First case of canine peritoneal larval cestodosis caused by Mesocestoides lineatus in Germany

Wood mouse (Apodemus sylvaticus L.) as intermediate host for Mesocestoides canislagopodis (Rudolphi, 1810) (Krabbe 1865) in Iceland

Mesocestoides canislagopodis is a common parasite of the arctic fox (Vulpes lagopus) in Iceland. In the past, household dogs (Canis familiaris) and cats (Felis catus) were also reported in Iceland to be infected. Recently, scolices of a non-maturing Mesocestoides sp. were detected in the intestines of the gyrfalcon (Falco rusticolus), and tetrathyridia were isolated in the body cavity of rock ptarmigan (Lagopus muta) and subsequently described. All stages were confirmed, using both morphological and molecular methods, to belong to the same species, M. canislagopodis. In the present study, post-mortem examination of wood mice (Apodemus sylvaticus), sampled in autumn 2014 on a farm in Northeast Iceland, revealed the presence of tetrathyridia in the peritoneal cavity and in the liver. Most tetrathyridia in the peritoneal cavity were free, but some were encapsulated in a thin connective tissue stroma and loosely attached to the inner organs. They appear as whitish, heart-shaped, flattened, unsegmented bodies with a slightly pointed posterior end. In the liver, tetrathyridia were seen as pale-tanned nodules embedded in the parenchyma. Comparative molecular analysis, both at the generic level (D1 domain LSU ribosomal DNA), and at the specific level (cytochrome c oxidase subunit I (cox1) and 12S mitochondrial DNA), revealed that the tetrathyridia belonged to M. canislagopodis. A. sylvaticus represents a new second intermediate host record in Iceland, and the first description of a rodent as intermediate host for this species, thus participating in the life cycle of the parasite.

Prevalence of Intestinal Parasites in Dog Faecal Samples from Public Environments in Qinghai Province, China

Dogs are popular companions in our daily lives for company, hunting, protection or shepherding, but they also serve as reservoirs for zoonotic parasites. We analysed faecal samples from urban and rural environments in Qinghai Province on the Qinghai-Tibet Plateau of China to determine the prevalence of intestinal parasites. A total of 682 faecal samples were collected from four urban and two rural environments from October 2019 to December 2020. The samples were analysed for common intestinal parasites using a species-specific PCR approach. The total number of samples with parasites was 40 (5.87%): 23 (3.37%) were positive for helminths, and 17 (2.49%) were positive for protozoa. The following parasites were identified, and their respective prevalence rates were calculated: Cryptosporidium canis (1.32%), Giardia duodenalis (1.17%, assemblages D (n = 6) and C (n = 2)), Taenia hydatigena (1.03%), Taenia multiceps (0.59%), Toxocara canis (0.59%), Echinococcus shiquicus (0.29%), Dipylidium caninum (0.29%), Taenia pisiformis (0.15%), Mesocestoides lineatus (0.15%), Trichuris vulpis (0.15%), and Ancylostoma spp. (0.15%). The overall prevalence was significantly higher in dog faecal samples from rural environments than in those from urban environments (16.19% vs. 3.99%). E. shiquicus, T. pisiformis, M. lineatus, T. vulpis, and Ancylostoma spp. were only found in dog faecal samples from rural environments. The results of the present study indicate that intestinal parasite-positive dogs are important sources of environmental contamination, suggesting a significant zoonotic infection risk in humans and other animals. This has implications for the ongoing control of intestinal parasite infections in dogs in Qinghai Province, China.

Successful treatment of pleural and peritoneal larval mesocestoidosis with fenbendazole in two dogs

Mesocestoides spp. are common intestinal tapeworms of dogs and cats. The presence of numerous larval stages in the pleural or peritoneal cavities causes larval mesocestoidosis, that is a potentially life-threatening disease in massive infection. In vivo diagnosis of larval mesocestoidosis is challenging and confirmed diagnosis is often made post-mortem. For this reason, therapeutic recommendations are empirical and there is currently no data on the best treatment options in dogs and cats. Both fenbendazole and praziquantel have been used to treat canine larval mesocestoidosis but failure of complete clearance of larvae has been described for both. Treatment with fenbendazole at 100 mg/kg orally twice a day, for 1-3 months has been reported as being effective. However, it is known that administration of high, off-label doses of fenbendazole can lead to adverse reactions. Here, we report the efficacy of fenbendazole at a lower dosage (50 mg/kg twice a day) in two dogs with pleural and peritoneal mesocestoidosis.

