Trace element status in canine endocrine diseases.

A balanced trace element status is essential for the optimal functioning of all organisms. However, their concentrations are often altered in diverse medical conditions. This study investigated the trace element profiles in plasma samples of dogs with endocrine diseases and used chemometric techniques to explore their associations with biochemical data. Thirteen elements (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se and Zn) were measured in 40 dogs with hyperadrenocorticism (HAC), 29 dogs with diabetes mellitus (DM), 11 dogs with hypothyroidism (HT) and 30 control dogs using inductively coupled plasma mass spectrometry (ICP-MS). Statistically significant differences were observed for As, Cu, Mo, Se and Zn. In comparison with the control group, the HT patients had higher As and lower Se levels, while the HAC group had higher concentrations of Mo. All three disease groups had higher Cu and Zn concentrations than the control group, with the DM group having higher Cu concentrations and the HAC group higher Zn concentrations than the other endocrinopathy groups. The chemometric analysis revealed distinctive association patterns for discriminating each pathology group and the control group. Moreover, the analysis revealed the following associations: Mo with glucose levels and Cu with fructosamine levels in the DM group, As with cortisol levels in the HAC group, and Se with TT4 levels and As with TSH levels in the HT group. The study findings provide valuable insights into the complex relationships between trace elements and endocrinopathies, elucidating the associations with biochemical markers in these diseases. Larger-scale studies are necessary to fully understand the observed relationships and explore the potential clinical applications.

Influence of haemolysis on blood biochemistry profiles in cattle.

Although haemolysis is the most common source of preanalytical error in clinical laboratories, its influence on cattle biochemistry remains poorly understood. The effect of haemolysis and its clinical relevance were investigated in 70 samples in which haemolysis was artificially induced (by spiking with increasing amounts of haemolysate, yielding 0.0%, 0.2%, 0.5%, 1.0%, 2.5%, 5.0% and 10% haemolysis degree (HD)), focusing on key parameters for bovine metabolic health assessment, including albumin, alkaline phosphatase (ALP), aspartate aminotransferase (AST), blood urea nitrogen (BUN), calcium (Ca), cholesterol, creatinine, creatine kinase (CK), gamma-glutamyl transferase (GGT), globulins, magnesium (Mg), phosphorus (P), total bilirubin (TBIL) and total proteins (TP). Preanalytical haemolysis significantly affected most (8 of 14) of the biochemical parameters analysed, leading to significant increases in concentrations of albumin (starting at 5% HD), cholesterol (at 5% HD) and P (at 10% HD) and to significant decreases in Ca (at 2.5% HD), creatinine (at 5% HD), globulins (at 10% HD), TBIL (at 2.5% HD) and TP (at 10% HD). Comparison of the present and previous data indicated that, for each parameter, the HD required to produce significant bias and the clinical relevance of over- and underestimation are variable and appear to depend on the analytical technique used. Therefore, different laboratories should evaluate the influence of haemolysis in their analytical results and provide advice to clinicians accordingly. Affected parameters should be interpreted together with clinical signs and other analytical data to minimize misinterpretations (false or masked variations). Finally, due to the significant impact on numerous parameters and the limited potential for correction, we recommend rejection of samples with >10% HD.

Trace Element Levels in Serum Are Potentially Valuable Diagnostic Markers in Dogs.

The objective of this study was to obtain information about the role of trace element imbalance in the pathogenesis of certain diseases in dogs and to evaluate the suitability of trace element profiling as an additional tool in the diagnosis. Serum trace element concentrations (copper, molybdenum, selenium and zinc) were measured in a cohort of healthy (control) dogs (n = 42) and dogs affected by hepatic (n = 25), gastrointestinal (n = 24), inflammatory/infection (n = 24), and renal (n = 22) diseases. These data were analyzed together with data on basic biochemical parameters (alanine aminotransferase, alkaline phosphatase, blood urea nitrogen, creatinine, albumin, globulin, and glucose) by using chemometric techniques. The chemometric analysis revealed distinctive association patterns between trace elements and biochemical parameters for each clinical disorders. The findings provide clear evidence for the important role of trace elements in disease, particularly in relation to acute phase reactions, with serum copper providing an indirect measurement of ceruloplasmin (positive acute-phase protein) and serum selenium and zinc acting as negative acute phase reactants. Molybdenum may also be a suitable marker of incipient renal disease. Thus, the analysis of trace element profiles, by multielement techniques, in a single serum sample would be a valuable additional tool for the diagnosis of certain diseases.

Serum Concentrations of Essential Trace and Toxic Elements in Healthy and Disease-Affected Dogs.

This study was designed (i) to establish reference ranges for the essential trace element and background levels of toxic element exposure in the healthy/normal dog population, and (ii) to evaluate whether trace element concentrations vary in dogs suffering from different pathologies. Blood serum samples were collected from 187 healthy and diseased dogs at the Veterinary Teaching Hospital, Faculty of Veterinary Medicine, University of Santiago de Compostela (northwest Spain). The samples were acid digested, and the concentrations of trace elements (Co, Cr, Cu, Fe, Mn, Mo, Ni, Se and Zn) and toxic elements (As, Cd, Hg and Pb) were determined by inductively coupled plasma-mass spectrometry (ICP-MS). This enabled us to establish reference ranges for the essential trace elements and the level of toxic element exposure in dogs, and to identify several clinical situations associated with variations in trace elements in serum. Relative to concentrations in healthy control dogs, statistically significant differences were observed in the concentrations of Cu (significantly higher in hepatic, inflammatory/infectious and oncological categories), Mo (significantly higher in renal category), Se (significantly lower in gastrointestinal category) and Zn (significantly lower in gastrointestinal, inflammatory/infectious and renal categories). Trace element concentrations can be a cause or consequence of disease, and the study findings indicate that trace element determination in serum provides useful information on the pathogenesis of certain diseases. Further research on the serum concentrations of trace elements, particularly in relation to other biochemical parameters and diagnostic tools, may provide valuable information for the diagnosis of diseases in dogs and the disease prognosis.

