Imidocarb Research Articles

Imidocarb Dipropionate Lacks Efficacy against Theileria haneyi and Fails to Consistently Clear Theileria equi in Horses Co-Infected with T. haneyi.

Control of Theileria equi, the primary cause of equine theileriosis, is largely reliant on acaracide use and chemosterilization with imidocarb dipropionate (ID). However, it is currently unknown if ID is effective against Theileria haneyi, the recently identified second causative agent of equine theileriosis, or if the drug maintains effectiveness against T. equi in the presence of T. haneyi co-infection. The purpose of this study was to address these questions using ID treatment of the following three groups of horses: (1) five T. haneyi infected horses; (2) three T. haneyi-T. equi infected horses; and (3) three T. equi-T. haneyi infected horses. Clearance was first evaluated using nPCR for each Theileria sp. on peripheral blood samples. ID failed to clear T. haneyi in all three groups of horses, and failed to clear T. equi in two of three horses in group two. For definitive confirmation of infection status, horses in groups two and three underwent splenectomy post-treatment. The T. equi-nPCR-positive horses in group two developed severe clinical signs and were euthanized. Remaining horses exhibited moderate signs consistent with T. haneyi. Our results demonstrate that ID therapy lacks efficacy against T. haneyi, and T. haneyi-T. equi co-infection may interfere with ID clearance of T. equi.

Clinical and laboratory aspects found in canine with trypanosoma spp infection in north Mato Grosso

Trypanosoma is a hemoflagellate protozoan that infects a variety of animal species and is transmitted in different ways. It is a zoonosis and anthropozoonosis of great importance in veterinary medicine. The present work aims to describe the clinical and laboratory alterations in a free-living dog in a rural area, infected by Trypanosoma spp, treated in the municipality of Sinop, north of Mato Grosso. Blood samples were collected for blood count, alanine aminotransferase (ALT) activity, creatinine, creatine kinase concentrations. The results found were a normochromic microcytic anemia, lymphopenia, trypomastigote forms of Trypanosoma spp. ALT and creatinine measurements were normal, but the serum creatine kinase level was above normal limits. Imidocarb dipropionate at a dose of 7 mg / kg subcutaneously in a single dose was prescribed.

Efficacy of long-acting oxytetracycline and imidocarb dipropionate for the chemosterilization of Anaplasma marginale in experimentally infected carrier cattle in Argentina.

The expansion of anaplasmosis to non-endemic areas in Argentina has created the need for specific treatments to eliminate Anaplasma marginale from carriers. The most recent studies have failed to chemosterilize A. marginale infections. In this work, we compare the efficacy of long-acting oxytetracycline (OTC) and imidocarb dipropionate (IMD) to chemosterilize the A. marginale infection. For this purpose, twenty steers were randomly clustered into two groups of ten animals each 78days after A. marginale experimental infection (day 0). Cattle from group 1 (G1) were treated with three doses of 20mgkg-1 of OTC (Terramycin® LA, 200mg/ml) 7days apart by intramuscular injection. Cattle from G2 were treated with two doses of 5mgkg-1 of IMD (Imizol®, 120mg/ml) 14days apart by intramuscular injection. The efficacy of sterilizing treatments was evaluated by detection of DNA by nested PCR, anti-MSP5 antibodies by ELISA and by inoculation of splenectomized calves with blood from the steers 104days post-treatment (dpt). The results showed 50% efficacy of the OTC treatment to chemosterilize persistent A. marginale infections in cattle and the failure of the IMD treatment under the evaluated conditions. The persistence of specific antibody levels in the sterilized animals (56 dpt) was shorter than the period of DNA detection. The ELISA was the test of choice to confirm the sterilizing outcome after 60 dpt. In spite of its limitations, the sterilization of A. marginale carrier status using OTC, could be useful for high-value bovines in non-endemic areas.

Primeiro relato da ocorrência de Hepatozoon spp. no município de Santa Teresa-ES

Hepatozoonosis is a disease caused by a protozoan of Hepatozoon genus. In Brazil, Hepatozoon canis has been reported to cause disease in dogs. Transmission occurs after ingestion of infected ticks, and the muscles and leukocytes are parasitism locations. Muscle tremors, myalgia and clinical hyperthermia are signals that can occur in affected dogs. Diagnosis can be accomplished by the detection of gamonts forms inside leukocytes from blood smears and for the treatment, imidocarb dipropionate is the drug of choice. The objective of this work is to describe the first case of canine hepatozoonosis in the municipality of Santa Teresa-ES, using the medical records of the infected animal. This study highlights the possibility of underdiagnosis of the disease, probably due to the lack of veterinarian’s knowledge about it and it also reviews the literature about this little-known parasite.

