Efficacy of various anticoccidials against experimental porcine neonatal isosporosis

The efficacies of 20 mg/kg body weight (BW) of toltrazuril (Toltra) 2 days post-infection (dpi), 2 mg/kg BW of diclazuril 2 and 3 dpi and 200 mg/kg BW of sulphadimidine 2, 3 and 4 dpi were compared in a model for piglet isosporosis. Weight gain (first 4 weeks of life) and diarrhoea and oocyst excretion from 4 to 11 dpi were evaluated (10–12 piglets/group). Additionally, animals were killed and examined for pathohistological changes of the small intestines 5, 7, 11 and 14 dpi (n = 3 per group and time point) and lengths of the intestinal villi. Diarrhoea (semi-liquid or liquid faeces) was seen from 5 dpi in all groups except Toltra, and the differences in prevalence and intensity of diarrhoea were statistically significant (p < 0.05) between Toltra and the other groups, which were similar (trial 1). Oocyst excretion was greatly reduced in the Toltra group, which was also statistically significant for the mean and median excretion rates and the percentage of excreting piglets between Toltra and the other groups (p < 0.05). Weight gain was highest in Toltra (p < 0.05). Histopathology revealed mostly villous necrosis and atrophy in the small intestines except the duodenum, which peaked at 7 dpi, in all groups except Toltra. Between 5 and 11 dpi, the Toltra group had significantly longer villi than the other groups. Reduced weight gain and diarrhoea caused by Isospora suis was controlled by a single application of Toltra in the pre-patent period, while neither diclazuril nor sulphadimidine improved the clinical picture of isosporosis.     

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.     

Diagnosis of imported canine filarial infections in Germany 2008 - 2010

Filarial infections of dogs are attracting attention across Europe because of the risk of spread into previously non-endemic areas (e.g. Dirofilaria repens with Culicidae as vectors) and as emerging zoonotic agents. The occurrence of filarial infections in German dogs has been analysed based on 8,545 samples collected either from imported animals or following travel into endemic regions. All samples were tested by means of modified Knott's test and heartworm antigen assay within the period 2008 - 2010. Heartworm antigen was detected in 127 samples (1.49 %; 95 % CI: 1.25 - 1.77 %), but only 38 dogs also had microfilariae in their blood samples. On the other hand, 125 animals (1.46 %; 95 % CI: 1.23 - 1.74 %) were only positive in the Knott's test. For discrimination by means of PCR and sequencing a total of 73 blood samples as well as two samples of adult worms were included, which have been sent by veterinarians during 2008 - 2010. A mono-infection caused by D. repens was detected in 35 cases, while D. immitis was proven in 15 samples, with 6 of these showing a combination of D. immitis and D. repens. Imported Dipetalonema dracunculoides (transmitted by Rhipicephalus sanguineus or Hippobosca longipennis) or Acanthocheilonema reconditum (fleas and lice serve as intermediate hosts) infections were diagnosed in 24 cases and in a single sample a co-infection of A. reconditum and D. repens was evident. D. repens was the most common filarial infection imported and it was introduced into Germany from eleven European countries. Slovenia and Hungary are reported for the first time as endemic for D. repens and A. reconditum, respectively. Furthermore this study reports, to the best of our knowledge, for the first time import of D. dracunculoides from the Canary Islands, A. reconditum from Majorca, D. immitis from Corfu and a co-infection of D. repens and A. reconditum from Spain as well as mixed infections of D. repens and D. immitis from Corfu, Sardinia and Bulgaria. Co-infections with other arthropod-borne infections as well as therapeutical follow-up were also considered. Selamectin (as spot-on formulation) was not able to clear microfilaraemia in dogs infected with either D. repens, A. reconditum or D. dracunculoides, whereas a topical moxidectin/imidacloprid formulation was able to eliminate microfilariae in one dog infected with A. reconditum.     

Cross-reactivity of anti-Eimeria tenella antibody fragments on merozoites and sporozoites of different chicken Eimeria species

Eimeria tenella-specific antibodies were examined for the cross-reactivity on the sporozoites and merozoites of E. tenella, Eimeria maxima, Eimeria acervulina and Eimeria brunetti in an indirect fluorescence antibody test. Two of nine antibodies showed cross-reactivity with sporozoites of E. maxima, E. acervulina and E. brunetti; however, the localization of specific fluorescence differed between species. No antibody binding was observed on merozoites. The suitability of these antibodies to alter the infectivity of Eimeria sporozoites and/or merozoites must be verified in cell culture models and in vivo experimental infections.     

Prostanoids during acute sarcocystiosis in growing pigs

The stable metabolites of thromboxane A₂, prostaglandin E₂, and prostaglandin F₂ (TxB₂, PgEM, and PgFM, respectively) were measured in the blood plasma of nine castrated male pigs, each inoculated with 2×10⁵ sporocysts ofSarcocystis miescheriana (group A), and in that of nine non-infected controls (group B). all infected pigs developed mild disease, the clinical signs being most severe between days 14 and 17 post infection (p.i.). In the infected pigs of group A, the TxB₂ plasma levels increased with the onset of the acute phase of illness (12 day p.i), reaching peak values at day 14 p.i. The mean TxB₂ values were significantly higher in the infected pigs from day 12 p.i. until the termination of the experiment on day 21 p.i. The PgEM values increased steadily in the infected pigs from day 12 p.i. until day 21 p.i. but remained relatively constant in the control pigs during the same period. In contrast, PgFM values remained low in the infected pigs throughout the experiment, and no significant differences between infected and non-infected pigs could be found. We conclude that the elevated TxB₂ and PgEM values reflect a major involvement of prostanoids in the pathogenesis of sarcocystiosis.Supported by the German Research Council (DFG)     

