Parasitological examination results of zoo animals in Germany between 2012 and 2022.

Parasitic infections in zoo animals are a critical concern for both animal health and management. The aim of this study was to assess the occurrence of endo- and ectoparasites among zoo animals in Germany. A retrospective analysis of the submitted samples of a diverse range of zoo animals (5768) from a ten-year period (2012-2022) was conducted. Overall, 31.1% of those samples tested positive for at least one parasite. In the examined samples, helminths (28.4%) were found more often than protozoans (10.3%) or ectoparasites (0.8%). Among the various animal groups the following parasites were found most commonly: Artiodactyla: Coccidia (34.6%), Strongylida (23.4%); Perissodactyla: Strongylida (19.3%), Ascaridida (12.0%); Carnivora: Ascaridida (16.6%), Coccidia (8.1%); Rodentia: Oxyurida (18.2%), Coccidia (10.5%); Marsupialia: Coccidia (9.4%), Oxyurida (5.9%); Primates: Trichuris spp. (9.7%), Oxyurida (2.2%); Aves: Capillaria (7.8%), Ascaridida (7.6%); Reptilia, Amphibia, Insecta: Oxyurida (18.7%); Pisces: Ciliates (6.2%). Furthermore, potentially zoonotic parasites were identified, including Toxoplasma gondii (0.1%), Cryptosporidium sp. (0.1%). By examining the occurrence of specific parasites, these findings demonstrate the importance of parasites in the context of zoo animal health. They also highlight the need for effective strategies to control parasite burden to improve the overall welfare of zoo animals.

Morphological and Molecular Identification of Physaloptera alata (Nematoda: Spirurida) in a Booted Eagle (Aquila pennata) from Portugal.

Physaloptera spp. are parasitic nematodes that infect the gastrointestinal tracts of many carnivores and omnivores. Although they are distributed worldwide, Physaloptera spp. have not been studied in raptors in Portugal. In this study, we report Physaloptera alata in a booted eagle (Aquila pennata) in Portugal. Adult nematodes were discovered in the gizzard of a young booted eagle, and morphological features were consistent with those of the genus Physaloptera. DNA was extracted and a PCR assay performed to amplify a region of the 18S small subunit of the ribosomal RNA gene and the cytochrome c oxidase subunit I gene. The resulting PCR products were Sanger-sequenced, and comparison with the available sequences in the GenBank database confirmed the initial morphological classification as Physaloptera sp. Phylogenetic analysis clustered the sequence within the Physaloptera group. The presence of this parasite in raptors from Portugal is of particular importance to wildlife rehabilitation centers, disease ecologists, and wildlife professionals. Furthermore, we produced a new genetic sequence and have added it to the GenBank database of parasites in birds of prey.

Fenbendazole treatment against Dentostomella translucida in Syrian golden hamsters.

Dentostomella translucida is an oxyurid nematode that was first discovered in the Mongolian gerbil but has also been detected in other wild and housed rodents. In conventional laboratory animals, oxyurid nematode parasites are widespread infections. A proven treatment strategy for pinworm eradication is the oral application of benzimidazoles, such as fenbendazole. In general, this drug is regarded as safe with minimal side effects. Nevertheless, in Sprague Dawley rats, a significantly reduced litter size could be seen after longer treatment with fenbendazole. Even though Dentostomella translucida was already described in Syrian golden hamsters (Mesocricetus auratus), data on treatment with fenbendazole and its effects on reproduction is lacking. Therefore, the main purposes of the study were (1) the verification of the effectiveness of fenbendazole as medicated feed (150 ppm) against this parasite in naturally infected Syrian golden hamsters in conventional husbandry and (2) monitoring of possible effects on reproduction during the treatment. Results show that fenbendazole treatment was highly effective against Dentostomella translucida, as numbers of pinworm eggs in the faeces were significantly reduced already after the first week of treatment in all animals. After four weeks of treatment, eggs were eradicated entirely. Interestingly, the average weaning weight was significantly reduced during treatment, but the litters were in good health.

