Traumatic sheep myiasis: A review of the current understanding

Skin disease in sheep (Ovis aries): A retrospective report of 299 cases at a university veterinary medical teaching hospital (1986-2020)

BACKGROUND

Skin diseases in sheep are important animal health and production problems, especially in wool-producing sheep.

HYPOTHESIS/OBJECTIVES

To document the type, signalment, associations and prevalence of skin disease in a referral hospital population.

ANIMALS

Case population at a university veterinary medical teaching hospital.

MATERIALS AND METHODS

Retrospective study by searching computerised medical records of sheep examined between 1 January 1986 and 1 January 2021.

KEYWORDS

'alopecia, Arcanobacterium pyogenes, Corynebacterium, Demodex, dermatitis, Dermatophilus, dermatophyte, ectoparasite, examination, fibre damage, foot rot, fungus, interdigital necrobacillosis, itching, lice, Malassezia, melanoma, mite, pruritus, rubbing, scabies, skin, SCC, squamous cell carcinoma, Staphylococcus, Trueperella pyogenes, wool break, wool loss'.

RESULTS

Two thousand and two records, totalling 11,799 sheep, had the age, breed and sex reported. Older sheep were more likely to present with skin disease (p < 0.0001; standard deviation 36.6 ± 1.15 confidence interval). The American Merino, East Friesian, Rambouillet, Suffolk and Shetland breeds were at higher risk of developing skin disease (p < 0.0001). Males, whether rams or wethers, were more likely to present with skin disease than ewes (p = 0.0019). Owing to the lack of dermatological examination reported, the four largest flocks (a total of 7,892 sheep) were excluded from disease analysis. Of the remaining 3,907 sheep, 299 (7.6%) had skin disease recorded. The most common diagnoses made were pododermatitis, bacterial abscesses, squamous cell carcinoma and myiasis. Fifty-five of 299 sheep were presented primarily for nonskin disease.

CONCLUSIONS AND CLINICAL RELEVANCE

Clinicians should include a dermatological examination in sheep regardless of the reason for presentation.

Divergent Genetic Pathways Underlying Convergent Parasitic Behaviours in Blowflies

Blowfly (Diptera: Calliphoridae) exhibit diverse feeding strategies, with most species developing on decomposing organic matter. However, parasitism has evolved within the family, and some species convergently gained the ability to explore the tissues of living vertebrate hosts, which imposes critical veterinary, medical, and agricultural issues worldwide. It is yet unknown how this phenotype has evolved and whether it is determined by the same genetic architecture in different species or not. To address these questions, we evaluated key behavioural phenotypes in species with contrasting feeding habits, focusing on female oviposition preferences and larval survival on distinct diets, both critical aspects of their life cycles. These assays allowed us to propose hypotheses of how oviposition and larval behaviours contribute to feeding habits displayed in nature for parasitic and saprophagous species. Additionally, a transcriptome-wide analysis revealed genes and functional pathways potentially linked to parasitic behaviour by comparing gene expression profiles and coding sequence evolution. In the genetic analysis, we identified genes with important functions related to the measured behaviours, revealing that distinct genes may underlie each independent case of parasitism evolution, suggesting a non-parallel evolutionary pathway for this convergent trait.

Traumatic myiasis in animals from Iraq: a five years (2019-2023) survey, and a comprehensive epidemiological overview