In vitro and in vivo growth inhibitory activities of cryptolepine hydrate against several Babesia species and Theileria equi.

Piroplasmosis treatment has been based on the use of imidocarb dipropionate or diminazene aceturate (DA), however, their toxic effects. Therefore, the discovery of new drug molecules and targets is urgently needed. Cryptolepine (CRY) is a pharmacologically active plant alkaloid; it has significant potential as an antiprotozoal and antibacterial under different in vitro and in vivo conditions. The fluorescence assay was used for evaluating the inhibitory effect of CRY on four Babesia species and Theileria equi in vitro, and on the multiplication of B. microti in mice. The toxicity assay was evaluated on Madin–Darby bovine kidney (MDBK), mouse embryonic fibroblast (NIH/3T3), and human foreskin fibroblast (HFF) cell lines. The half-maximal inhibitory concentration (IC50) values of CRY on Babesia bovis, B. bigemina, B. divergens, B. caballi, and T. equi were 1740 ± 0.377, 1400 ± 0.6, 790 ± 0.32, 600 ± 0.53, and 730 ± 0.025 nM, respectively. The toxicity assay on MDBK, NIH/3T3, and HFF cell lines showed that CRY affected the viability of cells with a half-maximum effective concentration (EC50) of 86.67 ± 4.43, 95.29 ± 2.7, and higher than 100 μM, respectively. In mice experiments, CRY at a concentration of 5 mg/kg effectively inhibited the growth of B. microti, while CRY–atovaquone (AQ) and CRY–DA combinations showed higher chemotherapeutic effects than CRY alone. Our results showed that CRY has the potential to be an alternative remedy for treating piroplasmosis.

A tick cell line as a powerful tool to screen the antimicrobial susceptibility of the tick-borne pathogen Anaplasma marginale

Anaplasma marginale is the causative agent of the severe bovine anaplasmosis. The tick Rhipicephalus microplus is one of the main vectors of A. marginale in tropical and subtropical regions of the world. After the tick bite, the bacterium invades and proliferates within the bovine erythrocytes leading to anemia, impairment of milk production and weight loss. In addition, infection can cause abortion and high mortality in areas of enzootic instability. Immunization with live and inactivated vaccines are employed to control acute bovine anaplasmosis. However, they do not prevent persistent infection. Consequently, infected animals, even if immunized, are still reservoirs of the bacterium and contribute to its dissemination. Antimicrobials are largely employed for the prophylaxis of bovine anaplasmosis. However, they are often used in sublethal doses which may select pre-existing resistant bacteria and induce genetic or phenotypic variations. Therefore, we propose a new standardized in vitro assay to evaluate the susceptibility of A. marginale strains to different antimicrobials. This tool will help health professionals to choose the more adequate treatment for each herd which will prevent the selection and spread of resistant strains. For that, we initially evaluated the antimicrobial susceptibility of two field isolates of A. marginale (Jaboticabal and Palmeira) infecting bovines. The least susceptible strain (Jaboticabal) was used for the standardization of an antimicrobial assay using a culture of Ixodes scapularis-derived tick cell line, ISE6. Results showed that enrofloxacin (ENRO) at 0.25, 1 or 4 μg/mL and oxytetracycline (OTC) at 4 or 16 μg/mL are the most efficient treatments, followed by OTC at 1 μg/mL and imidocarb dipropionate (IMD) at 1 or 4 μg/mL. In addition, this proposed tool has technical advantages compared to the previously established bovine erythrocyte culture. Thereby, it may be used to guide cattle farmers to the correct use of antimicrobials. The choice of the most suitable antimicrobial is essential to eliminate persistent infections, prevent the spread of resistant strains and help controlling of bovine anaplasmosis.

