Injectable Ivermectin Research Articles

Survival and reproduction of Onthophagus landolti (Coleoptera: Scarabaeidae) exposed to ivermectin residues in cattle dung.

Two bioassays were conducted in parallel to assess the effects of cattle treated with either 1% ivermectin (IVM) or 3.15% IVM (dosed at 0.2 and 0.63mgkg-1, respectively) on reproduction and survival of Onthophagus landolti Harold. Adult beetles were exposed 10 days to faeces of treated cattle starting at: one day before treatment (controls), 3, 6, 14, 28 and 35 days post-treatment. Adult survival of O. landolti was not affected by either of the two treatments. Faecal residues of 1% IVM almost completely suppressed fecundity of beetles at 3, 6 and 14 days post-treatment (dPT), and reduced fecundity of O. landolti at 28 dPT ( 38.3%), relative to controls. Meanwhile, IVM residues after treatment with 3.15% IVM almost completely suppressed fecundity of beetles at 3, 6, 14 and 28 dPT, and reduced fecundity of O. landolti at 35 dPT (80.9%), relative to controls. Larval survival was significantly reduced only at 3 dPT with 1% IVM. Meanwhile, treatment with 3.15% IVM significantly reduced larval survival at 6, 14 and 28 dPT. Larval mortality was recorded only in L-I and L-II instars. Moreover, in both bioassays, most of the L-I and L-II specimens that survived showed signs of toxicity. In conclusion, residual IVM in cattle faeces after treatment with injectable IVM has a detrimental effect on the fecundity of adult O. landolti up to 4 weeks post-treatment and on the subsequent larval survival.

Interferences on microbial inhibitor tests related to ivermectin treatment in lactating dairy goats.

This Research Communication reports interferences related to the administration of ivermectin in lactating dairy goats on the response of microbial tests for screening antibiotics in milk. Twenty-eight Murciano-Granadina goats, naturally infested with Sarcoptes scabiei var. caprae, were treated with a subcutaneous injection of ivermectin (200 µg/kg b.w.). To prevent re-infestation, a second dose was applied 7 d later. Individual milk samples were collected, daily, up to 15 d post-treatment. Milk samples were analysed by microbial inhibitor tests (BRT MRL, Delvotest SP-NT MCS and Eclipse 100) and ivermectin residues were quantified by HPLC. A large number of positive results were obtained for all microbial tests, especially on the first day after treatment (BRT MRL = 46·4%; Delvotest SP-NT MCS = 14·3%; and Eclipse 100 = 17·8%). However, the highest concentration of drug residues in milk (24·3 ng/ml) was detected on the tenth day after treatment, when positive outcomes were relatively lower (BRT MRL = 17·8%; Delvotest SP-NT MCS = 10·7%; and Eclipse 100 = 7·4%). Results herein suggest that factors related to the ivermectin treatment other than drug residues in milk, or alterations produced by the parasitic disease itself affecting the immune response of animals, could be the cause of false-positive results in microbial tests. It can be concluded that the application of ivermectin in dairy goats infested with sarcoptes mange during lactation produces persistent drug residues in milk, and could also cause false-positive results in microbial inhibitor tests for screening antibiotics.

Evaluation of Anthelmintic Efficacy of Ivermectin, Levamisole HCl and Albendazole Administered through Different Routes against Naturally Occuring Gastrointestinal Nematodiasis in Black Bengal Goat Inducing Hematological Parameters and Live Weight Indices

