Prevalence and risk factors for patent Toxocara infections in cats and cat owners' attitude towards deworming

Understanding the research and practical needs required to control toxocariasis in Iran

Human toxocariasis (HT) is a widespread zoonotic infection globally, notably prevalent in tropical areas. Enhancing our understanding of toxocariasis can lead to increased attention towards the socioeconomic impact and control of this neglected zoonosis. We conducted a comprehensive review of all available articles and official documents on toxocariasis in Iran to identify research gaps and critical needs for its control. This review highlights that despite numerous studies exploring various aspects of toxocariasis in definitive and paratenic hosts, as well as humans and environmental contamination, significant data deficiencies and gaps persist across different regions in the country. These gaps involve investigating the worm burden and reinfection rates in definitive hosts, developing more sensitive methods to detect and differentiate of Toxocara species, and understanding the behavior of definitive host animals. Additionally, identifying potential paratenic hosts for HT and exploring the organ-specific affinity and survival duration of Toxocara larvae within these hosts are essential areas for exploration. It's also imperative to comprehend the sylvatic and domestic cycles of the parasite in paratenic hosts. Furthermore, assessing egg density in the environment, exploring potential new sources such as water, and identifying regions with optimal climatic conditions for the survival and development of Toxocara eggs are crucial for the formulation of effective prevention and control strategies. Identifying at-risk groups, developing early diagnosis techniques, employing imaging methods, and identifying long-term complications in humans are also crucial. Community health organizations should prioritize health education for the public and professionals. Furthermore, accurately estimating definitive host populations, monitoring and preventing their movements in public places, implementing regular deworming practices for pets and stray hosts, and recognizing the infection's significance as a health priority are critical. This comprehensive understanding advocates for a holistic "one health" approach to control of HT.

Toxocara cati Infection in Cats (Felis catus): A Systematic Review and Meta-Analysis

Introduction: Toxocariasis is an infection caused in canines, felines, humans, and other vertebrates by species of the genus Toxocara, such as T. canis and T. cati. The embryonated eggs of these parasites are the primary means of acquiring the infection for both definitive hosts, dogs and cats, respectively, and for intermediates, such as humans and other vertebrates. When deposited on park soils, environmental contamination becomes a risk to environmental, human, and animal health. Objective: To determine the global prevalence of Toxocara cati in cats (Felis catus). Methods: A systematic review of the literature was carried out in six databases (Scopus, PubMed, ScienceDirect, SciELO and Google Scholar) to evaluate the global prevalence of Toxocara cati in cats, defined by coproparasitological, histological, and molecular techniques. A meta-analysis was performed using a random effects model to calculate pooled prevalence and 95% confidence intervals (95% CI). A two-tailed 5% alpha level was used for hypothesis testing. Results: Two hundred and eighty-nine studies were included. The global pooled prevalence of Toxocara cati in cats using coproparasitological methods was 17.0% (95.0% CI: 16.2-17.8%). In the subgroup analysis according to country, Nepal had the highest prevalence of T. cati infection (94.4%; 95% CI 89.7-99.2%). The pooled prevalence of T. cati infection by PCR in four studies was 4.9% (95.0% CI: 1.9-7.9%). Conclusions: This systematic review underscores the need for preventive action against toxocariasis due to its widespread prevalence. The interplay between animal and human health should be emphasised, necessitating measures like deworming cats, hygiene practices, and public education to mitigate risks. Safeguarding feline health can also reduce human transmission, benefiting both species.

Effects of metformin on parasitological, pathological changes in the brain and liver and immunological aspects during visceral toxocariasis in mice

There are currently insufficient anthelmintic medications available for the treatment of toxocariasis. For instance, Albendazole (ABZ) is the preferred medication, but its effectiveness against tissue-dwelling parasites is limited. In addition, Metformin (MTF) is a widely used oral antidiabetic medication that is considered to be safe for treatment. This study aimed to investigate any potential effects of MTF, alone or in combination with ABZ, on mice infections caused by Toxocara canis (T. canis). The efficacy of the treatment was assessed in the acute and chronic phases of the infection by larval recovery and histopathological, immunohistochemical, and biochemical studies. The results showed that combined therapy significantly reduced larval counts in the liver, brain, and muscles and ameliorated hepatic and brain pathology. It reduced oxidative stress and TGF-β mRNA expression and increased FGF21 levels in the liver. It decreased TNF-α levels and MMP-9 expression in the brain. In addition, it increased serum levels of IL-12 and IFN-γ and decreased serum levels of IL-4 and IL-10. In the acute and chronic phases of the infection, the combined treatment was more effective than ABZ alone. In conclusion, this study highlights the potential role of MTF as an adjuvant in the treatment of experimental T. canis infection when administered with ABZ.

WormWatch: Park soil surveillance reveals extensive Toxocara contamination across the UK and Ireland

BACKGROUND

Toxocarosis is a globally distributed zoonotic disease, but sources of infection are not well documented over large geographical scales. To determine levels of environmental contamination, soil from 142 parks and recreational areas across the UK and Ireland was assessed for the presence of Toxocara.

METHODS

Toxocara ova (eggs) were isolated from soil samples by sieving and flotation and then enumerated. Individual eggs were isolated and imaged, and a subset was characterised by species-specific PCR and Sanger sequencing.

RESULTS

Characteristic Toxocara-type eggs were found in 86.6% of parks, with an average of 2.1 eggs per 50 g of topsoil. Representative eggs were confirmed as Toxocara canis by Sanger sequencing, with many eggs containing developed larvae, hence being viable and potentially infective. Positive samples were more common, and egg density was higher, in parks with greater perceived levels of dog fouling.

LIMITATIONS

Samples were collected at a single timepoint and with limited spatial mapping within parks. Further study is needed to discern spatiotemporal differences within parks and recreational areas.

