Therapeutic and persistent efficacy of a single injection treatment of ivermectin and moxidectin against Boophilus microplus (Acari: Ixodidae) on infested cattle

Abstract

The effectiveness of a single treatment with either ivermectin or moxidectin was determined by administering a single subcutaneous injection of each endectocide at 200 microg per kg body weight to cattle infested with all parasitic developmental stages (adults, nymphs, and larvae) of Boophilus microplus (Canestrini). The percentage reduction in the number of females that reached repletion following treatment (outright kill) was 94.8 and 91.1% for ivermectin and moxidectin, respectively. In addition, the reproductive capacity of the females that did survive to repletion was reduced by > 99%, regardless of the endectocide. Based on these two factors, the therapeutic level of control obtained against ticks on the cattle at the time of treatment was 99.0 and 99.1% for ivermectin and moxidectin, respectively. Engorged females recovered from either group of treated cattle weighed approximately 3-times less than untreated females, and the egg masses produced by treated females weighed approximately 5-8-times less than egg masses produced by untreated females. Partitioning of data into three separate 7-d post-treatment intervals allowed for an estimation of the efficacy of each endectocide against each individual parasitic development stage (adult, nymph, and larva). Results indicated that both endectocides were > or =99.7% effective against ticks that were in either the adult or nymphal stage at the time of treatment. However, the level of control against ticks in the larval stage of development at treatment was significantly lower at 97.9 and 98.4% for ivermectin and moxidectin, respectively. Analysis of the persistent (residual) activity of the two endectocides indicated that neither material provided total protection against larval re-infestation for even 1-wk following treatment. Against larvae infested 1-4 wk following treatment, the level of control with moxidectin ranged from 92.4% (1 wk) to 19.5% (4 wk). These control levels were higher at each weekly interval than for ivermectin, which ranged from 82.4% (1 wk) to 0.0% (4 wk). The potential for the use of these injectable endectocide formulations in the US Boophilus Eradication Program is discussed.

Injectable eprinomectin for cattle: Tick efficacy and pharmacokinetics

“…Since the efficacy of subcutaneously administered EPM against R. microplus has not yet been reported, the results of the present experiment could not be compared with other data. However, efficacy similar to that found in previous studies using different doses with pour on formulations was achieved; these studies include those of Davey, Miller, George, and Miller () (0.5 mg/kg), Aguirre et al () (1 mg/kg), and Lifschitz et al () (1.0 mg/kg and 1.5 mg/kg). Similar studies were conducted by Davey et al () with injectable ivermectin and moxidectin and by Davey, Miller, George, and Klavons () with injectable doramectin.…”

“…Mean pharmacokinetic parameters, standard deviation, and coefficient of variation obtained from plasma analysis of 12 treated animals NASCIMENTo ET Al.subcutaneously administered EPM against R. microplus has not yet been reported, the results of the present experiment could not be compared with other data. However, efficacy similar to that found in previous studies using different doses with pour on formulations was achieved; these studies include those ofDavey, Miller, George, and Miller (2005) (0.5 mg/kg),Aguirre et al (2005) (1 mg/kg), andLifschitz et al (2016) (1.0 mg/kg and 1.5 mg/kg). Similar studies were conducted by…”

“…Pharmacokinetics of avermectins are known to be influenced by the route of administration (Lanusse et al, 1997), but are also affected by the formulation (Shargel, Wu-Pong, & Yu, 2004), which may explain the differences found in our study. Davey et al (2005) with injectable ivermectin and moxidectin and by Davey, Miller, George, and Klavons (2007) with injectable doramectin. These two studies used a dose of 200 μg/kg, which was similar to that used in this experiment.…”

Effect of ivermectin on the integument and dorsoventral muscles of the tick Argas (Persicargas) persicus (Oken) (Ixodoidea: Argasidae)

“…It has exceptional potency against endo-and ectoparasites of human and domestic animals at extremely low doses which accounts for its large margin of safety (Dryden and Payne 2005;Mamak et al 2006;Badiaga et al 2008;Ly et al 2009;Canga et al 2009). Knowledge of the impact of IVM on ticks was mainly confined to biological parameters of hard ticks after subcutaneous injection of their hosts (Davey et al 2005;Pereira 2009;Sajid et al 2009). Information about the histopathological consequences of IVM against acarine organs remains limited (Montasser 2003;.…”

Biological Parameters of <i>Rhipicephalus</i> (<i>Boophilus</i>) <i>microplus</i> (Acari: Ixodidae) Fed on Rabbits, Sheep, and Cattle

“…In China, R. microplus is the most widespread tick species distributed in 23 provinces [ 4 ] and the vector of Babesia bovis , B. bigemina , Anaplasma marginale , and Coxiella burnetii [ 2 , 5 , 6 ]. Consequently, there are lots of papers which reported the control techniques of R. microplus , such as medicine treatment [ 7 - 9 ], bio-control ( Beauveria bassiana and Metarhizium anisopliae ) [ 10 - 13 ], and vaccination [ 14 ].…”