This study aimed to evaluate the efficacy of ivermectin, levamisole HCl and albendazole against gastrointestinal nematodes in naturally infected goats of government goat development farm, Sylhet, Bangladesh. The study included 52 black Bengal breed of which 30 were naturally infected and randomly selected 20 on the basis of their weight and egg count. Twenty black Bengal goats of 12-13 month old irrespective of sex infested with gastrointestinal nematodes were selected for this experiment and randomly divided into four equal groups (group A, B, C and D) where each group consisted of 5 goats and goats of group D were kept as control group. One injectable ivermectin (200?gkg-1 body weight, S/C) preparations (Techno Drugs Ltd. Bangladesh) and two solid levamisole HCl, albendazole (7.5 mgkg-1 body weight, orally) preparations (The ACME Laboratories Ltd. and Square Pharmaceuticals Ltd. Bangladesh) were used for positive control of gastrointestinal nematodes as group A, B and C. Goats of group D was kept as control without giving any treatment. Before trials (day 0), total egg count, blood samples and initial body weight were recorded. During the study period the fecal and blood samples were collected directly from rectum and examined on 7th, 14th, 21st and 28th day using McMaster fecal egg counting method. Body weight was recorded on day 28 following the treatments. The results of the comparative efficacies of different anthelmintic of ivermectin was 86.75%, followed by levamisole HCl 85.07% and albendazole 92.81%. McMaster fecal egg counting method discloses the percentage of Haemonchus spp. (15.38%), with Trichostrongylus spp, Strongyloides spp., and Cooperia spp. also present. After treatment with ivermectin, levamisole HCl and albendazole, Total Erythrocyte Count (TEC), Hemoglobin (Hb) content and Packed Cell Volume (PCV) were increased significantly (p<0.01 and p>0.05) in goats but Erythrocyte Sedimentation Rate (ESR) and Total Leukocyte Count (TLC) were decreased significantly (p<0.05 and p>0.01) in all treated goat and body weight was increased significantly (p<0.01) on day 28.International Journal of Natural Sciences (2015), 5(1) 26-34

COMPARATIVE STUDIES ON REPRODUCTIVE MALE RABBITS AS AFFECTED BY IVERMECTIN OR BOTH OF GARLIC AND CINNAMON OILS TREATMENTS 1. ACARICIDAL EFFICACY OF IVERMECTIN, GARLIC AND CINNAMON OILS AGAINST Sarcoptes scabiei IN SUFFERING INFESTED RABBITS.

Thirty-six V-Line male rabbits of ten months age, average weight 3.5 kg were used. They were allocated randomly into six equal groups. First and second were served as a negative (NC) and positive (PC) control, third group was injected by double therapeutic dose (DTD) 1mg/kg body weight of ivermectin via subcutaneous injection, fourth groupwas treated with 5% garlic oil (GO), fifth group was treated with 5% cinnamon oil (CO), while, sixth group was treated with 5% garlic oil + 5% cinnamon oil mixture (MO). Groups were treated GO, CO and MO received daily topically treatment for 7 successive days. Groups PC and IV were treated with paraffin oil and (DTD) ivermectin. Results showed that: Total disulfide (e.g. disulfide, Dipropyldisulfide, Propenyl propyl disulfide, allyl methyl disulfide) and Trisulfides, Diallyl (e.g. Dipropyl trisulfide) found in garlic oil. Cinnamic acid, Cinnamaldehyede, cinnamat, Caryophyllene, Cinnamyl acetate, Phellanderene, Pinene, Eugenil, and α-Terpinol found in cinnamon oil. Garlic or cinnamon oils and their mixture (5%) were highly efficacious against S. scabiei var. cuniculi larvae as 100 % mortality was reached 24 hrs. with treatment. On the other hand, all mites treated with oils (5 %) and ivermectin double dosage (1%) died 72 hrs. Garlic or cinnamon oils (5%) and their mixture had a good acaricidal effect on the Sarcoptic scabie is similarly to ivermectin (1%) in vitro. In vivo treatment of P. soroptes sp. infections with the essential oil components trans-cinnamic acid resulted in high mite mortality. Rabbits treated with ivermectin injection (IV) or garlic and cinnamon oils topically showed a significant increase in live body weight and feed intake compared with infested and untreated rabbits (PC). While, rabbits treated with garlic and cinnamon improved in live body weight and feed intake compared with those of infested and treated with ivermectin (IV).

Macrocyclic Lactones Block Melanoma Growth, Metastases Development and Potentiate Activity of Anti–BRAF V600 Inhibitors

