Stefania Perrucci

Anthelmintic resistance in cyathostomin populations from horse yards in Italy, United Kingdom and Germany.

BackgroundA large survey was carried out in 2008 in Europe to evaluate the efficacy of fenbendazole (FBZ), pyrantel (PYR), ivermectin (IVM) and moxidectin (MOX), i.e. the major anthelmintic molecules used in current practice against cyathostomins affecting horses. A total of 102 yards and 1704 horses was studied in three countries: 60 yards and 988 horses from Italy, 22 and 396 from the UK, 20 and 320 from Germany. The survey consisted of Faecal Egg Count Reduction Tests (FECRTs) with a faecal egg count reduction (FECR) categorization of (I) resistance present if FECR <90% and the lower 95% confidence limit (LCL) <90%, (II) resistance suspected if FECR ≥ 90% and/or LCL <90% and (III) no resistance if FECR ≥ 90% and LCL >90%. The calculation of FECR data was performed employing bootstrap analysis of group arithmetic means.ResultsThe testing of FBZ on a total of 80 yards resulted in resistance present on more than 80% of the UK and German yards and on significantly fewer in Italy, i.e. in 38% (p < 0.01). PYR, IVM and MOX were tested on a total of 102 yards. For PYR resistance present was found in 25% of the yards with no significant differences between countries. For IVM resistance present was encountered in one Italian and two UK yards (3%), resistance present to MOX was not found in any yard in any country.ConclusionThe results indicate that single and/or multiple drug resistance in equine cyathostomins is present in the three countries, is widespread particularly for FBZ and/or PYR and in one UK yard multiple resistance present was detected to FBZ, PYR and IVM. Macrocylic lactones proved to be the most effective drugs, with some evidence of resistance to IVM and highest activity of MOX, despite a single case of reduced efficacy in Germany. These data call for the development and implementation, among practitioners, owners and managers, of further plans to reduce the expansion of the anthelmintic resistant populations and to use those anthelmintics that remain effective in a manner that preserves their efficacy as long as possible.

Intestinal and lung parasites in owned dogs and cats from central Italy

Prevalence and risk factors of intestinal and lung parasites were investigated in 239 owned dogs and 81 owned cats from central Italy. In 36 dogs and 20 cats found infected by nematodes, pre and post-treatment faecal egg count (FEC) was also evaluated. About 31% of dogs and about 35% of cats resulted positive for at least one intestinal or lung parasitic species. Helminthic, intestinal and zoonotic infections resulted prevalent in examined animals. Examined dogs resulted infected by Toxocara canis (13.0%), Toxascaris leonina (1.7%), Trichuris vulpis (3.3%), Ancylostoma caninum (2.0%), Uncinaria stenocephala (1.25%), Strongyloides stercoralis (0.8%), Angiostrongylus vasorum (0.4%), Dipylidium caninum (1.25%), Taeniidae eggs (0.4%), Giardia duodenalis (3.8%), and Cystoisospora (Isospora) spp. (7.5%). Examined cats were infected by Toxocara cati (22.2%), Capillaria aerophila (1.2%), Ancylostoma tubaeformae (1.2%), U. stenocephala (3.7%), Aelurostrongylus abstrusus (1.2%), Mesocestoides sp. (1.2%), D. caninum (1.2%), G. duodenalis (1.2%) and Cystoisospora spp. (4.5%). The presence of clinical signs and the young age (less than 6 months) were identified as risk factors by univariate and multivariate statistical analysis. In 63.9% treated dogs and in 80.0% treated cats, percentages of post-treatment FEC reduction higher than 90% were found. Results obtained in this study are discussed.

Acaricidal activity of aqueous extracts of camomile flowers, Matricaria chamomilla, against the mite Psoroptes cuniculi

Abstract.  Arcaricidal properties of decoctions, infusions and macerates of dried flower heads of camomile, Matricaria chamomilla L. (Asterales: Asteraceae) were tested in vitro against the mite Psoroptes cuniculi Delafond (Parasitiformes: Psoroptidae). This mite species is responsible for otoacariasis in domestic animals. Mites were exposed to the extracts for 24, 48 or 72 h. All the extracts tested showed highly significant acaricidal activity when compared with controls. Among them, a decoction of 10% was the only formulation which gave 100% activity at all the three observations times.

Effects of worm control practices examined by a combined faecal egg count and questionnaire survey on horse farms in Germany, Italy and the UK.