Naphthylisoquinoline alkaloids and their synthetic analogs as potent novel inhibitors against Babesia canis in vitro

Babesia canis is the predominant and clinically relevant canine Babesia species in Europe. Transmitted by vector ticks, the parasite enters red blood cells and induces a severe, potentially fatal hemolytic anemia. Here, we report on the antibabesial activities of three extracts of the West African tropical plant species Triphyophyllum peltatum (Dioncophyllaceae) and Ancistrocladus abbreviatus (Ancistrocladaceae) and of 13 genuine naphthylisoquinoline alkaloids isolated thereof. Two of the extracts and eight of the alkaloids were found to display strong activities against Babesia canis in vitro. Among the most potent compounds were the C,C-coupled dioncophyllines A (1a) and C (2) and the N,C-linked alkaloids ancistrocladium A (3) and B (4), with half-maximum inhibition concentration (IC50) values of 0.48 μM for 1a, 0.85 μM for 2, 1.90 μM for 3, and 1.23 μM for 4. Structure-activity relationship (SAR) studies on a small library of related genuine analogs and non-natural synthetic derivatives of 1a and 2 revealed the likewise naturally occurring alkaloid N-methyl-7-epi-dioncophylline A (6b) to be the most potent (IC50, 0.14 μM) among the investigated compounds. Although none of the tested naphthylisoquinolines showed 100 % inhibition of parasite infection – as displayed by imidocarb dipropionate (IC50, 0.07 μM), which was used as a positive control – the antibabesial potential of the dioncophyllines A (1a) and C (2) and related compounds such as 6b, its atropo-diastereomer 6a (IC50, 1.45 μM), and 8-O-(p-nitrobenzyl)dioncophylline A (14) (IC50, 0.82 μM) is to be considered as high. The SAR results showed that N-methylation and axial chirality exert a strong impact on the antibabasial activities of the naphthylisoquinolines presented here, whereas dimerization, as in jozimine A2 (5) (IC50, 140 μM), leads to a significant decrease of activity against B. canis. Alkaloids displaying good to high activities against B. canis like the dioncophyllines 1a, 2, 6a, and 6b were found to cause only a small degree of hemolysis (< 0.7 %), whereas compounds with moderate to weak antibabesial activities such as 6-O-methyl-4′-O-demethylancistrocladine (15a) (IC50, 14.0 μM) and its atropo-diastereomer 6-O-methyl-4′-O-demethylhamatine (15b) (IC50, 830 μM) caused a high degree of hemolysis (7.3 % for 15a and 11.2 % for 15b). In this respect, the most effective anti-Babesia naphthylisoquinolines are also the safest ones.

Validated Stability Indicating Chromatographic Methods for Quantification of Imidocarb Dipropionate; Application for the Determination of Its Residues in Bovine Meat and Milk Samples.

Imidocarb dipropionate (IMD) is an immunomodulator agent commonly used for treatment of anaplasmosis in cattle. Thus, two sensitive, specific, and precise stability-indicating chromatographic methods have been developed, optimized, and validated for its determination in presence of its acid, alkaline, and oxidative stressed degradation products. The first method is based on separation of IMD and its forced induced degradation products on reversed phase cyano column using isocratic elution system consisted of sodium acetate buffer-methanol-acetonitrile (55: 30:15, v/v/v), pH 4.6 at a flow rate of 1.2 mL/min, and UV detection at 254 nm. The second method utilized TLC combined with densitometric determination of the separated bands at 254 nm. The separation was achieved using silica gel 60 F254 TLC plates with a mixture of ethyl acetate-methanol-ammonia-water (8.5:1:0.5:0.2, v/v/v/v) as a developing system. HPLC analysis was applied in range of 0.25-40 µg/mL with LOD of 0.073 µg/mL. While densitometric measurements showed linearity in the range of 0.1-1.8 µg/band with LOD of 0.02 µg/band. The suggested methods were validated in compliance with the ICH guidelines and were successfully applied for determination of IMD in its commercial veterinary formulations with good recoveries. Furthermore, the proposed HPLC method was extended to the determination of IMD residues in bovine meat and milk samples. Bovine meat, HPLC, Imidocarb dipropionate, Milk, TLC.

