Anticoccidial Treatment Research Articles

On the efficacy of preventive toltrazuril treatments and the diagnosis of Cystoisospora suis infections in intensively raised piglets in farms from southeast Spain

This study investigated the presence and abundance of Cystoisospora suis oocysts in faecal samples from 131 one- to three-week-old pig litters belonging to eight intensively raised, indoor herds in Spain. Seven herds used preventive anticoccidial toltrazuril treatments administered orally or by intramuscular injection, and one did not use preventive anticoccidial treatments. The diagnosis was performed using two oocyst flotation-concentration methods, Bailenger’s method in every herd and the more recent Joachim’s method in four herds. Oocysts were detected in every farm, the proportion of oocyst-positive samples was higher with Bailenger’s technique, and the estimated overall prevalence (95% confidence interval) was 40 (32–49)%, including 47 (29–65)% in non-medicated litters, 52 (38–67)% in orally medicated litters and 28 (16–40)% in intramuscularly medicated litters (p < 0.05). However, mixed logistic regression models indicated that the risk of infection was not significantly associated with preventive anticoccidial treatments (p > 0.05), and increased with age, was higher in herds with partially compared to fully slatted dung floors in farrowing pens and in litters with pigs with diarrhoea (p < 0.05). The median (range) oocysts per gram of faeces (OpG) in infected litters by Bailenger’s method was 623 (35–49048) and mixed negative binomial models revealed no significant association between infection intensity in positive litters and pen’s floor type and piglets age, faecal consistency and treatment status (p > 0.05). The apparent low efficacy of Toltrazuril suggests treatment administration failures, reduced residual efficacy or low susceptibility of C. suis strains in study farms and needs further investigation.

A questionnaire-based survey in Spain provides relevant information to improve the control of ovine coccidiosis.

Ovine coccidiosis is a widespread intestinal parasitic disease caused by Eimeria spp. Lambs are infected by the ingestion of sporulated oocysts, experiencing diarrhea and low growth rates. Control should be based on measures to reduce infection pressure and stress on the animals as well as on appropriate diagnosis and strategic treatment. To obtain information on how control measures are implemented in the ovine sector in Spain, a questionnaire-based survey was completed in 2022 by 154 veterinarians and 173 farmers working in this sector. Coccidiosis was highlighted as a relevant disease by 34% of the respondents. The period of greatest risk seemed to differ between production systems, being mainly early after weaning (7-15 days after weaning) in meat flocks and feedlots and later (1-2 months after weaning) in dairy flocks. The absence of cleaning and disinfection measures was identified as a risk factor by 51% of the veterinarians, with 22% mentioning overcrowding of animals and 22% indicating that coccidiosis has more incidence in flocks with large number of animals. The use of laboratory diagnosis methods (fecal oocyst count) was unusual in 70 and 84% of the veterinarians and farmers, respectively. Regarding control, dairy flocks usually housed a larger number of animals under intensive conditions, and they implemented more frequently control measures for coccidiosis than meat flocks. Anticoccidial drugs were used in 79% of the flocks, and in 74-82% of them, they were applied based on clinical criteria. Comparing protocols for anticoccidial treatment among different production systems, in meat flocks, anticoccidial drugs were applied more frequently when clinical signs were observed, and coccidiostats were used for less than 28 days compared to dairy flocks. These results highlight the need for improvement in the use of anticoccidial treatments adjusted to the new regulatory framework in the EU, which in turn will rationalize the use of antimicrobial compounds and may help to mitigate the impact of coccidiosis in flocks.

Recombinant GMA56 and ROP17 of Eimeria magna conferred protection against infection by homologous species.

