Histopathology, microbiology and the inflammatory process associated with Sarcoptes scabiei infection in the Iberian ibex, Capra pyrenaica

Abstract

BackgroundSarcoptic mange has been identified as the most significant infectious disease affecting the Iberian ibex (Capra pyrenaica). Despite several studies on the effects of mange on ibex, the pathological and clinical picture derived from sarcoptic mange infestation is still poorly understood. To further knowledge of sarcoptic mange pathology, samples from ibex were evaluated from histological, microbiological and serological perspectives.MethodsSamples of skin, non-dermal tissues and blood were collected from 54 ibex (25 experimentally infected, 15 naturally infected and 14 healthy). Skin biopsies were examined at different stages of the disease for quantitative cellular, structural and vascular changes. Sixteen different non-dermal tissues of each ibex were taken for histological study. Acetylcholinesterase and serum amyloid A protein levels were evaluated from blood samples from ibex with different lesional grade. Samples of mangy skin, suppurative lesions and internal organs were characterized microbiologically by culture. Bacterial colonies were identified by a desorption/ionization time-of-flight mass spectrometry system (MALDI TOF/TOF).ResultsThe histological study of the skin lesions revealed serious acanthosis, hyperkeratosis, rete ridges, spongiotic oedema, serocellular and eosinophilic crusts, exocytosis foci, apoptotic cells and sebaceous gland hyperplasia. The cellular response in the dermis was consistent with type I and type IV hypersensitivity responses. The most prominent histological findings in non-dermal tissues were lymphoid hyperplasia, leukocytosis, congestion and the presence of amyloid deposits. The increase in serum concentrations of acetylcholinesterase and amyloid A protein correlated positively with the establishment of the inflammatory response in mangy skin and the presence of systemic amyloidosis. A wide variety of bacterial agents were isolated and the simultaneous presence of these in mangy skin, lymph nodes and internal organs such as lungs, liver, spleen and kidney was compatible with a septicaemic pattern of infection.ConclusionsThe alteration of biomarkers of inflammation and its implication in the pathogenesis of the disease and development of lesions in non-dermal tissues and septicaemic processes are serious conditioners for the survival of the mangy ibex. This severe clinical picture could be an important factor when considering the decision to eliminate animals that exceed a certain disease threshold from a population.

First description of sarcoptic mange in the endangered Iberian lynx (Lynx pardinus): clinical and epidemiological features

“…Several macro-and microscopical alterations reported in non-dermal tissues during the necropsy of the female cub (Table 2) are common findings in severely affected mangy animals. Poor body condition and caquexia, generalized linfadenomegaly, the presence of abdominal ascitic fluid, and vascular alterations in the liver, kidneys, or subdural space have been described in several wild mammal species suffering from advanced stages of sarcoptic mange (Nakagawa et al 2009;Espinosa et al 2017). Alterations compatible with severe pneumonia reported during the necropsy of N4-keres and subsequently confirmed by the histopathological findings could be suggested as the final cause of death of this lynx owing to their severity.…”

“…Alterations compatible with severe pneumonia reported during the necropsy of N4-keres and subsequently confirmed by the histopathological findings could be suggested as the final cause of death of this lynx owing to their severity. Sepsis and pneumonia (secondary to bacterial infections) related to sarcoptic mange have frequently been found in some wild species and even humans and suggested to be the definite cause of death in serious sarcoptic mange cases, as a consequence of immunosuppression (Huffam and Currie 1998;Walton and Currie 2007;Nakagawa et al 2009;Espinosa et al 2017). Furthermore, animals concomitantly suffering from other pathologies may be more prone to the clinical development of underlying scabies.…”

Epidemiological and Histopathological Investigation of Sarcoptic Mange in Camels in Egypt

“…Samples were then processed by sectioning where the paraffin-embedded tissues were sectioned to a 4-5 µm thickness. Sections were mounted on slides, stained by hematoxylin and eosin (H&E) and then examined under light microscopy for the presence of mange mites and any associated histopathological changes [31,32]. The resulting histopathological changes were then ranked according to their degree of severity into three categories: mild, moderate and severe histopathological findings, as described elsewhere [33].…”

Recommendations for the management of sarcoptic mange in free–ranging Iberian ibex populations

“…However, no positive results were obtained in chronically ill ibex (León-Vizcaíno et al, 2001), similarly as in other species (Skerratt, 2003;Kido et al, 2014). We consider that in ibex with severe sarcoptic mange the multi-systemic complications derived from the action of the mites (Espinosa et al, 2017d(Espinosa et al, , 2017c require additional treatment if the animal is to completely recover, which include the provision of intravenous fluids, antimicrobials and high-caloric nutrition. In free-ranging ibex, parenteral antiparasitic treatment is considered impractical for economic reasons, while the capture and handling of severely affected ibex for treatment purposes may often result in short-term mortality (López-Olvera et al, 2009).…”

“…From a clinical point of view, under natural conditions the multi-systemic clinical picture is severe and entails a very marked reduction in body condition, disorders of haematological and biochemical parameters (Pérez et al, 2015), septicaemic processes (Espinosa et al, 2017d), oxidative stress phenomena (Espinosa et al, 2017c), and an increase in inflammation biomarkers causing tissue damage in dermal and non-dermal tissues (Raéz-Bravo et al, 2015;Espinosa et al, 2017d), all of which greatly reduce survival possibilities and/ or hamper the recovery of ibexes in chronic phases of disease. For ethical and humanitarian reasons, the ending of the suffering of infected animals is necessary.…”