IntroductionMelanoma is the most aggressive form of skin cancer. Targeted antimelanoma therapies such as BRAF V600 inhibitors have shown spectacular results. However, these therapies are restricted to BRAF V600 mutated melanoma and display both adverse effects and resistance outbreaks. MethodsA high-content screening campaign identified compounds that displayed antimelanoma activities that can potentiate anti–BRAF V600 inhibitors. We identified ivermectin, a US Food and Drug Administration (FDA)-approved macrocyclic lactone widely used as an anthelmintic and insecticidal agent. ResultsMacrocyclic lactones possess in vitro cytotoxicity against either BRAF wild type (wt) or BRAF V600 mutated melanoma cells lines. Daily intraperitoneal injections of ivermectin strongly reduce pulmonary metastasis implantation in vivo in murine and melanoma models. Interestingly, these macrocyclic lactones are also able to trigger vemurafenib-dependent cytotoxicity in vitro in BRAF-wt melanoma cells, although vemurafenib action was thought to be restricted to melanoma bearing the BRAF V600 mutation. These macrocyclic lactones are also able to increase the in vitro antimelanoma activity of another BRAF V600 clinical inhibitor, dabrafenib. Serine/threonine p21-activated protein kinase 1 (PAK1) is the key target of ivermectin responsible for its antimelanoma activity. ConclusionIvermectin is a promising agent that could strongly increase melanoma therapy efficiency because it is cytotoxic for BRAF-wt and BRAF mutated melanomas and because it increases the efficiency of antimutated BRAF inhibitors independent of the BRAF status of tumors. Because ivermectin is FDA approved and a study of ivermectin would be able to include all patients in the same protocol, this combination treatment should be next investigated in clinical studies.

Evaluating the Effects of Ivermectin Treatment on Communities of Gastrointestinal Parasites in Translocated Woylies (Bettongia penicillata).

Wildlife species are often treated with anti-parasitic drugs prior to translocation, despite the effects of this treatment being relatively unknown. Disruption of normal host-parasite relationships is inevitable during translocation, and targeted anti-parasitic drug treatment may exacerbate this phenomenon with inadvertent impacts on both target and non-target parasite species. Here, we investigate the effects of ivermectin treatment on communities of gastrointestinal parasites in translocated woylies (Bettongia penicillata). Faecal samples were collected at three time points (at the time of translocation, and 1 and 3months post-translocation) and examined for nematode eggs and coccidian oocysts. Parasite prevalence and (for nematodes) abundance were estimated in both treated and untreated hosts. In our study, a single subcutaneous injection of ivermectin significantly reduced Strongyloides-like egg counts 1month post-translocation. Strongyle egg counts and coccidia prevalence were not reduced by ivermectin treatment, but were strongly influenced by site. Likewise, month of sampling rather than ivermectin treatment positively influenced body condition in woylies post-translocation. Our results demonstrate the efficacy of ivermectin in temporarily reducing Strongyloides-like nematode abundance in woylies. We also highlight the possibility that translocation-induced changes to host density may influence coinfecting parasite abundance and host body condition post-translocation.

PREVALENCE OF GASTROINTESTINAL NEMATODES PARASITES FROM SHEEP AND EVALUATION OF SOME ANTHELMINTHIC RESISTANCE IN ERBIL GOVERNORATE

Prevalence and anthelmintic resistance status of gastrointe stinal nematodes in 430 sheep investigate by faecal examination was conducted in Qushtapa , Khabat, Benslawa, Salahaddin subdistricts in Erbil , from April t o July 2012 . The mean eggs per gram (EPG) count determined by using modified McMaster technique , sh owed that (40.4 6 %) of the sheep were infested, the higher infection was 17.2% Nematodirus sp p . , 13.02% Strongylus sp p . , 4.18% Marshaligia sp p . , 2.79% Trichurus sp p . and 3.25% with coccidia . Four farms were selected randomly each divided to control an d three treatment groups: Levamisol, Albendazol e and Ivermectin groups . Anthelmintic efficacy was measured after treatment dates were investigated with faecal egg count reduction test , the F E C RT percentage for Levamisol in sheep ranged from 80.3 to 94.7 wh ich show m ost effective in Khabat with FE C R T of 94.7% while with Albendazol e ranged from 75.5% to 80.2%, suspected resistant in all group , but t he injectable Ivermectin in sheep ranged from 85.2 to 94.8 and show effective in Bnaslawa and Salahaddin with FE CR of 94.6% and 94.8% respectively. All the anthelmintic were found to be low ef fective, but resistance to Albendazol e was suspected. Based on the findings, it was concluded that development of anthelmintic resistance could be prevented by avoiding fre quent dosing and under dosing, while strategic deworming should be practiced by both animal health workers and animal owners.

Ivermectin treatment of bovine psoroptic mange: effects on serum chemistry, hematology, organ weights, and leather quality.