Comparison of therapeutic efficacy of different drugs against Trypanosoma vivax on experimentally infected cattle

In this study, we evaluated the therapeutic efficacy of diminazene diaceturate at a dose of 7 mg/kg (DA), imidocarb dipropionate at 4.8 mg/kg (IMD), isometamidium chloride at 0.5 and 1.0 mg/kg (ISM 0.5 and ISM 1.0) and combinations applied through different methods to treat Trypanosoma vivax in experimentally infected calves. Thirty male Girolando calves were kept indoors and infected intravenously with T. vivax trypomastigotes (approximately 1 × 106). On D-1, the calves were randomized based on the quantity of infecting parasites per animal, yielding six groups of five animals each: G1: positive control group without treatment; G2 animals treated with DA on Day 0 intramuscularly (IM); G3 animals treated with IMD on Day 0 and D + 14 subcutaneously; G4 animals treated with ISM 0.5 on Day 0 IM; G5 animals treated with ISM 1.0 on Day 0 IM; G6 animals received DA on Day 0 and ISM 1.0 on D + 14, both IM. Throughout 180 days, blood samples were collected for the evaluation of T. vivax using the Woo, Brener and PCR methods. The results indicated that the treatment protocols with DA and/or ISM 0.5 and ISM 1.0 had high efficacy (100 %) against T. vivax. Interestingly, cattle that received ISM remained free of parasites until D + 180. In contrast, animals treated with IMD had relapsed T. vivax detected on the 10th and 14th days post-treatment (DPT). Cattle that received ISM 1.0 did not exhibit relapsed T. vivax in the blood, even after reinfection performed on the 50th DPT. However, treatment with DA on Day 0 failed to prevent a new infection of T. vivax on the 50th DPT. The animals that received ISM 1.0 had a transient decrease in packed cell volume similar to that found in the control group. The reappearance of T. vivax in herds in Brazil treated with DA likely occurred due to the short half-life of the drug and not necessarily due to T. vivax resistance to DA.

Closing the empty anti-Babesia gibsoni drug pipeline in vitro using fluorescence-based high throughput screening assay

In the current study, we evaluated the usefulness of a SYBR Green I (SG I) fluorescence assay for evaluation of the inhibitory effects of antibabesial drugs against the in vitro growth of Babesia gibsoni. Linearity and high-throughput screening (HTS) assays exhibited the validity of the SG I fluorescence assay for B. gibsoni parasite when performed at low hematocrits (HCTs) (2.5% and 5%) without daily changing of the medium. Interestingly, 5% HCT showed the highest value of the signal/noise ratio. Of note, there were no significant differences (P > .05) in the IC50s of the commonly used antibabesial drugs (diminazene aceturate and/or imidocarb dipropionate) that calculated by either the SG I fluorescence assay with and without daily medium changing or by the fluorescence and microscopy methods at 2.5% and 5% HCTs. Such results confirmed that both HCTs are valid for mass drug screening against the in vitro growth of B. gibsoni. While the results of the HTS assay add merit to the assay when performed at 5% HCT especially when incubating the plates for 2 h in a dark after adding lysis buffer with SG I stain. Next, nine different drugs were screened to confirm the assay's usefulness. MMV396693, pyronaridine tetraphosphate and nerolidol drugs exhibited the highest effectiveness against the in vitro growth of B. gibsoni, next to diminazene aceturate. In summary, SG I fluorescence assay with 5% HCT without daily changing of the medium for B. gibsoni offers a novel approach for the large-scale screening of huge chemical libraries in in vitro cultures.

Nano Green Voltammetric Determination of Imidocarb Dipropionate and Its Residues in Bovine Meat, Milk and Urine Samples

Imidocarb dipropionate (IMD) is an antimicrobial agent that is widely used in veterinary medicine for treatment of many diseases especially anaplasma marginale in cattle. This may lead to the retention of its residues in edible bovine tissues, milk and urine samples. Thus the quick determination of minor concentrations of IMD is of great interest to ensure food safety. A novel electrochemical sensor was introduced for the sensitive, fast and selective determination of IMD in drug substance and commercial product, furthermore its application to determine IMD residues in bovine meat, milk and urine samples. The prepared nanoparticles sensor was based on a multiwalled carbon nanotube composite modified with gold nanoparticles GNPs/MWCNT. The linear response obtained for IMD using the GNP/MWCNT was found to be over the range of 0.20–3.6 n mol l−1 with a good linearity and high correlation (0.9999). The limits of detection and quantification were found to be 36 p mol l−1 and 109 p mol l−1 respectively. The developed method was simple, rapid, economic, and challenging to green chemistry. The high sensitivity, good reproducibility, and wide linear range mark the modified electrode suitable for determination of the residues in bovine meat and milk as real samples with excellent recoveries.