First description of peritoneal and pleural metacestodosis caused by Mesocestoides vogae in a European wild cat (Felis silvestris silvestris)

Tapeworms of the genus Mesocestoides (Cestoda: Cyclophyllidea: Mesocestoididae) are still enigmatic to scientists, due to their high morphological variability, low host specificity, and unknown details of their life cycle. They are found worldwide, with carnivorous mammals as the main definitive hosts, and the disease is potentially zoonotic. After ingestion by a definitive host, the tetrathyridium can occasionally migrate through the intestinal wall and reach the peritoneal cavity or abdominal organs causing peritoneal metacestodosis. Here, we report on a case of metacestodosis of a European wild cat (Felis silvestris silvestris) found dead in Croatia. At necropsy, a large number of white, rice-like structures were found free in the abdominal and thoracic cavities, as well as along the serous surfaces and in the lungs. DNA isolated from the nodules was genotyped and based on a 320-base pair long 12S fragment classified as Mesocestoides vogae. Although post-mortem changes were advanced, severe emaciation due to the severe parasitic infection and gastrointestinal bleeding was diagnosed as the likely cause of death. Intestinal cestodosis was previously reported in wild cats, but according to our knowledge, this is the first description of peritoneal and pleural metacestodosis caused by M. vogae tetrathyridia (metacestodes) in any wild carnivore species.

Clinical forms of peritoneal larval cestodiasis by Mesocestoides spp. in dogs: diagnosis, treatment and long term follow-up

Canine peritoneal larval cestodiasis (CPLC) is a little-known parasitological infestation of the peritoneal cavity of wild and domestic carnivores with Mesocestoides spp. larvae. While adult Mesocestoides tapeworms reside within the small intestine, the larvae occasionally penetrate the host's intestinal wall, causing a potentially life-threatening peritonitis. Severity of infection as well as the host response influences the prognosis significantly, and early diagnosis and treatment are essential. However, due to the lack of specific symptoms, this condition is underdiagnosed and, furthermore, no clear effective treatment has yet been described. The aim of this study is therefore to report two clinical cases of CPLC in dogs and to illustrate their clinical presentation and follow-up to serve as a reference for clinicians and researchers alike. Both animals were presented with abdominal distention as their main complaint. They underwent clinical examination, abdominal ultrasonography, abdominocentesis, and laparotomy followed by biochemical, cytological, parasitological, and molecular examination of the collected samples. After surgical lavage, the dogs received anthelmintic treatment with either fenbendazole (FBZ) or praziquantel (PZQ). Overall, timely and prolonged administration of high doses of FBZ seems to be the most effective treatment method. Irrespective, to date, no treatment capable of complete eradication of the infection and prevention of recurrence of disease has been found. In conclusion, further investigation into appropriate treatment plans as well as diagnostic development is needed.

Massive infection of a song thrush by Mesocestoides sp. (Cestoda) tetrathyridia that genetically match acephalic metacestodes causing lethal peritoneal larval cestodiasis in domesticated mammals

Background

Peritoneal larval cestodiasis induced by Mesocestoides Vaillant, 1863 (Cyclophyllidea: Mesocestoididae) is a common cause of severe infections in domestic dogs and cats, reported also from other mammals and less frequently from birds. However, there is a limited knowledge on the taxonomy of causative agents of this disease.

Results

In the present study, we investigated a massive, likely lethal, infection of a song thrush Turdus philomelos (Passeriformes: Turdidae) by Mesocestoides sp. tetrathyridia. We performed combined morphological and phylogenetic analysis of the tetrathyridia and compared them with the materials obtained previously from other birds and mammals. The metrical data fitted within the wide range reported by previous authors but confirmed the limited value of morphological data for species identification of tetrathyridia of Mesocestoides spp. The molecular analyses suggested that the isolates represented an unidentified Mesocestoides sp. that was previously repeatedly isolated and sequenced in larval and adult forms from domestic dogs and cats in Europe, the Middle East and North Africa. In contrast to the present study, which found encysted tetrathyridia, four of the five previous studies that identified the same species described infections by acephalic metacestodes only.