Linguatula serrata in an imported dog in Germany: Single-case or emerging disease?

Linguatula serrata is a worm-like parasite with zoonotic potential that inhabits the nasal cavities of canids. Although most cases of linguatulosis are associated with unspecific and rather mild respiratory symptoms, cases of unusual infestations and severe courses in both animals and humans have been reported. In central and northern Europe, the pathogen used to appear only sporadically, however, within the last few years the number of detections has increased noticeably. In July 2020 an approximately nine-month-old dog, imported from Romania, was presented in a veterinary practice in Gotha, central Germany, due to persistent worsening cough. Despite antibiotic treatment the tussis became more severe until the dog expectorated multiple worm-like structures. Three of these specimens were sent to the Institute of Parasitology (Faculty of Veterinary Medicine, University of Leipzig, Leipzig) for morphological and genetic species identification. The latter was based on a 1000-bp fragment of the mitochondrial cytochrome c oxidase subunit I gene (cox1) and the complete nuclear 18S rRNA gene. The dog presented in this study suffered from a severe respiratory impairment caused by worm-like parasites inhabiting its upper respiratory tract. The detected parasites were morphologically identified as female specimens of the so-called tongue-worm L. serrata, which was confirmed by pairwise alignment and phylogenetic analysis of the produced sequences. We report an unusually severe case of L. serrata infection in an imported dog and discuss the spread of this potentially dangerous parasite in central and northern Europe.

Diplotriaena obtusa infection in an Eurasian blue tit (Cyanistes caeruleus) in Germany. Pathology and phylogenetic analysis.

Diplotriaena obtusa is a nematode found in air sacs of a wide number of birds, including Passerine species. During a period of increased mortality of blue tits (Cyanistes caeruleus) in Germany, we collected adult nematode worms from the air sacs of a deceased male blue tit. The nematodes showed morphological features consistent with Diplotriaena ssp. A polymerase chain reaction (PCR) assay targeting the small subunit (SSU) 18S rRNA gene identified the parasite species as Diplotriaena obtusa. Phylogenetic analysis confirmed species identification. Further examinations against infectious pathogens like Suttonella ornithocola, Salmonella spp., Pasteurella spp., Chlamydia spp., Influenza A virus, Usutu virus and West Nile virus were negative. This is the first report of D. obtusa in a blue tit from Germany.

Toxocara vitulorum infection in European bison (Bison bonasus) calves from Central Germany.

Whitish roundworms were found in the faeces of a female (3 months old) and a male (1 month old) European bison calf from an animal park in Central Germany. Since the faeces samples were not assignable to the individual animals, it is not certain if both calves were infected. The worms were identified as Toxocara vitulorum by morphological and molecular analysis, and a treatment with doramectin was initiated. To monitor the success of the therapy, faecal samples were examined before and after treatment by combined flotation/sedimentation technique, followed by a quantitative McMaster analysis in case of positive results. Additionally, stages of several Eimeria species and Trichuris sp. were found. Eggs of T. vitulorum were detected one week after application of doramectin, so, a second treatment was performed. However, no eggs of T. vitulorum were found at the time of the second treatment. Because of the difficulty of T. vitulorum eradication in infected herds, further investigations in the following year will be conducted.

First report of pulmonary cysticercosis caused by Taenia crassiceps in a Cape fur seal (Arctocephalus pusillus).

The cestode Taenia crassiceps parasitizes in the intestine of domestic and wild carnivores, especially in red foxes. Usually, the metacestode stage, also known as Cysticercus longicollis, is located in muscles, peritoneal and pleural cavity of wild rodents. In this case, larval stages were found in a female Cape fur seal, which lived in a German zoo since June 1998. In January 2019, the animal presented clinical signs in terms of inappetence and reduced mobility and, within a short time, it developed dyspnoea and died. Pathological and parasitological examinations were performed. In a large mass of the right thoracic wall and in nodular lung lesions, metacestodes with numerous protoscoleces were identified. Morphological and molecular analyses led to the diagnosis of a Taenia crassiceps infection. Probably, the urban fox population was the source of infection. Thus, regarding the zoonotic potential of this cestode, a regularly performed parasitological examination of pet dogs is recommended.