One of the most common rabbits coccidia species, Eimeria magna is mainly parasitic in the ileal and jejunal epithelial cells. E. magna infection can affect the growth performance of rabbits or cause other secondary diseases. Traditional methods of anticoccidial treatment typically result in drug resistance and drug residue. Therefore, vaccination is a promising alternative. Gametocyte antigen 56 (GAM56) and rhoptry kinase family proteins (ROPs) are involved in oocyst wall formation and parasite invasion, respectively. A virulence factor, ROP17 contains a serine/threonine kinase catalytic domain. In this study, recombinant E. magna GAM56 (rEmGAM56) and ROP17 (rEmROP17) proteins were obtained from a prokaryotic expression system and their reactogenicity was investigated with immunoblotting. To assess the potential of rEmGAM56 and rEmROP17 as coccidiosis vaccines, New Zealand White rabbits were subcutaneously immunized with 100 μg rEmGAM56 (rGC group) or rEmROP17 (rRC group) twice at 2-week intervals followed by homologous oocyst challenge. The rabbit serum was collected weekly to detect the specific antibody levels. The cytokine levels of pre-challenge serum were measured by enzyme-linked immunosorbent assay and the rabbits were observed and recorded post-challenge for the onset of clinical symptoms. The weight gain, oocyst output, and feed conversion ratio were calculated at the end of the experiment. The results showed that both rEmGAM56 and rEmROP17 had good reactogenicity. The rEmGAM56- or rEmROP17-immunized rabbits had milder clinical symptoms and feed conversion ratios of 3.27:1 and 3.37:1, respectively. The rEmGAM56-immunized rabbits had 81.35% body weight gain and 63.85% oocyst output reduction; the rEmROP17-immunized rabbits had 79.03% body weight gain and 80.10% oocyst output reduction. The ACI of rGC and rRC groups were 162.35 and 171.03, respectively. The specific antibody levels increased rapidly after immunization. Significantly increased interleukin (IL)-2, interferon (IFN)-γ, and IL-17 levels were evident in the rGC and rRC groups (p < 0.05). The rEmGAM56 and rEmROP17 elicited humoral and cellular responses, which protected against E. magna infection in rabbits. Thus, rEmGAM56 and rEmROP17 are potential vaccine candidates against E. magna, and rEmROP17 performed better than rEmGAM56.

Coccidiosis in Small Ruminant and Antiparasitic Activity of Essential Oils

Coccidiosis have been reported to cause severe economic losses in small ruminants livestock industry. Subclinical coccidiosis is common among small ruminants and clinical occurs mainly in young's animals. Coccidiosis is caused by highly host-specific Eimeria species. Strategies to control traditionally rely on the use of management practices combined with anticoccidial treatments. The development of alternative, safer, and ecofriendly anticoccidial agents have become priority in most parts of the world. Essential oils have been shown to exhibit antiparasitic activity and may control protozoal pathogens. The purpose of this review is to provide an overview of Eimeria species in sheep and goats and demonstrated life cycle, clinical signs, diagnosis, treatment and potency use of essential oils in the treatment of coccidiosis.

Coccidiosis in Bali Cattle from Extensive Farm Management

Bali cattle (Bos sondaicus) is an indigenous bovine domesticated in Indonesia and harboring prominent genetic traits for livestock production. Parasite infection, however, may act as a large constraint for the husbandry. Bovine coccidiosis is well-known as a major gastrointestinal protozoa which causes a significant loss due to intestinal damage and drug cost. Coccidia wall is derived from thick structures that lead to disinfection difficulties. Furthermore, the tropical climate largely supports its life cycle throughout the year. This study aims to determine the prevalence of coccidia in Bali cattle with an extensive rearing system at Balai Pembibitan Ternak Unggul dan Hijauan Pakan Ternak Denpasar, Indonesia. All of the samples were evaluated using native and flotation method that was followed by descriptive analysis. Deworming is reportedly a routine activity, but no report on anticoccidial treatment. Eimeria spp. were found in 24.19% fecal samples (15/62). The result indicated that coccidiosis is circulated and being observed less compared to worms in the investigated area.

Yucca schidigera Improves Performance and Lowers Oocyst Counts in Eimeria Challenged Broilers.

