Mammary gland, skin and soft tissue tumors in pet cats: findings of the feline tumors collected from 2002 to 2022

Introduction

Cancer is a leading cause of death in cats, and the rate of such disease has been increasing recently. Nonetheless, feline oncology represents an important area of study not only for the health and wellbeing of cats but also for human health since various types of cancer in cats share similarities to those found in humans. Therefore, epidemiological studies on feline oncology may suggest environmental and genetic factors contributing to cancer in cats, which can eventually be translated to improve human cancer care.

Method

To provide an initial understanding of the epidemiology of feline neoplasms, a descriptive study was undertaken using a dataset documenting cases of feline cancer gathered from the Liguria region (northwest Italy) spanning from 2002 to 2022. The database includes tumor location, morphological codes of the International Classification of Diseases for Oncology, 3rd Edition (ICD-O-3), feline's breed, sex, neuter status, date of birth, date of diagnosis, national territorial unit code of the town of the owner's residence, and an alphanumeric string uniquely identifying the owner's surname.

Results and discussion

The dataset involves a population of 4,399 cats, including 3,195 females (1,425 neutered) and 1,204 males (750 neutered). Our results indicate that mammary gland tumors are the most represented tumors in the female population, while soft tissue and skin cancers appear to have a higher abundance in the male population during the periods investigated (2002-2022). Moreover, Poisson regression analysis showed that not neutered female cats have a significantly increased risk of developing mammary gland tumors compared to the neutered female population [proportional morbidity ratio (PMR) neutered vs. not neutered = 0.58, 95% CI: 0.47-0.72]; meanwhile, for both sexes, for soft tissue and skin tumors, being neutered appears to be a risk factor (PMR neutered vs. not neutered = 2.26, 95% CI: 1.86-2.73; PMR neutered vs. not neutered = 1.16, 95% CI: 0.89-1.51). Finally, the evaluation of the Ligurian municipalities pollution, based on wild boars data (i.e., biomonitors), which coexisted with cats, was correlated to cancer development for all the tumors investigated (in polluted areas, estimated PMRs ranged from 42.61 to 80.13, 95% CI: 29.94-105.11). Overall, the data presented here suggest the use of the feline population as a possible animal model for human health, i.e., sentinel.

First report of Enterocytozoon bieneusi in Erinaceus europaeus and Hemiechinus auritus hedgehogs from recovery centers of Portugal

Enterocytozoon bieneusi microsporidia are emerging pathogens infecting a wide range of vertebrate and invertebrate hosts, known to have zoonotic features since they infect both wild and domestic animals, and humans. Despite their significance, there is very limited epidemiological data on microsporidia in hedgehogs, especially European hedgehogs (Erinaceus europaeus) and long-eared hedgehogs (Hemiechinus auritus), the former known as synantropic hedgehogs, and the latter suited as pets. As such, the present study aimed to assess the presence of E. bieneusi in hedgehogs from Portugal. For this purpose, fecal samples from 110 hedgehogs of three species-E. europaeus (n = 106), H. auritus (n = 1), and Atelerix albiventris (n = 3)-were collected and tested for E. bieneusi by PCR targeting the internal transcribed spacer region and the flanking small and large subunits of the rRNA. We found an overall occurrence of 22.7% (25/110; 95% confidence interval [CI]: 15.28-31.70), with 22.6% (24/106; 95% [CI]: 15.08-31.79) in E. europaeus, 100% (1/1) in H. auritus, and 0% in A. albiventris. Interestingly, three novel genotypes were identified, all belonging to the potentially zoonotic Group 1. Our findings highlight the importance of hedgehogs as potential reservoirs for E. bieneusi and emphasize the need for further research to understand their role in transmission dynamics and assess the associated risks to public and veterinary health.