BackgroundFor the control of worm infections, the strategic use of anthelmintics, often accompanied by additional farm and/or pasture management procedures, is currently applied on most horse farms in industrialized countries. However, the particular effects of the specific worm control procedures are often unclear and have only been investigated to a limited extent. We examined faecal egg count (FEC), faecal egg count reduction (FECR) and questionnaire data on farm and pasture management procedures. The aim of this study was to determine whether specific worm control practices reported to be applied in European horse farms affect worm prevalence.ResultsThis study involved 20 German, 26 Italian and 16 UK horse farms for each of which FEC were performed on a minimum of 16 horses. In total, 2029 horse faecal samples were quantitatively analysed for helminth eggs, resulting in 56.3% of the faecal samples being positive for strongylid eggs. The prevalence in the 742 German horse samples (48.1%) was significantly lower than that in the 737 Italian (61.1%) and the 550 UK (60.9%) samples. As expected, a significant effect of horse age on the infection prevalence was observed, with adult horses showing lower prevalences and lower mean FEC than foals and yearlings. The majority of the participating farms were stud farms (n = 29), followed by riding stables (n = 27) and racehorse stables (n = 6). The prevalence of strongyle infection by farm type differed between countries. While in Germany, horses on riding farms were significantly less often strongyle positive, in the UK horses on stud farms showed the lowest strongyle prevalences, whereas in Italy, no significant difference between farm types were seen. On all farms, horses received routine/preventive anthelmintic treatment. An effect of treatment frequency on strongyle prevalence was only encountered with adult horses. On farms performing more than one annual treatment, faecal samples were significantly less often positive. Furthermore, by comparing the FECR results of individual horses with their pre-treatment FEC, it was found that high pre-treatment FEC were associated with a significantly higher probability for a FECR below 90%.ConclusionOverall, age-dependent strongyle infection patterns and general worm control approaches were found to be similar on horse farms in the three countries. Also, a negative association of pre-treatment FEC and treatment efficacy was consistently found in all countries. However, mean strongyle prevalences and frequencies of anthelmintic treatments were considerably different. In addition to the age-dependent prevalence patterns, the finding of a possible negative association between high FEC and reduced FECR might argue for a focus on horses showing high pre-treatment FEC when monitoring anthelmintic treatment efficacy in the field.

Composition and Acaricidal Activity of Laurus novocanariensis and Laurus nobilis Essential Oils Against Psoroptes cuniculi

Abstract The major components of Laurus nobilis and L. novocanariensis leaf oils were identified and their acaricidal activity against Psoroptes cuniculi evaluated. Monoterpenes were predominant in L. nobilis oil (91.8%), while sesquiterpenes were only 1.4%. The main components of this oil were 1,8-cineole (39.2%), α-terpinyl acetate (11.3%), sabinene (10.6%) and linalool (7.4%). The acaricidal activity of L. nobilis oil, at a concentration of 10%, led to a mortality rate of 73%; at 5% the average activity was significantly reduced to 51%, while dilutions of 2.5%, 1.25% and 0.625% were ineffective. Laurus novocanariensis oil, compared to L. nobilis, was richer in sesquiterpenes; the main constituents were α-pinene (10.4%), 1,8-cineole (9.6%) and β-selinene (7.2%). After 24 h of contact, the oil of L. novocanariensis killed all the mites when used at 10% and 5% concentrations. At lower concentrations the mortality significantly decreased; a dilution of 0.625% was ineffective.

The activity of volatile compounds from Lavandula angustifolia against Psoroptes cuniculi

Previously we demonstrated the acaricidal properties of Lavandula angustifolia Miller essential oil and of linalool, one of its main components, against Psoroptes cuniculi detected following direct contact of the substances with the mites.

Distribution and species-specific occurrence of cyathostomins (Nematoda, Strongylida) in naturally infected horses from Italy, United Kingdom and Germany

A broad scale study was carried out in 2008 to evaluate the distribution and species-specific occurrence of cyathostomin populations in horse yards from Europe. In total 102 properties and 3123 horses were included in Italy (60 yards and 1646 animals), United Kingdom (22 yards and 737 animals) and Germany (20 yards and 740 animals). Individual faecal samples were examined with a McMaster technique while pooled samples were subjected to the microscopic examination of in vitro cultured larvae and to a Reverse Line Blot (RLB) assay able to molecularly identify the most diffused 13 species of cyathostomins. All yards were positive for the presence of cyathostomins both at the McMaster technique and at the microscopic examination of cultured larvae. One thousand and nine hundred thirty-one horses (61.8%) showed a positive faecal egg count, i.e. 1110 (67.4%), 463 (62.8%) and 358 (48.3%) from Italy, UK and Germany respectively. Out of the 1931 positive animals 1133 (36.3%) showed a faecal egg count per gram >150, specifically 694 (42.2%) from Italy, 237 (32.2%) from UK and 202 (27.3%) from Germany. The molecular results showed that all 13 species that can be detected by the RLB were found in each of the three countries, with a range of 3-13 species present in individual yards. The five most prevalent were Cylicocyclus nassatus, Cylicostephanus longibursatus, Cyathostomum catinatum, Cylicocyclus goldi and Cyathostomum pateratum. The relevance of these results and related biological and epidemiological features are discussed, together with their significance for both future studies of cyathostomins and further intervention programs aiming to control the spread of anthelmintic-resistant populations.

