Anthelmintic Drugs: Their Efficacy and Cost-Effectiveness in Different Parity Cattle

Cost-benefit ratio of anthelmintic treatment and its comparative efficacy in commercial dairy farms

Intestinal parasitic infection is one of the major challenges in obtaining optimal production and maintaining the health and welfare of all animals including cattle and buffaloes. Anti-parasitic treatments appear to be a reliable countermeasure. However, the effectiveness and selection of suitable anthelmintics require situational assessments in a given locality. In the current study, the efficacy and impact of benzimidazole (albendazole) were assessed in a total of 400 (100 each) on the performance of buffaloes, buffalo-heifer, cattle, and cattle-heifers at two commercial dairy farms in the Province of Punjab, Pakistan. Additionally, the cost-benefit ratio was calculated by assessing the inputs (medication, feed, and labor cost) and outputs (milk and weight gain). The qualitative and quantitative examination of helminth eggs in each type of animal indicated a prevalence of 73.3, 78.3, 76.6, and 85.0% in cattle, cattle-heifers, buffaloes, and buffaloes-heifers, respectively. Specifically, a highest rate (10.0-13.3%) of Haemonchus sp. infection was only observed in cattle and heifers, while Fasciola sp. infections (10.0-11.6%) were the most often found species in buffaloes and heifers. The highest anthelmintic impacts (egg per gram of feces, p < 0.001) were observed on day 14 post-medication. Until 60 days of post-anthelmintic treatment, an average increase of 0.8 and 0.7 L in milk production per day in cattle and buffaloes, respectively while a total of 11.45 and 9.45 kg body weight were noticed in cattle-heifer and buffaloes-heifer, respectively. Cumulative cost-benefit analysis indicated a positive correlation between treated and non-treated animals. These findings reiterate the importance of anthelmintic drugs in reducing the impacts of parasites on the productivity, health, and well-being of an animal under high infection challenges.

Environmental risk assessment of the anthelmintic albendazole in Eastern Africa, based on a systematic review

This study performs an environmental risk assessment (ERA) of the anthelmintic medicine albendazole (ABZ) in the eastern African region. A systematic literature search strategy was applied to obtain quantitative information on the physicochemical characteristics, the metabolization-fate, the ecotoxicity and the environmental occurrence in different countries worldwide serving as model regions. In addition, insilico tools were employed to obtain data on physicochemical characteristics and toxic hazards of ABZ and its metabolites. Moreover, ERA models were used to predict environmental concentrations in different compartments and compare them with the measured environmental concentrations. Finally, the environmental risk of ABZ in the eastern Africa was estimated by calculating the risk quotient (RQ), and its uncertainty estimated by Monte Carlo simulation. The predicted environmental concentrations of ABZ in surface water in the model region based on consumption (1.6-267 ng/L) were within the range of values obtained from the measured environmental concentrations of the same region (0.05-101,000 ng/L). Using these models with adapted input variables for eastern Africa, the predicted surface water concentration in that region was 19,600 ± 150 ng/L (95% CI). The calculated soil concentrations of ABZ in the model regions and the eastern Africa were found to be 0.057 ± 0.0 μg/kg and 0.022 ± 0.0 μg/kg, respectively. The environmental risk expressed as risk quotient of ABZ in eastern Africa estimated for the aquatic compartment (146 ± 1) indicated a significant environmental risk calling on appropriate actions from the competent authorities to reduce this risk in this region.

Efficacy of VERYL® in the treatment of cattle naturally infected with gastro-intestinal nematodes in Kenya