Simple SummaryCoccidiosis, caused by protozoa of the Eimeria species, is one of the most common causes of intestinal problems in poultry. In addition to economic losses and animal welfare being jeopardized, emerging resistance of the parasites against chemical and ionophore anticoccidial treatments is lurking. There is a demand for (natural) alternatives to the current treatments. In this trial, a Yucca schidigera product was tested for effectiveness in Eimeria-challenged chicken. Yucca schidigera is a plant which is native to the Mojave Desert, Chihuahuan Desert, and Sonoran Desert of southeastern California, Baja California, New Mexico, southern Nevada, and Arizona. Adding Yucca schidigera abolished the effect of the challenge, resulting in comparable or better performance results compared to the unchallenged birds. Therefore, Yucca schidigera can be considered as an effective alternative for anticoccidial treatment in broilers.Coccidiosis is one of the main challenges for the worldwide poultry industry, and several anticoccidial treatments have been used to fight these protozoa. Resistance of Eimeria parasites against anticoccidials—and the public opinion about these treatments—demands for alternatives. In this trial, we tested Yucca schidigera (500 g/T) as a natural alternative in broilers challenged with Eimeria. This treatment was compared to three other treatments: An unchallenged control, a challenged control, and a challenged anticoccidial (625 g/T) treatment with focus on performance, oocyst per gram counts (OPG), and lesion scores. Both the anticoccidial and the Yucca schidigera group showed significant improvement in body weight (2.150 and 2.058 vs. 1.998 and 1.971 kg). growth (60.2 and 57.6 vs. 55.8 and 55.1 g/d). and feed-conversion ratio (1.456 and 1.510 vs. 1.527 and 1.575), compared to both control groups. No significant differences were found between the treatments on OPG collection days 18 and 25. On day 35, lowest OPG counts were found in the unchallenged group (93), followed by the Yucca schidigera group (114), the anticoccidial group (243), and the challenged group (650). Adding Yucca schidigera abolished the effect of the challenge resulting in comparable (FCR) or better (ADG) performance results compared to the unchallenged birds. Yucca schidigera consistently showed lower numbers for OPG counts compared to the anticoccidial and challenged group. Therefore, Yucca schidigera can be considered as an effective alternative for anticoccidial treatment in broilers.

Immunoprotection against mixed Eimeria spp. infections in goat kids induced by X-irradiated oocysts

Strategies to control goat coccidiosis traditionally rely on the use of management practices combined with anticoccidial treatments, and limited effort has been made, so far, to address immunological control of caprine Eimeria infections. Previously, we showed that monospecific immunization with X-Rad-attenuated Eimeria ninakohlyakimovae oocysts induced considerable immunoprotection upon challenge. In the present study, we conducted a similar vaccination trial but using a mixture of caprine Eimeria species typically present in natural infected goats. For immunization, sporulated oocysts were attenuated by X irradiation (20 kilorad). All infections were performed orally applying 105 sporulated oocysts of mixed Eimeria spp. per animal. In total, 18 goat kids were grouped as follows: (G1) immunized + challenge infected; (G2) primary + challenge infected; (G3) challenge infection control; and (G4) non-immunized/non-infected control. Overall, goat kids infected with attenuated oocysts (= immunized) shed less oocysts in the faeces and showed a lower degree of clinical coccidiosis than animals infected with non-attenuated oocysts. Animals of both challenge groups (G1 and G2) showed partial immunoprotection upon reinfection when compared to challenge infection control (G3). However, the degree of immunoprotection was less pronounced than recently reported for monospecific vaccination against Eimeria ninakohlyakimovae, most probably due to the complexity of the pathogenesis and related immune responses against mixed Eimeria spp. infections. Nevertheless, the data of the present study demonstrate that immunization with attenuated Eimeria spp. oocysts may be worth pursuing as a strategy to control goat coccidiosis.

Diversity and prevalence of Eimeria species in goats of Nepal

This study aimed to determine the prevalence of Eimeria and identify its different species in adult goats brought to the Kathmandu valley, Nepal, for commercial meat purposes. Eimeria spp. were present in 916 samples out of 991 examined samples (92.4%). A total of 15 different morphologic forms of Eimeria were detected, with the prevalence rates as follows: E. ninakohlyakimovae (83.0%), E. alijevi (75.2%), E. capralis (75.2%), E. masseyensis (67.2%), E. hirci larger form (63.2%), E. tunisiensis (47.3%), E. charlestoni (33.0%), E. jolchejevi larger form (32.4%), E. arloingi (32.4%), E. caprina (19.3%), E. aspheronica (16.5%), E. jolchejevi smaller form (13.5%), E. christenseni (9.4%), E. hirci smaller form (9.4%), and E. caprovina (8.1%). The current data support the fact that Eimeria species are predominant in adult populations. Therefore, coprologic diagnosis and anticoccidial treatments should be implemented in these populations before their transport to new sites to avoid the transmission.

