Mortality and heavy metals environmental exposure: a study in dogs

Introduction

Dogs are human companions and share environmental conditions with their owners. Epidemiological studies have shown that dogs seem to be good sentinel animals for the association of diseases and/or mortality provoked by chronic exposure to heavy metals (Cd, Pb).

Methods

In the present work, we analyze the registered death cases and population from the National Canine Registry from 2020 to 2022, involving a dog population of 582,564 and 17,507 deaths. The mortality rate in male and not-purebred dogs is higher than in female and purebred dogs, respectively. The mortality cases were cross-referenced with the environmental pollution data relating to the concentration of Cd and Pb detected, between 2012 and 2022, in the various municipalities of the Liguria region. We then calculated SMR (Standardized Mortality Rate) throughout the region and found that mortality increases from the eastern to the western Ligurian coast.

Results and discussion

We observed that the most polluted areas present the highest SMRs (IRR = 1.36, 95%CI: from 1.31 to 1.41). Considering dog ages, we found that mortality in young dogs is not affected by pollution, while mortality in old dogs (10-20 years old) is heavily affected by it (IRR = 8.97, 95%CI from 8.09 to 9.93). In conclusion, the data suggest the importance of canine health and biomonitor studies and provide a basis for future research involving both animal and human health.

Brucella ceti Infection in Striped Dolphins from Italian Seas: Associated Lesions and Epidemiological Data

Brucella ceti infections have been increasingly reported in cetaceans. In this study, we analyzed all cases of B. ceti infection detected in striped dolphins stranded along the Italian coastline between 2012 and 2021 (N = 24). We focused on the pathogenic role of B. ceti through detailed pathological studies, and ad hoc microbiological, biomolecular, and serological investigations, coupled with a comparative genomic analysis of the strains. Neurobrucellosis was observed in 20 animals. The primary histopathologic features included non-suppurative meningoencephalitis (N = 9), meningitis (N = 6), and meningoencephalomyelitis (N = 5), which was also associated with typical lesions in other tissues (N = 8). Co-infections were detected in more than half of the cases, mostly involving Cetacean Morbillivirus (CeMV). The 24 B. ceti isolates were assigned primarily to sequence type 26 (ST26) (N = 21) and, in a few cases, ST49 (N = 3). The multilocus sequence typing (cgMLST) based on whole genome sequencing (WGS) data showed that strains from Italy clustered into four genetically distinct clades. Plotting these clades onto a geographic map suggests a link between their phylogeny and the topographical distribution. These results support the role of B. ceti as a primary neurotropic pathogen for striped dolphins and highlight the utility of WGS data in understanding the evolution of this emerging pathogen.

Reproducibility and Feasibility of Classification and National Guidelines for Histological Diagnosis of Canine Mammary Gland Tumours: A Multi-Institutional Ring Study

Simple Summary

Tumours of the mammary gland are common in humans, as in canine species. They are very heterogenous with numerous morphological variants and different biologic behaviours. In the last few decades, several efforts have been made to classify these tumours histologically and establish the level of malignancy by using histologic grading systems. However, reproducibility and diagnostic agreement of such classification and grading have been only rarely assessed. In this study, we tested the variability in diagnoses performed by 15 pathologists using the same classification and grading system. Prior to the study, pathologists agreed on guidelines regarding how to apply these systems. Pathologists worked blindly on 36 digital histologic slides of canine mammary tumours. The agreement was statistically analysed using Cohen’s kappa coefficient that, when equal to 1, indicates perfect agreement. The overall agreement in the identification of hyperplastic-dysplastic/benign/malignant lesions was substantial (kappa 0.76), while outcomes on morphological classification had only a moderate agreement (k = 0.54). Tumour grade assigned by pathologists was the least concordant and kappa could not be calculated. Although promising, the results underline that each diagnostic/grading system should be assessed and optimized for standardization and high diagnostic agreement.

