Control of induced infestations of three African multihost tick species with sustained-release ivermectin

Soll, M. D.; Carmichael, I. H.; Swan, G.E.; Gross, Sheila J.

doi:10.1007/bf01270432

Cited by 18 publications

(10 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the current unavailability of the bolus does not diminish its potential for long-term toxic impact in cow-pats. It is significant that the same devices, some delivering 50% more ivermectin than that examined by Wall & Strong (1987), are constantly being tested against arthropod and nematode pests of cattle (Soil et a\., 1989;Taylor & Kenny, 1990;Zimmerman et ah, 1991); no one can doubt that it is only a matter of time before the bolus is marketed. The consequences for dung insects and pastureland ecology will be severe (Wall & Strong, 1987;), a conclusion supported by Houlding et al (1991) who assert that the detrimental impact of abamectin on Australian dung beetles could be considerably more serious if sustained-release administration were to be deployed.…”

Section: Impact Of the Type Of Treatmentmentioning

confidence: 97%

Avermectins: a review of their impact on insects of cattle dung

Strong

1992

Bull. Entomol. Res.

117

View full text Add to dashboard Cite

Avermectins administered to cattle for control of parasitic infections by injection or slow-release bolus are excreted in the faeces and have a variety of harmful effects upon Diptera and Coleoptera that develop in cow-pats: these effects are reviewed. Diptera Cyclorrhapha are severely affected, the extent of the response depending on the drug concentration in the dung. At high levels, larvae are killed or paralysed while at lower levels their metamorphosis is inhibited. At very low levels, adult emergence is reduced and a significant number of imagines show morphological abnormalities. These responses are induced by concentrations of avermectins well below levels occurring in faeces after routine treatment. Diptera Nematocera are less sensitive than Cyclorrhapha but larval and pupal development are affected at higher dose levels. Larval dung beetles and some immature adults cannot survive in the pats of recently dosed livestock. Mature adult beetles are more resistant, but contact with treated dung leads to impaired reproduction. Dung eliminated up to 5 weeks after cattle have been treated with a single injection or up to 14 days after topical dosing shows harmful activity against dung insects, and ivermectin-containing pats retain much of their toxicity after several weeks exposure on pastureland. The impact on dung insects is more pronounced and of longer duration when ivermectin is delivered daily at 40 (ig per kg cow by sustained-release bolus. Following topical or injection treatments, the rate of cow-pat degradation (measured by actual loss of biomass) is significantly delayed. When cattle are treated with a bolus delivering 40 mg ivermectin per kg cow per day, their dung remains intact on grassland for at least three months. The conclusions drawn from the various papers on these effects are compared and contrasted. In particular, attention is drawn to the general failure to recognize the importance of delayed reactions to non-lethal doses of avermectins, and to our lack of consideration of long-term consequences for cow-pat insects and the wider implications for ecology.

show abstract

Section: Impact Of the Type Of Treatmentmentioning

confidence: 97%

Avermectins: a review of their impact on insects of cattle dung

Strong

1992

Bull. Entomol. Res.

117

View full text Add to dashboard Cite

show abstract

“…The effects of ivermectin on ixodid ticks are not only of chemotherapeutic importance but also have inherent biological interest. A diverse number of sublethal effects have been recorded amongst ticks feeding on livestock treated with ivermectin, including the inhibition of engorgement, premature detachment, and reduced fecundity (Drummond et al, 1981;Lancaster et al, 1982;Soll et al, 1987) suggesting that GABA may play a central role in neurotransmission. This view is reinforced by in-vitro experiments which have demonstrated that ivermectin inhibits neurotransmission within both isolated tick neuromuscular junctions and salivary gland tissue (Gration et al, 1986;Kaufman et al, 1986;Lindsay and Kaufman, 1986); the latter plays a central role in the co-ordination of the processes of feeding, detachment and vitellogenesis in ticks.…”

Section: Introductionmentioning

confidence: 98%

In-vivo effects of ivermection onRhipicephalus appendiculatus: the influence of tick feeding patterns and drug pharmacokinetics