CONCLUSION

Toxocara is widespread in soil in public parks, indicating a need for further efforts to reduce egg shedding from pet dogs. Standardised methods and large-scale surveys are required to evaluate risk factors for egg presence and the impact of interventions.

Epidemiological Survey on Gastrointestinal and Pulmonary Parasites in Cats Around Toulouse (France)

Various feline parasites are potentially zoonotic thus establishing factors associated with parasitism is of animal and public health interest. The aim of this study was to determine the prevalence of endoparasites in client-owned cats, living in the area of Toulouse, France, over the period 2015 - 2017, and to investigate possible risk factors. A total of 498 faecal samples from cats of the University Animal Hospital of Ecole Nationale Vétérinaire de Toulouse were analysed, 448 from cats presented for consultation and 50 at post-mortem. Analysis was performed using a commercial flotation enrichment method with a hypersaturated sodium chloride solution and Baermann technique. Further examination of the gastrointestinal tract contents was conducted on necropsied cats. Overall, 11.6 % of cats were positive for endoparasites; 50 (11.2 %) consultation cases and 8 (16 %) post-mortem cases, with no significant difference in prevalence between the groups. Amongst infected cats, most were infected by a single species of parasite and 10.3 % (n=6) were infected with two or more. The most common parasite was Toxocara cati with a prevalence of 9.4 % (n=47). Other endoparasites encountered were: Cystoisospora sp 1.0 % (n=5), Aelurostrongylus abstrusus 1.0 % (n=5), Strongyloides sp 0.6 % (n=3), Dipylidium caninum 0.4 % (n=2), Aonchotheca putorii 0.2 % (n=1), Ancylostomatidae 0.2 % (n=1) and Toxascaris leonina 0.2 % (n=1). The examination of the gastronintestinal tract contents of the necropsied cats revealed Mesocestoides sp 0.4 % (n=2) and Tænia (Hydatigera) tæniaeformis sensu lato 0.2 % (n=1) which are seldomly diagnosed by flotation methods. In this study, increasing age and neutered status were statistically associated with reduced odds of infection by endoparasites (helminth and coccidian). Predictors of significantly increased risk included being male, intact, and not receiving regular anthelmintic treatment. The same risk factors were highlighted specifically for Toxocara cati infections, with rural location being an additional risk factor for infection.

Prevalence of major digestive and respiratory helminths in dogs and cats in France: results of a multicenter study

Background

The local distribution of helminths in dogs and cats and the evaluation of risk of contamination represent an important challenge for veterinarians due to their effects on animal health and their potential zoonotic risk. The overall goal of this study was to estimate the prevalence of the digestive and respiratory helminths infecting client-owned dogs and cats in France.

Methods

Faecal samples were collected from 414 pet dogs and 425 pet cats at 20 study sites during 2017–2018 and analysed by coproscopy. The samples included specimens collected from animals of both genders and various breeds and ages from a variety of living environments, and with different lifestyles and feeding regimes. Associations between parasitic infection and qualitative factors were explored.

Results

Overall, 125 (14.9%) samples (15.2% in dogs and 14.6% in cats) were positive for at least one of the species of helminths identified. Infection rates were highest for Toxocara canis and Toxocara cati (8.5% and 11.3%, respectively), while Toxascaris leonina was found only in one cat (0.2%). The apparent prevalence of Ancylostoma caninum and Uncinaria stenocephala in dogs was 1.7% and 4.3%, respectively. No hookworms were found in cats. Whipworms (Trichuris vulpis) were identified in 2.7% of the dogs. Tapeworms (Dipylidium caninum and Taeniidae) were rarely found (< 1% in dogs and < 3% in cats). The prevalence of Angiostrongylus vasorum Crenosoma vulpis, and Strongyloides stercoralis in dogs, Aelurostrongylus abstrusus in cats and Eucoleus spp. / Capillaria spp. in both dogs and cats was < 1%. Significantly higher fecal parasite emission rates were identified in young individuals, in animals with outdoor access, in animals living in the countryside and in intact animals (especially in cats). In addition, cats not fed exclusively with commercial diets and living with other animals (dogs and/or cats) were at higher risk for parasites. For dogs, hunting/herding and walking off-leash were found to be additional risk factors. Furthermore, pets with no reported history of deworming or dewormed > 1 year before the study were positive for parasites significantly more often than pets dewormed < 1 year before study participation.

Conclusions

The overall prevalence of helminths (some of which are zoonotic), the risk factors and the reportedly low deworming frequencies identified in this study (20.5% animals having never been dewormed and only 26.4% dewormed ≥ 3 times/year) illustrate the need for improving pet owners’ adherence to anthelmintic guidelines in France.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05368-7.

Brain food: rethinking food-borne toxocariasis

Human toxocariasis is a neglected tropical disease, which is actually global in distribution and has a significant impact on global public health. The infection can lead to several serious conditions in humans, including allergic, ophthalmic and neurological disorders such as epilepsy. It is caused by the common roundworm species Toxocara canis and Toxocara cati, with humans becoming accidentally infected via the ingestion of eggs or larvae. Toxocara eggs are deposited on the ground when infected dogs, cats and foxes defecate, with the eggs contaminating crops, grazing pastures, and subsequently food animals. However, transmission of Toxocara to humans via food consumption has received relatively little attention in the literature. To establish the risks that contaminated food poses to the public, a renewed research focus is required. This review discusses what is currently known about food-borne Toxocara transmission, highlighting the gaps in our understanding that require further attention, and outlining some potential preventative strategies which could be employed to safeguard consumer health.

