In vitro and in vivo effect of Citrus limon essential oil against sarcoptic mange in rabbits.

The effect of lemon oil (Citrus limon) on Sarcoptes scabiei var. cuniculi was evaluated in vitro and in vivo. The mite samples were collected from naturally infected rabbits. The lemon oil was prepared in six concentrations by dilution with distilled water (2.5, 5, 10, 20, 50, and 100 %). In vitro application was done in five replicates for each concentration in petri dishes in the laboratory. The treated mites were observed at 1, 12, and 24 h post application (PA) for lemon oil effect. In addition, oxidative stress profile was evaluated for the treated mite. Dependent on in vitro results, 20 % lemon oil was used in vivo trial. Twenty-four naturally infected rabbits were divided into three groups of eight: 20 % lemon oil, deltamethrin, and untreated control. The infected parts of rabbits were treated topically once a week for four successive weeks. In vitro application results showed that lemon oil 10 and 20 % diluted in water caused mortality to 100 % of mites after 24 h PA. The oxidative stress profile revealed that mites treated with 20 % lemon oil had significantly (P < 0.05) higher hydrogen peroxide and malondialdehyde when compared with mites treated with deltamethrin or distilled water. In vivo application of 20 % lemon oil on naturally infected rabbits showed complete recovery from clinical signs, absence of mite in microscopic examination from the second week of treatment. In addition, productive performance was significantly better than infected untreated group. Also, the treated tissue showed stoppage of scale formation and hair growth faster than deltamethrin-treated rabbits. Consequently, lemon oil has remarkable miticidal activity in vitro and in vivo applications.

Prebiotic supplementation effect on Escherichia coli and Salmonella species associated with experimentally induced intestinal coccidiosis in rabbits.

BACKGROUND: Coccidian infection may enhance the proliferation of gut Enterobacteriaceae. Bacterial infections in rabbits can negatively affect the body condition and cause high mortality, especially at young ages. Therefore, the effect of prebiotic supplementation on the presence of Escherichia coli and Salmonella species in rabbits experimentally infected with intestinal coccidiosis was investigated. METHODS: Thirty male rabbits aged 35-40 days were divided into three equal groups. These groups were; prebiotic supplemented (PS), positive control (PC), and negative control (NC) groups. The prebiotic group was supplemented with 2 g/L of Bio-Mos® until the end of the experiment. At day ten post prebiotic supplementation; the PS and PC groups were inoculated orally with 5.0 × 104 sporulated oocysts of mixed species of rabbit Eimeria. The daily fecal examination was carried out from the day 4 post-infection (PI) until the day 8 PI. At day 5 and day 8 PI, 5 rabbits from each group (PS, PC, and NC) were humanely slaughtered and parts of intestinal tissue were collected for microbiological analysis. RESULTS: There was a significant decrease (P≤ 0.05) in the oocyst count in the PS group (25.12 × 104 ± 10.36) when compared with the PC group (43.43 × 104 ± 11.52) and this decrease was continued till the end of the experiment. Eleven E. coli isolates were detected in the collected samples with an overall prevalence of 24.4%. The highest prevalence of E. coli was in the PC group (13.33%) while the lowest one was in the PS group (4.44%). Meanwhile, four Salmonella serovars were isolated with an overall prevalence of 8.89%. The NC group showed one serovar (2.22%) and PC revealed three serovars (6.67%) while the prebiotic supplemented group didn't show any salmonella isolate. Of E. coli isolates, five isolates (O78, O125, O152, O115 and O168) showed high resistance to florfenicol and neomycin (100%). Also, of salmonella serovars, thee serovars (Salmonella entrica subsp. enterica serovar Macclesfield, Salmonella entrica Subsp. enterica serovar Canada and Salmonella entrica Subsp. enterica serovar Kisangani) showed high resistance to sulphamazole, amoxicillin and flumequin (75%) while it was sensitive to levofloxacin and ciprofloxacine (75%). The bacterial colony in this study was the same results at days 5 and 8 PI. CONCLUSION: The use of prebiotic as prophylaxis in this experiment significantly reduced the prevalence of E. coli and salmonella associated with the intestinal coccidiosis in rabbits.

