Special Issue "Anaemia Associated Disorders in Sheep"

A special issue of Animals (ISSN 2076-2615). This special issue belongs to the section "Small Ruminants".

Deadline for manuscript submissions: 30 April 2022.

Special Issue Editors

Dr. Delia Lacasta
E-Mail Website
Guest Editor
Faculty of Veterinary Medicine, University of Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain
Interests: pathology; diseases; sheep health management
Special Issues and Collections in MDPI journals
Dr. Aurora Ortín
E-Mail Website
Guest Editor
Departamento de Patología Animal, Facultad de Veterinaria, Instituto Agroalimentario de Aragón-IA2, Universidad de Zaragoza-CITA, C/Miguel Servet 177, 50013 Zaragoza, Spain
Interests: welfare and pathology of small ruminants; respiratory disorders; sheep and goats

Special Issue Information

Dear Colleagues,

A wide variety of disorders can lead to anaemia in sheep, and the achievement of an accurate diagnosis may become complex. In-depth knowledge of these disorders is essential to determine the aetiology of the anaemia, establish a prognosis and implement effective therapeutic and preventive measures.

Nutritional deficiencies of trace minerals (Fe, Cu, Se, Co) and vitamin B12 are important causes of anaemia in sheep, and parasitic diseases, mainly those caused by haemoparasites and transmitted by ticks (babesiosis, anaplasmosis and theileriosis), lead to this problem too. In addition, poisoning by toxic plants and chronic copper poisoning are also causes of anaemia. Other diseases, such as enterotoxaemia by Clostridium perfringes type D or leptospirosis, should be considered when anaemia is present. Of course, any other disorder that causes bleeding should not be ignored.

We encourage you to share new information about any disorder that can lead to anaemia in sheep.

Dr. Delia Lacasta
Dr. Aurora Ortín
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Animals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • sheep
  • anaemia
  • haemolysis
  • haemorrhage
  • erythroid hypoplasia

Published Papers

This special issue is now open for submission, see below for planned papers.

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: Anaemia in lambs from Mycoplasma ovis
Authors: Peter
Affiliation: The University of Sydney
Abstract: Mycoplasma ovis (formerly Eperythrozoon ovis) is a parasitic bacterium of the erythrocytes of small ruminants, widely distributed in many global sheep and goat producing areas where it is often considered endemic. The parasite is transmitted mechanically by biting flies and contaminated instruments, causing morbidity and mortalities from anaemia, usually 4-6 weeks following blood-exposure lamb marking procedures, including vaccination, castration, mulesing and ear tagging. Affected animals developed haemolytic anaemia and may present with jaundice, sometimes recognised at abattoirs where carcasses are condemned. The diagnosis relies on microscopic evaluation of Giemsa-stained blood smears and PCR. This can be challenging, as mustering of anaemia-affected animals may precipitate mortalities. Further, in lambs displaying anaemia, the parasite is frequently no longer observed in smears, hence healthy in-contact animals should be tested. Differential diagnoses include Haemonchosis and copper deficiency, with consideration of the possibility that both endoparasitism and haemoparasitism may both be present in the one animal. M. ovis parasitaemia may persist, with recrudescence occurring following stressful events, although older sheep are generally resistant following development of immunity. Human infections have been reported. Antimicrobial therapy is ineffective, with control requiring management decisions to avoids marking procedures occurring during periods (e.g. spring) when M. ovis transmission is likely.

Title: Anaemia associated with Haemonchus contortus infection in pasture-based sheep production systems: epidemiology, pathogenesis, clinical effects and prevention.
Authors: Dr. Flay
Affiliation: City University of Hong Kong
Abstract: Preliminary Abstract: Haemonchus contortus is a common parasitic nematode infection of grazing sheep. Infection can result in significant health and production effects due to the haematophagic habits of these abomasal parasites. Clinical signs of infection are related to blood loss; resulting in anaemia, weakness and sometimes death of infected sheep, while disease severity is typically linked to H contortus burdens. When environmental conditions are favourable, large numbers of H contortus larvae can develop and survive on pasture contributing to a rapid increase in worm burdens in sheep grazing these contaminated pastures. In many flocks worldwide, preventative measures must be utilized during key ‘risk-periods’ to reduce the risk of clinical disease development and to maximize productivity. This review will summarise the epidemiology of infection in pasture-based, sheep-raising systems with a focus on the pathology and pathogenesis of infection, the clinical effects and response to infection, and will conclude with a brief outline of common preventative measures.