Efficacy of oral Cynara scolymus and Silybum marianum on toxicity of imidocarb dipropionate in horses.

BackgroundDespite hepatotoxic effects, imidocarb dipropionate is the drug of choice for treatment of equine piroplasmosis. It is important, therefore, to identify adjuvant therapies that may improve the safety of imidocarb dipropionate by reducing the risk of liver damage during its use. The aim of the present study was to evaluate the hepatoprotective and hepatoregulatory effects of treatment with Cynara scolymus and Silybum marianum during administration of imidocarb dipropionate.MethodsTen healthy horses, seroconverted to Theileria equi by C-ELISA, were treated with 5 mg/kg/day of imidocarb dipropionate for three consecutive days. The study population was divided into two groups. The control group did not receive any complementary treatments. The treated group received a daily oral supplement containing C scolymus and S marianum for 30 days. Physical, haematological and histological examinations of hepatic fragments were performed.ResultsAll haematological values remained within normal range for the study population. Histological analysis revealed that treated group animals had 62 per cent less lobular inflammation, 55 per cent less pigment accumulation, 65 per cent less steatosis and 57 per cent less portal inflammation than control group animals, with an equivalent percentage of hydropic degeneration.ConclusionC scolymus and S marianum supplements resulted in beneficial hepatoprotective effects in horses treated with imidocarb dipropionate.

Chemoprophylaxis for babesiosis and anaplasmosis in cattle: case report.

Cattle tick fever (CTF) causes significant economic losses in the livestock sector. The pathogenic action of the hemoparasites is associated with anemia, weight loss, abortion and reduced productivity, which result with animal death. Programs to prevent CTF involve several procedures, including immunization, chemoprophylaxis and use of ectoparasiticides, together with the vector control in the environment. The objective of this study was to report an acute outbreak of CTF in a group of 157 Hereford cattle from a farm without presence of the vector, that were moved to a farm in the same state with a high tick infestation (Rhipicephalus microplus). On the day before the transportation, the animals received a chemoprophylaxis with imidocarb dipropionate (3 mg/kg, SC), which was repeated 21 days after the first application. After 42 days, some animals showed signs compatible with CTF, which was confirmed through clinical examination, necropsy, histopathological and hemoparasitological analyses. The morbidity rate was 37.6% and the mortality rate was 24.8%. Calves that were recently weaned were the group most affected with the tick fever, morbidity (100% and mortality (73%). Chemoprophylaxis in association with use of ectoparasiticides was not sufficient to control the outbreak of the disease.

Comparative Efficacy of Imidocarb Dipropionate and Oxytetracycline-Doxycycline Combination Therapy in Ehrlichia Infected Dogs

Comparative Efficacy of Imidocarb Dipropionate and Oxytetracycline-Doxycycline Combination Therapy in Ehrlichia Infected Dogs

Emerging status of anaplasmosis in cattle in Sirajganj district with therapeutic evaluation of traditional treatments

The present study was carried out to detect the prevalence of anaplasmosis in cattle at Rayganj and Ullahpara upazila in Sirajganj district of Bangladesh and to evaluate the therapeutic efficacy of traditional drugs like Oxetetracycline (Renamycine®), Imidocarb diproprionate (Babenil®) and Diminazine aceturate (Berenil®) against anaplasmosis in cattle. The study was conducted from July 2016 to December 2016. During six months of study period a total of 150 blood samples were collected from clinically ill and suspected cattle, among which 28 samples were positive for anaplasmosis by Geimsa stained blood smear method. It was observed that the overall prevalence of anaplasmosis in cattle was 18.67%, where 16.25% was Geimsa stained blood smear at Rayganj and 21.43% at Ullapara upazila respectively and the variation was not statistically significant (p&gt;0.05). In respect of age the prevalence of anaplasmosis was significantly (p&lt; 0.05) higher (31.7%) in 2-3 years of age group cattle than above 3 years (16.67%) and 6 months to 2 years age (10.20%) group. On the basis of sex, it was observed that the variation in prevalence in male (15.94%) and female (20.99%) was not statistically significant (p&gt;0.05). Breed-wise prevalence was higher in crossbred cattle (19.5%) than local cattle (17.8%), was not statistically significant (p&gt;0.05). It was observed that among three drugs used in this study, the best effectiveness of drugs was seen by Oxytetracycline (Renamycine LA®) @ 10 mg/kg body weight followed by Imidocarb dipropionate (Babenil®) @ 3.5 mg/kg body weight moderately and less by Diminazine aceturate (Berenil®) @ 3.5 mg/kg body weight. From the study it was evident that cattle were infected with the organisms and caused a heavy economic loss which recommended taking necessary preventive measurements.&#x0D; Asian Australas. J. Biosci. Biotechnol. 2019, 4 (3), 162-168