The occurence of endoparasites in Slovakian household dogs and cats

Pets play a pivotal role as definitive or reservoir hosts for many zoonotic parasites. Dogs and cats without any clinical signs may be a carrier for the infection. In a one-year study, collected fecal samples of 257 dogs and 50 cats were examined coproscopically for endoparasite infections. Out of 307 investigated fecal samples, 107 (34.9%) were positive for the presence of the propagative stages of endoparasites In 257 dogs fecal samples, following 12 different species of endoparasites were detected: Giardia duodenalis, Cystoisospora spp., Sarcocystis spp., Hammondia/Neospora-like eggs, Angiostrongylus vasorum larvae, Capillaria aerophila, Crenosoma vulpis, Toxocara spp., Toxascaris leonina, Trichuris vulpis, Strongyloides stercoralis, and eggs from the family Ancylostomatidae. Only 4 different parasitic species were found in 50 domestic cat fecal samples - G. duodenalis cysts Cystoisospora spp., T. cati, and larvae of Aelurostrongylus abstrusus. It was confirmed that significant differences were found concerning age for G. duodenalis, T. canis, S. stercoralis, and family Ancylostomatidae. Close and frequent contact between pets and people increases the risks for the transmission of zoonotic diseases.

Endoparasite prevalence and infection risk factors among cats in an animal shelter in Estonia

Cats are important hosts for different zoonotic parasites that can be hazardous to human health. To date, few studies have attempted to identify the factors affecting parasitic infections in shelter animals. This study aims to analyse the presence of endoparasites in shelter cats in Tartu, Estonia, and identify factors affecting endoparasite prevalence and intensity. The risk factors considered were age, location (urban vs rural cats) and time spent in shelter. In total, 290 faecal samples were collected from cats at an animal shelter in 2015-2016 and investigated for endoparasites using the concentration flotation technique. In total, 138 shelter cats (47.6%) were infected with endoparasites and their overall prevalence was: Toxocara cati (36.6%), Cystoisospora spp. (12.4%), Taeniidae gen. sp. (4.1%), Toxoplasma gondii/Hammondia hammondi (3.4%), Eucoleus aerophilus (2.1%), Cryptosporidium spp. (2.1%), Ancylostoma sp. (0.7%) and Giardia sp. (0.7%). Coinfections occurred in 38 cats (13.1%) most frequently of T. cati and Cystoisospora spp. (4.5%), Cystoisospora spp. and T. gondii/H. hammondi (2.1%). Where species identification of cestode and nematode samples was not possible according to morphology, genetic analysis of the mitochondrial cox1 gene was carried out. DNA was successfully analysed for 6 out of 13 samples that required genetic identification, revealing Ancylostoma tubaeforme in one nematode sample and Hydatigera taeniaeformis in five cestode samples. Cats from rural areas had significantly higher endoparasite prevalence than cats from urban areas. Helminth prevalence decreased to some extent due to anthelmintic treatment in cats available for adoption (held ≥15 days in the shelter), whereas the prevalence of infection with protists increased significantly in these animals. It is important to note that the analysis revealed lower infection intensity for quarantine cats (held 1-14 days in the shelter) compared with cats available for adoption. The relatively high prevalence of endoparasites (including zoonotic) in shelter cats ready for adoption suggests that current anthelminthic procedures require improvements.

Toxocara cati and Other Parasitic Enteropathogens: More Commonly Found in Owned Cats with Gastrointestinal Signs Than in Clinically Healthy Ones

Intestinal parasites are involved in the health and wellbeing of cats and some of them, due to their zoonotic potential, represent a problem for public health. This study aimed to assess the prevalence of parasitic infections in cats with gastrointestinal signs. Fecal samples collected from 137 cats were analyzed by the flotation method using a sodium chloride saturated solution. The overall prevalence of intestinal parasites was 50.4%. Intestinal parasites were significantly (p < 0.0001) more common in cats with digestive clinical signs (66.7%) than in clinically healthy ones (19.2%). Toxocara cati (40.2%) was the most frequently identified intestinal parasite, followed by Cystoisospora spp. (10.2%), hookworms (3.7%), Taeniidae (2.2%), Giardia duodenalis (2.2%), and Toxoplasma gondii (0.7%). Toxocara cati (53.3%, p < 0.0001) and Cystoisospora spp. (15.6%, p < 0.001) were significantly more frequently diagnosed in cats with clinical signs. A lack of deworming in the last three months (OR: 15.9), outdoor access (OR: 13.8), the presence of digestive symptoms (OR: 5.4), and young age (OR: 4.2) were identified as risk factors for T. cati infection by logistic regression analysis. Regardless of age, gastrointestinal signs like vomiting, diarrhea, and inappetence were positively associated with T. cati.

Protective effect of the probiotic Lactobacillus acidophilus ATCC 4356 in BALB/c mice infected with Toxocara canis

Human toxocariasis consists of chronic tissue parasitosis that is difficult to treat and control. This study aimed to evaluate the action of the probiotic Lactobacillus acidophilus ATCC 4356 on larvae of Toxocara canis and the effect of IFN-γ cytokine on parasite-host in vivo (1.10⁹ CFU) and in vitro (1.10⁶, 1.10⁷, 1.10⁸, 1.10⁹ CFU) interactions. Four groups of six BALB/c mice were formed: G1 - L. acidophilus supplementation and T. canis infection; G2 - T. canis infection; G3 - L. acidophilus supplementation; and G4 - PBS administration. Mice were intragastrically suplemented with probiotics for 15 days before inoculation and 48 h after inoculation with 100 T. canis eggs. The inoculation of T. canis was also perfomed intragastrically. The recovery of larvae took place through digestion of liver and lung tissues; the evaluation of IFN-γ gene transcription in leukocytes was performed by qPCR. The in vitro test consisted of incubating the probiotic with T. canis larvae. The supplementation of probiotics produced a reduction of 57.7% (p = 0.025) in the intensity of infection of T. canis larvae in mice, whereas in the in vitro test, there was no larvicidal effect. In addition, a decrease in the IFN-γ gene transcription was observed in both, T. canis-infected and uninfected mice, regardless of whether or not they received supplementation. The probiotic L. acidophilus ATCC 4356 reduced T. canis infection intensity in mice, however, the probiotic did not have a direct effect on larvae, demonstrating the need of interaction with the host for the beneficial effect of the probiotic to occur. Yet, the proinflammatory cytokine IFN-γ did not apparently contributed to the observed beneficial effect of probiotics.