Combinatorial Effect of Dietary Oregano Extracts and 3,4,5-Trihydroxy Benzoic Acid on Growth Performance and Elimination of Coccidiosis in Broiler Chickens.

We aimed to compare the combinatorial effect of 3,4,5-trihydroxybenzoic acid (THB) and oregano extracts (OE) with THB alone on the growth performance and elimination of deleterious effects in coccidiosis-infected broilers. A total of 210 one-day-old broilers were randomly assigned to one of five dietary treatments, with six replicates each, for 35 days. Dietary treatments were: 1) non-challenged, non-treated (NC); 2) challenged, non-treated (PC); 3) PC+ Salinomycin (0.05 g/kg; AB); 4) PC+THB (0.1 g/kg; THB); and 5) PC+THB+OE (0.1 g/kg; COM). On day 14, all groups except for NC were challenged with a 10-fold dose of Livacox® T anticoccidial vaccine to induce mild coccidiosis. All treatments significantly improved (P<0.05) body weight, average daily gain, and average daily feed intake, compared to PC, on days 21, 28, and 35. However, all treatments significantly reduced (P<0.05) the feed conversion ratio of PC by more than 14.60% on day 35, 11.76% during growing period, and 10.36% through the entire period. Broilers receiving anticoccidial treatments had 54.23% and 51.86% lower lesion scores (P<0.05) at 4 and 7 days post-infection, respectively, compared to PC. Additionally, the villus height of COM was significantly longer (P < 0.05) than that of THB. Although the molecular action of COM remains unclear, OE addition to THB reduced the shedding of oocysts better than THB alone (P<0.05, 9-11 days post-infection). Most importantly, COM effectively minimized the mortality of challenged birds from as high as 11.90% (PC) to 0%, a level similar to NC and AB, while THB maintained a mortality of 2.38%. In conclusion, the anticoccidial effect of THB can be enhanced by the addition of OE for better animal performance and the elimination of deleterious effects from coccidiosis-infected broilers for 35 days.

Avain Coccidial Review

Dep. Pathology and Poultry Diseases /coll. Vet.Med./ AL-Qadissiyah University Summary Coccdiosis consider sever disorder and necessary from an financial factor of view in poultry industry which has been controlled efficaciously for decades using more often than not anticoccidial products so the understood this disorder may additionally be help to control it. The economic impact of coccidiosis is probably underestimated, and increasing anticoccidial treatments might be useful to the broiler sector. Furthermore, a connection between subclinical coccidiosis and bacterial enteritis renders selecting the perfect tools and technique for poultry producers very difficult. Implementing sound shuttle and rotation programs is now a part of the solution for not just controlling clinical, but also subclinical coccidiosis.

Piglet coccidiosis in Belgium and the Netherlands: Prevalence, management and potential risk factors.

