia in ewes, the relative benefit of these 2 supplements is not entirely clear. Therefore, the objectives of the present study were to determine the changes during 24 h in key blood metabolites and insulin in response to PG or GLY drenching in prolific ewes. To this end, 36 multiparous late-pregnant Afec-Assaf ewes (∼132.4 d pregnant) bearing 2 to 4 fetuses, divided into 2 blocks (18 ewes in each block), with a blood β-hydroxybutyrate (BHB) concentration of 0.5 to 1.6 mmol/L were included. Ewes were divided into 3 groups (12 ewes each; 6 ewes in each experimental day), according to their BHB levels, expected litter size, body weight, and body condition score, and were drenched with the following: (1) control group (CTL), 55 mL of water; (2) PG, 106 mL of PG (100% PG, 448 calories); or (3) GLY, 108 mL of Koforin 80 (80% GL; 448 calories). Blood samples were taken before drenching and every hour after drenching for 24 h. Plasma concentration of glucose, BHB, nonesterified fatty acids, lactate, glycerol, and insulin were determined. Because there were no effects of treatments after 12 h in the first block, the data were analyzed for 12 h after drenching rather than 24 h. The plasma glucose concentration during the first 5 h after drenching was the highest in the GLY, BHB concentration was the lowest in the PG, and the nonesterified fatty acid levels were lower in the PG compared with the CTL ewes during the first 5 h after drenching. However, glucose concentration was higher in the PG ewes at 9, 11, and 12 h after drenching than in CTL or GLY ewes. The mean lactate concentration in plasma for 12 h was 2.5- and 1.9-fold higher in the PG compared with the CTL and GLY ewes, respectively, and except at 11 h after drenching, it was significantly higher at each time point. The insulin concentration was higher in the GLY than in both other groups at 2 to 5 h after drenching. These results suggest that during the first few hours after drenching the effect of PG was more effective in reducing the BHB concentration, whereas the GLY effect was more effective in enhancing glucose concentration. The increased concentration in lactate following PG treatment suggests that the PG contribution to gluconeogenesis is mediated through its metabolism to lactate. In contrast, the lack of an effect on lactate, and the faster increase in blood glucose in response to GLY suggest that GLY has a more advanced entry point to gluconeogenesis, which influences the immediate response in enhancing the glucose blood concentration.

Evaluation of prognostic indicators for goats with pregnancy toxemia

OBJECTIVE

To evaluate potential prognostic indicators for does with pregnancy toxemia (PT) and their offspring.

DESIGN

Retrospective cohort study.

ANIMALS

56 does.

PROCEDURES

Medical records were searched to identify does with PT. Signalment, history, clinical signs, examination findings, treatments, number of offspring present, and duration of hospitalization for does as well as outcome (death vs survival to hospital discharge) for does and their kids were recorded. Variables of interest were examined for association with outcome by contingency table analyses.

RESULTS

Boer goats were overrepresented, compared with the general population of goats for the facility in the last year of the study. Most (15/36) does had appropriate body condition scores. All pregnancies involved twins (11/56), triplets (37), or quadruplets (7). Neutrophilia (26/26) and hyperglycemia (32/40) were common in does. Most (39/56) does survived to hospital discharge. Does with high BUN concentration and those with serum bicarbonate concentration < 15 mEq/L were more likely to die than does without these findings. Forty-nine does survived to delivery of offspring; survival to discharge for these does was positively associated with outcome of their offspring. Among offspring of dams that survived to their delivery, twins had a higher survival rate than quadruplets. Death was more likely for offspring delivered by cesarean section than for those delivered vaginally.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested Boers were more likely to develop PT than goats of other breeds in the population examined at the study hospital. In contrast with other studies, hyperglycemia was common in affected does. Further research is needed to confirm associations with outcome identified in this study.

Validation of a handheld β-hydroxybutyrate acid meter to identify hyperketonaemia in ewes

Background

The end of pregnancy is the period with the highest risk of occurrences of ketosis and pregnancy toxemia due to fat mobilization and increasing non-esterified fatty acids in the liver which are converted in ketone bodies, mainly β-hydroxybutyrate acid (BHB). This ketone body may also become elevated in the bloodstream. The present study validates the use of a handheld meter for determining the blood concentration of BHB and ascertaining the predictive value and accuracy of BHB measurements in diagnosing hyperketonaemia in ewes.

Methods

A total of 19, non-pregnant, crossbred ewes were subjected to 2 h of intravenous infusion of a saturated BHB solution. Over 6 h of evaluation, 247 blood samples were obtained in 13 sampling moments. The BHB concentration was measured by an enzymatic colorimetric method in an automated biochemical analyzer (gold-standard) and by a handheld meter using an electrochemical enzyme technique.