Conclusions

The tetrathyridia of the examined Mesocestoides sp. are described in the present study for the first time. However, the possible match with the species that were previously reported to infect birds remains uncertain. The phylogenetic analyses also suggested the rejection of two cases that were previously identified as Mesocestoides corti as they were likely caused by the same species as in the presently reported infection case. The newly provided DNA sequences should allow the assignment to species in the future, when adults of the genus Mesocestoides are more thoroughly sequenced.

Electronic supplementary material

The online version of this article (10.1186/s13071-019-3480-1) contains supplementary material, which is available to authorized users.

Differential Effects of the Flavonolignans Silybin, Silychristin and 2,3-Dehydrosilybin on Mesocestoides vogae Larvae (Cestoda) under Hypoxic and Aerobic In Vitro Conditions

Mesocestoides vogae larvae represent a suitable model for evaluating the larvicidal potential of various compounds. In this study we investigated the in vitro effects of three natural flavonolignans—silybin (SB), 2,3-dehydrosilybin (DHSB) and silychristin (SCH)—on M. vogae larvae at concentrations of 5 and 50 μM under aerobic and hypoxic conditions for 72 h. With both kinds of treatment, the viability and motility of larvae remained unchanged, metabolic activity, neutral red uptake and concentrations of neutral lipids were reduced, in contrast with a significantly elevated glucose content. Incubation conditions modified the effects of individual FLs depending on their concentration. Under both sets of conditions, SB and SCH suppressed metabolic activity, the concentration of glucose, lipids and partially motility more at 50 μM, but neutral red uptake was elevated. DHSB exerted larvicidal activity and affected motility and neutral lipid concentrations differently depending on the cultivation conditions, whereas it decreased glucose concentration. DHSB at the 50 μM concentration caused irreversible morphological alterations along with damage to the microvillus surface of larvae, which was accompanied by unregulated neutral red uptake. In conclusion, SB and SCH suppressed mitochondrial functions and energy stores, inducing a physiological misbalance, whereas DHSB exhibited a direct larvicidal effect due to damage to the tegument and complete disruption of larval physiology and metabolism.

Molecular identification of Mesocestoides sp. metacestodes in a captive gold-handed tamarin (Saguinus midas)

Mesocestoides spp. are tapeworms harbored in the intestine of many domestic and wild carnivores, birds of prey and, rarely, of humans. The life cycle is assumed to involve three hosts and the metacestode juvenile stage (tetrathyridium) may reproduce asexually, provoking severe systemic infections. In the present study, a case of a peritoneal infection by Mesocestoides sp. occurred in a captive gold-handed tamarin (Saguinus midas) is described. Phylogenetic positions based on CO1 and 12S loci were analysed to describe in details this unusual finding of Mesocestoides in a callitrichid monkey. The phylogenetic analyses has not clearly resolve relationships between the metacestode forms from the tamarin and any of the described Mesocestoides species available so far, including those described from non-human primates, thus supporting the hypothesis of a new taxon within the genus.

Zoonotic intestinal parasites of carnivores: A systematic review in Iran

AIM

Parasitic infections, especially of the zoonotic-parasitic type, are the most important health, economic, and social problems in developing countries, including Iran. The aim of this study was to review systematically the available data on gastrointestinal parasites of carnivores in Iran and their ability to infect humans.

MATERIALS AND METHODS

Studies reporting intestinal parasites of carnivores were systematically collected from nine electronic English and Persian databases and Proceedings of Iranian parasitology and veterinary congresses published between 1997 and 2015. A total of 26 studies issued from 1997 to 2015 met the eligibility criteria.

RESULTS

The pooled proportion of intestinal parasites of carnivores was estimated as 80.4% (95% confidence interval=70.2-88.8%). The overall prevalence of gastrointestinal parasites in dogs, cats, foxes, and jackals were 57.89%, 90.62%, 89.17%, and 97.32%, respectively. Dipylidium caninum (20.45%), Toxocara spp. (18.81%), Taenia hydatigena (15.28%), Mesocestoides lineatus (11.83%), Echinococcus granulosus (10%), and Toxascaris leonina (8.69%) were the most frequently observed parasites.

CONCLUSION

High prevalence rates of zoonotic intestinal parasites of carnivores particularly Echinococcus spp. and Toxocara spp. increase the risk of acquiring zoonotic infections such as cystic hydatid, alveolar cysts, and visceral or ocular larva migrants in Iranian people. Therefore, it is essential for public health centers to develop more effective control strategies to decrease infections rates in carnivores' populations.

