RECURRENT EAR MITE ( OTODECTES CYNOTIS ) INFESTATION IN THREE RELATED GROUPS OF PATAGONIAN CAVIES ( DOLICHOTIS PATAGONUM )

Otodectes cynotis (Acari: Psoroptidae) infestations in Southern pudus (Pudu puda): In situ and ex situ data of an unexpected host-parasite record

Otodectes cynotis (Acari: Psoroptidae) constitutes an obligate, non-burrowing ectoparasite and causes otodectic mange primarily in domestic and wild carnivores. Only few studies have described this parasite in herbivore hosts so far. In the current study, we report O. cynotis infestations in Southern pudus (Pudu puda), categorized in the IUCN red list as near threatened. Otodectes cynotis was detected in free-ranging animals in Chile (in situ), as well as in zoo-housed pudus at the Zoo Wuppertal, Germany (ex situ). During clinical work, two free-ranging pudus temporarily rehabilitated at the Centro de Rehabilitación de Fauna Silvestre (CEREFAS), Valdivia, Chile, were observed with low to moderate yellowish-brown secretions and encrustations inside the pinna and external auditory canal accompanied by an inflammatory Otitis externa. Analysis via light microscopy exhibited the presence of mange mites, which were identified as O. cynotis via morphological characteristics and molecular analysis. At the Zoo Wuppertal, ear mites were detected in 15 pudus between 2015 and 2024, however, a definite species identification (O. cynotis) was carried out in 4 animals within the current study between 2023 and 2024. Some affected pudus showed bald spots around the ears and the head and exhibited headshaking behavior, whilst others were asymptomatic. In some cases, mites were found as a secondary finding when clinical examination under general anesthesia was performed for other reasons. To the best of our knowledge, this signifies the first report of O. cynotis infestations in pudus by combining morphological and molecular identification. We here present clinical in situ and ex situ data and show that zoological gardens and widlife rehabilitation centers play an important role in research and monitoring of neglected wildlife diseases.

Efficacy and innocuity of lotilaner in the treatment of otodectic mange in ferrets

Otodectes cynotis is a contagious ear mite generally responsible of a parasitic otitis. This prospective study evaluates the efficacy, safety and impact on quality of life (QoL) of oral lotilaner for the treatment of Otodectes infestation in ferrets. Ferrets of weight greater than 500 g, with Otodectes mites confirmed on ear swabs examination and that did not receive an acaricidal treatment in the previous two weeks were included. Oral lotilaner (Credelio 12 mg, ELANCO FRANCE, Sèvres, France) was administered at inclusion day (D0) and 28 days later (D28). Parasitic counts and clinical examination were performed at D0, D28 and D56. A QoL and owner satisfaction questionnaire was given at D0 and D56. Statistical analysis was performed with Shapiro-Wilk test for normality and Wilcoxon test for mean comparison (significance: p<0.05). Eleven ferrets were included, two were asymptomatic. Mean weight was 1.2 kg (0.68-2.66). Mean lotilaner dose was 12.3 mg/kg (9-17.6). Mean eggs, adults or nymphs, larvae, and fragments counts were 30.4 (3-104), 11.2 (1-61), 5.4 (0-36), 3.5 (1-7) respectively at D0; 0, 0, 0.1 (0-1), 0.5 (0-3) respectively at D28; 0, 0, 0, 0.14 (0-1) respectively at D56. Differences were statistically significant from baseline in all cases (p<0.05). Pruritus was absent in all cases at D56. No adverse effects were reported. All owners were "completely satisfied" with the treatment. Mean impact of the disease on QoL was 4.5/18 (SD=4.15) at D0 and 0 at D56 (significant difference, p<0.05). Oral lotilaner appears as a safe, efficient, easy to use and satisfactory treatment of Otodectes cynotis infestation in ferrets.

First report on the occurrence of psoroptic mange in llamas (Lama glama) of the Andean region

An outbreak of Psoroptes sp.-caused mange was detected in a llama herd of Larcas, Jujuy province, Argentina. Infested llamas showed alopecia, erythema, hyperpigmentation, hyperkeratosis, and inflammation of the ear pinnae, as well as crusts and serous, serosanguineous, or purulent drainage with unpleasant smell in the external ear canal. Microscopic evaluation of skin scrapings revealed 0.5- to 0.7-mm-long acari identified as Psoroptes sp. based on their morphology. Histology showed a typical allergic reaction with perivascular to periadnexal mixed inflammatory infiltrate. Phylogenetic tree analysis showed that the cytochrome c oxidase subunit I gene sequences analyzed from the sampled acari clustered into a single P. ovis clade including sequences isolated from rabbits and bighorn sheep, with P. natalensis as a sister taxon that infested bighorn sheep from the USA. Phylogenetic analysis of cytochrome b sequences showed three well-supported clades, one of which contained the sequences of the Larcas llamas and US bighorn sheep isolates. This is the first report on P. ovis infestation of llamas raised in their original location. Investigations on mange etiological agents acting on South American camelids and their distribution are necessary to implement control strategies to mitigate the negative impacts of these parasitic infections.