Investigation of Pre- and Post-Weaning Mortalities in Rabbits Bred in Egypt, with Reference to Parasitic and Bacterial Causes.

This study was conducted to investigate the causes of mortality in young rabbits. A total of 110 V-Line breed female rabbits aged 5 m were used in this study. Rabbit kits were examined daily in pre- and postweaning stages to detect clinical disorders that caused death. The postmortem examination was carried out on dead kits. Furthermore, rabbits were examined for the probable bacteriological and parasitological causes of death. Fecal samples were collected from each dead kit and examined by standard microbiological procedures for bacterial pathogens and macroscopically and microscopically for the presence of endo- and ectoparasites. Throughout two breeding seasons, 2238 newborns were obtained, of which 1736 died, accounting for a 77.57% mortality rate. During preweaning (1st month of age) and postweaning (up to 3 months of age), 1501 (67.10%) and 235 (31.90%) deaths were recorded, respectively. A postweaning fecal examination revealed that 198 out of 229 (86.50%) were diarrheic rabbits due to Eimeria infection. Cittotaenia spp. eggs were detected in 4.37% of fecal samples, and mites (Sarcoptis scabiei) were present in 6.55%. E. coli was detected in 100% of examined animals during pre- and postweaning periods; however, Salmonella spp. were 97.22% and 43.67, respectively. Managemental risk factors were the main causes in preweaning mortality, including insufficient milk supply (37.37%), cannibalism (26.38%), mange infestation of a rabbit doe (22.20%), mastitis (4.30%), lack of doe care (5.00%), bronchopneumonia (2.13%), and enteritis (1.80%). However, risk factors in postweaning mortality included sudden death with general septicemia (13.80%), enteritis (9.63%), bronchopneumonia (5.43%), mange infestation (2.04%), and malnutrition (0.81%). In conclusion, the etiology of preweaning mortality in kits was related mainly to the doe, especially managemental risk factors. However, a combination of multiple pathogenic agents (parasites and bacteria) and managemental factors was reported in the postweaning stage. Careful attention must be paid to avoid these causes.

Erratum: Saeed, E.-A.; Shawky, M.A.; El-Sayed, M.A.-K.; Shymaa, A.H.; Lilian, N.M.; Eman, M.F.; Asmaa, A.K. Investigation of Pre- and Post-Weaning Mortalities in Rabbits Bred in Egypt, with Reference to Parasitic and Bacterial Causes. Animals 2020, 10, 537.

The authors wish to make the following correction to their paper [...].

First Report of Cattle Tick Rhipicephalus (Boophilus) annulatus in Egypt Resistant to Ivermectin.

Tick control is mainly dependent on the application of acaricides, but resistance has developed to almost all classes of acaricides, including macrolactones. Therefore, we aimed to investigate ivermectin resistance among tick populations in middle Egypt. The larval immersion test was conducted using a commercial formulation of ivermectin (1%). Different concentrations of the immersion solution (0.0000625% (625 × 10-7%), 0.000125% (125 × 10-6%), 0.0005% (5 × 10-4%), 0.001% (1 × 10-3%), 0.0025% (2.5 × 10-3%), 0.005% (5 × 10-3), and 0.01% (1 × 10-2%)) were prepared by diluting a commercial ivermectin (1%) with distilled water containing 1% (v/v) ethanol and 2% (v/v) TritonX-100. Field populations of Rhipicephalus annulatus were collected from five different localities in Beni-Suef province, Egypt. Adult engorged female ticks were collected and assessed for oviposition and egg fertility. Eggs were collected, and hatched larvae were then used in the experiment. Application of acaricides was conducted on 10-day-old larvae. There was a significant difference in the LC50 (50% lethal concentration) among the examined localities on the log dose-response plot, where, the LC50 of tick populations from two localities (Emin elaros and Aldiabia) was higher than the other localities (Alhalabia, Alkom, and Beshnna). Besides, tick populations from Emin elaros and Aldiabia showed higher LC90 values with lower slope values compared to those from Alhalabia, Alkom, and Beshnna. According to these values (LC50, LC90, and slope values), as well as a history of acaricide failure to ticks in these areas, R. annulatus developed resistance to ivermectin. This study documents the first report of field populations of R. annulatus resistant to ivermectin in Egypt.

