White muscle disease in foals: focus on selenium soil content. A case series

Abstract

BackgroundWhite muscle disease (WMD) is a nutritional myopathy caused by selenium (Se) deficiency. In most soils, Se is present in low concentrations, sometimes even below 0.2 mg/kg, a trend which is seen in many countries. Apart from total soil Se concentrations, soil conditions may be such that the bio-availability of Se is so low that it causes very low uptake in plants which can ultimately lead to deficiency problems in animals. This is the first case series to report clinical WMD in foals in areas deficient in Se, in the Netherlands.The aim of the current report is to provide an overview of the clinical history, symptoms and (clinical) pathology of 8 newborn foals living at 4 different premises and suffering from WMD together with the effectiveness of Se and vitamin E (Vit E) supplementation in the affected foals, their dams and herd members. Hands on practical information is provided to apply a correct and effective Se supplementation management in horses and which pitfalls need to be avoided for a successful approach.Case presentationCase features and history were mapped out for all foals. Se and Vit E status were assessed for the foals, their dams and herd members, at admission and after 3 months of Vit E/Se supplementation.Common symptoms were muscle weakness, inability to rise, lethargy and inadequate suckle reflex together with increased serum muscle enzymes and low glutathione peroxidase (GSH-Px) and low to normal serum vit E levels. Necropsy revealed necrosis of skeletal muscles consistent with nutritional myopathy. Se status of the dams and herd members correlated well with the Se status of the foals. All surviving foals (n = 6) showed normal Vit E and GSH-Px levels after supplementation, likewise, all horses tested at premises 1, 3 and 4. However, dams and herd members in premises 2 showed no normalization. Horses of that premises were diagnosed with pyrrolizidine intoxication one year prior to the study.ConclusionsCertain regions in the Netherlands are sufficiently Se deficient to predispose newborn foals to develop WMD, especially when they are being fed a diet that mainly consists of locally harvested roughage.

A Summary of New Findings on the Biological Effects of Selenium in Selected Animal Species—A Critical Review

“…The content of selenium in blood also differs according to the breed—Jovanović et al [ 270 ] vs. Pavlata et al [ 267 ] ( Appendix Table A1 ), sex [ 313 ] and the age of the animal [ 314 ] as well as geographical area, which is related to the selenium content in the soil and thus also in plants [ 315 , 316 ]. Generally, most soils in many countries are poor in selenium [ 317 , 318 , 319 , 320 ], sometimes even below 0.2 mg∙kg −1 [ 321 ]. The soil selenium concentration depends on soil-climate interactions.…”

“…Conversely, the areas with low to moderate precipitation but relatively low aridity (e.g., cool and moist climates) and high clay content are likely to have higher soil selenium concentrations [ 322 ]. In addition to the total soil selenium content, soil physical-chemical conditions are also important, because can cause lower bioavailability of selenium and thus its lower uptake by plants, which can ultimately lead to its deficiency in animals [ 321 ]. For example, the negative influence of sulfate (SO 4 2− ) and phosphate (PO 4 3− ) has been recently described [ 323 ].…”

Expression Quantitative Trait Loci in Equine Skeletal Muscle Reveals Heritable Variation in Metabolism and the Training Responsive Transcriptome

“…Variation in the expression of these genes may therefore potentially underpin variation in haematological phenotypes in horses, which may in turn influence traits relevant to aerobic capacity. It is also noteworthy that selenium deficiency has been associated with significant myopathy (White muscle disease) (Lofstedt, 1997; Delesalle et al, 2017) and reduced exercise tolerance in horses (Brady et al, 1978; Avellini et al, 1999). In addition, selenoproteins have been shown to be involved in several metabolic pathways and the response to oxidative stress in muscle (Rederstorff et al, 2006).…”

Does copper deficiency predispose children to otitis media with effusion?

“…Another reason for the inconsistency of the different results may be due to different geographical sampling, as serum selenium depends on diet and soil selenium concentration. 19 This is the reason that we selected all patients from the same community and the same geographical region.…”