Piglet coccidiosis caused by Cystoisospora suis is one of the most important causes of diarrhea in suckling piglets. The parasite has a fast development and multiplies quickly and effectively under the conditions of a farrowing unit. Control measures include cleaning and disinfection and anticoccidial treatment. In Europe, toltrazuril-based products are authorized for this purpose and are applied to piglets on affected farms in the first week of life. To observe the effect of treatment and disinfection on the control of piglet coccidiosis in the field, 23 farms (11 from Belgium, 12 from the Netherlands, mean number of sows=1413) were sampled twice by litter in the second and third week of life and fecal scores and the presence of C. suis oocysts were determined. A questionnaire was used to collect data on farm sizes, management and hygiene measures as well as treatment (product, dose and piglet age). Thirteen farms regularly treated with toltrazuril (treatment age: 1-6days, mean 4.3days) and 19 applied disinfection. Parasite excretion was documented on 60.9% and diarrhea on 78.3% of farms and in 34.3%/15.7% of the litters. Only 2.4% of the litters showed both, so subclinical infection appeared to be common. No significant differences between farms that did not treat against coccidiosis and farms that applied toltrazuril was observed with regard to C. suis oocysts shedding and/or diarrhea. However, in litters that were treated within the first three days of life, oocyst excretion was significantly less often observed than in litters with later treatment (p = 0.033). No significant effect of disinfection could be shown, but most farms applied disinfectants that have no proven effect against coccidia (oxygen-releasing agents or glutaraldehyde + ammonia) while the only farm that used chlorocresols (which are effective against coccidia) did not show oocyst shedding. Current control measures thus appear to be insufficient on most of the examined farms. It is therefore recommended to treat piglets timely and to apply effective disinfectants to reduce C. suis infections. Furthermore, regular evaluation of sustained efficacy of all implemented measures are necessary.

Comparative evaluation of single or combined anticoccidials on performance, antioxidant status, immune response, and intestinal architecture of broiler chickens challenged with mixed Eimeria species

Poultry production faces several threats and challenges, one of the most important of which is avian coccidiosis which causes annual losses exceeding US$ 3 billion. Discovering new drugs or combinations of existing anticoccidials has become inevitable to overcome the emergence of coccidiosis resistance. This study evaluated a new combination of maduramicin and diclazuril in comparison to the well-known product Maxiban72 which consisted of narasin and nicarbazin, and the single effect of monensin as treatments for avian coccidiosis. A total of 750 1-day-old Indian River broiler chicks were allocated equally into 5 experimental groups with 6 replicates each as follows: 1) negative unchallenged control group (NC) fed the basal diet; 2) positive control group (PC) received the basal diet and inoculated with Eimeria; 3) PC + 100 mg monensin sodium (Atomonsin)/kg diet (MS); 4) PC + 5 mg maduramicin ammonium (Madramycin) + 2.5 mg diclazuril (Atozuril)/kg diet (MMD); and 5) PC + 40 mg narasin + 40 mg nicarbazin (MaxibanT72)/kg diet (NN). Anticoccidials improved (P < 0.01) growth performance, dressing (%) and carcass yield of inoculated birds compared to untreated-inoculated ones. Erythrogram and leukogram parameters were affected by Eimeria challenge. Total protein, globulin, cholesterol, triglycerides, superoxide dismutase and glutathione peroxidase levels in PC birds' serum were reduced (P < 0.05) while their values of liver enzymes, malondialdehyde and catalase were elevated (P < 0.01) when compared to NC ones. Serum immunoglobulin A, and jejunal gene expressions of interleukin-6 and interferon gamma were increased (P < 0.05) in PC group compared to NC group. Anticoccidial drugs restored values of the aforementioned biomarkers near to those of NC. Jejunal architecture in inoculated birds was improved by the anticoccidial treatments in MS, MMD, and NN. Fecal oocyst counts were significantly reduced in MMD, NN, and MS groups compared to PC group. Conclusively, although all examined anticoccidial drugs were effective in treating Eimeriosis, the anticoccidial combinations in MMD and NN groups were more effective than the single administration of MS in treating avian coccidiosis.

Patterns of Eimeria excretion in young Icelandic calves

Faecal samples were collected from a total of 11 calves on three dairy farms (four from two farms and three from one) where calves generally thrive well and no anti-coccidial treatment is habitually carried out. One of the farms keeps calves in groups on hay/straw bedding, one keeps calves in pairs on plastic slats and then in groups on concrete slats, and the third one keeps calves in groups on concrete slats. Faecal consistency and the total number of Eimeria spp. oocysts per gram faeces (OPG) were determined and species identification was carried out by morphology. Eimeria oocysts were detected in all calves at some point of the study period, and diarrhoea was seen in 55% of the calves. The highest peak in oocyst excretion was 69,300 OPG. The first peak in oocyst excretion was seen 2-3 weeks after calves had been moved to group pens, and a second peak was seen 2-3 weeks later. Nine Eimeria species were found, including E. bovis and E. zuernii. The results are in accordance with previous studies showing that one of the risk factors for Eimeria infection in calves is entering a group pen where older calves are already being kept.