Role of cats in human toxocarosis

Toxocara cati, the feline ascarid, is ubiquitous in domestic cats globally and is increasingly recognised as an important zoonotic species. In the definitive host, infections with the adult ascarid usually do not present any clinical signs; if clinical signs do appear, it is usually in kittens infected with T. cati, especially by the transmammary route. Diseases may include cachexia, a pot-bellied appearance, respiratory disorders, diarrhoea, vomiting, among other signs, and these may present as early as 3 weeks of age. However, infections with Toxocara spp. larvae in paratenic hosts (including humans and many other animals), can result in serious complications from the migration of larvae. Historically, there has been an assumption that Toxocara canis was the most likely cause of Toxocara spp.-related disease; while it is probably true that T. canis is responsible for the majority of infections, it is important that those caused by T. cati are accurately identified so that the contribution of this parasite to human disease can be established and then handled appropriately. Overall, the detection of infections in cats and the control of parasite stages in the environment are essential to minimise the infection risk to other animals or humans.

Coprological survey of endoparasite infections in owned dogs and owners' perceptions of endoparasite control in Belgium and the Netherlands

Infections with endoparasites are common in dogs. Some of these parasites are potentially zoonotic and therefore a public health concern. A survey was conducted in twenty-six small animal practices to evaluate the prevalence of endoparasites in Belgian and Dutch owned dogs older than 6 months as well as risk factors associated with infection. Out of 239 faecal samples screened (168 in Belgium and 71 in the Netherlands), 18 dogs were tested positive for at least one type of endoparasite with three dogs co-infected with two parasitic species. Toxocara sp. was the most frequently found endoparasite (4.6%). Three other dogs were positive for Angiostrongylus vasorum (1.4%) using the Baermann method and confirmed in one dog by the Angiodetect® test. Age and predation behaviour were identified as two risk factors associated with endoparasite infection. Although the majority (77%) of the owners in this study reported to administer at least one anthelmintic treatment per year, only a minority of them (24.3%) were aware of the risk to human health, indicating that owner awareness is sub-optimal. For dog owners, human toxocarosis and other potential zoonoses remain an underestimated health concern. The implementation of sustainable parasite control strategies should be promoted taking also into account the public health risk.

Comparison of the Level of Awareness about the Transmission of Echinococcosis and Toxocariasis between Pet Owners and Non-Pet Owners in Greece

Ζoonotic parasitic diseases that can occur through animal contact pose risks to pets, their owners and to their bond. This study aims to assess the level of knowledge about zoonoses, specifically echinococcosis and toxocariasis, among cat/dog owners and non-pet owners in Greece. Multiple-choice questionnaires were designed to obtain data regarding the knowledge of pet and non-pet owners on echinococcosis and toxocariasis, including signs and symptoms of these zoonoses, ways of transmission and precautions that need to be taken into account in order to avoid it. A total of 185 questionnaires were retrieved and data was expressed as absolute (Ν) and relative frequencies (%). Associations between pet ownership, residence and outcome variables were evaluated using the Fisher exact test and Chi-squared test, respectively. Multifactorial linear regression analysis was used to investigate the cross-sectional association between demographic characteristics and the awareness of helminthic zoonoses. All tests were two-sided and statistical significance was set at p < 0.05. Our study revealed a disturbing lack of awareness of echinococcosis and toxocariasis (mean zoonotic knowledge score 8.11 ± 3.18) independently of pet ownership. Surprisingly, in some cases the ignorance of pet owners exceeded that of non-pet owners. Given the progressive impact of toxocariasis in public health and the high prevalence of echinococcosis in the Mediterranean region, measures should be taken to inform people about zoonoses and eliminate their putative transmission.

Survey of UK pet owners quantifying internal parasite infection risk and deworming recommendation implications

Background

Dogs and cats in the UK are exposed to many internal parasites which can pose risks to the health of both the pet and their owners. By understanding these endemic parasites and the risks they pose, we can assess the lifestyle of pets and recommend the correct deworming frequency. Studies identifying risk factors were discussed in the European Scientific Counsel Companion Animal Parasites (ESCCAP) guidelines. To this date, there has been very little information on how pet owners in the UK deworm their pets and if the protocols they follow align with ESCCAP recommendations. The objective of this study was to look at the current deworming protocols of UK cat and dog owners in conjunction with their lifestyle and risk.

Methods

An online survey was conducted in the UK targeting pet owners who own at least one dog and/or cat and were responsible for product purchase, the pet’s health care and veterinary visits. These survey results were analysed against the ESCCAP guidelines and each pet placed into a risk category. By comparing the current deworming frequency with that recommended for their risk category, the compliance of UK pet owners with ESCCAP recommendations was evaluated.

Results

A total of 500 dog owners and 500 cat owners completed surveys. Overall, the study found none of the pets fell into risk group A, with all pets meeting the risk level for at least deworming four times a year (risk group B and above). The majority of animals fell into the highest risk category D with 97% of dogs and 68% of cats. The average deworming per year in the UK was 3.1 for dogs and 3.1 cats, below the minimum recommended by ESCCAP.

Conclusions

For both felines and canines, the dosing frequencies are lower than recommended to both reduce zoonotic risk for reducing Toxocara spp. egg-shedding and improve pet health. This research highlights the need for improved education around dog and cat patient risk assessments and greater adherence to recommended deworming aligned with the ESCCAP guidelines.