The present study surveyed traumatic myiasis cases admitted to the governmental Veterinary hospitals (belonging to the Iraqi Ministry of Agriculture) distributed throughout Iraq, between 2019 and 2023, and highlights the epidemiological changes occurred in comparison to the previous situation. A total of 916 cases were detected in various animals from nine governorates, with an annual average of 183.2 cases/year, which is lower than the corresponding value estimated for the period 1996-2000 (23,510 cases/year) or for 2001-2018 (811.2 cases/year). Cases peaked during early summer, unlike the earlier surveys during winter, which assumes that the pupal development peaks during spring. Numbers and geographical distribution of the cases suggest emergent infestations in the northern region, persistent endemic infestations in the middle region, and cleared or lowered infestations in the southern region. Out of the 916 cases, sheep (610 cases) had the highest infestations, and the annual number of infested sheep was estimated at 54,000 animals, giving rise to a yearly economic loss mounts greatly over 1.5 million USD. Cattle (172 cases) was the second most frequently infested animal; however, cattle cases declined over years. Forty-four dog cases were detected, mostly in Diyala; nonetheless, dog myiasis is largely underreported in Iraq since millions of dogs live as strays. The Old World screwworm fly accounted for over 90% of the infestations, which underlines its historical role as the major contributor to traumatic myiasis in Iraq. In conclusion, significant changes in the epidemiology of animal traumatic myiasis in Iraq are strongly suggested. The Iraqi authorities should therefore consider these changes in updating various strategies established to effectively combat this economically important disease.

Molecular identification of Chrysomya albiceps (Diptera: Calliphoridae) in a case of primary cutaneous myiasis in sheep at southern Brazil

Sheep farming has been growing in Brazil, driven by an expanding consumer market due to greater acceptance of its meat and derivatives. There are several factors that limit sheep production, and one of them is infestation by ectoparasites, which cause stress in animals, weight loss, poor development, low productivity, low quality wool and reduced fertility. Chrysomya albiceps is a species of blowfly belonging to the Calliphoridae family that occurs in neotropical regions, where it causes secondary myiasis. We identified here a rare case of cutaneous myiasis with the presence of tissue lesions caused by C. albiceps in sheep in southern Brazil. We highlight the need to carry out more in-depth studies regarding the biology of these insects, with the aim of proving this atypical behavior for Brazil.

Occurrence and Characteristics of Cut Injuries in Hedgehogs in Germany: A Collection of Individual Cases

The number of European hedgehogs (Erinaceus europaeus) is in long-term decline across Europe. Recently, an additional threat to hedgehogs' lives has been cutting injuries caused by garden care equipment, but to date, there have been no reliable data on their spatial and temporal occurrence as well as characteristics such as mortality rate. Usually, found injured hedgehogs are admitted to care centres. In this study, data on hedgehogs with cutting injuries were collected from care centres throughout Germany. Over a period of 16 months, data on a total of 370 hedgehogs with cut injuries were reported by 71 care centres. At least 60% of these hedgehogs were found more than 12 h after the accident and at least 47% did not survive as a result of the injury. The comparatively high mortality rate coupled with a possible high number of unreported cases of hedgehogs with laceration injuries show that these accidents pose an additional, serious danger to hedgehogs, both impacting the welfare of individual animals and having a broader effect on the conservation potential of this species. Moreover, the data collected objectify the current discussion on the need for possible technical or political solutions to prevent such injuries.

How Well Does Australian Animal Welfare Policy Reflect Scientific Evidence: A Case Study Approach Based on Lamb Marking

The development and substance of animal welfare policy is subject to a range of social, cultural, economic, and scientific influences that commonly vary within and between countries. Discrepancies in policy can create confusion and mistrust among stakeholders and consumers and limit the ability to create a uniform minimum level of requirements to safeguard animal welfare, as well as create a level 'playing field' for farmers when trading with other jurisdictions. The livestock sector is receiving growing scrutiny globally for real and perceived violations of animal welfare, for example, the practice of mulesing in Australia. This article explores animal welfare legislation within Australia and how it reflects the scientific evidence surrounding routine husbandry practices in sheep, including tail docking, castration, and mulesing. While there is some variation between state and territory legislation, the most notable concern is the lack of enforceable recommendations surrounding the evidence-based use of analgesia and anaesthesia for painful husbandry procedures. The age at which these procedures are recommended to be performed is relatively consistent across Australian jurisdictions, but there is a marked difference compared to international legislation. The global context of animal welfare legislation, public perception, and producer perception of these procedures are also discussed, highlighting the difficulty of creating robust animal welfare legislation that promotes a good standard of welfare that is respected worldwide whilst being practical in an Australian setting given our unique geography and climatic conditions.