Increased serum nonesterified fatty acid and low ionised calcium concentrations are associated withpost partumcolic in mares

Evaluation of peritoneal l-lactate concentration in horses in the early post-partum period

BACKGROUND

Peritoneal fluid lactate concentration is an important diagnostic tool in horses with abdominal pain. Information on peritoneal lactate concentrations is lacking following parturition in the mare.

OBJECTIVES

To compare blood and peritoneal lactate concentrations in a population of mares within 36 h post-partum, report a normal reference range and identify any impact of retained foetal membranes (RFMs).

METHODS

This is a retrospective study evaluating healthy mares from which blood and peritoneal samples had been obtained within 36 h of parturition. Exclusion criteria included signs of abdominal pain within this period. Data was interrogated for normality using a Shapiro-Wilk test. Wilcoxon signed-rank test and Bland-Altman analysis were used to compare blood and peritoneal lactate concentrations. Linear regression was used to compare age and breed data with peritoneal lactate concentrations. Significance was defined as p < 0.05.

RESULTS

Forty mares met the inclusion criteria. Mean age was 12.6 ± 4.1 years, and most mares were multiparous (65%). Peritoneal lactate ((1.2 (IQR = 0.9-1.6) mmol/L) was increased compared to blood lactate concentration (0.7 (IQR = 0-1.1)mmol/L; p < 0.001). Plasma total protein (TP) concentrations were 68 (IQR = 64-74) g/L and peritoneal protein concentrations 8 (IQR = 4-9.7) g/L. Six mares developed RFM. The median fold-increase in peritoneal lactate concentration compared to blood lactate concentration was 0.9 (IQR: 0.01-1.7; range: 0-2.5). The reference range for peritoneal fluid lactate concentration was 0-2.5 mmol/L.

CONCLUSION

Peritoneal lactate concentrations in healthy post-partum mares remained within the normal reference range and were not influenced by RFM or parturition. Increased peritoneal lactate in this group warrants further investigation.

Determination of reference intervals for nonesterified fatty acids in the blood serum of healthy dogs

Background

Nonesterified fatty acids (NEFAs) are an important energy substrate in mammals. Measurement of the NEFA concentration in blood serum is common practice and enables reliable detection of a negative energy balance in several species. This parameter can be used to detect subclinical metabolic diseases or to optimise feeding to prevent severe negative energy balance. Since no reference values for dogs have been published, the aim of this study was to establish such values.

Methods

Blood serum from 85 healthy dogs was examined with a multiparameter clinical chemistry analyser. Given that NEFA values are not usually normally distributed, reference intervals (RIs) were calculated nonparametrically using bootstrapping (5000 replicates) for the 90% confidence intervals.

Results

The examined cohort had a median age of 62.16 months (2-180 months) and a median weight of 19.2 kg (3.0-55.0 kg) and comprised 27 (31.8%) males and 58 (68.2%) females, with 32 (37.6%) neutered or spayed. The fasting time was 5.9 h (range 0-23 h). The tested confounders age, sex, neuter status, bodyweight and body condition score did not significantly affect the NEFA concentrations.

Conclusions

The NEFA RI for dogs in this study was 0.2-1.47 mmol/L. The results may be used to adjust food composition and amount in healthy dogs or to detect metabolic disorders. Further research on NEFA metabolism in dogs maintained in standardised conditions and in specific nutritional situations or with particular diseases is warranted.

Outcomes of pregnant broodmares treated for colic at a tertiary care facility

OBJECTIVE

To evaluate, following colic admission during pregnancy, (1) broodmare survival; (2) the frequency of recurrent colic in broodmares and its associated variables, and (3) pregnancy outcome and the variables associated with a negative pregnancy outcome.

STUDY DESIGN

Ambidirectional observational cohort study.

ANIMALS

One hundred and four client-owned broodmare admissions.

METHODS

Admissions of pregnant mares from June 2010 until October 2016 were included. Data were collected until November 2017. Cox proportional hazards regression analysis was performed to evaluate variables associated with broodmare survival. Logistic regression analysis was used to examine the variables associated with recurrent colic and pregnancy outcome.

RESULTS

Broodmares from 73/104 (70.2%) admissions were discharged alive. Lesion category, admission hyperlactatemia (hazard ratio (HR) 3.24, 95%, CI 1.28-8.22, P = .013), and admission high packed cell volume (HR 2.89, 95% CI 1.29-6.47, P = .010) were associated with reduced survival. Recurrent colic was observed in broodmares from 33/70 admissions (47.1%). The final multivariable model for recurrent colic included Thoroughbred breed (OR 5.09, 95% CI 1.58-16.4, P = .006) and age (OR .876, 95% CI .747-1.03, P = .105). Overall, negative pregnancy outcome was 14/65 (21.5%). Lesion category, evidence of systemic inflammatory response syndrome (SIRS) in hospital (OR 31.2, 95% CI 2.09-466.5, P = .013), and diarrhea in hospital (OR 379.3, 95% CI 97.1-1482.0, P < .001) were associated with increased negative pregnancy outcome. Altrenogest administration was inversely associated with negative pregnancy outcome (OR 0.029, 95% CI .004-.222, P = .001).

CONCLUSION

Pregnant broodmares admitted for colic had lower survival than anticipated and were at risk of recurrent colic. Markers of broodmare disease severity were associated with pregnancy outcome.

CLINICAL SIGNIFICANCE

Lesion category, hematologic variables (packed cell volume and l-lactate concentration), evidence of SIRS, and diarrhea were useful for predicting broodmare and pregnancy outcomes.

Effect of Starch Source in Pelleted Concentrates on Fecal Bacteria in Prepartum and Postpartum Mares

Dietary starch source has been shown to affect fecal bacterial communities of horses fed minimally processed cereal grains. However, processing may increase foregut starch digestibility, reducing effects of starch source on fecal bacterial communities. This study aimed to determine the effect of starch source in pelleted concentrates on fecal Lactobacillus spp., amylolytic bacteria, and cellulolytic bacteria in broodmares mares, during the prepartum and postpartum period. Thoroughbred mares (n = 18) were paired by last breeding date then randomly assigned to either an oat-based or a corn and wheat middlings-based pelleted concentrate fed with forage. Mares were fed their assigned concentrates beginning on 310 days of gestation, and fecal samples were collected at 324 days of gestation, before parturition, 1 day, 14 days, and 28 days postpartum. Fecal samples were enumerated by serial dilution and inoculation into selective, enriched media for Lactobacillus spp., amylolytic bacteria, and cellulolytic bacteria. Data were log transformed then analyzed using a mixed model ANOVA with repeated measures (SAS 9.3) to test the main effects of treatment, time of sample, and treatment by time interaction. Starch source did not affect enumerated bacterial communities (P > .05); thus, pelleting concentrates may alter some of the effects of starch sources on the hindgut microbiota. Sample date did not affect amylolytic bacteria (P > .05); however, lactobacilli and cellulolytic bacteria decreased 1 day postpartum (P < .05). Although we did not observe an effect of starch source on fecal bacteria in mares, parturition did appear to alter the hindgut microbiota.