Diversity of Parasitic Diarrhea Associated with Buxtonella Sulcata in Cattle and Buffalo Calves with Control of Buxtonellosis.

The association between parasite isolates, including Buxtonella sulcata, in suckling and post-weaning calves and diarrhea was studied with the aim to control diarrhea caused by B. sulcata. A total of 1100 diarrheic fecal samples were collected from 609 suckling calves and 491 post-weaning calves with diarrhea. Salt floatation and modified Ziehl-Neelsen techniques were applied for the microscopic examination of the presence or absence of parasite eggs and oocysts/cysts. The microscopic findings revealed that 20.36% of the calves had parasitic diarrhea, with a prevalence rate of 19.54% in suckling calves and 21.38% in post-weaning calves. The most frequently detected parasites according to morphological characters were Eimeria species, Buxtonella sulcata, Toxocara vitulorum, Cryptosporidium species, and Moneizia species. In suckling calves, Eimeria species, B. sulcata, and T. vitulorum had the highest prevalence rates of infection, corresponding to about 37.14%, 32.86%, and 20.00%, respectively. However, in post-weaning calves, B. sulcata infection was more prevalent (30.15%) than infections with Eimeria species and T. vitulorum. The highest parasite score density was found in multiple infections with B. sulcata, Eimeria species, and T. vitulorum; however, the score density of B. sulcata when present alone in the fecal specimens was higher than in specimens co-infected with other parasites. The risk factors affecting the prevalence rate of parasitic diarrhea, such as sex, season, housing system, and feed stuff, are discussed. Concerning the treatment of diarrhea caused by B. sulcata in post-weaning cattle calves, 20 calves were divided into 4 equal groups. Group A was given sulphadimidine sodium (1.0 g/10 kg body weight) and metronidazole (500 mg/40 kg body weight); group B was treated with oxytetracycline hydrochloride (500 mg/45 Kg of body weight) and metronidazole (500 mg/40 kg body weight); group C was daily administered garlizine (allicin), 2 g/ L in drinking water; group D was the untreated control group. All medications were administered orally for four successive days. The results showed that the cyst count was significantly lower in the drug-treated groups, and the metronidazole + oxytetracycline hydrochloride and metronidazole + sulphadimidine combinations achieved 98.77% and 96.44% efficacy, respectively. Garlizine had 72.22% efficacy. Intriguingly, B. sulcata infection was associated with other parasitic infections, but B. sulcata mono-infection was the most common cause of diarrhea. Moreover, the combinations of oxytetracycline hydrochloride or sulphadimidine with metronidazole are recommended to control buxtonellosis in calves. Further studies are recommended to investigate the bacterial, viral, and fungal infections associated with B. sulcata infection.

Prophylactic and Therapeutic Efficacy of Prebiotic Supplementation against Intestinal Coccidiosis in Rabbits.

This study was conducted to investigate the effect of prebiotic supplementation against intestinal coccidiosis in rabbits. Fifty male rabbits aged 35-60 days (1-1.5 kg) were divided into prophylactic and therapeutic experiments (five groups, 10 rabbits per group). Prophylactic experiment had prebiotic supplemented (PS-P), non-supplemented infected control (NI-P), and non-supplemented non-infected control (NN-P) groups. Ten days post-prebiotic supplementation (PPS), rabbits in groups PS-P and NI-P were infected orally with 5.0 × 104 sporulated oocysts of mixed Eimeria species. However, therapeutic experiment had prebiotic supplemented (PS-T) and untreated infected (UI-T) groups of naturally infected rabbits with Eimeria species. A significant reduction in oocyst count per gram feces (OPG) (p ≤ 0.05) was reported in the PS-P (57.33 × 103 ± 2.84) and NI-P (130.83 × 103 ± 43.38) groups during the experiment. Additionally, rabbits in groups (PS-P, 970.33 ± 31.79 g and NI-P, 870.66 ± 6.66 g) showed weight loss after infection. However, a significant (p ≤ 0.05) decrease in OPG was observed at day seven PPS in the PS-T group (4 × 103 ± 0.00) when compared with the UI-T group (32 × 103 ± 7.54). Furthermore, the PS-T group had a higher body weight than rabbits in the UI-T group. Histopathological findings of the intestinal tissues (duodenum, jejunum, and ileum) showed that the counts of the endogenous stages were significantly higher in the NI-P and UI-T groups than in the prebiotic-supplemented groups (PS-P and PS-T). Supplementation of the prebiotic did not have any adverse effects on biochemical parameters, such as AST, ALT, creatinine, total protein, and total cholesterol. In conclusion, prebiotic supplementation can be used to minimize the adverse effects of intestinal coccidiosis in rabbits, which in turn limits body weight loss, especially for the prophylaxis of coccidial infection.