Abstract

Histological diagnosis of Canine Mammary Tumours (CMTs) provides the basis for proper treatment and follow-up. Nowadays, its accuracy is poorly understood and variable interpretation of histological criteria leads to a lack of standardisation and impossibility to compare studies. This study aimed to quantify the reproducibility of histological diagnosis and grading in CMTs. A blinded ring test on 36 CMTs was performed by 15 veterinary pathologists with different levels of education, after discussion of critical points on the Davis-Thompson Foundation Classification and providing consensus guidelines. Kappa statistics were used to compare the interobserver variability. The overall concordance rate of diagnostic interpretations of WP on identification of hyperplasia-dysplasia/benign/malignant lesions showed a substantial agreement (average k ranging from 0.66 to 0.82, with a k-combined of 0.76). Instead, outcomes on ICD-O-3.2 morphological code /diagnosis of histotype had only a moderate agreement (average k ranging from 0.44 and 0.64, with a k-combined of 0.54). The results demonstrated that standardised classification and consensus guidelines can produce moderate to substantial agreement; however, further efforts are needed to increase this agreement in distinguishing benign versus malignant lesions and in histological grading.

Processed animal proteins (PAPs) in animal nutrition: Assessment of the chemical risk of essential and non-essential elements

BACKGROUND

Processed animal products (PAPs) could be a great alternative to common protein supplements and represent a good example of recycling and valorization of by-products. Due to the reintroduction of certain types of PAPs in feed, a deeper knowledge of these heterogeneous matrices is needed. Thus, the aim of this study is to evaluate the levels of essential elements and inorganic contaminants in 55 PAPs considered as potential alternatives to common protein supplements.

METHODS

PAPs samples were analysed for essential (cobalt, nickel, chromium, copper, zinc, iron and manganese) and non-essential elements (arsenic, cadmium, lead and mercury) by Inductively Coupled Plasma Mass Spectrometer (ICP-MS), Graphite Furnace Atomization Atomic Absorption Spectrometer (GF-AAS) and dual cell Direct Mercury Analyzer spectrometer (DMA-80).

RESULTS

Essential elements were found with the following decreasing order iron>zinc>copper>manganese>chromium>nickel>cobalt (mg kg-1). Only one sample was found non-compliant to lead concentration according to the European Union Regulation while negligible values of others non-essential elements were found.

CONCLUSIONS

This study suggests that PAPs could be a useful supplement for animal diet due to their natural content of essential elements. A careful monitoring of chemical elements should be required and eventually guidelines have to be drafted for a correct use of PAPs to ensure a safe and sustainable feed production.

Neuropathological Characterization of Dolphin Morbillivirus Infection in Cetaceans Stranded in Italy

Simple Summary

There is abundant literature reporting demyelination in dogs and pinnipeds affected by morbillivirus infection, but myelinopathy is poorly investigated in stranded cetaceans affected with the virus. Also, the neuropathogenesis of cetacean morbillivirus infection has not been fully clarified, leaving questions on cell tropism unanswered. A novel dolphin morbillivirus lineage of Atlantic origin circulating in Italian waters replaced the previous Mediterranean strain in late 2015; however, differences in virulence and pathogenesis between the two strains have not yet been documented. The aims of the present study were to: describe histopathological changes and immunohistochemical findings in the central nervous system of 31 cetaceans which tested positive on molecular investigations for the two dolphin morbillivirus strains; characterize by double indirect immunofluorescence staining the areas of myelin damage. The most frequently observed morbillivirus-associated lesions were astro-microgliosis, neuronal necrosis, spongiosis, malacia, and non-suppurative meningoencephalitis. Demyelination was detected by means of a specific myelin biomarker. Inside and around the demyelinated areas there were morbillivirus antigen-bearing cells of mainly neuronal and microglial origin, associated with marked astro and microglia reactivity. Molecular and immunohistochemical analysis suggested a higher neurotropic affinity of the novel circulating strain.