Small-scale farmers' perception and practice on coccidiosis management in broiler farm at Gazipur, Bangladesh.

Farmers' knowledge and farm management practices can potentially help to mitigate the prevalence and severity of chicken coccidiosis, a devastating protozoan disease. Here, we assessed the farmers' perception and on-farm practices of coccidiosis management in small-scale broiler farms at Gazipur district, Bangladesh. A semi-structured questionnaire was used to obtain data from the randomly selected 119 small-scale broiler producers followed by detection of coccidiosis cases through gross and microscopic examination of 58 broilers. Overall bird-level prevalence of coccidiosis was 34.48% in this study. Survey data revealed that most of the farmers maintained all-in-all-out strategy (68.91%), good quality chicks (73.11%) and floor system rearing (96.63%) in their farms, and a mixture of old and new litter was used as bedding in all the study farms. Interval between flocks in 57.99% of farms was 8 to 14 days. Prevalence of coccidiosis was recorded in all surveyed farms, even though routine anticoccidial treatment. At the age of 15 to 18 days of broiler, 68.07% of farmers used chemoprophylaxis. Usage of amprolium was the highest (74.78%) followed by toltrazuril (55.46%), sulphaquinoxaline (23.52%), sulphaclozine (28.57%), sulphadimidine (24.36%) and sulphadimethoxine (24.36%). Traditional herbal medicines like extracts of bollygum (Litsea glutinosa), sal (Shorea robusta) and arjuna (Terminalia arjuna) bark and leaves were also in-use by 4.20% farmers during coccidiosis outbreak. In conclusions, this study explored the field scenario of coccidiosis, relevant farmers' knowledge and practices, and recommends the judicious use of drugs for safe broiler production.

Population pharmacokinetics of ethanamizuril in normal and coccidiosis-infected chickens through ultra-performance liquid chromatography-Tandem Mass Spectrometry.

Ethanamizuril is a new triazine compound that shows potential for application in novel anticoccidial treatment. In this study, a pharmacokinetic model of ethanamizuril was established on the basis of the blood concentration of 81 experimental animals. The final model showed that ethanamizuril was distributed as a two-compartment model with first-order absorption after oral administration in chickens. Its clearance rate and volumn of centralcompartment distribution (Vc ) were affected by age and body weight, and volumn of centralcompartment distribution (Vc ) and volume of peripheralcompartment distribution(Vp ) were influenced by weight and infection. External verification revealed that the model had good prediction accuracy and stability.

Efficacy of an Oral Solution Prepared from the Ultrasonic Extract of Radix dichroae roots against Eimeria tenella in Broiler Chickens.

This study was conducted to determine the optimal dose of the oral solution of the ultrasonic extract of Radix dichroae (UERD) and to provide experimental support for a safe clinical dose for anticoccidial treatment of broiler chickens. Radix dichroae root extracts were prepared using the ultrasonic extraction method. The anticoccidial activity of the oral solution prepared from the ultrasonic extract of Radix dichroae roots was tested in broiler chickens following oral infection with a field isolate of E. tenella. Ninety Lingnan yellow broiler chickens (14 days old) were randomly divided into nine groups (n = 10), including six UERD oral solution treatments (0.25, 0.50, 1.50, 2.50, 3.50, and 5.00%), a toltrazuril group (0.10%), an E. tenella-infected control group, and a healthy control group. All groups were inoculated orally with 7 × 104 sporulated E. tenella oocysts (Guangdong strain) except for the healthy control group. The chickens in the seven drug-treated groups were administered a UERD oral solution or toltrazuril in drinking water for 7 days. The anticoccidial efficacy of the UERD oral solution was evaluated by the bloody diarrhoea severity level, relative body weight gain (rBWG), lesion score, oocyst per gram (OPG), and anticoccidial index (ACI). Compared with the infected control group, there were no significant differences in the groups treated with UERD oral solution or toltrazuril with regard to the lesion changes in the caecal regions (P > 0.05); however, the blood contents, OPG, and oocyst score in three UERD oral solution treatment groups (0.50, 1.50, and 2.50%) were significantly reduced, and the bloody diarrhoea was also alleviated. The ACI in three UERD oral solution treatment groups (0.50%, ACI = 143.7; 1.50%, ACI = 151.0; and 2.50%, ACI = 144.3) was higher than that in the toltrazuril group (ACI = 127.0), and the rBWG in the 1.50% UERD oral solution treatment group (95.0%) was similar to that in the healthy control group (100%), which was also 12.5% higher than that in the toltrazuril group (82.5%). The findings of this study demonstrated that the UERD oral solution (0.50% ～ 2.50% dose range) showed better prevention, anticoccidial efficacy, and growth promotion effects than toltrazuril (0.10%), and the 1.50% dose level of UERD oral solution in water is the clinically recommended dose according to the present study conditions.