Control of clinical coccidiosis of calves due to Eimeria bovis and Eimeria zuernii with toltrazuril under field conditions

The efficacy of metaphylactic treatment with toltrazuril (Baycox 5% suspension) against natural infections with Eimeria bovis and/or Eimeria zuernii in calves was investigated. The study was conducted with 208 calves on five calf-rearing farms in Germany and the Czech Republic. All participating farms had a notable incidence of coccidiosis. Animals were treated 14 days after stabling in the respective facility. One group was treated with 15 mg toltrazuril/kg body weight, and a second group served as the sham-treated control. Assessment of efficacy was based on faecal consistency and oocyst excretion of E. bovis and E. zuernii, both investigated throughout the study. Duration and rate of oocyst excretion as well as number of scour days with E. bovis or E. zuernii oocyst shedding and the severity of diarrhoea were significantly lower in the toltrazuril-treated groups. It is concluded that a single metaphylactic treatment with toltrazuril controls coccidiosis of housed calves under various field conditions.     

Control of piglet coccidiosis by chemical disinfection with a cresol-based product (Neopredisan 135-1®)

Isospora suis is a common pathogen in piggeries and one of the main causative agents of scours in suckling piglets. Besides specific treatment, optimised hygiene including chemical disinfection is considered essential in the control of isosporosis. The suitability of the cresol-based product Neopredisan 135-1(R) (NP) to inactivate oocysts in vitro and to reduce infection pressure in commercial piggeries was evaluated. Under in vitro conditions, NP at a final concentration of 2 or 4% induced lysis of more than 95% of sporulated oocysts at a contact time of 30 min and destroyed all oocysts after a contact time of 90 min or more. A total of six trials (T1-T6) were performed on two farms (I and II). T5 was split into two parts, T5/1 and T5/2. Two groups of litters kept in farrowing crates either disinfected conventionally before farrowing (controls, group C) or disinfected with 4% dilution of NP before farrowing and with 2% NP one to three times thereafter (group NP) were compared in each trial. Altogether, 81 litters were randomly allocated to group NP and 77 litters to group C (comprising a total of 1,465 piglets). Piglet faeces were collected individually 5 days after birth and six times thereafter in intervals of 2 or 3 days from four piglets per litter and microscopically examined for oocysts of I. suis. Diarrhoea scores, other clinical data (skin turgidity, coat length etc.), weights and loss of piglets until weaning were recorded. One trial (T3) could not be analysed because of insufficient cleaning before disinfection. In group C, litter prevalence of I. suis ranged between 40 and 80%. The proportion of positive litters was considerably reduced by approximately 50% in disinfected crates except for one trial, and the number of affected piglets decreased by up to 80%. Diarrhoea and oocyst excretion were significantly associated. Diarrhoea was less frequently observed in disinfected crates. In general, isosporosis appeared mild to subclinical, and no significant effects of disinfection on other clinical data, weight gain and number of weaned piglets were noted. It is concluded that NP efficiently inactivates oocysts of I. suis, and that additional disinfection after farrowing is suited to reduce infection pressure. No clear relation of infection prevalence to the frequency of intermediate disinfection (one, two or three times) was seen, and thus, single intermediate disinfection 1 week after farrowing is considered sufficient.     

Efficacy of imidacloprid 10%/moxidectin 1% (Advocate®/Advantage Multi™) against fleas (Ctenocephalides felis felis) on ferrets (Mustela putorius furo)

Ferrets (Mustela putorius furo) are becoming increasingly popular as pets and are kept in households with other pet animals such as dogs and cats, from which they may catch flea infestations with the predominant flea species Ctenocephalides felis. In this study, the efficacy of imidacloprid/moxidectin spot-on (Advocate/Advantage Multi) was investigated in the therapy and prevention of flea infestation in ferrets. Sixteen adult ferrets of varying weights and ages and of both sexes were included. Ferrets were infested with 50 fleas each on days -7, -1, 7, 14, 21, and 28. On study day -6, the animals were randomized into two groups based on body weight and flea count. Each ferret allocated to group 1 was treated with 0.4 ml of imidacloprid 10%/moxidectin 1% (Advocate/Advantage Multi). The ferrets in group 2 remained untreated. Flea counts were performed by combing 24 to 48 h after infestation. The primary efficacy criterion was the reduction in the number of fleas at each time point post treatment compared to the ferrets in the untreated control group. On day 1, the therapeutic efficacy was 100%. The preventative efficacy was 100% at 1 and 2 weeks post treatment, and it was >97% and >90% at 3 and 4 weeks post treatment. No local or systemic side effects were observed in any of the ferrets treated.     

Case report of systemic coccidiosis in a radiated tortoise (Geochelone radiata)

More than 30 species of coccidian parasites have been described in Chelonidae (tortoises and turtles). Eimeria spp. are apparently the most common coccidia in chelonians. Findings of Caryospora cheloniae, Isospora sp., and Mantonella sp. have also been published, but reports about systemic coccidiosis are rare. We describe a case of a coccidiosis diagnosed cytologically in a radiated tortoise (Geochelone radiata) which was captive-bred in Germany. Infection was systemic and involved the lymphoid system. Intracytoplasmatic stages of parasite development were identified cytologically, histologically, and ultrastructurally. The systemic coccidiosis was associated with variable degrees of inflammation in the different organs and contributed substantially to the cause of death in this tortoise. Fragments of coccidian 18S- and 28S-rRNA from the tortoise liver were sequenced; the 18S-rRNA sequence had the highest identity to intranuclear coccidia described previously in a travancore tortoise (Intestudo forstenii) and a leopard tortoise (Geochelone pardalis). The analysis of maximum likelihood phylogenetic tree showed relation to species of the order Sarcocystidae. The biology of these coccidia and the route of infection in this case remained unclear.