Metal toxicosis in horses

Horse Whole Blood Trace Elements from Different Sicily Areas: Biomonitoring of Environmental Risk

Horses are excellent bioindicators for the assessment of environmental pollution. The aim of this study was to evaluate the levels and potential bioaccumulation of 28 mineral elements in 75 horse whole blood samples collected from five pollution-prone areas of Sicily, Italy. A direct mercury analyzer (DMA-80) was used for Hg determination, and an inductively coupled plasma mass spectrometer (ICP-MS) for all other elements. A one-way ANOVA test, followed by Bonferroni's multiple comparison for post hoc comparison, was applied to assess statistically significant differences between mineral elements and the five experimental groups. The levels of mineral elements in hay and concentrate were below the limits set by Regulation No. 744/2012. The mineral content of whole blood samples was slightly influenced by the region of origin of the horse. p values < 0.05 were statistically meaningful. However, the concentrations of mineral elements in horses' whole blood remained within reference ranges. In conclusion, the present study shows that the mineral content does not represent a toxicological risk for the analyzed horses. In addition, the study areas did not appear to show a high mineral element contamination.

Data on multiple regression analysis between boron, nickel, arsenic, antimony, and biological substrates in horses: The role of hematological biomarkers

The objective of this study was to evaluate the biomarkers of exposure to boron, nickel, arsenic, and antimony in an industrial region, evaluating the bioaccumulation in biological substrates and the correlation with biomarkers such as hematological parameters. Through indication of the accumulation of some minerals in the horse's biological substrates reflects environmental pollution. Moreover, an additional aim of the study was to show whether these contaminants have an influence on the hematological parameters in horses. Blood, serum, mane, and tail samples from 20 horses from an industrial area were analyzed to determine boron (B), nickel (Ni), arsenic (As), antimony (Sb) concentration. Hematological parameters (red blood cell [RBC], white blood cells [WBC], hemoglobin [Hb], hematocrit [Hct], mean corpuscular volume [MCV], mean corpuscular hemoglobin [MCH], mean corpuscular hemoglobin concentration [MCHC], platelet [PLT]) as a biomarker of blood in relation to the bioaccumulation of these elements were analyzed also. Descriptive statistical analysis was performed and single regression analysis (Pearson) and multiple regression analysis (p < 0.05) between blood factors, As, B, Ni, and Sb concentrations, and for each mineral in different substrate, respectively. Results showed a significant correlation between tail and mane concentrations with serum and blood for boron concentration (r = -1 p < 0.05). No significant correlation between sample (feed, hay, mane, tail, and water) concentrations and As, Ni, and Sb were found. A significantly negative correlation with blood parameters (r = -1 p < 0.05) was observed in Boron concentration for mane and tail. This suggests that the mane and tail may be a potential means to investigate suspected exposure to excessive levels of trace minerals.

Nutritional Considerations when Dealing with an Underweight Adult or Senior Horse

Weight loss occurs when the supply of energy is insufficient to meet the energy needs of an individual. The energy supply may be reduced by inadequate provision of feed, inadequate consumption, reduced digestion and absorption, or disruption in metabolic processing. Increased energy expenditure occurs with exercise and during cold temperatures, pregnancy, and lactation. Underlying clinical disease, particularly chronic inflammation, neoplasia, and protein-losing conditions, can cause weight loss or exacerbate existing weight loss. A methodical approach to weight-loss investigation and treatment is necessary, because of the often multifactorial nature of this condition.

Bioaccumulation of Mineral Elements in Different Biological Substrates of Athletic Horse from Messina, Italy

The objective of this study was to evaluate the levels and the potential bioaccumulation of vanadium (V), chromium (Cr), cobalt (Co), copper (Cu), zinc (Zn), cadmium (Cd), lead (Pb), and bismuth (Bi) in horses from the industrial risk area of Sicily (Italy). Different biological substrates (whole blood, serum; tail and mane) and samples of hay, concentrate and water provided to the horses were processed by means of Thermo Scientific iCAP-Q ICP-MS spectrometer for mineral concentration. One-way analysis of variance (ANOVA) was applied to show the differences in various trace elements in the biological substrates. Pearson's test was applied to evaluate the correlation of mineral concentrations between whole blood and serum; and tail and mane. The results showed statistical differences of tested mineral elements among biological substrates; Cr whole blood concentrations were negatively correlated with serum concentrations and a positive correlation between whole blood and serum was observed for Cd and Bi. This latter also showed a positive correlation between mane and tail. The concentrations of V, Cr, and Pb in tail with serum and whole blood samples were negatively correlated, while the concentrations of Cd in tail and serum samples were positively correlated. Minerals had a non-homogenous distribution in the organism, showing different concentrations in the biological substrates.

Blood Response to Mercury Exposure in Athletic Horse From Messina, Italy

Mercury (Hg) exists in various chemical forms, and it is different to health effects. The most toxic effects occur in the central nervous system during fetal development with irreversible alterations of the nerve cells of the cerebral cortex and, it is essential to monitor the tissue residues of Hg to protect the animal's health. The present investigation was carried out during May 2019 in 20 horses located in equine sport center near the area of Milazzo, Messina, that is a part of Sicilian territory heavily polluted by many toxic substances. The purpose of this study was to determine the concentration of Hg in blood, serum, food, and water administered to horses and from the hematological profile as a biomarker of blood in relation to the bioaccumulation of Hg. The hematologic parameters (red blood cell, white blood cell, hemoglobin concentration, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and platelets) were processed with an automated hematology analyzer, and Hg concentrations were determined by DMA-80. To carry out the variation in the Hg levels in serum and blood, the data were subjected to paired t-test analysis; post-hoc comparisons were performed using Tukey's test. The differences were considered statistically significant when P < .05. Paired t-test showed that in blood samples, Hg concentrations were significantly higher than the serum, and blood samples were positively correlated with serum (r = 0.99; P < .0001). The Hg contents determined in blood, serum, hay, and water samples were below the respective benchmarks, and therefore, we can exclude any toxicological risk for athletic horse.