Morphological and molecular characterisation of the nematode parasite Graphidioides affinis (Secernentea: Trichostrongylidae) in Patagonian maras, Dolichotis patagonum, kept in a zoo in Sofia, Bulgaria

Introduction

Patagonian maras, rodents endemic to South America, are classified as a near-threatened species. Various factors affect their health including parasitic diseases. The aim of this study was to perform morphometric, molecular and phylogenetic characterisation of one such parasitic disease agent, the nematode Graphidioides affinis, specimens of which were found in captive Patagonian maras.

Material and Methods

In March 2023, 18 Patagonian maras kept at the Sofia Zoo in Bulgaria were investigated with the use of coprological methods. Following the investigation, the animals were dewormed with the use of albendazole. Dead adult nematodes found in the faeces of dewormed maras were collected and preserved in 70% ethanol, and morphometrically, molecularly and phylogenetically analysed.

Results

The morphometric analyses confirmed the nematodes to be Graphidioides affinis. The partial nucleotide sequences of the small subunit ribosomal rDNA (SSU), the internal transcribe spacer 2 (ITS2) and the large subunit ribosomal DNA (LSU) of G. affinis were obtained. These are the first available nucleotide sequences of this parasite. The phylogenetic analyses of the species showed its distinctiveness in comparison to other gastrointestinal nematodes, as it was grouped separately.

Conclusion

The Patagonian maras kept in a European zoo retained their original parasitofauna which are related to South America.

A rapid evidence assessment of the potential risk to the environment presented by active ingredients in the UK's most commonly sold companion animal parasiticides

A number of parasiticides are commercially available as companion animal treatments to protect against parasite infestation and are sold in large volumes. These treatments are not intended to enter the wider environment but may be washed off or excreted by treated animals and have ecotoxic impacts. A systematic literature review was conducted to identify the existing evidence for the toxicity of the six most used parasiticides in the UK: imidacloprid, fipronil, fluralaner, afoxolaner, selamectin, and flumethrin. A total of 17,207 published articles were screened, with 690 included in the final evidence synthesis. All parasiticides displayed higher toxicity towards invertebrates than vertebrates, enabling their use as companion animal treatments. Extensive evidence exists of ecotoxicity for imidacloprid and fipronil, but this focuses on exposure via agricultural use and is not representative of environmental exposure that results from use in companion animal treatments, especially in urban greenspace. Little to no evidence exists for the ecotoxicity of the remaining parasiticides. Despite heavy usage, there is currently insufficient evidence to understand the environmental risk posed by these veterinary treatments and further studies are urgently needed to quantify the levels and characterise the routes of environmental exposure, as well as identifying any resulting environmental harm.

A scoping review of rodent-borne pathogen presence, exposure, and transmission at zoological institutions

BACKGROUND

Rodents are one of the major taxa most likely to carry zoonotic diseases, harboring more than 85 unique zoonotic pathogens. While the significance of rodents' capacity to carry and transmit disease has been characterized in urban settings, the zoo environment is particularly unique given the overlap of collection, free-living, and feeder rodents as well as non-rodent collection animals, staff, and visitors.

ELIGIBILITY CRITERIA

This scoping review examines reports of rodent-borne pathogen detection or transmission in zoo settings extracted from the literature. Papers were included in the final analysis if there was evidence of presence or exposure to a pathogen in a rodent at a zoological institution.

SOURCES OF EVIDENCE

Publications were included from PubMed, CAB Abstracts and Biological Abstracts searched in August 2019.

CHARTING METHODS

Data extracted from publications on pathogen presence/exposure included publication identifiers, study identifiers, infectious agent identifiers, rodent identifiers, and non-rodent collection animal identifiers. Extraction from papers with evidence of disease transmission included number of rodents involved in transmission, non-rodent collection animal species and numbers, and job title of humans involved, diagnostic tests performed, and clinical outcomes.

RESULTS

Aggregate literature examined included 207 publications presenting evidence of pathogen presence and/or exposure in rodents across 43 countries in over 140 zoological institutions. A total of 143 infectious agent genera were identified, comprising 14 viral genera, 31 bacterial genera, 83 parasitic genera, and 15 fungal genera. Of these infectious agents, over 75 % were potentially zoonotic. The most common disease-causing agent genera identified were Leptospira, Toxoplasma, Salmonella, and Yersinia. Additional screening for evidence of pathogen transmission across species yielded 30 publications, indicating an area for future investigation to better inform surveillance and management priorities in order to reduce exposure, infection, and transmission.

CONCLUSIONS

Analyzing the breadth of rodent species and pathogens identified at zoos highlights the unique opportunity zoos have to be at the forefront of the early detection and identification of novel hosts and geographic ranges of rodent-borne pathogens with high impact on both endangered species and people. The overlap of these populations at zoos exemplifies the importance of considering One Health when prioritizing surveillance and risk mitigation of rodent reservoirs at zoos.