Abstract

Cetacean morbillivirus (CeMV) is responsible for epidemic and endemic fatalities in free-ranging cetaceans. Neuro-inflammation sustained by CeMV is a leading cause of death in stranded cetaceans. A novel dolphin morbillivirus (DMV) strain of Atlantic origin circulating in Italian waters since early 2016 has caused acute/subacute lesions associated with positive immunolabelling of the virus. To date, myelin damage has not been fully documented and investigated in cetaceans. This study describes neuropathological findings in the brain tissue of 31 cetaceans found stranded along the Italian coastline and positive for DMV infection on molecular testing. Cell changes in the areas of myelinopathy were revealed by double indirect immunofluorescence. The most frequent DMV-associated lesions were astro-microgliosis, neuronal necrosis, spongiosis, malacia, and non-suppurative meningoencephalitis. Myelin reduction and areas of demyelination were revealed by means of a specific myelin biomarker. Morbilliviral antigen immunolabelling was mainly observed in neurons and microglial cells, in association with a marked activation of microglia and astrocytes. These findings extend our knowledge of DMV-associated brain lesions and shed light on their pathogenesis.

Cadmium and wild boar: environmental exposure and immunological impact on macrophages

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Wild boar represents useful bioindicator for Cadmium environmental exposure.

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Cadmium can be absorbed by wild boar moMФ with subsequent cell viability decrease.

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Moderate cadmium concentration down-regulated IL-12p40, TNF-α expression in moMФ.

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Moderate cadmium concentration decreased antimicrobial molecules expression in moMФ.

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Moderate cadmium concentration down-regulated expression of several TLRs in moMФ.

Cadmium (Cd²⁺) is regarded as one of the most toxic heavy metals, which can enter the food chain through environmental contamination and be bioaccumulated. Its exposure in Ligurian wild boars was monitored between 2016–2020 and revealed high level of this heavy metal in different provinces. In one of these polluted area, 21 wild boars were additionally sampled and the relationship between hepatic and renal Cd²⁺ concentration suggested that majority of these animals presented chronic intoxication. Cd²⁺ exposure of wild boar might lead to an immunosuppression status, thus in vitro experiments on wild boar monocyte-derived macrophages (moMФ) were carried out. Effects of Cd²⁺ scalar doses were evaluated through viability and adsorption assays, ELISA, qPCR. Moderate doses of this environmental pollutant (20 μM) were absorbed by moMФ, with subsequent reduction of their viability. This heavy metal did not trigger release of either IFN- β, anti-inflammatory or pro-inflammatory cytokines by moMФ, instead 24 h treatment with 20 μM of Cd²⁺ resulted in down-regulated expression of TNF-α, IL-12p40, several TLRs, CD14, MD2, BD2, MyD88, p65, and NOS2. The results of our monitoring activity suggested that wild boar can be useful to monitor environmental exposure of this heavy metal and can help in understanding the type of contamination. In addition, in vitro experiments on wild boar moMФ revealed that Cd²⁺ exposure negatively affected the immune function of these cells, likely leading to increased susceptibility to infection.

Retrospective data analysis of animal poisoning events in Liguria

Confirmed animal poisoning cases were 215/497 (43.2%) from 2009 to 2018.

Anticoagulant rodenticides (79.2%) were the main cause of animal poisoning.

The most affected areas are located along the coast.

Dogs and cats were 40.0% of confirmed animal poisoning.

Intentional poisoning represents a serious risk to domestic and wild animals, and it can be an environmental and human health issue as well . This paper is a retrospective study, which covers a decade, based on animal poisoning cases and poisoned baits that were submitted for diagnostic examinations to the Veterinary Medical Research Institute for Piedmont, Liguria and the Aosta Valley (IZS-PLVA) in Liguria region. All data were collected through a passive surveillance system introduced in Italy by a decree of the Ministry of Health in January 2009.