Helminth infections in domestic dogs from Russia

Dogs are the hosts for a wide helminth spectrum including tapeworms, flatworms, and nematodes. These parasites affect the dog health and cause morbidity and mortality, especially in young and old animals. Some species, as Toxocara canis, Ancylostoma caninum, Dipylidium caninum, and Echinococcus spp. are well-known zoonotic parasites worldwide, resulting in high public health risks. Poor data about canine helminth species and prevalence are available in Russia, mainly due to the absence of official guidelines for the control of dog parasites. Moreover, the consequent low quality of veterinary monitoring and use of preventive measures, the high rate of environmental contamination by dog feces and the increase of stray dog populations, make the control of the environmental contamination by dog helminths very difficult in this country. This paper reviews the knowledge on canine helminth fauna and prevalence in Russia. Practical aspects related to diagnosis, treatment, and control of parasitic diseases of dogs in Russia are discussed.

Occurrence of Mesocestoides canislagopodis (Rudolphi, 1810) (Krabbe, 1865) in mammals and birds in Iceland and its molecular discrimination within the Mesocestoides species complex

The life cycle of Mesocestoides tapeworms (Cestoda: Cyclophyllidea: Mesocestoididae) requires three hosts. The first intermediate host is unknown but believed to be an arthropod. The second intermediate host is a vertebrate. The primary definitive host is a carnivore mammal, or a bird of prey, that eats the tetrathyridium-infected second intermediate host. One representative of the genus, Mesocestoides canislagopodis, has been reported from Iceland. It is common in the arctic fox (Vulpes lagopus) and has also been detected in domestic dogs (Canis familiaris) and cats (Felis domestica). Recently, scolices of a non-maturing Mesocestoides sp. have also been detected in gyrfalcon (Falco rusticolus) intestines, and tetrathyridia in the body cavity of rock ptarmigan (Lagopus muta). We examined the taxonomic relationship of Mesocestoides from arctic fox, gyrfalcon, and rock ptarmigan using molecular methods, both at the generic level (D1 domain LSU ribosomal DNA) and at the specific level (cytochrome c oxidase subunit I (COI) and 12S mitochondrial DNA). All stages belonged to Mesocestoides canislagopodis. Phylogenetic analysis of the combined 12S-COI at the specific level confirmed that M. canislagopodis forms a distinct clade, well separated from three other recognized representatives of the genus, M. litteratus, M. lineatus, and M. corti/vogae. This is the first molecular description of this species. The rock ptarmigan is a new second intermediate host record, and the gyrfalcon a new primary definitive host record. However, the adult stage seemed not to be able to mature in the gyrfalcon, and successful development is probably restricted to mammalian hosts.

[Canine peritoneal larval cestodosis caused by Mesocestoides spp. larval stages]

In a female dog with unspecific clinical symptoms, sonography detected a hyperechoic mass in the middle abdomen and blood analysis a middle grade systemic inflammatory reaction. Laparotomy revealed a peritoneal larval cestodosis (PLC). The diagnosis of an infection with tetrathyridia of Mesocestoides spp. was confirmed by parasitological examination and molecularbiological analysis. Reduction of the intra-abdominal parasitic load as well as a high dose administration of fenbendazole over 3 months led to a successful treatment which could be documented sonographically and by decreased concentrations of C-reactive protein (CRP). Seven months after discontinuation of fenbendazole administration, PLC recurred, pre-empted by an elevation of serum CRP values. According to the literature a life-long fenbendazole treatment was initiated. In cases of unclear chronic granulomatous inflammations in the abdominal cavity in dogs, PLC should be considered. CRP concentration and sonographic examinations are suitable to control for treatment success and a possibly occurring relapse.

Tetrathyridiosis in a domestic shorthair cat

CASE SUMMARY

This report describes the clinical and parasitological findings in a domestic shorthair cat with isolated thoracic tetrathyridiosis. The cat was a stray from Malta that had lived in Germany for several years since as an indoor-only cat. Therefore, the process of infection remains very unusual. In this case it must be considered that the cat had been infected years previously while in Malta, and had lived at least 4 years without any clinical signs. It was possible to diagnose this uncommon disease and initiate an effective treatment with fenbendazole, praziquantel and supportive care. Clinical signs, as well as radiographic findings, were regressive with this treatment.

