Lead, cadmium and other metals in serum of pet dogs from an urban area of NW Poland

Cadmium in Selected Organs of Game Animals from Areas with Different Degrees of Industrialisation and Its Intake by Human Consumers

The aim of this study was to determine the concentration of cadmium (Cd) in the organs of game animals from areas with different degrees of industrialisation and to assess its intake following the consumption of the livers of these animals. The material for this study consisted of liver and kidney samples taken from roe deer (Capreolus capreolus), red deer (Cervus elaphus), and wild boar (Sus scrofa) from five regions differing in land use and industrialisation. Compared to the kidneys, the liver was an indicator of the current state of the environment and Cd intake, while the kidney was used to assess the long-term accumulation of Cd in the body. The cadmium concentration in the samples was determined by inductively coupled plasma atomic emission spectrometry. The cadmium concentrations of the organs were found to vary according to geographical location, with the highest levels being observed in Southern Poland, i.e., areas characterised by the highest degree of industrialisation and the presence of heavy industry. However, high Cd concentrations were also reported in the northeastern region. Examples of excessive cadmium levels in the kidneys were noted in all tested regions. Cd intake by humans was evaluated by calculating the estimated daily cadmium intake, and this was compared with the tolerable weekly intake (TWI). The TWI was only exceeded by children frequently consuming wild boar liver from the southwest region.

Pets, Genuine Tools of Environmental Pollutant Detection

In a shared environment, our companion animals became unintended sentinels for pollutant exposure consequences, developing even earlier similar conditions to humans. This review focused on the human-pet cohabitation in an environment we all share. Alongside other species, canine and feline companions are veritable models in human medical research. The latency period for showing chronic exposure effects to pollutants is just a few years in them, compared to considerably more, decades in humans. Comparing the serum values of people and their companion animals can, for example, indicate the degree of poisonous lead load we are exposed to and of other substances as well. We can find 2.4 times higher perfluorochemicals from stain- and grease-proof coatings in canine companions, 23 times higher values of flame retardants in cats, and 5 times more mercury compared to the average levels tested in humans. All these represent early warning signals. Taking these into account, together with the animal welfare orientation of today's society, finding non-invasive methods to detect the degree of environmental pollution in our animals becomes paramount, alongside the need to raise awareness of the risks carried by certain chemicals we knowingly use.

Sentinel animals for monitoring the environmental lead exposure: combination of traditional review and visualization analysis

In nature, certain animals share a common living environment with humans, thus these animals have become biomonitors of health effects related to various environmental exposures. As one of the most toxic environmental chemicals, lead (Pb) can cause detriment health effects to animals, plants, and even humans through different exposure pathways such as atmosphere, soil, food, water, and dust, etc. Sentinel animals played an "indicative" role in the researches of environmental pollution monitoring and human health. In order to comprehend the usage of sentinel animals in the indication of environmental Pb pollution and human Pb exposure completely, a combination of traditional review and visualization analysis based on CiteSpace literature was used to review earlier researches in this study. In the first instance, present researches on exposure sources and exposure pathways of Pb were summarized briefly, and then the studies using sentinel animals to monitor environmental heavy metal pollution and human health were combed. Finally, visualization software CiteSpace 5.8.R3 was used to explore and analyze the hotspots and frontiers of lead exposure and sentinel animals researches at home and abroad. The results showed that certain mammals were good indicators for human lead exposure. Sentinel animals had been widely used to monitor the ecological environment and human lead exposure. Among them, the blood lead levels of small mammals, particularly for domestic dogs and cats, had a significant correlation with the blood lead levels of human living in the same environment. It indicated that certain biological indicators in animals can be used as surrogates to monitor human body exposure to heavy metals. This study also explored the challenges and perspectives that may be faced in sentinel animal research, in order to provide a certain theoretical basis and train of thought guidance for future research.