Current anthelmintic treatment is not always effective at controlling strongylid infections in German alpaca herds.

BACKGROUND: Endoparasites are considered a major health problem of South American camelids as shown in a recent survey among German and Austrian camelid owners. Although prophylactic and therapeutic measures such as application of anthelmintics are commonly used, treatment efficacy is usually not assessed. Owners have expressed significant concerns regarding the effect of antiparasitic therapy, so this study aimed to evaluate the outcome of anthelmintic treatment in German alpaca herds with different drugs. RESULTS: Overall, 617 samples from 538 clinically healthy alpacas > 1 year-old from 27 farms (n = 11-157 animals/herd) were examined. The most common parasites detected by flotation were Eimeria spp. (75.1%) followed by strongylids (55.0%), Nematodirus spp. (19.3%), cestodes (3.1%) and Trichuris (2.7%). After initial coproscopical examination by flotation and strongylid egg quantification by the McMaster technique, positive animals excreting at least 150 eggs per gram of faeces were included in a faecal egg count reduction test (FECRT) using fenbendazole (n = 71 samples), moxidectin (n = 71) or monepantel (n = 66). Pre-treatment larval cultures (n = 23 positive pooled farm samples) revealed Haemonchus (87% of the farms), Cooperia (43.5%), Trichostrongylus (21.7%), Ostertagia (13.0%), Nematodirus and Oesophagostomum (4.3% each). Fenbendazole treatment reduced egg excretion by 45%, moxidectin by 91% and monepantel by 96%. On the farm level, 13/18 farms that used fenbendazole, 6/6 farms that used moxidectin and 2/5 farms that used monepantel had individual FECR values < 90% (fenbendazole) or < 95% (moxidectin, monepantel). Haemonchus and Cooperia were overrepresented on the farms with reduced treatment efficacy. CONCLUSIONS: Gastrointestinal strongylids are common in German alpacas and fenbendazole in particular was not sufficiently effective to reduce strongylid egg excretion. Although the FECRT could not unambiguously determine anthelmintic resistance in the present study, the finding that small ruminant strongylids, especially Haemonchus, are common in alpacas indicates that determination of effective anthelmintic doses, monitoring of efficacy and adapted (selective) treatment regimens must be implemented as part of sustainable deworming practices in this species in accordance with recommendations for ruminants.

Eimeria tenella oocysts attenuated by low energy electron irradiation (LEEI) induce protection against challenge infection in chickens.