Psoroptic mange is a skin disease which may result in serious health and welfare problems and important economic losses. Apart from the effect on weight gain, little information is available concerning other responses of the organism consequent to the successful therapy of bovine psoroptic mange. Accordingly, serum chemistry, hematology, organ weights, and leather quality of young bulls with experimentally induced clinical Psoroptes ovis mange and treated with either ivermectin long-acting injection (IVM LAI; IVOMEC(®) GOLD, Merial) or saline (n = 16 each) were examined 8 weeks after treatment when all IVM LAI-treated bulls were free of live P. ovis mites while the saline-treated bulls maintained clinical mange. IVM LAI-treated bulls had higher (p < 0.05) alkaline phosphatase, creatinine, cholesterol, glucose, and albumin levels and lower (p < 0.01) total protein and β- and γ-globulin levels than the saline-treated bulls. Complete blood counts revealed higher leukocyte counts associated with higher eosinophil counts and higher platelet counts in the saline-treated compared to the IVM LAI-treated bulls (p < 0.01). Correlating with body weight, the warm carcass weight of the saline-treated bulls was lower than that of the IVM LAI-treated bulls (p < 0.05). Absolute and relative (organ weight divided by body weight) weights of the spleen, thymus, omental fat, and perirenal fat were higher (p < 0.01) for the IVM LAI-treated bulls than for the saline-treated bulls, while the IVM LAI-treated bulls had lower (p < 0.05) absolute and relative weights of the liver, adrenal glands, and selected lymph nodes than the saline-treated bulls. The leathers produced from the IVM LAI-treated bulls showed significantly (p < 0.001) less severe gouging or etching than leathers from the saline-treated bulls, and significantly (p < 0.05) more leather from the IVM LAI-treated bulls was of usable quality than the size of leather from the saline-treated bulls. Overall, these findings provided evidence that many changes, which are indicative of impaired protein and energy metabolism, immune system function, and performance resultant from clinical psoroptic mange, improved substantially within 8 weeks of successful treatment with injectable ivermectin.

Ear mite infestation in a lop-eared rabbit (Oryctolagus cuniculus) and successful treatment with ivermectin

A 2-year-old female lop-eared rabbit (Oryctolagus cuniculus) was presented to the veterinary clinic at a zoo with pruritus, alopecia, and crusting of the ear. Examination of skin scrapes revealed an infestation with the rabbit ear mite, Psoroptes cuniculi. Weekly subcutaneous ivermectin injection over a three-week period resulted in remission of the clinical signs and improvement of the overall conditions of the rabbit.

Therapeutic efficacy of ivermectin, fenbendazole and albendazole against naturally occuring gastrointestinal nematodiasis infection in Black Bengal Goat of Bangladesh

This study aimed to evaluate the efficacy of ivermectin, fenbendazole and albendazole against gastrointestinal nematodes in naturally infected goats of government goat development farm, Sylhet, Bangladesh. The study included 50 black Bengal breed of which 30 were naturally infected and randomly selected 20 on the basis of their weight and egg count. Twenty black Bengal goats of 13-15 month old irrespective of sex infested with gastrointestinal nematodes were selected for this experiment and randomly divided into four equal groups (group A, B, C and D) where each group consisted of 5 goats and goats of group D were kept as control group. One injectable ivermectin (200 µgkg-1 body weight, S/C) preparations (Techno Drugs, Limited, Bangladesh) and two solid fenbendazole, albendazole (7.5 mgkg-1 body weight, orally) preparations (Techno Drugs, Limited and Square Pharmaceuticals Ltd, Bangladesh) were used for positive control of gastrointestinal nematodes as group A, B and C. Goats of group D was kept as control without giving any treatment. Before trials (day 0), total egg count, blood samples and initial body weight were recorded. During the study period the fecal and blood samples were collected directly from rectum and examined on 7th, 14th, 21st and 28th day using McMaster fecal egg counting method. Body weight was recorded on day 28 following the treatments. The therapeutic efficacy was evaluated through determination of parasitic prevalence, body weight gain/loss and hematological findings. Pre and post-treatment EPG (eggs per gram) values were recorded, and efficacies compared. The results showed that the efficacy of ivermectin was 100%, followed by fenbendazole 95.33% and albendazole 90.11%. The observed differences in efficacy between these three brands of anthelmintics were most likely due to variations either in quality or the administered doses. The body weight of the treated animals was slightly increased, which were significant (p&lt;0.05). After treatment with ivermectin, fenbendazole and albendazole, Total Erythrocyte Count (TEC), Hemoglobin (Hb) content and Packed Cell Volume (PCV) were increased significantly (p&lt;0.01 and p&gt;0.05) in goats but Erythrocyte Sedimentation Rate (ESR) and Total Leukocyte Count (TLC) were decreased significantly (p&lt;0.05 and p&gt;0.01) in all treated goat and body weight was increased significantly (p&lt;0.01) on day 28. The farm management practices along with results of the present study revealed the efficacy of multiple anthelmintics against gastrointestinal nematodiasis in goat. Additional detailed studies are required to clarify the current status of the efficacy of the anthelmintics widely used in different agro ecologies, animal species and livestock management systems in Bangladesh.