Therapeutic efficacy of linalool for the topical treatment of parasitic otitis caused by Psoroptes cuniculi in the rabbit and in the goat

The persistence in the environment and the toxicity to nontarget organisms shown by drugs commonly used in controlling ectoparasites of animals and plants are increasingly becoming a problem (Menzies, 1972; Couch, 1975; Halley et al., 1993). In addition, arthropods have become resistant to pesticides (Beesley, 1973; Roush, 1993). In light of these problems, alternative drugs such as new, natural and more biodegradable compounds are needed to control acari and insect pests. Compounds of natural origin have served mankind as a source of medicinal agents since its earliest times, with higher plants as the principal source (Balandrin et al., 1993). The biological activity of many essential oils from plants against a large number of pathogens and arthropods has been confirmed by many laboratory investigations (Sharma et al., 1981; Chaumont & Bardey, 1989; Buchbauer etal., 1993; Panizzi et al., 1993; Perrucci et al., 1995). The biological activity of essential oils is mostly due to monoterpenoids that are their principal components (Charlwood & Charlwood, 1991). Linalool, an alcoholic monoterpenoid that is the constituent of many plant essential oils, has been found to be toxic against several species of acari and insects (Hink et al., 1988; Rice & Coats, 1994a, b; Perrucci, 1995). In some of our previous studies (Perrucci et al., 1995,1996) this compound has been found in vitro-to be acaricidal against Psomptes cuniculi (Delafond) (Acari: Psoroptidae), a mite causing ear mange in several animal species (Sweatman, 1958). Linalool is presently used in commercial flea shampoos for pets and in insecticidal sprays for house plants (Powers et al., 1988; Rice 8i Coats, 1994~). In this study the therapeutic efficacy of linalool for the topical treatment of parasitic otitis caused by Psoroptes cuniculi is evaluated in vivo in the rabbit and the goat. Forty-five New Zealand rabbits, 5 months old and with no clinical signs of ear mange, were experimentally infected using fresh scabs collected from the ears of three rabbits with ear mange caused by Rcuniculi. The scabs, containing all life stages of the mite, were broken into small pieces and mixed with sterile

Genetic variability of Eucoleus aerophilus from domestic and wild hosts

Eucoleus aerophilus (syn. Capillaria aerophila) is a trichuroid nematode affecting domestic and wild carnivores and, sometimes, humans. This parasite has a worldwide distribution and may cause significant clinical disease in pet animals. The present paper investigates the sequence variation in partial mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of E. aerophilus isolates from pets and wild animals from different countries. Forty-four egg pools of E. aerophilus were collected from dogs, cats and foxes from Italy, while seventeen adult stages of E. aerophilus were obtained from red foxes and beech martens from Portugal, Romania, Serbia and UK. Fifteen different haplotypes were characterized and five were shared between pets in Italy and wildlife from Europe. The remaining haplotypes were either confined only in hosts or countries, or in a given host from a country. The phylogenetic analysis showed that all haplotypes clustered as a monophyletic group with a strong nodal support, indicating that all sequence types represented E. aerophilus. The results here presented have implications for a better understanding of the epidemiology, phylo-geography and clinical impact of E. aerophilus. In particular, the geographic distribution of E. aerophilus haplotypes in different host species and geographic regions, and their variation in terms of pathogenic impact and zoonotic role, warrant further investigations.

Cryptosporidium parvum infection in a mare and her foal with foal heat diarrhoea.

Cryptosporidium infection was molecularly investigated in mares and in their neonatal foals for which the occurrence of foal heat diarrhoea was also assessed. Thirty-seven mare/foal pairs were included in the study. All foals were born in the same stud farm during 2006-2008 breeding seasons. Two faecal samples, one prior to and one after delivery were collected from each mare, whereas three faecal samples were taken from each foal, i.e. at 8, 10 and 12 days of age. All samples (74 from mares and 111 from foals) were divided into two aliquots, one of which was examined for the presence of Cryptosporidium by a commercially available microplate ELISA kit, while the second aliquot of all ELISA-positive samples was molecularly examined. Nine out of 37 examined foals presented foal heat diarrhoea and one of them scored positive for Cryptosporidium, together with its mare. More specifically, four samples belonging to the same mare/foal pair resulted positive for Cryptosporidium upon both ELISA and PCR. The sequence analysis of the COWP gene showed the occurrence of the zoonotic species Cryptosporidium parvum. The possibility that foal heat diarrhoea-like episodes may be due to neonatal cryptosporidiosis and their relevance for the health of horses and of humans handling diarrhoeic neonatal foals and their mares are discussed.