Jackson¹,

Chesterman²

1989

Exp Appl Acarol

View full text Add to dashboard Cite

Sublethal effects seen amongst Rhipicephalus appendiculatus feeding on ivermectin-treated rabbits were diverse and dependent both on drug dose, pharmacokinetics and tick feeding patterns: changes in drug formulation, the time of infestation relative to treatment, and the tick instar used, profoundly influenced acaricidal activity. Death was a sequel to paralysis only if tick feeding was interrupted for sufficient time to produce irreversible dehydration. Concurrent pharmacokinetic investigations revealed that, for the larvae of R. appendiculatus, the mean critical lethal dose of ivermectin imbibed over a 5-day engorgement period was 3500 micrograms/kg. This quantity of ivermectin was achieved in the blood-meals of larvae feeding on rabbits treated subcutaneously with a single dose of Ivomec injection (MSD)* greater than or equal to 800 micrograms/kg, provided infestation took place within 24 h of treatment. At lower drug doses, or if larval infestations were delayed for greater than 24 h post-treatment, the quantity of circulating ivermectin (and thus imbibed by the tick larvae) fell below 3500 micrograms/kg and an increasing percentage of larvae successfully engorged and detached. More than 90% of such larvae moulted to the nymphal stage. Nymphae and larvae exhibited similar susceptibility to ivermectin on treated rabbits which could be explained by similar feeding patterns. However, adult female and male ticks were markedly less susceptible and interpretation of ivermectin-induced effects was more complex.

show abstract

“…Numerous studies have shown that ivermectin can control a variety of tick species (Drummond et al 1981. Nolan et al 1981Lancaster et al 1982;Miller et al 1983Miller et al , 1998Pegram and Lemche 1985;Cramer et al 1988;Taylor and Kenny 1990, Soll et al 1989.…”

Section: Because Of the United States Boophilus Eradicationmentioning

confidence: 98%

The Ivomec SR Bolus for Control of <I>Boophilus annulatus</I> (Acari: Ixodidae) on Cattle in South Texas

Miller¹,

Davey²,

Oehler³

et al. 2001

View full text Add to dashboard Cite

When Hereford heifers infested with Boophilus annulatus (Say) were treated with a single Ivomec SR Bolus, the concentration of ivermectin in the serum of the treated cattle reached a maximum of 8.8 +/- 0.9 ppb at 2 wk posttreatment. The single bolus treatment resulted in 84.4% control of standard engorging B. annulatus females on treated cattle over the 20-wk trial. Although fewer engorged ticks were collected from the sentinel heifers exposed in the treated pasture than those in the control pasture at weeks 4, 10, and 16 posttreatment, none of the differences was statistically significant. Each exposure of sentinel cattle found free-living ticks in both the treated and control pastures, indicating the infestation was not eliminated by the treatment. When the trial was repeated using two Ivomec SR Boluses/heifer, the concentration of ivermectin in the serum of the treated cattle reached a maximum level of 31.2 +/- 3.9 ppb at week 13 posttreatment. The use of two boluses/heifer resulted in 99.6% control of standard engorging B. annulatus females over the 20-wk trial. No ticks were found on sentinels placed in the treated pasture after week 9 posttreatment, an indication that the treatment had eliminated the free-living population in the treated pasture. From these studies, we conclude that a single Ivomec SR Bolus is incapable of sufficient control of B. annulatus to meet the rigid requirements of the Cattle Fever Tick Eradication Program in South Texas. Although two boluses per animal did eliminate the ticks from treated heifers and the pasture they were in, the treatment would not be sufficiently efficacious for mature cattle (>400 kg) for it to be useful in the program.

show abstract

Control of induced infestations of three African multihost tick species with sustained-release ivermectin

Cited by 18 publications

References 10 publications

Avermectins: a review of their impact on insects of cattle dung

Avermectins: a review of their impact on insects of cattle dung

In-vivo effects of ivermection onRhipicephalus appendiculatus: the influence of tick feeding patterns and drug pharmacokinetics

The Ivomec SR Bolus for Control of <I>Boophilus annulatus</I> (Acari: Ixodidae) on Cattle in South Texas

Contact Info

Product

Resources

About