The best methods of control sarcoptic mange infested cattle, sheep and rabbit farms

This paper studied to identify the best method to control scabies for animals, cattle, sheep and rabbits. Ivermectin Injection method is considered under the skin of the animal accompanied by anti-surface of the animal body, such as the use of Tincture iodine or sulfur ointment or spray a pesticide recommended is the best method to kill scabies in animals where control is internal and external at the same time.

Occurrence of Knemidokoptes mutans and Laminosioptes cysticola in backyard poultry in India.

Birds reared in backyard poultry farming system are more prone to parasitic infestation resulting in economic losses to rural community. The present study reports occurrence of Knemidokoptes mutans and Laminosioptes cysticola mites in a male Aseel bird. Clinical signs observed in the affected bird include hyperkeratosis with whitish film layer on shank and hock region of legs. Focal areas of sloughing of skin with oozing of blood were also observed on the back and on the legs. Examination of skin scrapings from the affected sites revealed different developmental stages of Knemidokoptes mutans and Laminosioptes cysticola mites. This paper reports occurrence of L. cysticola for the first time from India. The bird was treated with ivermectin injection through intramuscular route.

Treatment and control of Trixacarus caviae infestation in a conventional guinea pig (Cavia porcellus) breeding colony.

A case of sarcoptic mange caused by Trixacarus caviae in a conventional guinea pig breeding colony is reported. The infestation was reported in a large colony of guinea pigs during the month of July, 2013 affecting 30 breeder guinea pigs. Severely infested animals were treated individually with subcutaneous injection of ivermectin 1% w/v (Neomec®) at the rate of 400µg/kg body weight 10days apart. Three doses of ivermectin were sufficient to eliminate the parasite which tested negative after 30days of the first treatment. The entire colony was given preventive dose of ivermectin spray (2mg/ml solution) following the same schedule. Strict hygienic measures were followed. New hair growth in the severely affected animals was evidenced on 30th day of treatment.

EVALUATION OF THE CLINICAL EFFICACY OF THREE MEDICATIONS USED FOR TREATMENT OF EARMITE-INDUCED OTITIS EXTERNA IN CATS: A PRELIMINARY STUDY

The aim of this study was to compare the clinical outcome of three different medications (ivermectin injection, canaural eardrops and frontline combo) in treatment of ear mite infestation accompanied by otitis externa in cats using a randomized trial. Cases presented to the Small Animal Clinic, Faculty of Veterinary Medicine, Assiut University for investigating signs of ear mite infestation and/or otitis externa were recruited (n=17) and randomly assigned to one of the 3 groups for evaluation of response to treatment over a period of 30 days. Cases that did not respond to treatment within 2 weeks of treatment were changed to one of the other two medication. A simple questionnaire was designed to evaluate owner satisfaction of the medication price, ease of administration, cat tolerance and improvement of signs. Recruited cases were either brought to the clinic for re-evaluation or the owner was contacted by phone to evaluate progress of each case. In the ivermectin-treated group (Group 1; n=7), 75% of cases recovered from ear mite infestation based on signs resolving and disappearance of presenting signs. Only 60% of cases treated with frontline (Group 2) showed an improvement of signs (n=5). All cases treated with Canaural (Group 3) showed complete recovery with complete absence of presenting signs and signs of otitis externa (n=5). Average age of cats in all groups ranged from two to 72 months (mean= 17.33, median=6.5). Statistically there were no significant difference between the three medications (p>0.5), but according to the clinical findings, we can suggest that Canaural is the most suitable when otitis externa is present along with ear mite infestation. Frontline Combo is not as effective as the two other medications used in this study