Title: Comparative study of the therapeutic effects of different antibiotics to treat ovine anaplasmosis in lambs
Authors: Guest Editor
Affiliation: Spain
Abstract: Simple Summary: Ovine anaplasmosis is causing relevant economic losses during the last years due to icteric carcasses condemnation. They are apparently healthy lambs in good body condition that, after being slaughtered, show an icteric coloration of their carcasses. Anaplasmosis produces strong hemolysis that leads to an increase in bilirubin that stains the carcasses. In the present work, the therapeutic effect of different antibiotics in 2-month-old lambs is analysed. The evolution of the bacterial load in blood is studied using molecular techniques, as well as the evolution of blood parameters and carcass condemnation of treated lambs.

Title: Copper intoxication as a cause of anaemia in sheep
Authors: Marta
Affiliation: Spain.
Abstract: Copper is an essential element for sheep, as well as for other animals. However, the ovine species has a high susceptibility to copper intoxication. Some breeds are more sensitive to this poisoning and lambs have higher risk to develop it than adults. Copper intoxication can occur as a result of several factors, such as the accidental use of copper-rich diets or mineral supplements, the exposure to toxic copper levels (copper-contaminated feedstuff, excessive copper in anthelmintics, footbaths…) or the low intake of molybdenum, zinc, calcium, and sulfate. The clinical signs depend on the acute or chronic exposure to copper. In the case of chronic toxicosis, which is more frequent, copper is accumulated progressively within the liver during a subclinical period. The increased copper concentrations in cytoplasm lead to lipid oxidation and oxidative damage in hepatocytes and erythrocytes causing an acute haemolytic crisis that causes anaemia, haemoglobinuria, jaundice, and death within 1–2 days. Acute poisoning is mostly related to severe gastroenteritis and is generally due to the administration of excessive amounts of copper. If the animal survives, clinical signs commonly associated with chronic copper and death can occur after few days. Several alternatives have been investigated in order to prevent and treat copper poisoning, which can cause severe economic losses in affected farms.

Title: Anaemia in sheep caused by the consumption of plants.
Authors: Delia
Affiliation: Spain
Abstract: Plant toxicology is as old as mankind. Plants have successfully developed several physical or chemical strategies to avoid being eaten by animals. However, a large number of animal species base their diet on the ingestion of plants, as is the case of sheep. This situation generates the possibility that the ingestion of certain plants may lead to pathology for livestock, which is generally complex to diagnose and difficult to treat. The diagnosis of the poisoning by plants is based essentially on the clinical symptoms and the verification of the ingestion of the plant by the herd. However, the diagnosis is often difficult because several plants can cause similar symptoms, and the time between ingestion and the onset of symptoms is highly variable. Within plant toxicology, there is a group of plants of great importance that cause damage to the circulatory system, causing anaemia of diverse severity. Anaemia caused by plants can be produced by two different mechanisms: haemorrhagic processes and haemolytic processes, depending on the type of plant involved. There is a group of plants containing anticoagulant compounds which are responsible for haemorrhagic processes. These plants are generally consumed in times of food shortage. These plants contain a high concentration of coumarin group compounds, which compete with vitamin K, inhibiting blood coagulation and causing the haemorrhagic disorders. The haemolytic disorders are caused by another group of plants which are mostly grown for human consumption. These plants contain compounds that are capable of altering the metabolism of the erythrocytes and damaging their membrane which favors the lysis of these cells. However, these haemolytic disorders appear less frequently and generally in animals that feed almost exclusively on a diet consisting of these plants and for a long time.

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