In vitro and in vivo studies were performed to assess whether Eimeria tenella (E. tenella) oocysts, exposed to low energy electron irradiation (LEEI), might be considered potential vaccine candidates against cecal coccidiosis. Sporulated oocysts were exposed to LEEI of 0.1 kGy to 10.0 kGy. Reproduction inhibition assays (RIA) were performed in MDBK cells to assess infectivity of sporozoites excysted from irradiated and non-irradiated oocysts. LEEI of 0.1 kGy or 0.5 kGy resulted in 73.2% and 86.5% inhibition of in vitro reproduction (%IRIA), respectively. Groups of 12 one day old (D1) chicken were orally inoculated with Paracox®-8 (G1), 2.0 × 103 non-irradiated oocysts (G2) or 1.0 × 104 irradiated oocysts exposed to LEEI of 0.1 kGy (G3, G4) or 0.5 kGy (G5). Chicken of groups G1, G2, G4 and G5 were challenged 3 weeks later (D21) by a single inoculation of 7.5 × 104 non-attenuated oocysts of the same strain while G3 remained unchallenged. All chickens were subject to necropsy 7 days after challenge (D28) to estimate lesion scores (LS) and oocyst index (OI). A positive control (PC, non-vaccinated, challenged) and a negative control (NC, non-vaccinated, non-challenged) were kept in parallel. Chicken of group G5 had similar weight gain as the Paracox®-8 group (G1) after challenge and higher weight gains as compared to the other vaccinated groups. Feed conversion ratio (FCR) did not differ between chickens inoculated with oocysts irradiated with 0.5 kGy (G5) and negative control (NC) before challenge (1.25-1.52). After challenge FCR was 1.99 (G5) to 2.23 (G4) in the vaccinated chicken compared to 1.76 in group NC. LS and OI were significantly lower in all vaccinated groups as compared to group PC. Progeny oocysts collected from the feces of chickens following vaccination with irradiated oocysts exhibited lower in vitro infectivity/reproduction in MDBK cells with %IRIA of 89.7% and 82.4% for progeny of oocysts irradiated with 0.5 kGy and 0.1 kGy, respectively, suggesting hereditary attenuation by LEEI treatment. Seroconversion was demonstrated by ELISA before challenge (D21) in all vaccinated groups, however, chicken inoculated with irradiated oocysts displayed higher antibody levels than those inoculated with precocious oocysts (G1). In Western blot analysis chicken vaccinated with virulent (G2) or 0.1 kGy-irradiated E. tenella oocysts (G3, G4) showed more protein bands compared to G5 (0.5 kGy). We conclude that LEEI could be a promising technology for production of attenuated oocyst vaccines.

First detection of Baylisascaris procyonis in wild raccoons (Procyon lotor) from Leipzig, Saxony, Eastern Germany.

Baylisascaris procyonis is a zoonotic nematode mainly harbored by the North American raccoon. It can cause severe neurological problems in paratenic hosts and humans. In Germany, raccoons are spread throughout the country. However, the presence of B. procyonis in the German raccoon population has not been thoroughly studied. For this study, 32 wild raccoons were collected in the urban area Leipzig, Saxony, Eastern Germany. Adult ascaroid nematodes were isolated from the intestines and morphologically identified as B. procyonis. Species confirmation was conducted through PCR. In total, adult B. procyonis worms were found in 24 raccoons. The results of the present study add new information about the presence of the parasite in Saxony, Germany. Similarly, the results highlight the importance of the raccoon as a reservoir of zoonotic parasites.

Trematodes from the Northern Lapwing, Vanellus vanellus (Charadriidae), from Central Germany.

Seventy-five previously frozen Northern Lapwings, Vanellus vanellus (Linnaeus, 1758) were dissected and examined for trematodes. The available birds were euthanized after suffering severe injuries from a hail storm. Trematode specimens were found in the air sacs, body cavities and kidneys. They were cleared, stained in Alaun-Carmine and examined via light microscopy. Trematodes were assigned to two different families and three different species: Uvitellina vanelli and Selfcoelum sp. from the family Cyclocoelidae and Tanaisia valida of the family Eucotylidae. A prevalence of 12% (for both, Cyclocoelid and Eucotylid infections) was detected. While trematodes of the respiratory system have been discovered in V. vanellus before, the present study describes renal trematodiasis in this bird species for the first time. Furthermore, the first recovering of a trematode of the species Selfcoelum sp. in the Northern Lapwing is described. Full measurements and figures of trematodes are given. Criteria and critical points in specifying and recovering the parasites are discussed.

Diagnostics and epidemiology of alveolar echinococcosis in slaughtered pigs from large-scale husbandries in Germany.