Causes of Admission, Mortality and Pathological Findings in European Hedgehogs: Reports from Two University Centers in Italy and Switzerland

European hedgehogs (Erinaceus europaeus) are nocturnal insectivores frequently found in urban areas. In the last decades, their population has declined in various European countries and human activities have emerged as significant contributors to this trend. While the literature has mainly focused on trauma as the major cause of mortality, few authors have considered pathological findings. The present study is based on the results of full post-mortem examinations performed on 162 European hedgehogs in Italy and 109 in Switzerland. Unlike in previous studies, the main cause of mortality was infectious diseases (60.5%), followed by traumatic insults (27.7%). The lungs were the main organ affected, showing mostly lymphoplasmacytic (45.9%), granulomatous (18.1%) or suppurative (8.2%) pneumonia. Nematodes were detected in 57.2% of all lungs and were significantly associated with pneumonia (p-value < 0.001). To our knowledge, this is the first study to report infectious diseases as the main cause of hedgehog death, emphasizing the need for wildlife rescue centers to adopt appropriate diagnostic and therapeutic measures. Further research is necessary to determine the broad range of infectious agents that affect this species and elucidate their interplay with the host. Finally, citizen sensitization should be implemented to promote responsible behaviors that could reduce human-related traumatic events.

Health of Holochilus chacarius (Rodentia: Cricetidae) in rice agroecosystem in a neotropical wetland assessed by histopathology

Small mammals have a short lifetime and are strictly associated with their environment. This work aimed to use histopathology to assess the health of Holochilus chacarius in a rice agroecosystem in the Pantanal of Mato Grosso do Sul. During necropsy, fragments of the lung, kidney, skin, liver, and reproductive system of 33 animals were collected and submitted to histological processing. Tissue damages were evaluated as mild, moderate, and severe and arranged in a matrix for further statistical analysis. Furthermore, we used generalized linear models to verify the influence of tissue changes on the body condition, obtained by a regression between body mass and length. In the lungs, we found an intense inflammatory infiltrate associated with anthracosis that had a negative influence on the body's condition. Also, we observed degenerative and inflammatory changes in the liver, kidneys, skin, and reproductive system that ranged from mild to moderate. The histopathological lesions observed in this study may be associated with environmental alterations of anthropic origin such as the exposure to soot from wildfires and heavy metals, evidenced by lesions in the lung, kidney, and liver. The present study provided a histopathological matrix as a new approach that allows to classify and quantify the tissue alterations. Tissue changes when associated with body condition demonstrated to be an effective tool to assess the health of small free-living mammals, showing that these animals can be used as bioindicators of environmental condition.

Morbidity and Prognostic Factors Associated with Wild Hedgehogs Admitted to a Wildlife Rehabilitation Center in Catalonia (NE Spain) from 1995 to 2020

Wildlife rehabilitation centers (WRC) play a crucial role in the collection of data and the monitoring of hedgehog populations. The main objective of this study was to identify the morbidity and prognostic factors associated with the mortality of wild hedgehogs admitted at a WRC in Catalonia. A total number of 3397 hedgehogs admitted from 1995 to 2020 were studied. The principal cause of admission was orphaned/young category (41%) followed by misplacement (19%), natural disease (17%), and trauma (14%). The best outcomes for release were for misplacement (93.6%), orphaned/young (72.3%), and other causes (77.6%), and the lowest proportion of released animals were found for natural disease (41.4%) and trauma (44.7%) categories. The most common macroscopic findings were the respiratory and digestive lesions. Internal parasites were also prevalent in 61% of the animals but with no association with a higher mortality. In the multivariate analyses, the prognostic indicators related with the mortality outcome were the presence of systemic (OR = 3.6, CI 95%: 2.8-4.6) and neurological (OR = 4.3, CI 95%: 2.9-6.4) signs. Morbidity and prognostic factors in wildlife rehabilitation are essential for providing effective care, making informed decisions, optimizing resources, and improving rehabilitation success rates.

The first full study of heavy metal(loid)s in western-European hedgehogs (Erinaceus europaeus) from Portugal

The western-European hedgehog (Erinaceus europaeus) is an insectivore with a wide distribution in Portugal and a potential tool for biomonitoring relevant One Health hazards, including heavy metal(loid)s' pollution. The aim of this study was to positively contribute to the current knowledge about the metal(loid) pollution in Portugal. Forty-six hedgehogs (from rescue centres; with known provenance) were necropsied. Sex, age category and weight were determined. Spines, liver and kidney were collected, and metalloid concentrations were determined by inductively coupled plasma mass spectrophotometry (ICP-MS). In general, results did not present alarming metal(loid) concentrations, with the exception of cadmium (Cd) (in the kidneys) and copper (Cu). Hedgehogs from Viana do Castelo and Viseu showed elevated concentrations of arsenic (As) and Castelo Branco presented concerning values of cadmium (Cd). Adult and heavier hedgehogs tended to present higher levels of metal(loid)s. Sex does not seem to significantly affect the metal(loid)s' concentrations. Further analysis would be needed to prioritize areas with detail and allow the application of the necessary mitigation strategies.