Comparative treatment approach for Sarcoptes and Psoroptes mite infestation in a Boer cross

This case was carried out to compare the healing process and time for the treatment of mange in goats using a combination of Ivermectin with dexamethasone to the earlier Ivermectin with antihistaminics approach. A 3 ½ years old female Boer cross goat was presented with a complaint of crusty lesions on different parts of the body during a routine farm visit in Selangor, Malaysia. Microscopic examinations of the skin scrapes taken revealed Sarcoptes and Psoroptes sp. of mites, while hematological analysis showed slight leucocytosis, neutrophilia with left shift, monocytosis, hyperproteinemia and hyperglobulinemia. Ivermectin injection at 0.2 mg/kg subcutaneously was administered once every 2 weeks in 4 divided doses, while Dexamethasone injection at 1 mg/10 kg and multivitamin at 10 mg/kg IM for 5 days repeated at alternate weeks. Significant improvement was recorded 6 weeks after commencement of treatment and full recovery at 10 weeks. The current drug regimen proved more effective when compared with previous cases that were treated with a combination of ivermectin and antihistaminics.

Effectiveness Evaluation of Levamisole, Albendazole, Ivermectin, and Vernonia amygdalina in West African Dwarf Goats.

Anthelmintic drug resistance has led to the search for alternatives in controlling helminth infections. Fifty West African Dwarf goats without history of anthelmintic treatment were divided equally into five groups. Group A was treated with ivermectin injection subcutaneously, group B with levamisole subcutaneously, group C with albendazole orally, and group D with aqueous extract of Vernonia amygdalina and group E was untreated control. Faecal samples were collected before treatment from each animal and larval culture was carried out. Faecal egg count reduction (FECR) test was carried out for each group and the data analysed using FECR version 4 to calculate percent reduction in faecal egg count. Predominant helminth infections from larval culture were Haemonchus contortus (70%), Trichostrongylus spp. (61%), and Oesophagostomum spp. (56%). Mixed infection was present in all the animals. From the FECR test Vernonia amygdalina extract was more effective against helminths (100%), compared to ivermectin 96%, levamisole 96%, and albendazole 99%. The lower 95% confidence limit was 89 for ivermectin and levamisole and 91 for albendazole. There is low resistance to ivermectin and levamisole and susceptibility to albendazole while V. amygdalina has great potentials that could be explored for the treatment of helminth diseases in goats.

Concurrent infestation of Notoedres, Sarcoptic and Psoroptic acariosis in rabbit and its management

Acariotic mange in rabbits is one of the important constraints in rabbit husbandry. Sarcoptes scabies var. cuniculi and Psoroptes cuniculi are most common mites prevailed in rabbits, but Notoedrescati, is the rarest mite ever been reported in rabbit. Two New Zealand white rabbits were presented with clinical signs of pruritus, alopecia, scab and crust formation and lichenification on the upper lip, ear pinnae, eyelids, lower jaw and limbs. Deep skin scraping was taken separately from 4 to 5 different skin lesions from each rabbit, revealed mixed infestations of N. cati, S. cuniculi and P. cuniculi. Subcutaneous injection of ivermectin at weekly intervals for four weeks resulted in remission of clinical signs and improvement of health condition in rabbits. This is the first report of N. cati infestation of rabbit in Odisha.

Anthelmintic resistance in nematodes of beef cattle in south-west Western Australia