Co-infections caused by trypanosomes and gastro-intestinal nematodes (GINs) compromise cattle productivity and their control requires a holistic approach. The effectiveness of trypanocides and anthelmintics is compromised by increasing resistance. Use of combined chemotherapeutic products for synergy, mainly practiced in human medicine, is gaining importance in livestock. A trial to evaluate efficacy of VERYL®, containing diminazene diaceturate (3.5 mg/kg body weight) and levamisole chloride (5 mg/kg body weight) for the control of GINs in cattle, was conducted at KALRO-VSRI Muguga, Kenya, between June and August 2016. Thirty-eight cattle aged between 6 and 12 months, naturally infected with GINs, were randomly allocated into two groups; a treatment group received VERYL® intra-muscularly at 10 mL/100 kg bwt and a control group which received Veriben® (Diminazene aceturate) at 3.5 mg/kg bwt. Faecal egg counts (FECs), coproculture, packed cell volume (PCV) and local tolerance at the injection site were measured during the study. FECs were comparable between the treatment and control groups at day 0. However, treatment of cattle with VERYL significantly (p < 0.001) reduced FECs by day 7 and sustained to day 21 post-treatment. Coproculture results for the treatment and control groups revealed presence of Haemonchus, Cooperia, Ostertagia, Trichostrongylus and Oesophagostomum species. Cattle treated with VERYL® had a significant (p < 0.05) reduction in larval recoveries compared to the control group. VERYL® had minimal adverse effects which cleared after a short while and is thus recommended for controlling GINs in cattle.

Pilot study assessing the possible benefits of a higher level of implementation of biosecurity measures on farm productivity and health status in Belgian cattle farms

Over the last few years, the interest of decision-makers and control agencies in biosecurity (BS), aiming at preventing and controlling the introduction and spread of infectious diseases, has considerably increased. Nevertheless, previous studies highlighted a low implementation level of biosecurity measures (BSM), especially in cattle farms; different reasons were identified such as perceived costs, utility, importance, increased workload and lack of knowledge. In order to convince cattle farmers to adopt BSM, it is necessary to gather more information and evidence on their cost-effectiveness and their importance or utility in terms of disease prevention and control. The objectives of this study were to determine whether the farm or farmers' profile correlated with the implementation level of BSM and if there was a positive correlation between the BSM implementation and the farm production and health parameters. Data were collected through face-to-face interviews conducted in 100 Belgian farms as part of a stratified and randomized survey. The Regional Animal Health Services provided the farm health status and production data. A general BS score and five sub-scores related to the five BS compartments (bio-exclusion, bio-compartmentation, bio-containment, bio-prevention and bio-preservation) were calculated for each farm based on the implementation level of different BSM grouped in 16 domains. The study highlighted a significant and negative correlation between the mortality rates in adult cattle (over 24 months of age) and young calves (aged 0-7 days) and different BS compartment scores. The study also demonstrated that the farms having a higher general BS score were indeed more likely to have a BVD-free status. These evidence-based findings are encouraging as they demonstrate the benefits of implementing BSM and could promote their adoption by farmers.

DARK Classics in Chemical Neuroscience: Aminorex Analogues

Aminorex (5-phenyl-4,5-dihydro-1,3-oxazol-2-amine) and 4-methylaminorex (4-methyl-5-phenyl-4,5-dihydro-1,3-oxazol-2-amine) are psychostimulants that have long been listed in Schedules IV and I of the UN Convention on Psychotropic Substances of 1971. However, a range of psychoactive analogues exist that are not internationally controlled and therefore often classified as new psychoactive substances (NPS). Aminorex analogues encompass failed pharmaceuticals that reemerged as drugs of abuse, and newly synthesized substances that were solely designed for recreational use by clandestine chemists. NPS, sometimes also referred to as "designer drugs" in alignment with a phenomenon arising in the early 1980s, serve as alternatives to controlled drugs. Aminorex and its derivatives interact with monoaminergic neurotransmission by interfering with the function of monoamine transporters. Hence, these compounds share pharmacological and neurochemical similarities with amphetamines and cocaine. The consumption of aminorex, 4-methylaminorex and 4,4'-dimethylaminorex (4-methyl-5-(4-methylphenyl)-4,5-dihydro-1,3-oxazol-2-amine) has been associated with adverse events including death, bestowing an inglorious fame on aminorex-derived drugs. In this Review, a historical background is presented, as well as an account of the pharmacodynamic and pharmacokinetic properties of aminorex and various analogues. Light is shed on their misuse as drug adulterants of well-established drugs on the market. This Review not only provides a detailed overview of an abused substance-class, but also emphasizes the darkest aspect of the NPS market, i.e., deleterious side effects that arise from the ingestion of certain NPS, as knowledge of the pharmacology, the potency, or the identity of the active ingredients remains obscure to NPS users.