43.2% of the animal poisoning cases were confirmed by toxicological analysis, whereas toxic agents were detected in 31.1% of the baits. The most affected animal species were dogs and cats, followed by synanthropic birds,. Only 4% of the total poisoning events analysed involved wild animals and cases of livestock poisoning were minimal. An increased number of cases in January, March, April and August was noticed, but no seasonal trend was detected. The most affected areas were the ones with the highest level of urbanization and population density. The major cause of the poisonings and the most common substances detected in the examined baits were anticoagulants whereas cholinesterase inhibitors, organochlorine pesticides and carbamates were detected in a minor number of cases.

This study raises concerns about deliberate animal poisoning in ligurian region and highlights the necessity to fight this phenomenon as it endangers animals, humans and environment.

Using network analysis to identify seasonal patterns and key nodes for risk-based surveillance of pig diseases in Italy

The description of the pattern of livestock movements between herds provides essential information for both improving risk-based surveillance and to understand the likely spread of infectious diseases. This study provides a description of the temporal pattern of pig movements recorded in Italy on a 4-year period (2013-2016). Data, provided by the National Livestock registry, were described by social network analysis and the application of a walk-trap algorithm for community detection. Our results show a highly populated community located in Northern Italy, which is the focal point of the Italian industrial pig production and as a general pattern an overall decline of medium and backyard farms and an increase in the number of large farms, in agreement with the trend observed by other EU pig-producing countries. A seasonal pattern of all the parameters evaluated, including the number of active nodes in both the intensive and smaller production systems, emerged: that is characterized by a higher number of movements in spring and autumn, linked with the breeding and production cycle as pigs moved from the growing to the finishing phase and with periods of increased slaughtering at Christmas and Easter. The same pattern was found when restricting the analysis to imported pig batches. Outbreaks occurring during these periods would have a greater impact on the spread of infectious diseases; therefore, targeted surveillance may be appropriate. Finally, potential super-spreader nodes have been identified and represent 0.47% of the total number of pig holdings (n = 477). Those nodes are present during the whole study period with a similar ranking in their potential of being super-spreaders. Most of them were in Northern Italy, but super-spreaders with high mean out-degree centrality were also located in other Regions. Seasonality, communities and super-spreaders should be considered when planning surveillance activity and when applying disease control strategies.

Outbreak of febrile gastroenteritis caused by Listeria monocytogenes 1/2a in sliced cold beef ham, Italy, May 2016

In May 2016, two separate clusters of febrile gastroenteritis caused by Listeria monocytogenes were detected by the local health authority in Piedmont, in northern Italy. We carried out epidemiological, microbiological and traceback investigations to identify the source. The people affected were students and staff members from two different schools in two different villages located in the Province of Turin; five of them were hospitalised. The epidemiological investigation identified a cooked beef ham served at the school canteens as the source of the food-borne outbreak. L. monocytogenes was isolated from the food, the stools of the hospitalised pupils and the environment of the factory producing the cooked beef ham. All isolates except one were serotype 1/2a, shared an indistinguishable PFGE pattern and were 100% identical by whole genome sequencing (WGS). By combining a classical epidemiological approach with both molecular subtyping and WGS techniques, we were able to identify and confirm a Listeria gastroenteritis outbreak associated with consumption of sliced cold beef ham.

Using multi-criteria risk ranking methodology to select case studies for a generic risk assessment framework for exotic disease incursion and spread through Europe

We present a novel approach of using the multi-criteria pathogen prioritisation methodology as a basis for selecting the most appropriate case studies for a generic risk assessment framework. The approach uses selective criteria to rank exotic animal health pathogens according to the likelihood of introduction and the impact of an outbreak if it occurred in the European Union (EU). Pathogens were evaluated based on their impact on production at the EU level and international trade. A subsequent analysis included criteria of relevance to quantitative risk assessment case study selection, such as the availability of data for parameterisation, the need for further research and the desire for the case studies to cover different routes of transmission. The framework demonstrated is flexible with the ability to adjust both the criteria and their weightings to the user's requirements. A web based tool has been developed using the RStudio shiny apps software, to facilitate this.