Screening the Medicines for Malaria Venture Pathogen Box against piroplasm parasites

Diminazene aceturate (DA) and imidocarb dipropionate are commonly used in livestock as antipiroplasm agents. However, toxic side effects are common in animals treated with these two drugs. Therefore, evaluations of novel therapeutic agents with high efficacy against piroplasm parasites and low toxicity to host animals are of paramount importance. In this study, the 400 compounds in the Pathogen Box provided by the Medicines for Malaria Venture foundation were screened against Babesia bovis, Babesia bigemina, Babesia caballi, and Theileria equi. A fluorescence-based method using SYBR Green 1 stain was used for initial in vitro screening and determination of the half maximal inhibitory concentration (IC50). The initial in vitro screening performed using a 1 μM concentration as baseline revealed nine effective compounds against four tested parasites. Two “hit” compounds, namely MMV021057 and MMV675968, that showed IC50 < 0.3 μM and a selectivity index (SI)> 100 were selected. The IC50s of MMV021057 and MMV675968 against B. bovis, B. bigemina, T. equi and B. caballi were 23, 39, 229, and 146 nM, and 2.9, 3, 25.7, and 2.9 nM, respectively. In addition, a combination of MMV021057 and DA showed additive or synergistic effects against four tested parasites, while combinations of MMV021057 with MMV675968 and of MMV675968 with DA showed antagonistic effects. In mice, treated with 50 mg/kg MMV021057 and 25 mg/kg MMV675968 inhibited the growth of Babesia microti by 54 and 64%, respectively, as compared to the untreated group on day 8. Interestingly, a combination treatment with 6.25 mg/kg DA and 25 mg/kg MMV021057 inhibited B. microti by 91.6%, which was a stronger inhibition than that by single treatments with 50 mg/kg MMV021057 and 25 mg/kg DA, which showed 54 and 83% inhibition, respectively. Our findings indicated that MMV021057, MMV675968, and the combination treatment with MMV021057 and DA are prospects for further development of antipiroplasm drugs.

Concurrent infection of Leptospira icterohaemorrhagiae, Hepatozoon canis and Anaplasma phagocytophilum in a Labrador Retriever dog and its therapeutic management

In this report, concurrent infection of Leptospira interrogans serovar icterohaemorrhagiae, Hepatozoon canis and Anaplasma phagocytophilum in a Labrador Retriever dog and its successful therapeutic management have been described. A 3-year-old female dog was presented with a history of anorexia, fever, lethargy, weakness, vomiting, black-coloured faeces and yellowish urine. Clinical and laboratory examination revealed pyrexia, icteric mucous membranes, hepatomegaly, splenomegaly, anaemia, leukocytosis, thrombocytopaenia, hypoalbuminemia and hyperbilirubinemia. Hepatozoon canis and Anaplasma phagocytophilum infections were confirmed by blood smear examination. Leptospira icterohaemorrhagiae was confirmed by microscopic agglutination test (MAT). Animal was stabilised with polyionic fluids, and therapy was started with imidocarb dipropionate (6.6 mg/Kg, SC, single dose), doxycycline (5 mg/kg, PO, bid) for 28 days, N-acetyl cysteine (30 mg/Kg, IV, SID) for 5 days and fipronil (0.25%) spray for topical use. Supportive therapy was done with plasma volume expanders, multivitamins, haematinics and hepatoprotectants. The animal showed complete recovery after 2 months of therapy.