Epidemiology of Toxocara spp. in dogs and cats in mainland China, 2000-2019

Toxocariasis is a neglected parasitic zoonosis. Although some studies have reported the Toxocara prevalence in dogs and cats in mainland China, there is a lack of comprehensive analysis of these data. Here, we conducted the first systematic review based on relevant literatures published in Web of Science, PubMed and CNKI from January 2000 to July 2019 to assess the prevalence of Toxocara infection in dogs and cats in mainland China. A total of 68 eligible papers were retrieved, including 24,490 dogs and 844 cats, with 17.34% (4246/24,490) Toxocara canis prevalence in dogs and 22.04% (186/844) Toxocara cati prevalence in cats by faecal floatation method. The prevalence and risk factors of T. canis and T. cati infection in different geographical regions, years, breeds, ages and genders were estimated in this review. This review indicates that there was high prevalence of Toxocara infection in dogs and cats in China. This finding calls for measures to reduce the potential risk of Toxocara infection and toxocariasis in humans and animals.

Seroprevalence of Larval Toxocarosis in the Czech Republic

BACKGROUND

Larval toxocarosis (LT), a zoonotic disease transmitted by dogs, cats, and other carnivores, is caused by roundworms of the genus Toxocara. Humans become infected by ingesting embryonated eggs of this parasite. In this study, we present data on the seroprevalence of LT in the Czech Republic collected by the National Reference Laboratory for Tissue Helminthoses in 2012-2016.

METHODS

Using enzyme-linked immunosorbent assay, a total of 4428 adults and children with or without clinical symptoms were examined for the presence of IgG antibodies against Toxocara canis excretory-secretory antigens.

RESULTS

Of all the persons examined, specific Toxocara antibodies were detected in 160 (3.6%) individuals. There were, however, significant differences between various regions, with seropositivity rates ranging from 1.4 to 7.5%.

CONCLUSION

In comparison to studies from 1998 and 2004, our results suggest a decrease in overall Toxocara seroprevalence in the Czech population, whereby the rates are similar to or even lower than rates in some other Central European countries.

Survey of Spanish pet owners about endoparasite infection risk and deworming frequencies

BACKGROUND

Pets may be carriers of infectious agents including parasites. As part of a larger-scale study covering the whole of Europe, this study examines deworming measures reported by Spanish pet owners and identifies risk factors.

METHODS

An online questionnaire was administered to cat and dog owners in Spain. The replies provided were used to obtain information about the pets' living conditions and to accordingly classify each pet into one of the four ESCCAP infection risk categories (A, B, C or D) for which different deworming frequencies are recommended. Questions were also asked about pet care and owners' attitude toward their pets. The Kruskal-Wallis test was used to correlate risk groups with deworming frequencies.

RESULTS

Completed questionnaires were returned by 500 cat owners and 501 dog owners. According to responses, 96.21% of dogs were assigned to risk category D (maximum risk), and only 1.2%, 2.2% and 0.4% to A, B and C, respectively. Almost all cats were assigned to the minimum risk category A (indoor cats, 62%) or maximum risk category D (outdoor cats, 32.8%); only 3.4% and 1.8% of cats were classified as risk B and C respectively. More dogs were allocated to the higher risk group compared to cats, which were more frequently kept indoors. Cats were reportedly dewormed less frequently than dogs (2.56 and 3.13 times per year respectively), consistent with their different infestation risk. Thus, pets in the lower risk group A were either adequately dewormed or treated more often than necessary. Only a small proportion of cats were not dewormed at all (n = 14). Alarmingly, almost all pets in risk groups B, C or D (representing 95% of dogs and 39% of cats) were dewormed less often than recommended.

CONCLUSIONS

More effective health education is required for the management of zoonotic endoparasite diseases under the umbrella of One Health targeted at owners, veterinarians, general practitioners, and health authorities. To align deworming frequency with infection risk, pet owners should be provided with clear, compelling instructions.

Prevalence of patent Toxocara spp. infections in dogs and cats in Europe from 1994 to 2019

OBJECTIVES

To provide an overview of Toxocara prevalences in dogs and cats in Europe from the last 25 years.

METHOD

Systematic review of the literature.

RESULTS

Over the past 25 years, prevalence studies of Toxocara spp. have been published from 26 European countries. The average prevalences were 14.6% for T. canis in all dogs and 24.5% for T. cati in all cats. Specified for young dogs until 6 months old this was 41.2%, for young cats until 6 months old 25%, adult owned dogs 11.1%, adult owned cats 16.3%, stray dogs 17.6%, and stray cats 33.5%. A recent study in seven European countries showed a prevalence of 3.4% for adult dogs and 4.2% for adult cats. The prevalences seem not to decrease over the years.

CONCLUSION

The prevalence of patent Toxocara infections over the last 25 years did not show a distinct declining trend. Prevalence data provided by recent modern antigen tests showed much lower results than from older studies. Results from studies using less diverse methods and well-defined study-populations could provide more clarity.

Seroprevalence of human toxocarosis in Europe: A review and meta-analysis

Toxocarosis is distributed worldwide and represents the most prevalent zoonotic helminth infection in industrialized countries, thereby posing a substantial risk for public health. Thus, toxocarosis is one of CDC's Neglected Parasitic Infections that has been targeted for public health action. This systematic review and meta-analysis summarizes Toxocara seroprevalence in general populations from Europe, populations suspected of Toxocara infection and defined risk groups. Random-effects meta-analysis of proportions based on 41 publications resulted in an overall seroprevalence of 6.2% (95% CI: 4.7-8.3%) in the general population of Europe. Subgroup analysis according to decades (1970-2010s) revealed a significant increase in seroprevalence, with the highest value (12.4%; 95% CI: 6.5-22.3%) in the 2010s (χ²=17.87, df=4, P=0.001). There were no significant differences between pooled prevalence rates of European sub-regions (χ²=3.01, df=3, P=0.389). Furthermore, meta-analysis of seroprevalence according to age groups, based on data from 22 publications, indicated a significantly higher pooled seroprevalence of 14.9% (95% CI: 8.5-24.8%) in people more than 50 years of age than in younger age cohorts (χ²=8.33, df=2, P=0.016). Occupational groups exposed to contaminated soil and infected animals bear substantial risk for acquiring Toxocara infection. Due to the close link between animal infection and human Toxocara exposure, a "One Health" approach for the prevention of Toxocara infection in both humans and animals is required.