Efficacy of an injectable toltrazuril – gleptoferron (Forceris®) to control coccidiosis (Cystoisospora suis) in comparison with iron supplemented piglets without anticoccidial treatment

The efficacy and safety of an injectable combination product containing toltrazuril and gleptoferron (Forceris® – CEVA) for the control of coccidiosis due to Cystoisospora suis was investigated in neonatal piglets. The study was carried out on five European commercial pig farms in France, Germany and Spain and 122 litters consisting of 1508 piglets were selected and randomly allocated to one of two treatment groups. The first group received a single intramuscular injection per piglet of the test product, containing 45 mg toltrazuril and 200 mg iron and this was compared with a control group, which was administered a single intramuscular treatment of iron at 200 mg per piglet only. Body weights, faecal scores and oocysts counts, recorded as oocysts per gram of faeces, (OPG) were observed for 21 days. Only 1138 piglets were actually exposed to coccidiosis and data sets of these animals were selected for statistical analysis. The efficacy of the test product in the control of coccidiosis was shown in higher body weight gains, a lower percentage of animals with diarrhoea, fewer samples with positive oocysts counts as well as a lower excretion peak and a reduced area under the curve of OPG from study day (SD) 4 – SD 21. The combination product of toltrazuril and gleptoferron provided an effective alternative approach to current conventional separate treatment for the prevention of iron deficiency anaemia and coccidiosis in neonatal piglets. It reduced the numbers of potentially stressful interventions and work time.

Anticoccidial efficacy of Canary rue (Ruta pinnata) extracts against the caprine apicomplexan Eimeria ninakohlyakimovae.

Continuous use of anticoccidial treatments against Eimeria infections has resulted in the development of drug resistance. This study aimed to evaluate the anticoccidial efficacy of a methanolic extract derived from the endemic Canary rue (Ruta pinnata) plant of the Canary Islands, Spain, against Eimeria ninakohlyakimovae using in vitro assays. Freshly unsporulated oocysts were exposed to different concentrations of R. pinnata extract and thereafter evaluated for sporulation inhibition. Additionally, anticoccidial activity was examined by testing the viability of the E. ninakohlyakimovae sporozoites and their ability to infect bovine colonic epithelial cells after incubation with different concentrations of R. pinnata plant extract. The inhibition of oocyst sporulation by the extract was both time and concentration dependent, with certain combinations affording the same levels of sporulation inhibition as formaldehyde used as positive control (P < 0.001). Moreover, concentrations >0.1 mg/mL also affected not only the viability of the sporozoites but also their cell invasion capacity (P < 0.001). Altogether, these results show that methanolic fruit extracts from R. pinnata have important anticoccidial activity against oocysts and sporozoites of Eimeria. The potential efficacy of the extracts against other animal/human parasites remains to be elucidated, and further studies are needed to better understand its mode of action against coccidian parasites.

Controlled efficacy trial confirming toltrazuril resistance in a field isolate of ovine Eimeria spp.