A systematic review on modelling approaches for economic losses studies caused by parasites and their associated diseases in cattle

Parasites reside inside or outside their hosts and get host nutrition and blood. Here, we have emphasized economic losses in cattle caused by parasitic diseases due to ecto- and endo- parasites (flies, ticks, mites and helminths). We have outlined different methods/models including economic evaluation techniques and dynamic analysis as a major class, used for the calculation of economic losses caused by parasites in cattle. According to already conducted studies, a decrease in production is mentioned in quantity and percentage while financial losses are expressed in the form of account with respect to per head, herd or for the specific study area. The parasites cause the reduced production and financial losses due to control, treatment and mortality costs. We calculated the average decrease in milk production and organ condemnation as 1.16 L animal-1 day-1 and 12.95%, respectively, from overall cattle parasitic infections. Moreover, the average calculated financial and percentage losses were US$ 50.67 animal-1 year-1 and 17.94%, respectively. Economically important parasitic diseases mentioned here are caused by specific spp. of protozoans and helminths according to data collected from the literature. Protozoan diseases include tick-borne diseases, coccidiosis, neosporosis, trypanosomiasis and cryptosporidiosis. Losses due to tick-borne infections were encountered for decreased milk production, mortality, treatment and control. Losses from coccidiosis were due to decreased weight gain, treatment costs and mortality. While abortion losses were encountered in neosporosis. Trypanosomiasis caused losses due to a decrease in milk yield. Moreover, only diagnostic (conventional or molecular techniques) cost was taken into account for cryptosporidiosis. Economically important nematode parasites are Oesophagostomum spp., Cooperia spp., Trichostrongylus spp., Strongyloides spp., Ostertagia spp. and Haemonchus placei. Due to the zoonotic importance of echinococcosis, Echinococcus granulosus is the most economically important cestode parasite. Losses caused by echinococcosis were due to organ condemnation, carcass weight loss and decreases hide value, milk production and fecundity. While, fascioliasis is one of the most economically important trematodal disease, which causes cirrhosis of the liver due to parasite migration, and thus, the organ becomes inedible. So, it would be helpful for farmers and researchers to approach these methods/models for calculation of parasitic losses and should adopt suitable measures to avoid long-term economic losses.

Economic Significance of Tropical Theileriosis on a Holstein Friesian Dairy Farm in Pakistan

The dairy industry in Pakistan is booming, and investors are anxious to fund dairy farms that are using high-milk-producing (exotic) cattle breeds such as Holstein Friesians that are not native to the country. Unfortunately, the benefits of increased milk production do not provide resistance to pathogens present in regions where the exotic breeds are introduced. Therefore, the current study was conducted to evaluate the economic impact of Theileria annulata on a commercial Holstein Friesian dairy farm in the District of Ranjanpur, in the Province of Punjab, Pakistan. The economic impact of T. annulata infection was calculated for cattle with subclinical and clinical theileriosis. Losses were estimated based on milk production, morbidity, mortality, and tick control costs (organophosphate sprays). Animals were classified into groups after screening for mastitis, teat abnormality, abnormal parturition, intestinal parasites, and hemoparasites ( T. annulata, Babesia spp., and Anaplasma spp.). Microscopy was done for hemoparasites and intestinal parasites. PCR was used to confirm microscopic identification of T. annulata. Animals were classified into 3 groups: group A (normal), group B (subclinical theileriosis), and group C (acute theileriosis). Hemoparasites were observed microscopically in 28.7% of cows. Theileria annulata was found in 8%, and the herd incidence (new cases) of T. annulata was 2.8%. Milk production, animal rectal temperature, and body condition scores between group A and groups B and C were significantly different ( P < 0.05). But the enlargement of sub-scapular lymph node and interval of body condition score of the 3 groups were not significant ( P > 0.05). The total expenditure incurred due to theileriosis was US $74.98 per animal and 13.83% of total farm costs. Hence theileriosis caused significant economic loss of US $18,743.76 (0.02 million) on this Holstein Friesian dairy.