Zinc Concentration in Blood Serum of Healthy Dogs

The objective of this study was to establish a reference interval for serum zinc in dogs and to determine the factors that affected it. We collected samples from 197 clinically healthy animals of various breeds and ages and obtained information about their sex, neuter status, age, breed, diet, lifestyle, weight, and body condition score. Serum zinc concentration was measured by a colorimetric method using a clinical chemistry analyzer. We established the reference interval for serum zinc as 4.9-19.7 µmol/L. When assessing the relationship of zinc with various biochemical parameters, we found significant correlation with albumin and triacylglycerols. The only observed factor that significantly influenced serum concentration was sex. Female dogs had higher levels (median 11.0 µmol/L) than males (median 8.9 µmol/L). The difference between intact females and intact males was also significant (medians 11.6 and 9.0 µmol/L respectively), but it was only numerical for neutered animals (median of neutered females 10.7 µmol/L and of neutered males 8.7 µmol/L). Despite the general belief that homemade food for dogs contains a lower amount of zinc than a commercial one, diet did not influence zinc serum levels significantly. There was also no impact of age, breed, lifestyle, weight, or body condition score on serum zinc concentration.

Blood concentrations of potentially toxic trace elements (PTEs) and correlation with biochemical and hematological parameters in dogs from thrace region, Turkey

Environmental exposure to potentially toxic trace elements (PTEs) leads to health problems in animals as well as in humans. Dogs can be used as bioindicators for health status of both environment, animals and humans. The study material consisted of a total of 140 dogs from Thrace region in Turkey. Essential (Co, Cr, Cu, Fe, Zn) and non-essential (As, Cd, Hg, Ni, Pb) PTEs concentrations of blood samples were determined by ICP-MS. In addition, hemogram (RBC, MCV, MCH, MCHC, HCT, WBC, HGB, PLT) and biochemical parameters (Glucose, total protein, albumin, globulin, total bilirubin, triglyceride, cholesterol, BUN, AST, ALT, ALP, GGT) levels were determined. The possible correlations between PTEs and blood parameters were investigated. The results were compared according to gender, age (<2, 2-5, >5 years), sampled location with hemogram and biochemistry data. Essential element concentrations (ppb) were sorted as Zn > Fe > Cu > Cr > Co, and non-essentials were As > Ni > Pb > Hg > Cd. There were statistically important negative or positive correlations between elements and hematological (except Fe and Cd), and biochemical parameters (except Ni) (p < 0.05, p < 0.01). It was determined that Pb concentrations (9.34-23.30 ng ml^-1) were below the concentrations considered to be toxic in all locations, Cu concentrations (475.35-521.98 ng ml^-1) were within the normal reference range, Zn (3229.65-4.265.00 ng ml^-1) were higher than the reference values in all locations. Since the concentrations of elements and correlations between hematological, biochemical parameters as well as gender, age, and location in an area with heavy urban and industrial activity; indicate that the situation may be similar for other living things in the region, it constitutes a starting point for studies to be carried out in this direction.

Diet and dog characteristics affect major and trace elements in hair and blood of healthy dogs

Obtaining correct amounts of essential elements, and avoiding toxic metals are key factors in dog health. Through analyzing major and trace elements in hair and blood of 50 healthy companion dogs using ICP-MS, we study their associations with dog characteristics and diet, hypothesizing that eating the same diet long-term results in strong correlations between hair and blood element concentrations, and that dog characteristics and diet affect element status. The correlation between hair and blood was significant for Hg (R = 0.601, p = 0.000) and Pb (R = 0.384, p = 0.010). The following associations were significant (p < 0.05): Dark hair had higher Ca and Mg compared to light hair. Females had higher hair Zn, blood Mn, and blood As compared to males. Blood Mn and Se increased, while blood Pb decreased with age. Raw diet fed dogs had higher hair Zn and Se compared to dry or mixed diet fed dogs, and lower blood Mn compared to dry diet fed dogs. Dry and mixed diet fed dogs had higher blood Cd compared to raw diet fed dogs. Mixed diet fed dogs had higher hair Ca and Mg compared to raw or dry diet fed dogs, and higher hair Pb compared to dry diet fed dogs. Wild game consumption was associated with higher blood Pb, and rice consumption with higher blood As. In conclusion, hair provides an alternative for assessing Hg and Pb exposure, and major and trace elements status is affected by hair color, sex, age, and diet.