RELEVANCE AND NOVEL INFORMATION

Tetrathyridiosis is a rare finding in cats, especially in Germany, but it seems to be a potential differential diagnosis of pleural effusion. Mesocestoides corti, which was the causative parasite in this case, has not previously been isolated in Germany. Because tetrathyridiosis is only diagnosed post mortem in most cases, little is known about effective therapeutic options. Furthermore, clinical signs of this disease can be absent for several years and can potentially be triggered by neoplastic conditions or immunosuppression. Tetrathyridiosis seems to be a treatable disease that can be controlled by adequate antiparasitic therapy.

Case report: protein-losing enteropathy caused by Mesocestoides vogae (syn. M. corti) in a dog

An eight-year-old, neutered, female Shetland Sheepdog presented with a 6-week history of small intestinal diarrhea. Regenerative anemia, hypoproteinemia, and an increased plasma C-reactive protein concentration were detected on blood examination. Fecal examination and abdominal radiography were unremarkable. Abdominal ultrasonography showed diffusely hyperechoic mucosa in the small intestine. Gastroduodenoscopy, performed under general anesthesia, revealed mucosal edema and increased granularity in the duodenum and jejunum. Histopathological examination of the endoscopically biopsied small intestinal mucosa revealed tapeworm infection. A single administration of a combined anthelmintic drug (5mg/kg praziquantel, 14.4 mg/kg pyrantel pamoate, and 15 mg/kg febantel) was successful for deworming, and the dog fully recovered. The parasites were removed from stored frozen duodenal mucosa and morphologically identified as Mesocestoides sp. immature adult worms. Mitochondrial (mt) 12S rDNA and mt cytochrome c oxide subunit 1 genes were amplified from the parasites. DNA sequence analysis showed that the genes shared 100% identity with those of reported M. vogae (syn. M. corti). This is the first reported case of protein-losing enteropathy caused by M. vogae in a dog.

Tetrathyridia of Mesocestoides lineatus in Chinese snakes and their adults recovered from experimental animals

Morphological characteristics of Mesocestoides lineatus tetrathyridia collected from Chinese snakes and their adults recovered from experimental animals were studied. The tetrathyridia were detected mainly in the mesentery of 2 snake species, Agkistrodon saxatilis (25%) and Elaphe schrenckii (20%). They were 1.73 by 1.02 mm in average size and had an invaginated scolex with 4 suckers. Adult tapeworms were recovered from 2 hamsters and 1 dog, which were orally infected with 5-10 larvae each. Adults from hamsters were about 32 cm long and those from a dog were about 58 cm long. The scolex was 0.56 mm in average width with 4 suckers of 0.17 by 0.15 mm in average size. Mature proglottids measured 0.29 by 0.91 mm (av.). Ovaries and vitellaria bilobed and located in the posterior portion of proglottids. The cirrus sac was oval-shaped and located median. Testes were follicular, distributed in both lateral fields of proglottids, and 41-52 in number per proglottid. Gravid proglottids were 1.84 by 1.39 mm (av.) with a characteristic paruterine organ. Eggs were 35 by 27 µm in average size with a hexacanth embryo. These morphological characteristics of adult worms were identical with those of M. lineatus reported previously. Therefore, it has been confirmed that the tetrathyridia detected in 2 species of Chinese snakes are the metacestodes of M. lineatus, and 2 snake species, A. saxatilis and E. schrenckii, play the role of intermediate hosts.

Tetrathyridiosis and tubulopapillary carcinoma occurring simultaneously in the mammary gland of a cat

This report describes a case of tubulopapillary carcinoma and concomitant tetrathyridiosis in a 5-year-old female cross-breed cat. A mass was located at right inguinal mammary gland and measured 5.5 × 5 × 3 cm in size with multilobulated to solid appearance. The cut surface of the mass had a centrally located large cyst (approximately 3 cm in diameter) surrounded by other smaller cysts. Histologically, the mass was diagnosed as tubulopapillary mammary carcinoma, intensely positive for AE1/AE3 cytokeratins. The cyst found at post-mortem examination was tetrathyridia of Mesocestoides species surrounded by inflammatory cells and a loose fibrous capsule. To the authors' best knowledge, this is the first description of a tubulopapillary carcinoma and tetrathyridiosis found simultaneously in the mammary gland of a cat.