Toxic Causes of Intestinal Disease in Horses

Because most poisonings occur by toxin ingestion, the gastrointestinal system is the first exposed and, in most cases, it is exposed to the highest toxin concentrations. Consequently, enterocyte damage is common. However, because many toxins produce organ-specific damage, and enterocyte necrosis is easily confused with autolysis, many gastrointestinal lesions are overlooked or overshadowed by other clinical and pathologic changes. The objective of this work is to review several common toxins and poisonous plants that produce primarily gastrointestinal disease.

Gastritis, Enteritis, and Colitis in Horses

The gastrointestinal system of horses is affected by a large variety of inflammatory infectious and noninfectious conditions. The most prevalent form of gastritis is associated with ulceration of the pars esophagea. Although the diagnostic techniques for alimentary diseases of horses have improved significantly over the past few years, difficulties still exist in establishing the causes of a significant number of enteric diseases in this species. This problem is compounded by several agents of enteric disease also being found in the intestine of clinically normal horses, which questions the validity of the mere detection of these agents in the intestine.

Molecular and histologic evaluation of idiopathic hyperextension of the metacarpophalangeal and metatarsophalangeal joints in adult llamas

OBJECTIVE

To determine the molecular and histologic characteristics of hyperextension of the metacarpophalangeal and metatarsophalangeal joints in adult llamas.

ANIMALS

12 adult llamas (6 with bilateral hyperextension of the metacarpophalangeal or metatarsophalangeal joints [affected] and 6 age- and sex-matched clinically normal control llamas).

PROCEDURES

Llamas were euthanized, and specimens of superficial digital flexor tendon, deep digital flexor tendon, and suspensory ligament were obtained from 4 areas and snap frozen in liquid nitrogen or suspended in neutral-buffered 10% formalin. Histologic evaluation of collagen fiber orientation, elastin content, and proteoglycan content was performed by use of Masson trichrome, picrosirius red, Verhoeff, and Alcian blue stains. Total RNA was isolated from frozen suspensory ligament specimens. Gene expression of collagen types I and III, lysyl oxidase, and matrix metalloproteinase-13 was evaluated with a real-time quantitative reverse transcriptase PCR assay.

RESULTS

Gene expression of collagen types I and III, lysyl oxidase, and matrix metalloproteinase-13 in suspensory ligaments was similar between affected and control llamas. Collagen orientation and elastin content of the flexor tendons and suspensory ligaments were also similar between the groups. Proteoglycan content was low in most specimens but was focally increased in discrete lesions of suspensory ligaments in 2 affected and 2 control llamas.

CONCLUSIONS AND CLINICAL RELEVANCE

Hyperextension of the metacarpophalangeal or metatarsophalangeal joints in llamas did not appear to be caused by degeneration or inflammation of the suspensory ligament. Although focal proteoglycan accumulation existed in the suspensory ligaments of 2 affected llamas, widespread abnormal connective tissue proteoglycan accumulation was not found.

Toxins affecting the urinary system

Many different substances can induce toxic damage to various structural components of the equine kidney, and most lack pathognomonic signs. Some of these agents have specific treatments, although many do not. Supportive and symptomatic therapy is an important aspect of treatment of most cases of equine nephrotoxicosis. Regardless of cause, if the toxic substance is removed or neutralized before significant renal damage, full recovery of renal function may occur. Many horses already have significant renal damage before a definitive diagnosis is made, and the prognosis for full recovery thus remains guarded.

Morphologic and biochemical characterization of hyperextension of the metacarpophalangeal and metatarsophalangeal joints in llamas

OBJECTIVE

To determine the morphologic and biochemical characteristics of hyperextension of the metacarpophalangeal and metatarsophalangeal joints in llamas.

ANIMALS

12 adult llamas (6 with bilateral hyperextension of the metacarpophalangeal or metatarsophalangeal joints and 6 age- and sex-matched control llamas).

PROCEDURES

Llamas were evaluated by use of lameness examination, ultrasonography, and radiography. A CBC, serum biochemical analysis, and determination of concentrations of trace minerals in serum and liver samples were performed. Llamas were euthanized, and samples of the superficial digital flexor tendon, deep digital flexor tendon, and suspensory ligament were obtained from 4 areas and snap-frozen in liquid nitrogen or suspended in neutral-buffered 10% formalin. Immunohistochemical evaluation of collagen types I and III and assays for measurement of lysyl oxidase activity were performed.

RESULTS

2 affected llamas had a visible gait deficit associated with metacarpophalangeal joint hyperextension. Radiographic evidence of osteoarthritis was detected in 1 severely affected llama, and ultrasonographic changes of soft tissue mineralization and suspensory desmitis were observed in 2 llamas. Liver concentrations of copper were lower and serum concentrations of zinc higher in affected llamas, compared with values in control llamas. Lysyl oxidase activity and collagen distribution did not differ significantly between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Hyperextension of the metacarpophalangeal or metatarsophalangeal joints in llamas does not appear to be the result of injury or degeneration of the suspensory ligament or flexor tendons. Lower copper concentrations coupled with higher zinc concentrations in affected llamas may be indicative of secondary copper deficiency.