By means of the official meat inspection of domestic pigs, exceptionally high proportions of livers affected by encapsulated nodules containing whitish to light yellow, viscous to pasty material ("microabscesses") were detected. The swine had been raised on four different farms, being located in distinct regions of Germany (Brandenburg, Thuringia, Upper Franconia). Macroscopical and histological examination of 77 samples of livers revealed granulomatous to necrotizing hepatitis with attendance of numerous eosinophils. In 61 % (n = 47) of the lesions, eosinophilic, band-like acellular structures resembling the laminated layer of Echinococcus sp. were visible. Moreover, representative samples (n = 11) showed a positive reaction of these structures with Periodic acid-Schiff. Altogether, the findings were consistent with alveolar echinococcosis. Echinococcus multilocularis DNA could be demonstrated in selected samples (n = 7) by polymerase chain reaction. Epidemiological considerations suggest contamination of the forage with fox tapeworm eggs to be the most likely source of infection on two of the farms, as some of the fodder had been stored in the open, being amenable to infected definitive hosts. On the two other farms, mainly straw litter has to be taken into account regarding the transmission route, since carnivores excreting eggs of E. multilocularis could have gained access to the straw storage. The presented cases show that adequate mechanisms of meat inspection may provide important data for the purposes of surveillance and risk assessment of human alveolar echinococcosis.

Cryptosporidiosis: comparison of three diagnostic methods and effects of storage temperature on detectability of cryptosporidia in cattle faeces.

Three diagnostic methods (a modified Ziehl-Neelsen staining technique (MZN), a negative staining with carbol fuchsine (CF) and a commercial enzyme immunoassay (EIA) kit, ProSpecT® Cryptosporidium Microplate Assay (Remel, Lenexa, KS, USA)) for detection of Cryptosporidium oocysts in cattle faeces were compared regarding sensitivity and suitability under routine laboratory conditions, with particular emphasis on sample storage. In the 103 faecal samples examined, cryptosporidia infections were detected significantly more often by EIA (p<0.05; n=76) than by MZN (n=65) if ten random fields were evaluated microscopically, but not if the whole coverslip was scanned. In contrast, sensitivities of EIA and CF (n=69) did not differ significantly. Results were obtained very rapidly by CF. However, the hands-on time of CF is comparable to EIA, while MZN is more time consuming. EIA is more expensive than CF and MZN but easy to perform and to evaluate and does not need considerably experienced staff in contrast to CF and MZN. Moreover, 45 faecal samples stored for up to 27 days at different temperatures (+6°C, +16°C, +30°C, +40°C) were examined. The sensitivity of microscopic detection of oocysts in stained smears (CF, MZN) decreased in a temperature and time-dependent manner, while EIA results were not influenced by sample storage at any temperature.

Prevalence of Eimeria bovis and Eimeria zuernii in German cattle herds and factors influencing oocyst excretion.

The present study was designed to investigate the prevalence of the pathogenic coccidia species Eimeria bovis and Eimeria zuernii in shed-reared animals in German dairy and fattening facilities. Samples were obtained from 65 cattle farms distributed randomly across all the regions of Germany regardless of the occurrence of clinical problems. The samples were obtained rectally. Faecal consistency and the total number of oocysts per gram of faeces (OPG) were determined, along with the OPG values for E. bovis and E. zuernii. A questionnaire was completed for each farm to record information about herd size and management, along with individual animal data. Eimeria oocysts were detected in 62 of these farms, which give a prevalence of 95.4%. The farm prevalence of the pathogenic species was 76.9% for E. bovis and 83.1% for E. zuernii. The number of oocysts excreted could not be correlated significantly with farm type or farm management but depended on the floor type, the age of the calves and the time after rehousing. Furthermore, there was a positive correlation between OPG and the observation of diarrhoea. E. zuernii had a greater influence on the occurrence of diarrhoea than E. bovis. This study confirms that herd management frequently does not meet the requirements of effective coccidia control despite the fact that the pathogenic coccidia E. bovis and E. zuernii are ubiquitous in German cattle populations.

Prevalence of Eimeria bovis and Eimeria zuernii in German cattle herds and factors influencing oocyst excretion.