Molecular identification of Mesocestoides spp. from intermediate hosts (rodents) in central Europe (Poland)

Genus Mesocestoides is a representative of the small cyclophyllidean family Mesocestoididae that is found parasitizing the small intestine of carnivores. The life cycle of cestodes from this genus is complex and requires two intermediate hosts. Cysticercoids are produced in the first intermediate host (oribatid mites), which when eaten by the second intermediate host (mainly rodents, but also other mammalian species, birds, reptiles, or amphibians) form tetrathyridia in the body cavity. Because of the rich history of nomenclatural evaluation of Mesocestoididae, the taxonomic status within the genus Mesocestoides is still unclear. Additional problem constitute the difficulty or even the impossibility in the determination of tetrathyridia based on morphological features. Thus, the aim of our study was to identify a molecular characteristic of the isolates of Mesocestoides from the second intermediate hosts (rodents) based on nuclear and mitochondrial ribosomal DNA data. We choose to analyze metacestodes isolated from two species of rodents (Apodemus agrarius and Myodes glarolus) from different sites. As a result of amplification of 18S rDNA, we obtained partial sequences from four isolates ranging from 1,116 to 1,162 bp. In relation to mitochondrial sequence, 354 bp product of 12S rDNA was obtained from one isolate. The neighbor joining and maximum parsimony trees were constructed in order to examine the phylogenetic relationship within Mesocestoides spp. occurring in rodents from central Europe. The results of our research on the larval stages from rodents, living in a periphery of urban agglomeration as well as in an area of reserve protection, confirm the data of more frequently occurring Mesocestoides litteratus.

Normal and aberrant Mesocestoides tetrathyridia from Crocidura spp. (Soricimorpha) in Corsica and Spain

Tetrathyridia of Mesocestoides sp. were collected from the body cavities of the shrews (Insectivora), Crocidura russula, in Valencia, Spain and Crocidura suaveolens on the Mediterranean island of Corsica, France. Specimens were processed by routine microscopic and histological techniques, including examination with brightfield, phase-contrast, and differential-interference-contrast optics. Most tetrathyridia were clustered together inside host-derived fibrotic capsules, but some occurred free in the body cavity. All specimens examined from both locations had solid hindbodies, i.e., lacking a primary lacuna, thus conforming to the plerocercoid metacestode type; all possessed a single normal tetra-acetabulate scolex. All metacestodes from C. russula in Valencia were normal tetrathyridia. Those from C. suaveolens in Corsica were either normal tetrathyridia or had aberrant deep convolutions of an unusually elongated hindbody. No tetrathyridium from either location or host showed tegumental or excretory duct anomalies such as those reported by several authors from aberrant tetrathyridia and spargana in some other locations. No definitive evidence of asexual proliferation was visible in any of the tetrathyridia, but those with abnormally convoluted hindbodies from a single C. suaveolens in Corsica suggest the potential for asexuality by fission of the hindbody. These results add to our understanding of morphological and developmental variation among metacestodes in this widespread and variable genus.

Survival analysis of dogs diagnosed with canine peritoneal larval cestodiasis (Mesocestoides spp.)

Canine peritoneal larval cestodiasis (CPLC) is a poorly understood disease of dogs caused by asexual multiplication of larval Mesocestoides spp. tapeworms. In this study, we examined the descriptive statistics and survival characteristics of 60 dogs diagnosed with CPLC from 1989 to 2009. Clinically affected dogs presented with ascites (60%), anorexia/weight loss (42%), vomiting (23%), diarrhea (9%) and tachypnea (9%), while subclinical infections (22%) were incidentally detected, typically during ovariohysterectomy or neuter. Survival at 6 months and 1 year post-diagnosis were 72.3% and 60.5%, respectively, and survival was not affected by sex or age. Using Cox proportional hazard analyses, we determined that the most significant factors influencing survival were the severity of clinical signs at the time of diagnosis and application of an aggressive treatment strategy after diagnosis. Dogs that were not treated aggressively were >5 times more likely to die than dogs that were treated with a combination of surgery/lavage and high doses of fenbendazole.