BackgroundCoccidiosis due to Eimeria spp. infections in lambs causes increased mortality and substantial production losses, and anticoccidials are important for control of the infection. Anticoccidial resistance has been reported in poultry and swine, and we recently described reduced toltrazuril efficacy in ovine Eimeria spp. in some Norwegian sheep farms using a newly developed faecal oocyst count reduction test (FOCRT). The aim of the present study was to use a controlled efficacy trial to assess the efficacy of toltrazuril against a field isolate suspected of being resistant.MethodsTwenty lambs, 17–22 days old and raised protected against exposure to coccidia, were infected with a field isolate of 100,000 Eimeria spp. oocysts. This isolate was obtained from a farm with a previously calculated drug efficacy of 56% (95% confidence interval: -433.9 to 96.6%). At day 7 post-infection, 10 of the lambs were orally treated with 20 mg/kg toltrazuril (Baycox Sheep vet., Bayer Animal Health), while the other 10 lambs (controls) were given physiological saline. Clinical examinations were conducted, and weight gains recorded. Daily faecal samples were scored for diarrhoea on a scale from 1 to 5, and oocyst excretion was determined using a modified McMaster technique. Oocysts were morphologically identified to species level. At 17–24 days post-infection, the lambs were euthanized and necropsied.ResultsThe tested Eimeria isolate was resistant against toltrazuril, and resistance was seen in both pathogenic and non-pathogenic species. In addition, no significant differences in faecal score, growth, gross pathology or histological changes were identified between the two groups. The pathogenic E. ovinoidalis was the dominant species, and no significant difference in the individual prevalence of E. ovinoidalis post-treatment was found between treated (66.9%) and control lambs (61.9%). Other species identified included E. crandallis/weybridgensis, E. parva, E. marsica, E. faurei, E. pallida, E. ahsata and E. bakuensis.ConclusionsThis study confirms toltrazuril resistance in ovine Eimeria spp.; in addition, the data support the use of FOCRT as an appropriate tool for field evaluation of anticoccidial efficacy. Due to limited anticoccidial treatment alternatives, these findings may have important implications for the sheep industry, particularly in northern Europe.

Responses to dietary levels of methionine in broilers medicated or vaccinated against coccidia under Eimeria tenella-challenged condition

BackgroundCoccidiosis is a prevalent problem in chicken production. Dietary addition of coccidiostats and vaccination are two approaches used to suppress coccidia in the practical production. Methionine (Met) is usually the first limiting amino acid that plays important roles in protein metabolism and immune functions in chickens. The present study is aimed to investigate whether increasing dietary Met levels will improve the anticoccidial effects in broilers medicated or vaccinated against coccidia under Eimeria (E.) tenella-challenged condition. Two thousand male Partridge Shank broiler chicks were obtained from a hatchery. After hatch, birds were weighed, color-marked and allocated equally into two anticoccidial treatments, namely medicated and vaccinated groups. Chicks were either fed, from 1 d of age, diets containing coccidiostat (narasin) or diets without the coccidiostat but were inoculated with an anticoccidial vaccine at 3 d of age. At 22 d of age, 1080 chicks among them were randomly allocated evenly into 6 groups under a 2 × 3 treatment with 2 anticoccidial programs and 3 dietary methionine (Met) levels. Chicks medicated or vaccinated against coccidia were fed diets containing 0.45%, 0.56% or 0.68% of Met from 22 to 42 d of age. All chicks were orally introduced with an amount of 5 × 104 sporulated oocysts of E. tenella at 24 d of age. The growth performance, serum anti-oxidative indexes, intestinal morphology, cecal lesion scores, fecal oocyst counts and immune parameters were measured.ResultsThe results showed increasing dietary Met level from 0.45% to 0.56% and 0.68% improved weight gain and feed conversion of broilers medicated against coccidia. In contrast, higher dietary levels of Met did not improve growth performance of the vaccinated chickens. Higher Met levels helped the medicated chickens resist E. tenella infection, as indicated by improved intestinal morphology and immune functions as well as decreased cecal lesion and fecal oocyst counts.ConclusionsAnticoccidial vaccination is a better strategy for controlling coccidiosis than feeding narasin, due to not only greater growth performance, but also the lower Met supplementation. Furthermore, higher dietary Met levels improved growth performance of chickens medicated rather than vaccinated against coccidia under E. tenella-challenged condition.