Ameliorative effects of alpha-lipoic acid and imidocarb dipropionate on clinico-haematological changes induced by experimental Babesia canis vogeli infection in dogs

The aim of the study was to evaluate the effects of imidocarb dipropionate and alpha-lipoic acid (ALA) on clinico-haematological parameters of dogs inoculated with Babesia canis vogeli. Twenty-one dogs were divided into uninfected untreated (n = 4), infected untreated (n = 6), infected and treated with imidocarb dipropionate (6 mg/kg subcutaneously) alone (n = 3), infected and treated with ALA (15 mg/kg orally) alone (n = 5), and infected and treated with both imidocarb dipropionate and ALA (n = 3). Molecularly identified Babesia canis vogeli was experimentally inoculated into the infected groups, and treatment commenced at day 12 post-inoculation (PI). Behavioural events and blood samples were obtained and analysed before inoculation, at days 11 PI, 8, 15, and 43 post-treatment (PT). Behavioural events including vocalisation, licking/grooming, and tail wagging decreased post-inoculation. Treatments with imidocarb and ALA alleviated the clinical manifestations of dry muzzle, ocular discharge, and splenomegaly. At days 15 and 43 PT, imidocarb + ALA recorded the highest packed cell volume (41.13 ± 2.96%; 47.40 ± 3.72%) and erythrocyte count (6.10 ± 0.44 × 1012/L; 6.99 ± 0.56 × 1012/L) compared to other infected groups. The haemoglobin concentration at day 15 PT (13.80 ± 0.91 g/dL) increased in the imidocarb + ALA group. Thrombocytopenia was recorded in all the infected groups at day 11 PI. In conclusion, co-administration of imidocarb with ALA acted synergistically and also ameliorated the clinico-haematological changes in experimental canine babesiosis, and the agent may be a promising and potent drug in the management of canine babesiosis.

Lumefantrine and o-choline – Parasite metabolism specific drug molecules inhibited in vitro growth of Theileria equi and Babesia caballi in MASP culture system

Theileria equi and Babesia caballi are tick-borne apicomplexan haemoprotozoan parasites of equines and are responsible for considerable economic losses to stakeholders. Chemotherapeutic drugs that are available not only require multiple dosages but also prompt multiple organ toxicity in treated host though incapable of clearing parasitaemia completely. In this study, we have screened the in vitro inhibitory efficacy of four different drug molecules (o-choline, DABCO®, lumefantrine and eugenol) against T. equi and B. caballi, targeting different parasite metabolism pathways. Imidocarb dipropionate and diminazene aceturate were used as reference control drugs. The 50% in vitro growth inhibitory concentration (IC50) of lumefantrine, o-choline, DABCO® and eugenol for T. equi were: 30.90 μM; 84.38 μM; 443 μM; 120 μM and for B. caballi growth inhibition were: 5.58 μM; 135.29 μM; 150 μM; 197.05 μM, respectively. Imidocarb dipropionate inhibited the in vitro growth of T. equi at IC50 of 257.5 nM, while diminazene aceturate inhibited the in vitro growth of B. caballi at IC50 of 22 nM. DABCO® and eugenol were not so effective in inhibiting the in vitro growth of T. equi and B. caballi, while lumefantrine and o-choline significantly (p ≤ 0.05) inhibited the in vitro growth of these piroplasms targeting haem digestion and parasite membrane phospholipid synthesis.

Babesiosis in the UK and approach to treatment

Babesiosis is a vector-borne disease of cattle which, in the UK, is caused by two species — Babesia divergens and Babesia major. Disease is sporadically seen in western Britain with a peak in the spring and another in the autumn. The most recognisable clinical sign is haemoglobinuria which gives babesiosis the colloquial name of ‘redwater fever’. Other clinical signs are pyrexia of 40°C, anorexia, depression, weakness, tachycardia and pipe stem diarrhoea, which progress to severe dehydration, recumbency and death in up to 21% of cases. Diagnosis is based on history, clinical signs, confirmation of anaemia and examination of stained blood smears. Treatment involves administration of imidocarb dipropionate in all cases. Blood transfusion is indicated in cattle with a packed cell volume of less than 15%. Prevention is challenging in naïve adults as there is no commercially available vaccination; exposing youngstock to ticks should ensure natural immunity is acquired.