Who let the cats out? A global meta-analysis on risk of parasitic infection in indoor versus outdoor domestic cats ( Felis catus)

Parasitic infection risks in domestic animals may increase as a result of outdoor activities, often leading to transmission events to and from owners, other domestic animals and wildlife. Furthermore, outdoor access has not been quantified in domestic animals as a risk factor with respect to latitude or parasite transmission pathway. Cats are an ideal model to test parasitic infection risk in outdoor animals because there have been many studies analysing this risk factor in this species; and there is a useful dichotomy in cat ownership between indoor-only cats and those with outdoor access. Thus, we used meta-analysis to determine whether outdoor access is a significant risk factor for parasitic infection in domestic pet cats across 19 different pathogens including many relevant to human, domestic animal and wildlife health, such as Toxoplasma gondii and Toxocara cati. Cats with outdoor access were 2.77 times more likely to be infected with parasites than indoor-only cats. Furthermore, absolute latitude trended towards significance such that each degree increase in absolute latitude increased infection likelihood by 4%. Thus, restricting outdoor access can reduce the risk of parasitic infection in cats and reduce the risk of zoonotic parasite transmission, spillover to sympatric wildlife and negative impacts on feline health.

A systematic review and meta-analysis of canine, feline and human Toxocara infections in sub-Saharan Africa

Toxocariasis is an emerging zoonotic disease caused by Toxocara canis and T. cati. Toxocariasis and its etiological agents are of global public health importance, whose burden appears underestimated, especially in sub-Saharan Africa (SSA). The diversity in the transmission routes of these parasites contributes to disease prevalence and often hinders disease control measures. This study aimed to review the epidemiological distribution of Toxocara infections in SSA region. A systematic review and meta-analysis were performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis). We identified 94 relevant, peer-reviewed articles, out of which, 75 articles were found eligible based on Toxocara infections in dogs, cats and humans. Overall, 27,102 samples were examined for T. canis in dogs, T. cati in cats and Toxocara serology in humans, out of which 6142 were positive for Toxocara infection: 3717 (13.7%) in dogs (faecal, 3487; necropsy, 180; hair, 50); 266 (1%) in cats (faecal, 101; necropsy, 165); and 2159 (8%) in humans (serology). Overall mean prevalences of 19% (95% confidence interval (CI): 14-23%), 9% (95% CI: 0-28%) and 36% (95% CI: 24-49%) were recorded in dogs, cats and humans, respectively. Substantial heterogeneity was observed between studies and subgroups (I2 = 99%, P < 0.01). Findings from the review showed that studies on the epidemiology of Toxocara infections in the SSA region are limited. We strongly recommend focused, collaborative and coordinated studies to determine Toxocara spp. prevalence in various hosts, including food animals and the environment, through a 'One Health' approach across SSA countries.

French national survey of dog and cat owners on the deworming behaviour and lifestyle of pets associated with the risk of endoparasites

Background

Endoparasites in dogs and cats are a concern related to pet health and zoonotic risks. Several determinants may affect the endoparasite transmission and infection of dogs and cats such as pet’s lifestyle or regional parasite distribution. Although different zoonotic endoparasites, such as Toxocara spp. and Echinococcus spp., have been identified in France, little information exists about the deworming behaviors of owners or the frequency of occurrence of risk factors associated with endoparasite infection or transmission. Deworming guidelines, such as those created by the European Scientific Counsel Companion Animal Parasites (ESCCAP), recommend a deworming frequency according to the risk of infection of every pet and the potential risk for zoonotic transmission. The objectives of this study were to explore how lifestyles of dogs and cats from France were related to a particular risk of endoparasites and assess whether deworming frequencies complied with ESCCAP recommendations.

Methods

French data were extracted from a database created during a recent European pet owner survey regarding endoparasitic infection risk. Dogs and cats were grouped into risk categories based upon the ESCCAP guidelines. The compliance between the actual and recommended deworming frequencies were explored among the regions surveyed.

Results

The majority of dogs and cats were older than 6 months, had outdoor access, had contact with children or elderly people, and lived in rural and town areas. Most of the dogs were in contact with other dogs, snails or prey (83%), and ate slugs, snails, grass or dug in the garden (68%). Likewise, most of the cats hunted outside (57%) and caught prey animals (52%). Consequently, most of the dogs (89%) and cats (53%) were considered to be in the highest-risk category (D). However, independent of the region, the average deworming compliance for dogs was poor (6%). While deworming compliance for cats in category A (low-risk) was excellent (94%), for cats in category D it was poor (6%).

Conclusions

Deworming compliance is needed to enhance pet health and reduce zoonotic risks. Future studies are warranted to thoroughly investigate the compliance and effectiveness of deworming protocols, and the risk factors associated with endoparasites in France.

Survey of German pet owners quantifying endoparasitic infection risk and implications for deworming recommendations

BACKGROUND

Dogs and cats can transmit zoonotic helminths to humans, e.g. Toxocara spp. and Echinococcus multilocularis. Strategic deworming may help minimize this risk. Studies in several European countries have shown that pets are dewormed less frequently against roundworms and tapeworms than recommended by the European Scientific Counsel Companion Animal Parasites (ESCCAP). The objective of this study was to identify percentages of dogs and cats falling into the different risk categories defined by the German ESCCAP guidelines and to evaluate whether deworming frequency and parasite monitoring in Germany follows these guidelines.