Toxic element levels in ingredients and commercial pet foods

Nowadays, there is a growing concern about contamination of toxic metals (TM) in pet food due to the great potential for health risks of these elements. TM concentrations in commercial pet foods (n = 100) as well as in ingredients used in their composition (n = 100) were analyzed and compared to the Food and Drug Administration (FDA) maximum tolerable level (MTL), and the TM concentrations found in the different sources of carbohydrate, protein, and fat were compared. The TM concentrations were determined by inductively coupled plasma with optical emission spectrometry (ICP-OES). Concentrations above the MTL for aluminum, mercury, lead, uranium, and vanadium were observed in both dog and cat foods, and the percentage of dog foods that exceeded the MTL of these TM were: 31.9%; 100%; 80.55%; 95.83%; and 75%, respectively, and in cat foods: 10.71%; 100%; 32.14%; 85.71%; 28.57%, respectively. The MTL values of these TMs and the mean values in dog foods (mg/kg dry matter basis) (MTL [mean ± standard deviation]) were: aluminum: 200 (269.17 ± 393.74); mercury: 0.27 (2.51 ± 1.31); lead: 10 (12.55 ± 4.30); uranium: 10 (76.82 ± 28.09); vanadium: 1 (1.35 ± 0.69), while in cat foods were: aluminum: 200 (135.51 ± 143.95); mercury: 0.27 (3.47 ± 4.31); lead: 10 (9.13 ± 5.42); uranium: 10 (49.83 ± 29.18); vanadium: 1 (0.81 ± 0.77). Dry foods presented higher concentrations of most TM (P < 0.05) than wet foods (P < 0.05). Among the carbohydrate sources, there were the highest levels of all TM except cobalt, mercury, and nickel in wheat bran (P < 0.05), while among the protein sources, in general, animal by-products had higher TM concentrations than plant-based ingredients. Pork fat had higher concentrations of arsenic, mercury, and antimony than fish oil and poultry fat. It was concluded that the pet foods evaluated in this study presented high concentrations of the following TM: aluminum, mercury, lead, uranium, and vanadium.

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

Simple Summary

Establishing reference ranges for essential and toxic trace elements in dogs is important to assess health status and to enable assessments of the background levels of toxic element exposure. On the other hand, establishing whether trace element concentrations vary in relation to different pathologies is also important. Serum concentrations of trace elements may be effective diagnostic markers and may help in understanding the pathogenesis of different diseases (and the associated causal relationships).

Abstract

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.

Factors associated with lead (Pb) exposure on dogs around a Pb mining area, Kabwe, Zambia

Lead (Pb)-poisoning is a serious public health concern and dogs have been useful as a sentinel-animal for Pb exposure of humans. In the present study, the blood Pb concentrations (BLC), isotope ratios (208 Pb/206 Pb and 207 Pb/206 Pb), and biochemistry of 120 domestically owned dogs living around a Pb mining area, in Kabwe, Zambia were analyzed to determine factors associated with Pb exposure. The overall mean value of Pb in dog blood in the present study was 271.6 μg/L. The BLC in the dogs from sites near the mine were significantly higher than those in the dogs from a site 4 km from the mine (352.9 ± 205.1 μg/L versus 28.0 ± 13.9 μg/L). BLC significantly decreased with both increasing age of the dogs and distance from the mine. The Pb isotope ratios in the dog that resided near the mine showed values similar to those reported at the galena mine in Kabwe, which is considered to be the source of Pb exposure. In contrast to the high metal exposure that was determined in these dogs, the mean values of most analyzed parameters in the blood biochemical analysis were surprisingly within or close to the standard reference values. Moreover, none of the dogs showed overt signs of Pb-poisoning or other clinical symptoms. The results of analysis of Pb exposure of the dogs obtained in the present study, which are similar to the previously reported results in human in this location, suggest that dogs could be useful as a sentinel animal for Pb exposure of humans in Kabwe.