Breed performance in organic dairy farming in Northern Spain.

Organic farm management combines best environmental practices, a high level of biodiversity, preservation of natural resources and high animal welfare standards. To meet these criteria, farmers must have livestock well adapted to local organic conditions and information about how different breeds and crosses perform under different conditions. The objective of this study was to compare the performance of different pure breeds and cross-breeds of cattle in organic dairy systems in Northern Spain. The data analysed were obtained from monthly records kept between 2010 and 2016 on organic farms registered in the regional milk recording system. Analysis of various traits indicated that the Holstein-Friesian breed suits the organic production system in the study region. Although the reproductive performance of Holstein-Friesian cows was poorer (in terms of number of services per conception) than that of cross-breed and Brown Swiss cows, the Holstein-Friesian produced more milk and lived longer. In addition, there was no difference in calving type or calving ease between the different breed groups. The better milk fat and protein yields produced by the crosses may be useful traits for farmers interested in milk transformation. The advantage of continuing to use Holstein-Friesian cattle is that the breed is predominant worldwide, and the genealogy is well documented. If Holstein-Friesian cattle continue to be used, the main priority will be to search for well-adapted bulls (particularly for pasture-based conditions) and to elaborate a genetic merit index for organic and pasture-based systems with the aim of predicting and minimizing genotype × environment interactions.

Organic or conventional dairy farming in northern Spain: Impacts on cow reproductive performance.

Organic farming has traditionally given preference to indigenous breeds that are well adapted to local conditions; however, current trends towards increased yields may produce less robust animals with potentially low fertility. The Holstein-Friesian breed dominates dairy sector, although there is a general concern that these cows may not be well adapted to organic systems. This study aims to evaluate the reproductive performance of organic dairy herds in northern Spain, by comparing organically reared Holstein-Friesian with their counterparts reared on conventional farms and also with other organically reared breeds and crosses. Reproductive parameters were obtained for individual cows on organic, conventional pasture-based and conventional zero-grazing farms. The reproductive performance of Holstein-Friesian cows was slightly better in organic systems than in pasture-based conventional systems, but not than in zero-grazing conventional systems. The comparison of reproductive performance of Holstein-Friesian from organic and conventional systems and with other organically reared breeds and crosses enabled us to demonstrate that it is not the organic system that constrains the reproductive performance of Holstein-Friesian, but that the manifestation of oestrus is less marked than in other breeds. Breeding selection considering reproductive traits and appropriate management of oestrous detection would improve the reproductive performance of Holstein-Friesian cows.

Is lack of antibiotic usage affecting udder health status of organic dairy cattle?

This research communication aimed to compare somatic cell count (SCC), the main marker of udder health status, in organic farms not using antibiotics (O, n = 6), organic farms using antibiotics (OA, n = 7) and conventional farms (CA, n = 5) using antibiotic treatments, all of them at pasture. SCC was statistically significantly higher in O (173780) compared to CA (93325) and OA (107152). Milk yield had a significant diluting effect on SCC and differences between groups increased with parities. Stratified analysis of SCC depending on lactation number and % of monthly SCC test with different linear scores (LS) indicated that there is no difference in udder health in the primiparous heifers from the three groups of farms, but it deteriorates in older cows because of chronic infections in O (possibly due to lack of antibiotic use). Our results suggest that the non-use of antibiotics had an effect in udder health leading to higher occurrence of clinical and subclinical mastitis. Therefore, preventive management practices for mastitis control are essential in organic farms.

Use of homeopathy in organic dairy farming in Spain.

Organic farming principles promote the use of unconventional therapies as an alternative to chemical substances (which are limited by organic regulations), with homeopathy being the most extensive. Traditionally, Spain has had little faith in homeopathy but its use in organic farming is growing. Fifty-six Spanish organic dairy farmers were interviewed to obtain what we believe to be the first data on the use of homeopathy in organic dairy cattle in Spain. Only 32% of farms use some sort of alternative therapy (16.1% homeopathy, 10.7% phytotherapy and 5.3% using both therapies) and interestingly, a clear geographical pattern showing a higher use towards the East (similar to that in the human population) was observed. The main motivation to use homeopathy was the need to reduce chemical substances promoted by organic regulations, and the treatment of clinical mastitis being the principle reason. The number of total treatments was lower in farms using homeopathy compared with those applying allopathic therapies (0.13 and 0.54 treatments/cow/year respectively) and although the bulk SCC was significantly higher (p < 0.001) in these farms (161,826 and 111,218 cel/ml, respectively) it did not have any negative economical penalty for the farmer and milk quality was not affected complying with the required standards; on the contrary homeopathic therapies seems to be an alternative for reducing antibiotic treatments, allowing farmers to meet the organic farming principles.