Results

There was a high correlation between both methods (r = 0.98; P < 0.001). Considering the blood BHB concentrations range 0.8–1.6 mmol/L for moderate ketosis the handheld meter presented sensitivity and specificity of 0.98 and 0.81, respectively. For severe ketosis (BHB ≥ 1.6 mmol/L) sensitivity and specificity were 0.99 and 0.75, respectively. Thus, the handheld device can be useful for diagnoses of cases of mild or severe pregnancy toxemia at field conditions.

Biochemical, endocrine, and histopathological profile of liver and kidneys of sheep with pregnancy toxemia

ABSTRACT: The objective of the present study was to characterize the biochemical, hormonal, and mineral profile, and histopathology of the liver and kidneys, related to the severity of natural cases of pregnancy toxemia (PT) in sheep. A total of 45 sheep with PT were analyzed at the “Clínica de Bovinos”, Campus Garanhuns-UFRPE. The animals were submitted to clinical examination, followed by the collection of blood and urine. A necropsy was performed on thirteen animals that died and a histopathological examination was performed on samples of liver and kidneys. Increased creatinine, urea, glucose, fructosamine, non-esterified fatty acids, β-hydroxybutyrate, cortisol, chlorine, amylase, aspartate aminotransferase, gamma-glutamyltransferase, and folic acid were found, whereas insulin, potassium, and total and ionizable calcium presented low values for the species. Total protein, albumin, globulin, sodium, magnesium, and vitamin B12 remained within the normal range. In the macroscopic analysis of the liver, it was possible to observe an increase in organ and border size, yellowish coloration and parenchyma that varied from firm to friable. Vacuolation of the hepatocytes and renal tubular cells was observed. Metabolic disorders in sheep associated with hepatic and renal lesions are more apparent in overweight animals. With the greater impairment in hepatic and renal function, the clinical prognosis of animals with a high body score should be considered reserved.

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.

Achados bioquímicos, eletrolíticos e hormonais de cabras acometidas com toxemia da prenhez

A abrangência dos estudos sobre a toxemia da prenhez (TP) tem sido constante e inovadora em alguns conceitos, porém o estudo dos casos clínicos naturais em cabras é inexistente no Brasil. Diante disso, realizou-se análise das alterações clínicas, do perfil bioquímico, eletrolítico e hormonal com o objetivo de compreender a fisiopatogenia da enfermidade. Foram avaliadas 22 cabras atendidas na Clínica de Bovinos, Campus Garanhuns/UFRPE, diagnosticadas com TP, no período de 2007 a 2012. Realizou-se exame clínico e coleta de sangue e urina, para análise do perfil bioquímico e hormonal. Acentuadas alterações clínicas foram observadas, como decúbito, apatia, dispneia, aumento da temperatura corpórea, mucosas congestas, vasos episclerais injetados, desidratação, anorexia, hipomotilidade ou atonia ruminal, edema nos membros. Os resultados laboratoriais revelaram valores elevados para ureia, creatinina, ácidos graxos não esterificados (AGNE), β-hidroxibutirato, amilase e cortisol, enquanto as variáveis: proteína total, albumina, cálcio total, cálcio ionizado, fósforo, a relação cálcio e fósforo, sódio e insulina encontraram-se diminuídos. Outros parâmetros bioquímicos e eletrolíticos, como frutosamina, globulina, cloro, potássio e magnésio mantiveram-se dentro da faixa de normalidade. Quanto a glicemia, foram constatados três condições nas cabras com TP, normoglicêmicas (50%), hiperglicêmicas (27,28%) e hipoglicêmicas (22,72%). Dos 17 (77,27%) animais que obtiveram alta 10 (58,82%) eram normoglicêmicos. Vieram a óbito 22,8 % (5/22), no qual 60% (3/5) delas estavam hiperglicêmicas. A média de nascimento por cabra foi superior a duas crias. Verificou-se existir associação fortemente positiva dos AGNE's com a albumina (r=0,60), fraca com o β-hidroxibutirato (r=0,10) e glicose (r=0,03). Porém, existiu relação fortemente negativa dos AGNE's com a insulina (r= -0,70), moderada com o cortisol (r= -0,52) e amilase (r= -0,30). Marcadas alterações clínicas e metabólicas são observadas em cabras com TP, em que o aumento de certos metabólitos do perfil energético e hormonal se torna importante ferramenta para o diagnóstico e constitui um bom instrumento para avaliar a magnitude da condição clínica dos animais enfermos. Os dados encontrados servem de referência para estudos sobre nutrição e metabolismo em cabras com TP.