Serum Concentration of Macro-, Micro-, and Trace Elements in Silver Fox (Vulpes vulpes) and Their Interrelationships with Morphometric, Densitometric, and Mechanical Properties of the Mandible

The optimal content of macro-, micro-, and trace elements in tissues ensures proper systemic growth and development and optimal health status in animals and humans. However, very little is known on the elemental content in the plasma compartment in Silver fox. The aim of this study was to determine the content of selected elements in serum obtained from 8-month-old female (N = 8) and male (N = 7) silver foxes. Moreover, relationships of the evaluated elements with the morphological, densitometric, and mechanical parameters of the mandible were determined. Serum content of 12 different elements was measured using inductively coupled plasma-atomic emission spectrometry. The morphometric and densitometric properties of the mandible were determined using quantitative computed tomography method, while mechanical endurance was tested using a three-point bending test. Serum concentration of calcium was significantly higher by 20% in male foxes (P = 0.01), while manganese concentration was significantly lower in males by over 17% (P = 0.03). Positive correlations of serum concentration of calcium, phosphorus, and magnesium with the morphological traits of the mandible such as weight, length, and bone volume were stated (P < 0.05). In the group of elements playing regulatory functions, the positive relationships between serum concentrations of selenium, chromium, manganese, copper, and cobalt were found (P < 0.05). The elaborated experimental model may serve for further studies on foxes, especially focused on nutritional factors affecting elemental homeostasis, whole-body metabolism, and systemic growth and development. Daily diet formulation and precise delivery for farm foxes, together with relatively large animal population maintained at the same environmental conditions, regularly subjected to slaughter procedure, enable economical experimentation with various dietary and pharmacological manipulations.

Cadmium as a possible cause of bladder cancer: a review of accumulated evidence

Bladder cancer is a significant disease, the rates of which have increased over the few last years. However, its etiology remains as yet undefined. Cadmium, a widespread environmental carcinogen that has received considerable interest, presents evidence as a possible cause of bladder cancer. A literature review was conducted from the years 1984-2013 to study the accumulated evidence for cadmium as a possible cause of bladder cancer, including routes of cadmium exposure, accumulation, toxicity, carcinogenicity, and evidence from epidemiological and experimental studies. Special reference is devoted to cadmium nephrotoxicity, which illustrates how cadmium exerts its effects on the transitional epithelium of the urinary tract. Mechanisms of carcinogenesis are discussed. The effects of cadmium on gene expression in urothelial cells exposed to cadmium are also addressed. Despite different methodologies, several epidemiologic and nephrotoxicity studies of cadmium indicate that occupational exposure to cadmium is associated with increased risk of bladder cancer and provide additional evidence that cadmium is a potential toxic element in urothelial cells. In vitro studies provide further evidence that cadmium is involved in urothelial carcinogenesis. Animal studies encounter several problems such as morphology differences between species. Among the complex mechanisms of cadmium carcinogenesis, gene expression deregulation is the subject of recent studies on bladder cadmium-induced carcinogenesis. Further research, however, will be required to promise a better understanding of the mechanisms underlying cadmium carcinogenesis and to establish the precise role of cadmium in this important malignancy.

Evaluation of trace elements, oxidant/antioxidant status, vitamin C and β-carotene in dogs with dermatophytosis

The aim of the study was to determine zinc, copper and iron levels, erythrocyte oxidant/antioxidant status, vitamin C and β-carotene in dogs with dermatophytosis. A total of 23 dogs with clinically established diagnosis of dermatophytosis by trichogram and positive fungal culture and six dogs as control were included in this study. On cultural examination 52.17% fungal isolates were found to be Microsporum canis, 30.43% were Trichophyton mentagrophytes and 17.39% were M. gypseum. In comparison to healthy control, the dogs with dermatophytosis had significantly lower levels of zinc (P < 0.01), copper (P < 0.05), β-carotene and vitamin C levels (P < 0.05) and activities of superoxide dismutase (SOD) (P < 0.05) and catalase (P < 0.01), whereas the iron (P < 0.05) and malondialdehyde (MDA) (P < 0.01) levels were significantly increased. On correlation analysis, SOD activity was observed to be positively correlated (P < 0.05) with zinc and copper in both healthy and dermatophytosis affected dogs. In dermatophytosis affected dogs the MDA levels were negatively correlated (P < 0.05) with iron, β-carotene levels and the activities of antioxidant enzymes; SOD and catalase. Our results demonstrated that dermatophytosis in dogs is associated with significant alteration in oxidant/antioxidant balance and trace elements. It might be secondary consequence of dermatophytosis infection or contributing factor in its pathogenesis.