Molecular detection of Rhipicephalus (Boophilus) annulatus resistance against deltamethrin in middle Egypt.

This study was designed to investigate the susceptibility/resistance of Rhipicephalus (Boophilus) annulatus to commercial deltamethrin 5%. The work was based on in vitro bioassays; adult immersion test (AIT) and larval packet test (LPT). Fully engorged female ticks were collected from 11 locations in Beni-Suef Governorate, Egypt (Alfashin, Eminelaros, Ehnasia, Smusta, Belifia, Aldiabia, Alhalabia, Beshnna, Alkom, Nasr and Beba). Two concentrations of commercial deltamethrin 5% (200 and 400 ppm) were tested by AIT on R. (B.) annulatus. The mortality of ticks at 400 ppm was higher than 200 ppm which was not reached to 100%. Ehnasia tick population was the least susceptible to deltamethrin while Alfashin population was the most susceptible one. Different deltamethrin concentrations (0.000625, 0.00125, 0.0025, 0.005, 0.010 and 0.020) were used in LPT to evaluate the larval mortality. The highest LC50 appeared in Ehanasia tick population (0.01) with 95% confidence interval (0.005 to 0.01) meanwhile, the lowest LC50 appeared in Alfashin (0.0006) with 95%CI (0.0005 to 0.0007). Thus, it is possible to deduce that one population was considered susceptible; seven populations were resistant level I and three populations were resistant level II. Additionally, PCR revealed that the resistant alleles (R) appeared in two localities (Ehnasia and Aldiabia). It was concluded that at least two tick populations of the investigated locations were of possible resistant to deltamethrin.

Effect of high concentrations of lufenuron, pyriproxfen and hydroprene on Rhipicephalus (Boophilus) annulatus.

The activity of high doses of three insect growth regulators (IGRs), lufenuron (MATCH®), pyriproxfen® and hydroprene (Gentrol®), were tested on Rhipicephalus(Boophilus) annulatus adult females, eggs and larvae. Different concentrations of the IGRs were tested on eggs, larvae and adult ticks through immersion, larval packet and adult immersion bioassays, respectively. The tested IGRs did not show adulticidal activity against female ticks even at very high concentration. However, both hydroprene and pyriproxfen caused a significant decrease (P<0.05) in the reproductive indices of adult female ticks. Both lufenuron and pyriproxefen showed considerable ovicidal activity delaying the hatchability of the treated eggs until the 21st day and decreasing the hatchability percentages to 37.7% and 60.6% at concentrations ≥10X and ≥4X, respectively. Lufenuron (≥10X dose), hydroprene (≥4X dose) and pyriproxyfen (≥4X dose) induced highly significant larvicidal activity as they caused 100% mortality after 72 h of exposure. The oxidative profile of the hydroprene treated ticks had decreased glutathione peroxidase and increased malonaldehyde in comparison to the other IGR- treated and control untreated ticks. It is concluded that the IGRs did not show R. annulatus adulticidal effect, however, the deposited egg mass and its hatching percent decreased significantly when treated with hydroprene and pyriproxfen. The tested IGRs showed larvicidal activity against R. (B.) annulatus.