Metal and metalloid concentrations in wild mammals from SW Europe: European hedgehog (Erinaceus europaeus) and badger (Meles meles)

In recent years, there have been increasing ecological and global concerns associated to Potentially Toxic Elements (PTEs). Thus, the relevance of wild mammals as biomonitors has been globally recognised. In the present study, Cd, Pb, Hg, Zn and As concentrations were quantified in European hedgehog and badger inhabiting SW Europe, and cumulative trends in relation to age and sex were evaluated. Liver and kidney samples were collected, mineralised and PTE content was determined by ICP-MS. Zn was the most abundant element quantified in both organs (239 and 89.8 mg kg-1 for hedgehogs and 179 and 164 mg kg-1 dw for badgers). In hedgehogs, very high Hg concentration were quantified (4.35 and 15.5 mg kg-1 dw in liver and kidney), and Cd was the most abundant for badgers (4.70 and 7.61 mg kg-1 dw in liver and kidney). Positive correlations were observed for the concentrations of PTE in the organs of both species. Age-dependence increased only Cd concentration, with levels in adult kidneys being significantly higher. In this study, European hedgehog and badger were used as biomonitors for the determination of PTEs to provide current reference values in relatively non-polluted areas of SW Europe, and to enhance the use of these species for future ecotoxicological studies.

High Levels of Heavy Metal(loid)s Related to Biliary Hyperplasia in Hedgehogs (Erinaceus europaeus)

Heavy metal(loid) pollution of ecosystems is a current One Health problem. The liver is one of the most affected organs in cases of acute or chronic exposure to abnormal amounts of these substances, inducing histopathologic lesions. In order to assess the influence of heavy metal(loids), forty-five European hedgehogs (Erinaceus europaeus) were submitted to necropsy, and liver samples were collected for a routine histopathology exam and metal(loid)s determination (As, Cd, Co, Cr, Cu and Pb) by ICP-MS. Age was estimated during the necropsy exam. Biliary hyperplasia was the most frequent lesion observed (16/45; 35.56%). No statistically significant associations were found between biliary hyperplasia and age or sex. Metal(loid)s' concentrations were higher in animals with biliary hyperplasia (except for As). There was a statistically significant difference for both Cd and Co. For As, Cd and Co, cubs and juveniles animals showed significantly lower concentrations than elder individuals. Only for Pb were significant differences found between females and males. As described in the literature, exposure to metal(loid)s may be a cause of biliary hyperplasia, although further research (including the use of biochemical methods) is needed to support these results. To the authors' knowledge, this is the first report of this association in hedgehogs.

Hematology, Biochemistry, and Protein Electrophoresis Reference Intervals of Western European Hedgehog (Erinaceus europaeus) from a Rehabilitation Center in Northern Portugal

The Western European hedgehog (Erinaceus europaeus) can work as a bioindicator of environmental pollution and be a host for multiple zoonotic agents, making it relevant in terms of One Health studies. It is essential to deepen the knowledge on this species and calculate reference intervals (RIs) for the usual hematological and biochemical parameters. For this retrospective study (2017–2022), the archives of the Clinical Pathology Laboratory (LPC) of University of Trás-os-Montes and Alto Douro (UTAD) Veterinary Teaching Hospital were analyzed. Data of hematology, clinical biochemistry, and protein electrophoresis from 37 healthy hedgehogs of the Wild Animal Rehabilitation Center at UTAD, Northern Portugal, were included. It was possible to calculate RIs for almost all of the variables in the study, using Reference Value Advisor V2.1. Moreover, sex and age effects were investigated: alkaline phosphatase (p = 0.012, higher in males); total proteins (p = 0.034, higher in adults); mean cell volume (p = 0.007) and mean corpuscular hemoglobin (p = 0.010) (both higher in juveniles); and red blood cell distribution width (p = 0.021, higher in adults). Our study allowed for the first time to define RIs for a population of hedgehogs in Portugal, having a potentially relevant impact on species conservation and in the human–animal health interface.