RESULTS

According to questionnaire results from 500 dog and 500 cat owners, deworming of dogs in Germany averages 2.07 times/year while for cats this average is 1.72 times/year. In contrast, evaluation of risk factors placed only 2% (10/500) of dogs in ESCCAP category A with a recommended deworming/examination frequency of 1-2 times per year, while 4.8% (24/500) were placed in category B (4 treatments/examinations per year recommended), 30.8% (154/500) in category C (12 treatments/examinations per year against tapeworms and 4 treatments/examinations per year against roundworms recommended) and 62.4% (312/500) in category D (12 treatments/examinations per year recommended). All cats were placed either in risk group A [52.8% (264/500)] or D [47.2% (236/500)]. Generalized linear models indicated that risk group D cats were treated significantly more often against helminths than risk group A cats. There were no significant differences in deworming frequency between risk groups in dogs. The most important factor influencing deworming frequency was the frequency of veterinary visits. Dogs and cats were treated significantly more often if owners visited their veterinarian more than once yearly.

CONCLUSIONS

The percentage distribution of risk groups considerably varied between dogs and cats. Nevertheless, 62% of dogs and 47% of cats were assigned to category D for which monthly treatments/examinations are recommended by the ESCCAP guidelines. Veterinarians play a key role in instructing pet owners with regard to helminthoses and their prevention, and should take the time for adequate risk assessments. The reported low deworming frequencies despite the high potential parasite infection risk suggests that pet owner advice through veterinarians needs to be improved.

Survey of European pet owners quantifying endoparasitic infection risk and implications for deworming recommendations

Background

Zoonotic endoparasites pose risks to pets and people. The European Scientific Counsel Companion Animal Parasites (ESCCAP) created risk groupings for dogs (A-D) and for cats (A-B), with the highest risk pets (Group D dogs and Group B cats) receiving the most frequent testing and/or deworming recommendations. Little information exists on current deworming behaviours across Europe, alignment to accepted guidelines and the percentage of dogs and cats falling into ESCCAP groups. The study objectives were to evaluate the reported infection-risk behaviours of dogs and cats and assesses whether deworming frequency reported by pet owners complied with recommended deworming frequencies.

Methods

A total of 5001 pet owners from five different countries (France, Germany, Spain, Sweden and the UK) were surveyed regarding endoparasite infection risk and the frequency of deworming of dogs and cats. For the purposes of this study, ESCCAP risk groups for cats (A-B) were converted into four risk groups (A-D) using the additional risk factors outlined in the ESCCAP guidelines. This allowed direct comparison between cats and dogs as well as grouped higher risk cats into the appropriate deworming frequency.

Results

The three most common risk factors identified for dogs were contact with: other dogs, snails or prey; children or the elderly; going off lead outside their own garden. 85–98% of all dogs had risks putting them into Group D, the highest risk group. The three most common risk factors identified for cats were: hunting; catching prey; contact with children or the elderly. Using these revised groups, 33–68% of cats were in Group D. Despite the majority of dogs and cats falling into a risk category where ESCCAP recommends monthly deworming, dogs and cats averaged 2.3 and 2.2 dewormings per year, respectively. This frequency was less than the four times a year dosing frequency demonstrated to be required to reduce zoonotic Toxocara spp. ova shedding.

Conclusions

Overall, 93% of dogs and 54% of cats fell into Group D, the highest risk group. Deworming frequencies were considerably less than recommended by ESCCAP or required to both reduce zoonotic risk and improve pet health. Improved treatment compliance is needed.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-3149-1) contains supplementary material, which is available to authorized users.

Motivators and barriers for dog and cat owners and veterinary surgeons in the United Kingdom to using preventative medicines

Routine use of preventative medicines is advocated as part of responsible dog and cat ownership. However, it has been suggested that the number of owners in the United Kingdom (UK) using preventative medicines to protect their pets is in decline. The aim of this novel study was to use a qualitative methodology to explore the attitudes of pet owners and veterinary surgeons in the UK to using preventative medicine products in dogs and cats. Preventative medicine was defined as "a drug or any other preparation used to prevent disease, illness or injury." Semi-structured interviews were conducted by telephone with owners and veterinary surgeons who had recently participated in a preventative healthcare consultation. Thematic analysis of transcribed recordings of these interviews identified four themes. This paper reports the theme related to motivators and barriers to using preventative medicines. Owners' understanding varied widely about the importance of preventative medicines for pets, as did their confidence in the safety of prescription products. A good relationship with their veterinary surgeon or practice, seeing adverts on the television about specific diseases, advice from a breeder and having personally seen infected animals appeared to be motivators for owners to use preventative medicines. Concern about adverse events and uncertainty about the necessity of using preventative medicines were barriers. Owners who trusted their veterinary surgeons to advise them on preventative medicine products described little use of alternative information sources when making preventative medicine choices. However, owners who preferred to do their own research described reading online opinions, particular in relation to the safety of preventative medicines, which they found confusing. In contrast, veterinary surgeons described broad confidence in the safety and efficacy of prescription preventative medicines and described protection of pet health as a strong motivator for their use. Several expressed some concern about being seen to "sell" products, which may present a barrier to their advocacy. Veterinary surgeons were unsure about owners' level of understanding of the necessity of preventative medicines, particularly in relation to vaccinations, and few recalled instigating conversations with owners about product safety. Owner uncertainties about preventative medicine products may not be adequately addressed in the consulting room. This first qualitative study to investigate dog and cat preventative medicines suggests strategies are needed to increase discussion between pet owners and veterinary surgeons in the UK about the necessity, safety, efficacy and cost of preventative medicines.