The present study was designed to investigate the prevalence of the pathogenic coccidia species E. bovis and E. zuernii in shed-reared animals in German dairy and fattening facilities.Samples were obtained from 65 cattle farms distributed randomly across all the regions of Germany, regardless of the occurrence of clinical problems. The samples were obtained rectally. Faecal consistency and the total number of oocysts per gram of faeces (OPG) were determined for Eimeria spp., along with the separate OPG values for Eimeria (E.) bovis and E. zuernii. A questionnaire was completed for each farm to record information about herd size and management together with individual animal data. Eimeria oocysts, regardless of the kind of Eimeria spp., were detected in 62 of these farms, which gives a prevalence of 95.4 %. The farm prevalence of the pathogenic species was 76.9 % for E. bovis and 83.1 % for E. zuernii. The average oocyst excretion level was 2,950 OPG in terms of total Eimeria spp. oocyst excretion, 700 OPG for E. bovis and 1,500 OPG for E. zuernii.The number of oocysts excreted could not be correlated significantly with farm type or farm management but depended on the floor type which influences the infection pressure, on the age of the calves and the time after rehousing. In general, higher oocyst excretion rates were found in calves kept on litter compared to rearing on slatted floor. Younger calves and calves sampled early after housing shed higher amounts of oocysts than older calves and calves stabled a longer period before sampling, respectively. Furthermore, there was a positive correlation between OPG and the observation of diarrhoea, defined as observation of a loose to liquid faecal consistency. Excretion of E. zuernii oocysts was more closely linked to the occurrence of diarrhoea than E. bovis oocyst excretion. This study confirms that the pathogenic coccidia E. bovis and E. zuernii are ubiquitous in German cattle populations and a significant cause of diarrhoeal disease in calf rearing.

[Comparison of different methods for examining the feces of suckling piglets for Isospora suis]. / Vergleich verschiedener Verfahren zur Untersuchung von Saugferkelkot auf Isospora suis.

A highly sensitive diagnostic method is of great importance for detection of I. suis (Isospora suis). In the present study KSFV (combined sedimentation-flotation method) using different flotation solutions (NaCl, ZnSO4, NaCl-sucrose) was investigated regarding sensitivity, costs and expenditure of human labour in comparison to FV (flotation method) using NaCl-sucrose solution and to AM (autofluorescence microscopy). Ninety faecal samples were examined. Using AM, oocysts were detected in 83.3% of the samples. In cases of KSFV and FV, respectively, 41.1% to 53.3% of samples were tested positive. The quantity of detected oocysts was markedly higher in AM than in KSFV or FV. Therefore AM is the most sensitive of the comprised methods. The expenditure of labour is lowest in AM, time exposure is lower in FV than in KSFV. For performance of AM a fluorescence microscope is required contrary to KSFV and FV.

[The helminth and coccidial fauna of pheasants (Phasianus colchicus) in view of the specific environmental conditions in pheasantries and in the wild]. / Zur Helminthen- und Kokzidienfauna des Jagdfasans (Phasianus colchicus) unter Berücksichtigung der spezifischen Umweltbedingungen in Fasanerien und in freier Wildbahn.

Between October 1999 and January 2000 all together 151 male pheasants were examined for endoparasites. 33 one-year-old birds came from two pheasantries, the remaining 118 birds, aged between one and five years, were wildlife animals. The infestation extensy of all pheasants with endoparasites were 96.7%. A mostly low infestation with coccidia of the three species Eimeria (E.) phasiani, E. duodenalis and E. tetartooimia were detected in 41% of all birds. E. tetartooimia was found in Germany for the first time. In 67.5% of the pheasants the five different species of capillaria (Capillaria (C.) annulata, C. bursata, C. contorta, C. perforans, C. phasianina) and in 84.1% the nematode Heterakis gallinarum were present. Pheasants in the capture group showed higher infestation intensy and extensy. In 51.5% of the pheasants of the capture group Syngamus trachea was present. In one pheasant an acanthocephalus (Plagiorhynchus cylindraceus) was detected for the first time in Germany and in two pheasants a trematode of the genus Echinostoma was present.