Do Urban Hedgehogs (Erinaceus europaeus) Represent a Relevant Source of Zoonotic Diseases?

Urban fauna is defined as animal species that can live in urban environments. Several species, including the western-European hedgehog (Erinaceus europaeus), have now been identified as part of this urban fauna, becoming permanent residents of parks and gardens in different cities across Europe. Due to the importance that this phenomenon represents for zoonotic disease surveillance, several authors have been conducting zoonotic agents' surveys on hedgehog. The aim of this study is to compare zoonotic diseases' prevalence in hedgehogs in urban environments with those from more rural areas. A systematic review with meta-analysis of twelve studied of zoonotic diseases' (in urban and rural areas of Europe) was therefore conducted for this purpose. Fifteen different zoonoses have been assessed in urban environments and six in rural areas. Anaplasma phagocytophilum was the most prevalent zoonotic agent found in urban habitats (96%). Dermatophytosis shows statistically significant differences between locations (p-value < 0.001), with a higher prevalence in urban Poland (55%; n = 182). Our results suggest further research and a standardized monitoring of different hedgehog populations are essential to understanding the epidemiology of several zoonotic pathogens in different habitat types (urban, rural, natural, industrial, etc.) and preventing possible disease outbreaks.

Biomonitoring metals and metalloids in wild mammals: invasive versus non-invasive sampling

Heavy metal and metalloid pollution is a matter of concern in animal, human and environmental health (One Health) and also in wildlife conservation worldwide. Studying wild mammals in toxicology has been contributing significantly to our knowledge, namely to find out the most critical regions, to understand bioaccumulation and biomagnification phenomena or to evaluate their toxic effects. However, not all the animal tissues and organs provide the same information or should be interpreted in the same way. The best sample to use will depend on the objectives and conditions of the study. This review aims to compare invasive and non-invasive samples to biomonitor heavy metals, providing a brief resume of their advantages, limitations and examples of use. Further research, using a wider range of mammalian species, is required to establish what information can be obtained in biomonitoring studies that use non-invasive samples (such as hair, faeces and parasites) and/or invasive samples (such as blood, liver, kidney, bone and other organs).

Endoparasite Infections of the European Hedgehog (Erinaceus europaeus) in Central Italy

Simple Summary

The European hedgehog is a very common animal in Europe. This animal usually lives in woods but often it is possible to find it in gardens and parks in urban areas. Few studies describe parasites infecting the European hedgehog in Italy. In the present study, endoparasite infections and associated lesions were investigated in hedgehogs from two different regions of central Italy (Latium and Tuscany), where no investigations had been performed before. Several helminth and protozoan species were identified in the intestine and respiratory tract of the animals analyzed. The presence of the respiratory worm Crenosoma striatum was found to be associated with bronchial lesions. This study contributed to the knowledge of parasitic infections of the European hedgehog, the most frequently hospitalized animal in wildlife rescue centers.

Abstract

The European hedgehog is a synanthropic mammal, widely distributed in Europe. This species usually inhabits the edges of deciduous or mixed woods, but it is also very common in private gardens and public parks. Despite its popularity and frequency of contacts both with humans and with wild and domestic animals, few studies have examined the endoparasitic fauna of the hedgehog in Italy. In the present study, endoparasites of naturally deceased hedgehogs (n = 40) from central Italy (Latium and Tuscany regions) were investigated, along with concurrent gross and histopathological lesions. The most prevalent identified endoparasites were Crenosoma striatum (45%), Capillaria erinacei (42.5%) and Brachylaemus erinacei (22.5%), in accordance with previous reports from hedgehogs in southern Italy. In few subjects, Physaloptera clausa, Acanthocephalans and Cystoisospora rastegaeivae coccidia were also identified. The infection by the lungworm C. striatum was found to be significantly associated (p < 0.01) with bronchial hyperplasia and peribronchiolitis upon histopathological examination. Awareness of the most common parasitic infections in the hedgehog and of their effects on the health of these animals is extremely important, especially in wildlife rescue centers, where European hedgehog represents the most frequently hospitalized mammal species.