Molecular and morphological circumscription ofMesocestoidestapeworms from red foxes (Vulpes vulpes) in central Europe

Here we examine 3157 foxes from 6 districts of the Slovak Republic in order to determine for the first time the distribution, prevalence and identity ofMesocestodesspp. endemic to this part of central Europe. During the period 2001–2006, an average of 41·9% of foxes were found to harbourMesocestoidesinfections. Among the samples we confirmed the widespread and common occurrence ofM. litteratus(Batsch, 1786), and report the presence, for the first time, ofM. lineatus(Goeze, 1782) in the Slovak Republic, where it has a more restricted geographical range and low prevalence (7%). Using a combination of 12S rDNA, CO1 and ND1 mitochondrial gene sequences together with analysis of 13 morphometric characters, we show that the two species are genetically distinct and can be differentiated by discrete breaks in the ranges of the male and female reproductive characters, but not by the more commonly examined characters of the scolex and strobila. Estimates of interspecific divergence withinMesocestoidesranged from 9 to 18%, whereas intraspecific variation was less than 2%, and phylogenetic analyses of the data showed that despite overlapping geographical ranges, the two commonly reported European species are not closely related, withM. litteratusmore closely allied to North American isolates ofMesocestoidesthan toM. lineatus. We confirm that morphological analysis of reproductive organs can be used to reliably discriminate between these often sympatric species obtained from red foxes.

Interactions between anomalous excretory and tegumental epithelia in aberrant Mesocestoides tetrathyridia from Apodemus sylvaticus in Spain

Tetrathyridia of Mesocestoides sp. (Platyhelminthes: Cestoda) were collected from the body cavities of Apodemus sylvaticus (Rodentia: Muridae) in Murcia, Spain, and processed by routine microscopical and histological techniques, including examination with brightfield, phase-contrast, and differential-interference-contrast optics. All specimens examined had solid hindbodies (i.e., lacked a primary lacuna), thus conforming to the plerocercoid metacestode type. The vast majority of tetrathyridia were highly aberrant, often lacking a scolex, varying greatly in body size, and exhibiting buds or duplexed body forms indicative of asexual proliferation. All of the aberrant forms, including those with normal scoleces and apparent absence of proliferation, possessed anomalous multi-lobed invaginations of the hindbody tegument, which were attached at many points to abnormally dilated excretory ducts. The tegumental and excretory epithelia were joined basally, but did not share a common lumen. These abnormal connections between these aberrant tegumental modifications and the abnormally dilated excretory ducts have not been described previously for any metacestode. This report contributes to understanding previously published reports of abnormalities in other plerocercoid metacestodes, including Mesocestoides spp. and diphyllobothriidean spargana.

Effectiveness of praziquantel for treatment of peritoneal larval cestodiasis in dogs: a case report

Peritoneal larval cestodiasis (PLC) was incidentally identified in an adult female mixed-breed dog by explorative celiotomy done in response to abnormal blood values found during a routine work-up in preparation for an ovariohysterectomy. Ten days after ovariohysterectomy, treatment with fenbendazole began (50mg/kg, per os, every 12h, for 21 days). Two weeks after the end of treatment, samples of peritoneal fluid were obtained by paracentesis and examined. Motile peritoneal tetrathyridia were still evident. Fenbendazole was discontinued. After 10 days of withdrawal from fenbendazole, the dog was treated with a subcutaneous administration of injectable praziquantel (5mg/kg). The administration was repeated after a 15 days interval. Two weeks after the second administration, samples of peritoneal fluid were obtained again by paracentesis. Motile peritoneal tetrathyridia were not detected. Fourteen months after the last administration of praziquantel, the dog remained still free of peritoneal tetrathyridia as determined by abdominal ecography. Therefore, praziquantel was effective to eliminate peritoneal tetrathyridia definitely. Practitioners should be aware of PLC in order to early recognize this condition in case of incidental finding and implement adequate therapy as soon as possible.

Emesis in dogs: a review

Emesis is a common presenting sign in small animal practice. It requires a rational approach to management that is based upon a sound understanding of pathophysiology combined with logical decision making. This review, which assesses the weight of available evidence, outlines the physiology of the vomiting reflex, causes of emesis, the consequences of emesis and the approach to clinical management of the vomiting dog. The applicability of diagnostic testing modalities and the merit of traditional approaches to management, such as dietary changes, are discussed. The role and usefulness of both traditional and novel anti-emetic drugs is examined, including in specific circumstances such as following cytotoxic drug treatment. The review also examines areas in which common clinical practice is not necessarily supported by objective evidence and, as such, highlights questions worthy of further clinical research.