Prevalence of Toxocara species infection in the U.S.: Results from the National Health and Nutrition Examination Survey, 2011-2014

Toxocariasis is one of the most common neglected infections of poverty in the U.S. with a reported National Health and Nutrition Examination Survey (NHANES) III (1988–1994) seroprevalence of 13.9% based on enzyme immunoassay testing. We reviewed NHANES data from 2011–2014 to assess current levels. Sera collected from NHANES 2011–2014 participants six years and older were tested for exposure using rTc-CTL-1 antigen, a more sensitive and specific recombinant antigen for IgG antibodies for Toxocara spp. These results were subdivided into children (age 6–17) and adults (age ≥ 18) and then compared between various sociodemographic characteristics. Given prior associations of Toxocara exposure with atopic disease and lead exposure, we also reviewed laboratory values including complete blood counts and blood and urine lead levels. Data from 13,509 individuals with Toxocara antibody results were examined including 3337 children (15.2%) and 10172 adults (84.8%). Overall seroprevalence was 5.1%. In adults increased antibody positivity occurred with non-White ethnicity, male gender, less than college-level education and lower income. Among children, increased antibody positivity was solely related to a lack of health insurance. Additionally, seropositivity was associated with increased blood lead and eosinophil levels in adults and both blood and urine lead levels in children. Relative to NHANES III (1988–1994), current data suggest an overall decrease in Toxocara spp. seroprevalence from 13.9% to 5.1%, however this may be artificially lowered due to difference in testing methods used. Persistent disparities appear to be associated with at-risk populations such as minority ethnicity and low socioeconomic status.

Toxocariasis is a pervasive helminth infection transmitted to humans via embryonated eggs from soil contaminated by the feces of dogs and cats (Toxocara canis and T. cati, respectively). The most recent seroprevalence study of Toxocara infection in the United States used the National Health and Nutrition Examination Survey (NHANES) III data collected from 1988 to 1994. At-risk groups identified included male gender, non-White ethnicity and low education and socioeconomic status. Since the original study, dogs and cats have increased in number and an improved testing platform has been created using rTc-CTL-1 antigen to Toxocara spp. with a sensitivity and specificity of 90% and 99%, respectively. In this study, we assessed current seroprevalence based on the NHANES data from 2011 to 2014 using the more specific testing platform. Although overall seroprevalence appears to have decreased from 13.9% to 5.1%; persistent disparities remain associated with at-risk populations including minority ethnicity and low socioeconomic status. Continued work is needed to improve awareness of disease transmission and treatment amongst the general population as well as veterinarians who may care for dogs and cats within the United States and take responsibility for education of the public.

Abundance, zoonotic potential and risk factors of intestinal parasitism amongst dog and cat populations: The scenario of Crete, Greece

Background

The objectives of this study were to evaluate the prevalence and infection intensity of intestinal parasites in different dog and cat populations in Crete, Greece, estimate the zoonotic risk and identify risk factors.

Methods

Faecal samples from shelter, household and shepherd dogs and shelter and household cats were analyzed using sedimentation/flotation techniques. Giardia and Cryptosporidium were detected by a quantitative direct immunofluorescence assay (IFA). PCR and sequencing was performed to evaluate the zoonotic potential of Giardia and Cryptosporidium positive samples.

Results

Totals of 879 dog and 264 cat faecal samples were examined. In dogs, the overall prevalence was 25.2% (CI: 22.4–28.1) for Giardia spp.; 9.2% (CI: 7.3–11.1) for Ancylostoma/Uncinaria spp.; 7.6% (CI: 5.9–9.4) for Toxocara spp.; 5.9% (CI: 4.4–7.5) for Cryptosporidium spp.; 4.6% (CI: 3.2–5.9) for Cystoisospora spp.; 2.7% (CI: 1.7–3.8) for Toxascaris leonina; 1.7% (CI: 0.9–2.6) for Capillaria spp.; 0.8% (CI: 0.2–1.4) for taeniid eggs; 0.2% (CI: 0–0.5) for Dipylidium caninum; and 0.1% (CI: 0–0.3) for Strongyloides stercoralis. In cats, the prevalence was 20.5% (CI: 15.6–25.3) for Giardia spp.; 9.5% (CI: 5.9–13.0) for Cystoisospora spp.; 8.3% (CI: 5.0–11.7) for Toxocara spp.; 7.6% (CI: 4.4–10.8) for Ancylostoma/Uncinaria spp.; 6.8% (CI: 3.8–9.9) for Cryptosporidium spp.; 4.2% (CI: 1.8–6.6) for Capillaria spp.; 0.8% (CI: 0–1.8) for taeniid eggs; and 0.4% (CI: 0–1.1) for Hammondia/Toxoplasma. Concerning the risk factors evaluated, there was a negative association between age and Giardia infection and between age and T. leonina infection intensity for dogs. Sequencing results revealed the presence of mainly animal-specific G. duodenalis assemblages C and D in dogs and assemblages F, C and BIV-like in cats, with only a limited number of (co-)infections with assemblage A. As for Cryptosporidium, the dog-specific C. canis and the pig-specific C. scrofarum were detected in dogs and the cat-specific C. felis was detected in cats.

Conclusions

High levels of parasitism in both dogs and cats were recorded. Giardia was the most prevalent parasite in all dog and cat populations except for shepherd dogs. Genotyping results suggest a limited zoonotic risk of Giardia and Cryptosporidium infections from dogs and cats in Crete. Taeniid eggs were more prevalent in shepherd dogs suggesting access to carcasses and posing a threat for cystic echinococcosis transmission. Infection rates of Toxocara spp. in both dogs and cats show that companion animals could be a significant source of infection to humans.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-017-1989-8) contains supplementary material, which is available to authorized users.