Anticoagulant rodenticides (ARs) are increasingly recognized as a threat to nontarget wildlife. High exposure to ARs has been documented globally in nontarget predatory species and linked to the high ...prevalence of an ectoparasitic disease, notoedric mange. In southern California, mange associated with AR exposure has been the proximate cause of a bobcat (Lynx rufus) population decline. We measured AR exposure in bobcats from two areas in southern California, examining seasonal, demographic and spatial risk factors across landscapes including natural and urbanized areas. The long-term study included bobcats sampled over a 16-year period (1997–2012) and a wide geographic area. We sampled blood (N = 206) and liver (N = 172) to examine exposure ante- and post-mortem. We detected high exposure prevalence (89 %, liver; 39 %, blood) and for individuals with paired liver and blood data (N = 64), 92 % were exposed. Moreover, the animals with the most complete sampling were exposed most frequently to three or more compounds. Toxicant exposure was associated with commercial, residential, and agricultural development. Bobcats of both sexes and age classes were found to be at high risk of exposure, and we documented fetal transfer of multiple ARs. We found a strong association between certain levels of exposure (ppm), and between multiple AR exposure events, and notoedric mange. AR exposure was prevalent throughout both regions sampled and throughout the 16-year time period in the long-term study. ARs pose a substantial threat to bobcats, and likely other mammalian and avian predators, living at the urban-wildland interface.
Although kinship (parent-offspring or siblings) contact has been suggested as a driving factor for sarcoptic mange epizootic in raccoon dogs (Nyctereutes procyonoides), no effect has been reported. ...In contrast, habitat fragmentation caused by urbanization may result in a high occurrence of sarcoptic mange, because habitat fragmentation may promote contact infection by increasing the population density of raccoon dogs. The habitat distribution of raccoon dogs may therefore influence epizootic sarcoptic mange. The genetic relationship between raccoon dogs was analyzed to examine Sarcoptes scabiei transmission between kin. The relationship between S. scabiei infection and the habitat of raccoon dogs was also investigated. Seventy-five raccoon dogs from Takasaki, Gunma prefecture, were examined from 2012 to 2018; 23 were infested with S. scabiei. The genotypes were determined using 17 microsatellite loci, and the relationships were categorized into four patterns by the ML-Relate software. There was no significant difference between infested pairs and other two pairs (Chi-squared test: χ2=0.034, df=1, P=0.85). Although it was difficult to predicate because the mortality rate was unclear in this study, kinship contact does not seem to be an important factor for sarcoptic mange epizootic. S. scabiei infection rates were significantly associated with the location of village sections (OR=1.55, 95%CI=1.11–2.17, P=0.011). It is suggested that direct/indirect contact between individuals living closely together is an important factor for the transmission of S. scabiei.
Extraction and analysis of moxidectin in wombat plasma and faeces Doran, Gregory S; Wynan, Marie; Wynan, Ray ...
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences,
2024-Feb-01, 2024-02-00, 20240201, Letnik:
1233
Journal Article
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Sarcoptic mange in wombats results from a skin infestation by Sarcoptes mites and if untreated, results in a slow and painful death. Moxidectin is a pesticide used to treat internal and external ...parasites in cattle, but has shown to effectively treat other animals, including wombats. Two methods were developed to analyse wombat plasma, and methods were also developed to analyse faeces and fur. Moxidectin-D3 was used as an internal standard and behaved almost identically to moxidectin, resulting in recoveries of 95-105 % across the three matrices, even when matrix interferences caused signal suppression as high 20 %, or when moxidectin loss was high. This was presumably due to the high binding efficiency of plasma for MOX and MOX-D3. Moxidectin limits of detection were 0.01 ng/mL in plasma, 0.3 ng/g dry weight equivalent for faeces and 0.5 ng/g for fur. This study also developed a method to isolate plasma macromolecules, allowing the extraction of bound moxidectin for quantitative purposes, with an LoQ of 0.05 ng/mL. This method was subsequently used to determine that moxidectin was 97-99.4 % bound to lipoproteins in wombat plasma and 98-99 % bound in sheep, cow and horse plasma. The method reported for plasma was quick, cheap, and conducive to large sample batches, while providing high sensitivity. While faecal samples required additional cleanup steps to reduce the matrix effect, co-extracted matrix components such as undigested chlorophyll continued to result in ionisation suppression in the MS/MS. The methods reported here were used to monitor moxidectin in wombats treated with a single pour-on treatment, and confirmed that the moxidectin concentration in wombat plasma had decreased by more than 90 % by 28 days after application, while providing protection against sarcoptic mites over the majority of their life cycle. Clearance of moxidectin occurred via faecal elimination over the four week period and while moxidectin accumulated on fur due to application as a pour-on, concentrations declined rapidly by the four week period as fur fell out and was replaced by fresh fur that did not contain moxidectin.
Mange is a skin disease caused by mites that parasitize an animal's skin, often yielding inflamed immune responses and hair loss. At a population level, mange may reduce survival and cause population ...declines. Many forms of mange can be treated quite effectively when an animal is in hand; however, this is not often feasible for many free-ranging wildlife populations. Some animals, particularly territorial carnivores, will rub or roll to scent mark and transmit information about their presence to other individuals. We posited that rub stations comprised, in part, of anthelmintic medication and foreign scents that induce rubbing could be used to remotely treat mange in the wild. We deployed 39 rub stations containing lure and dye in Santa Monica Mountains National Recreation Area, Southern California, USA, October-November 2022. Carnivores rubbed or rolled at >97% of rub stations, with coyotes (Canis latrans), gray foxes (Urocyon cinereoargenteus), and bobcats (Lynx rufus) being the most abundant species. Time to first rub or roll was generally <1 wk. Several sympatric species (e.g., mule deer, Odocoileus hemionus) were detected at rub stations but did not rub. Our pilot test provides strong evidence that treating mange in wild carnivores may be possible using the remote medicinal rub stations we describe. Future efforts to add medicine to rub stations and monitor for a change in mange prevalence are a logical next step.