Molecular and histological characterization of bovine papillomavirus in North West Italy

Bovine papillomaviruses (BPVs) are group of worldwide-spread DNA virus that infect primarily cattle determining diseases of considerable economic relevance. Recently, research on BPVs, received a great impulse owing to the development of specific biomolecular analysis, mostly based on L1 gene sequencing, that resulted in the identification of new viral types. This work is aimed at the identification and molecular and histopathological characterization of BPVs circulating in North West Italy, one of the main national cattle breeding areas. In this study, 71 bioptic specimens were submitted both to histological examination and to PCR and sequencing analysis. Histopathology revealed various lesion types; however, no connections were demonstrated between involved viral types and histopathological findings. BPV DNA was demonstrated in all the analyzed samples and several viral types were detected. Particularly, molecular investigations revealed a broad diffusion of highly pathogenic BPV1 and 2 Deltapapillomavirus and presence of BPV3 and 9 Xipapillomavirus. Two cases of co-infection were also demonstrated. Phylogenetic analysis revealed presence of different clusters and therefore a noteworthy genetic variety among the analyzed viral types. This study provides information on the main BPVs types in North West Italy and our results demonstrate the complexity of viral epidemiology which is characterized by circulation of multiple viral types even inside single herds. Knowledge of the prevalence and of the variety of BPVs is a milestone for the development of appropriate prophylactic and therapeutic measures.

Data on milk dioxin contamination linked with the location of fodder croplands allow to hypothesize the origin of the pollution source in an Italian valley

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) have similar toxic, endocrine-disrupting, and carcinogenic activity. They are classified as persistent organic pollutants accumulating in the environment and the tissues of living organisms. High concentrations of PCDD/F and dl-PCB have been detected in bovine milk collected in a Piedmont valley (Northwestern Italy) since 2004. This geographic study describes the local distribution of pollution from PCDD/Fs and dl-PCBs. Since their presence in animal products could be traced back to the ingestion of contaminated fodder, dioxin levels in cow milk were related to the distribution of fodder cropland parcels. Specifically, the aim of the study was to determine, through an exploratory approach, whether the contamination was consistent with one common point source of contamination or different scattered sources. Data for PCDD/F and dl-PCB concentrations in the bulk milk from 27 herds, sampled over a 4-year period (2004-2007), were matched to the georeferenced land parcels the dairy farmers used for growing fodder. Isopleth maps of dioxin concentrations were estimated with ordinary kriging. The highest level of pollution for both PCDD/Fs and dl-PCBs was geographically juxtaposed: in both instances, the location of the local steel plant was within this extremely highly polluted area. The study results support the hypothesis for one common point source of contamination in the valley. The exploratory spatial analysis applied in this research may provide a valuable, novel approach to straightforward identification of a highly likely source of dioxin contamination of dairy products (even in the absence of top soil contamination data).

Heat-related mortality in dairy cattle: A case crossover study

The relationship between mortality and stressful weather is not only a complex health, social and environmental issue, but also becomes an economical problem when considering livestock. Future-climate scenarios suggest that higher global mean temperatures could result in marked changes in the frequency of extreme temperatures. The relationship between high temperature and mortality is well known in people living in urban areas, but it has been poorly investigated in livestock such as dairy cows. The aim of this study was to quantify the relationship between heat and mortality from all causes among dairy cows in Italy. We studied 6697 adult (≥24 months) dairy cows that died during the summer in the 5-year period 2002-2006 in three Italian districts (Brescia, Cuneo, Rome) which were selected because of the high livestock production and the availability of weather data for these geographical areas. A case-crossover design was applied using the temperature-humidity index (THI) as exposure of interest. Pooled odds ratio (OR) of mortality at high exposure values versus low exposure values was estimated. An exposure over the THI cut-off increased the risk of mortality by 1.6 times, with a 4% increase in mortality for each THI degree increase above the threshold. We found no effect modification for age-class, herd size or breed, but a certain degree of geographical heterogeneity was identified. The increased dairy cow mortality highlighted in this study should be considered when adopting animal welfare and farm management measures. This phenomenon can be prevented by adopting appropriate interventions to mitigate environmental thermal challenges.