Indicadores bioquímicos e hormonais de casos naturais de toxemia da prenhez em ovelhas

Toxemia da prenhez é considerada um transtorno metabólico de grande impacto econômico na produção de ovinos, porém as particularidades de repercussão sistêmicas deste distúrbio ainda são pouco esclarecedoras. O presente estudo teve por objetivo avaliar o perfil bioquímico e hormonal de 77 ovelhas com diagnóstico clínico de toxemia da penhez e comparar os achados laboratoriais de acordo com a resolução clínica dos animais, alta hospitalar (G1) e aqueles que morreram (G2). A manifestação clinica da doença foi observada no período do pré-parto em 100% dos animais, destes 66,2 % (n=51) receberam alta clínica e 33,8% (n=26) morreram. Dos casos de toxemia da prenhez estudados havia gestação múltipla em 55,8%. Dentre os parâmetros estudados, cortisol, uréia, AST e CK estavam mais elevados no G2 em relação ao G1 com diferenças significativas (P<0,05). Foi encontrado aumento nas concentrações de glicose plasmática, frutosamina, albumina, creatinina, ß-hidroxubutirato, ácido graxo não esterificado e L-lactato, porém não houve diferenças entre os grupos (P>0,05). Não ocorreram alterações nas taxas de colesterol e triglicerídios. Houve redução nos índices da insulina, não havendo diferenças entre G1 e G2 (P>0,05). Todas as ovelhas apresentaram cetonúria e acidúria.

Histological changes of the liver and metabolic correlates in ewes with pregnancy toxemia

The histological changes of the liver in ewes with pregnancy toxemia were characterized. Ten ewes were fed on grass ad libitum, and another ten were starved from day 130 of pregnancy for up to four days. Liver puncture biopsies were performed at days 70, 100, 130, and 140 of pregnancy, and at day 45 in postpartum. Seric hydroxybutyrate (HB), non-esterified fatty acids (NEFA), aspartate aminotransferase, and alkaline phosphatase were dosed. Histological preparations revealed similar incidence and intensity of mild liver steatosis in both groups at day 130. Starved ewes become toxemic (as indicated by HB), and at day 140 exhibited more severe injury in a higher proportion (9/9 vs. 4/10; P<0.01). Almost all of them (7/9) had large amounts of small lipid droplets in almost every hepatocyte over the whole liver acinus, and higher NEFA values. At day 45 in postpartum, both groups had mild steatotic changes as initially. A positive correlation between severity of liver damage seric and only aspartate aminotransferase was observed at day 140 in starved animals (P<0.05). This enzyme could be used to assess liver damage, but not alkaline phosphatase. All samples with degeneration corresponded to the microvesicular type. A short starvation period during late pregnancy in ewes produced reversible liver degeneration.

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.

Diagnostic techniques and clinicopathologic findings in ruminant neurologic disease

In ruminant species, cerebrospinal fluid (CSF) collection and analysis provide rapid (in some situations, instant) information to the veterinary clinician investigating a disease problem in the living animal. CSF analysis is particularly useful with respect to confirming the presence of an inflammatory lesion involving the leptomeninges,such as bacterial meningoencephalitis, and in investigating potential compressive lesions of the spinal cord. When correctly performed under local anesthesia, lumbar CSF collection in ruminants is a safe procedure and there are no harmful sequelae. Familiarity with the technique aids high extradural injection of lidocaine or xylazine, which has many applications in farm practice. There are few indications for cisternal CSF collection in food animals.

Spontaneous pregnancy toxaemia (ketosis) in sheep and the role of insulin

214 ewes suffering from pregnancy toxaemia (ketosis) were examined. Clinical signs during onset and course of disease and laboratory findings were compared between animals that survived and those which died. In the latter the onset of ketosis was earlier in pregnancy (day 143 +/- 7 vs. day 146 +/- 8) and duration of the disease was shorter (10 +/- 13 vs. 14 +/- 9 days). The animals that died showed more severe clinical signs and higher values of 3-hydroxy-butyrate (4.3 +/- 3.6 vs. 3.5 +/- 2.6 mmol/l) and cortisol (72 +/- 98 vs. 52 +/- 80 mmol/l) as well as lower values of insulin (37 + 12 vs. 3.5 + 2.6 mmol/l) and potassium (4.1 + 1.0 vs. 4.4 + 1.0 mmol/1) at onset of the disease than those which survived (all of differences with P < 0.05). Glucose levels did not differ between groups. Treated animals with glucose plus fructose infusions (n = 56) or with oral application of glucose precursors plus electrolytes (n = 126) had survival rates of 53.6% and 62.7%, respectively. Oral treatment with glucose precursors plus electrolytes and an additional subcutaneous insulin treatment (n = 15) led to an enhanced survival rate of 86.7% (P < 0.05). Low insulin levels in ketotic pregnant sheep and the therapeutic effect of insulin treatment support the hypothesis that insulin plays a causative role in the pathogenesis of ovine ketosis.