Disease outbreaks induced by humans increasingly threaten wildlife communities worldwide. Like predators, pathogens can be key top‐down forces in ecosystems, initiating trophic cascades that may ...alter food webs. An outbreak of mange in a remote Andean protected area caused a dramatic population decline in a mammalian herbivore (the vicuña), creating conditions to test the cascading effects of disease on the ecological community. By comparing a suite of ecological measurements to pre‐disease baseline records, we demonstrate that mange restructured tightly linked trophic interactions previously driven by a mammalian predator (the puma). Following the mange outbreak, scavenger (Andean condor) occurrence in the ecosystem declined sharply and plant biomass and cover increased dramatically in predation refuges where herbivory was historically concentrated. The evidence shows that a disease‐induced trophic cascade, mediated by vicuña density, could supplant the predator‐induced trophic cascade, mediated by vicuña behaviour, thereby transforming the Andean ecosystem.
An outbreak of Sarcoptic mange in a vicuña population in a remote protected area in the Argentine Andes reconfigured the tightly‐linked vertebrate food web, transforming a trophic cascade. Mange triggered a population crash in the large mammalian herbivore that released vegetation in predation refuge habitats, but not in habitats with high predation risk, where a behaviourally mediated trophic cascade driven by puma predation shielded vegetation from the effects of herbivory. This disease‐mediated shift also led to the near‐abandonment of the protected area by the dominant scavenger, the Andean condor, which was previously tethered to the region by a steady provisioning of vicuña carcasses from puma predation.
1. Emerging and invasive pathogens can have long-lasting impacts on susceptible wildlife populations, including localized collapse and extirpation. Management of threatening disease is of widespread ...interest and requires knowledge of spatiotemporal patterns of pathogen spread. 2. Theory suggests disease spread often occurs via two patterns: homogenous mixing and travelling waves. However, high-resolution empirical data demonstrating localized (within population) disease spread patterns are rare. 3. This study examined the spread of sarcoptic mange (aetiological agent Sarcoptes scabiei) in a population of bare-nosed wombats (Vombatus ursinus), and investigated whether pathogen spread occurred by homogenous mixing or a travelling wave. 4. Using 7 years of population surveys and 4 years of disease severity surveys, we show that mange was first detected in the east of a wombat population in northern Tasmania, and progressed westward as a travelling wave. Wombat mortality rates reached 100% behind the wave, with a 94% decline in overall wombat abundance within the park. 5. Synthesis and applications. Globally distributed pathogens may have severe impacts on susceptible host species. This is the first study to quantify population-level impacts of sarcoptic mange upon bare-nosed wombats, showing a wave of mange disease which resulted in a dramatic population decline. Successful management of the spread of this and similar pathogens may hinge on the capacity to establish transmission barriers at local or between-population scales.
In veterinary medicine, natural products provide an alternative to chemical agents for mite management. In the present study, the acaricidal efficacy of Urtica fissa leaf ethyl acetate extract ...against Sarcoptes scabiei mites was examined. The chemical composition of the extract was determined using liquid chromatography-mass spectrometry (LC-MS) analysis. The ethyl acetate extract was found to be extremely toxic to mites at a concentration of 100 mg/ml (m/v), killing all S. scabiei within two hours. The median lethal time (LT50) values for ethyl acetate extract concentrations of 25, 50, and 100 mg/ml against S. scabiei were 1.706, 1.204, and 0.750 h, respectively. The median lethal dosage (LC50) for S. scabiei was 19.14 mg/ml at two hours. The chemical composition of the ethyl acetate extract was evaluated using LC-MS, showing that the major components were schaftoside (8.259%), carnosol (6.736%), prostaglandin A2 (5.94%), 13(S)-HpOTrE (4.624%), nandrolone (4.264%), 1H-indole-3-carboxaldehyde (4.138%), 9-oxoODE (3.206%), and stearidonic acid (2.891%). In conclusion, these findings indicate that Urtica fissa contains promising new acaricidal compounds capable of successfully controlling animal mites.
Sarcoptic mange – Case report C. Braga; M. A. B. Lucas; I. Tancredi
Scientific electronic archives,
06/2018, Letnik:
11, Številka:
3
Journal Article
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Among the parasitic dermatitis that affect domestic animals, Sarcoptes scabiei is a common occurrence in dogs, it is a highly transmissible zoonosis. Non-seasonal disease, does not have predilection ...for race, sexual predisposition or age. Parasite obligatory and completes its entire life cycle around 3 weeks, in the host. Transmission occurs mainly by direct contact with an infected animal, indirect infection through hairs or fomites has also been described. Pruritus is the main clinical sign. The diagnosis of this disease is based on anamnesis, relating to compatible lesions. After treatment, the improvement in the animal can be observed in up to two weeks. The individual responsible for the treatment of the animal should make use of protective equipment and the environment in which the animal remains should be adequately sanitized.
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