Detection of animal-derived proteins in feedstuffs in Italy: a reproducibility study

Bovine spongiform encephalopathy is a prion disease of ruminants that was first recognized in 1986 in the United Kingdom. Early in the epidemic, it became obvious that the presence of meat and bone meal in feed rations was a common factor in all bovine spongiform encephalopathy cases. The first ban of derived animal proteins in feed was enforced in Europe in 1994 and implemented by Regulation 999/2001 that prohibited the feeding of animal-derived protein to farm animals. The only official method currently accepted by the European Union Commission for test for the presence of animal-derived proteins in feedstuffs is feed microscopy. In Italy, monitoring of feedstuff safety is provided by both the Ministry of Health and the Ministry of Agriculture. The quality of official control, usually assessed by verifying the reproducibility and the accuracy of the testing method, is of fundamental importance for all laboratories and institutions using these results for comparative purposes. The aims of this study were to assess the reproducibility of the official method over all the Italian surveillance network and to provide a model for evaluating the performance of the monitoring system. The accuracy of the identification of the animal class of derived protein detected (avian, mammalian, or aquatic organism) was assessed. The interlaboratory agreement within the overall network reached 0.97 (95% confidence interval of 0.95 to 0.98) for determining the presence or absence of animal-derived proteins (e.g., for mammalian, avian, or aquatic species), and specificity of the identification of the animal class indicated that fish proteins are more easily recognized than are avian or mammalian proteins.

BSE immunohistochemical patterns in the brainstem: a comparison between UK and Italian cases

The continuous monitoring of bovine spongiform encephalopathy (BSE) cases is an integral component of European research and surveillance programmes, to ensure that any changes in the presentation of transmissible spongiform encephalopathies (TSE) in cattle can be detected and defined. Monitoring is generally limited to the brainstem at the level of the obex, for reasons of practicality, safety and cost. Demonstration of disease-specific prion protein (PrP(d)) by immunohistochemistry is currently the most widely used confirmatory tool for both active and passive surveillance. This study assessed PrP(d) immunostaining in the brainstems (obex) of cattle with BSE in the UK and Italy. Immunoreactivity 'profiles' were created for each case based on the nature of the immunostaining, its relative intensity and precise neuroanatomical location. This study compares the obex immunostaining patterns of Italian cases (only active surveillance) and two UK groups (both active and passive surveillance). The neuroanatomical distribution and relative intensity of PrP(d) was highly reproducible in all cases. The overall staining intensity varied widely but was generally stronger in the active than in the passive surveillance populations. The conclusion to be drawn from this comparative study is that the pattern of immunopathology in these routine screening samples for BSE diagnosis and surveillance is the same in the UK and Italy, whether or not the animal was displaying typical, or indeed any, clinical signs at the time of sampling. This indicates that the current confirmatory diagnostic strategy remains appropriate for active surveillance applications.

Pathological prion protein in the tongues of sheep infected with naturally occurring scrapie

Tongue involvement by prion spreading was shown to be a common outcome after oral or intracranial experimental challenge with scrapie and transmissible mink encephalopathy sources in rodent models. It is also known that bovine spongiform encephalopathy, which is pathogenic for humans, is experimentally transmissible to sheep and can lead to a disease indistinguishable from scrapie. A recent European Food Safety Authority opinion recommended research into PrPsc accumulation in the tongues of ruminants. We report on the detection of PrPsc in the tongues of seven scrapie-infected sheep by immunohistochemistry and Western blotting.