Anthelminthic resistance in nematodes of beef cattle is an emerging issue globally with implications for effective parasite control. The prevalence of resistance in beef cattle in the Mediterranean-style climatic zone of south-west Western Australia was assessed on 19 farms, using faecal egg count reduction tests. Pre-treatment faecal worm egg counts were compared with counts at 14 days after treatments with ivermectin (injectable), fenbendazole (oral), or levamisole (oral). A separately grazed group treated with topical ivermectin (pour-on) and sampled at 28 days was included as a comparison against injectable ivermectin. The results demonstrate that resistance is common, with failure of at least one anthelmintic (<95% reduction for each species, by arithmetic means) for either of the major species Cooperia oncophora or Ostertagia ostertagi on 17 of the 19 properties. Resistance to ivermectin (injectable) was demonstrated in C. oncophora in 59% of tests, but ivermectin was fully effective against O. ostertagi by this route. Conversely, O. ostertagi resistant to fenbendazole and levamisole were present on 50% and 67% of farms respectively, with both fully effective against C. oncophora. The finding of Haemonchus placei on several properties was unexpected but the egg counts were low and there is no suggestion of pathogenic effects. An indication of reduced efficacy of the pour-on ivermectin formulation compared to the injectable was apparent against both C. oncophora and O. ostertagi, and this may have implications for resistance development, given the widespread use of topical treatments reported in this region. This survey confirms that anthelminthic resistance in nematodes of beef cattle is common in Western Australia and the pattern of occurrence is in general agreement with surveys elsewhere in Australia and in other countries.

The relative plasma availabilities of ivermectin in reindeer (Rangifer tarandus tarandus) following subcutaneous and two different oral formulation applications.

BackgroundOverwintering (breeding) reindeer (Rangifer tarandus tarandus) are commonly treated with ivermectin against parasitic infestations once yearly in autumn-winter roundups. The only preparations registered to reindeer are those for subcutaneous injection. However, also oral extra-label ivermectin administration is used. Twenty-six, 8-month-old reindeer calves were randomly allocated into three groups. Group 1 (n = 9) received oral ivermectin mixture (Ivomec® vet mixt. 0.8 mg/ml, oral ovine liquid drench formulation), Group 2 (n = 9) oral ivermectin paste (Ivomec® vet 18.7 mg/g equine paste), and Group 3 (n = 8) subcutaneous injection of ivermectin (Ivomec® 10 mg/ml vet inj.), each group at a dose of 200 μg/kg body weight. Blood samples were collected at treatment and at days 1, 2, 3, 6, 9 and 16 post treatment. Plasma concentrations of ivermectin were determined by high-pressure liquid chromatography (HPLC) with fluorescence detection.ResultsThe peak plasma concentration (Cmax) was reached by 2 days after each treatment. The Cmax and Area Under Curve (AUC) differed significantly between the groups: Cmax was 30.2 ± 3.9, 14.9 ± 5.7 and 63.1 ± 13.1 ng/ml, and AUC∞ was 2881 ± 462, 1299 ± 342 and 6718 ± 1620 ng*h/ml for groups 1, 2 and 3, respectively (mean ± standard deviation).ConclusionsThe differences in plasma concentrations of ivermectin are concomitant with earlier observed differences in antiparasitic efficacy, which discounts the use of the equine paste in reindeer in favour of the oral ovine liquid drench formulation, or preferably, the reindeer-registered subcutaneous injection formulation.

Multiday administration of ivermectin is effective in reducing alcohol intake in mice at doses shown to be safe in humans.

Ivermectin (IVM), an FDA approved anthelmintic agent, can significantly reduce ethanol intake in mice following acute administration. The current study evaluates the sustainability and safety of multiday IVM administration in reducing 10% v/v ethyl alcohol (10E) intake in mice at a dose shown to be safe in humans. We tested the effect of 10-day administration of IVM (3.0 mg/kg/day; intraperitoneally) on reducing 10E intake in C57BL/6J mice using a 24-h, two-bottle choice paradigm. On the 10th day of IVM administration, mice were sacrificed at 0, 0.5, 2, 8, 32, 48, and 72 h after injection. Brain tissue and plasma samples were collected and analyzed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Analysis of variance (ANOVA) was used to assess the effect of 10-day IVM administration on 10E intake, 10E preference, water intake, and total fluid intake with Dunnett's multiple comparison post-hoc test. Individual Student's t-tests were also used to further quantify changes in these dependent variables. IVM significantly decreased 10E intake over a 9-day period (P<0.01). Pre-IVM 10E intake was 9.1±3.2 g/kg/24 h. Following the 9th day of IVM injections, intake dropped by almost 30% (P<0.05). IVM had no effect on total water intake or mouse weight throughout the study; however, there was a significant decrease in both preference for 10E (P<0.01) and total fluid intake (P<0.05). Multiday administration of IVM significantly reduces 10E intake and preference in animals without causing any apparent adverse effects at a dose shown to be safe in humans.