Bluetongue and contagious ecthyma are sheep diseases that have very similar clinical presentation, thus, making it difficult to distinguish between the two based on clinical symptoms. In practice, a detailed clinical examination of sheep is underestimated and rarely is carried out. The paper presents and describes clinical cases of bluetongue and the malignant form of contagious ecthyma. The differences in the clinical presentation and diagnostic procedures for the two diseases are described in detail, as this information is necessary in order to establish correct disease control measures.Bolest plavog jezika i zarazni ektim su bolesti ovaca koje imaju sličnu kliničku sliku te ih je teško razlikovati na osnovu ispoljavanja kliničkih znakova. U praksi, detaljan klinički pregled ovaca je potcenjen i retko se sprovodi. U radu su prikazani klinički slučajevi bolesti plavog jezika i maligne forme zaraznog ektima. Detaljno su opisane razlike u kliničkoj slici kod ova dva oboljenja i postupak postavljanja kliničke dijagnoze koja je neophodna za primenu efikasnih mera suzbijanja bolesti

Nedić, Drago

Stevanović, Oliver

Veterinarski glasnik

English

Veterinar - Repository of the Faculty of Veterinary Medicine

STEVANOVIĆ Oliver and NEDIĆ Drago: Bluetongue and malignant contagious ecthyma in sheep57Veterinarski Glasnik 2019, 73 (1), 57-63UDC: 636.32/.38.09:616.98 https://doi.org/10.2298/VETGL181127012S *Corresponding author – e-mail: oliver.13.stevanovic.bih@gmail.comCase ReportCLINICAL PRESENTATION OF BLUETONGUE AND THE MALIGNANT FORM OF CONTAGIOUS ECTHYMA IN SHEEP: DESCRIPTION OF CASESSTEVANOVIĆ Oliver1*, NEDIĆ Drago2 1PI Veterinary Institute of  the Republic of  Srpska Dr. Vaso Butozan Banja Luka, Republic of  Srpska, B&H; 2University of  Belgrade, Faculty of  Veterinary Medicine and PI Veterinary Institute of  the Republic of  Srpska Dr. Vaso Butozan Banja Luka, Republic of  Srpska, B&HReceived 27 November 2018; Accepted 27 March 2019 Published online: 13 May 2019Copyright © 2019 Stevanović et al. This is an open-access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedAbstract Bluetongue and contagious ecthyma are sheep diseases that have very similar clinical presentation, thus, making it difficult to distinguish between the two based on clinical symptoms. In practice, a detailed clinical examination of  sheep is underestimated and rarely is carried out. The paper presents and describes clinical cases of  bluetongue and the malignant form of  contagious ecthyma. The differences in the clinical presentation and diagnostic procedures for the two diseases are described in detail, as this information is necessary in order to establish correct disease control measures.Key Words: sheep, bluetongue disease, contagious ecthyma, clinical presentationCASE PRESENTATIONCase 1: Description of bluetongue in sheepDuring the epizooty of  bluetongue, various clinical forms of  this disease in Republika Srpska, Bosnia and Herzegovina were observed in 2016. The first officially reported and described case of  bluetongue in sheep was diagnosed in a family farm in Vrbnica, Foča municipality. Vrbnica is a small village with 10 farms located near Zelengora mountain in Herzegovina.Epizootiological investigation. Initial symptoms of  disease in sheep were observed in July, 2016: the owner noticed bloating and discharge from the mouth with swollen lips in Veterinarski Glasnik 2019, 73 (1), 57-6358lambs. The sudden death of  four lambs and one sheep in the flock was observed. Until August 2016, the number of  affected sheep increased, and by the day of  clinical examination, a total of  12 sheep had died, the corpses of  which were uncontrollably disposed of  in the environment. According to the farmer, some animals recovered from the disease. During examination, there were about 100 sheep in the flock and 19 head of  cattle in the family farm, although many animals had not been marked. Sheep farming in Vrbnica is semi-nomadic, which is typical for this geographical area of  Herzegovina. During the summer, sheep are grazed with other flocks on the pastures of  Zelengora mountain without movement control. In winter, the same flocks are moved from the pastures to the village. Local veterinarians unsuccessfully tried to treat sheep with antibiotics and vitamins, but in the end, they reported suspicion of  bluetongue to the veterinary inspector. Furthermore, the owner stated that a similar disease had appeared in other sheep flocks on the pastures of  Zelengora mountain.Clinical examination. A number of  animals, including sheep and cattle, were not adequately marked on the farm, meaning animals did not have ear tags or other identification marks. In order to conduct proper sampling, triage of  animals was applied, i.e. sampling and clinical examination was carried out only in 32 sheep and 7 cattle with valid marking (ear tags). Sheep in the suspected flock had poor health status. It was clearly noticeable that the sick sheep were apathetic and depressed. On careful physical examination of  affected animals, it was noted that several types of  clinical changes, depending on the course of  the disease, existed in the flock. Clinical changes were more noticeable in lambs. Fever, general weakness, and edema of  ears, eyelids and lips were observed as initial clinical changes in lambs (Figure 1). These lambs expressed various degrees of  respiratory distress.Figure 1. Initial clinical picture in the flock: swelling of  ears, lips and eyelidsSTEVANOVIĆ Oliver and NEDIĆ Drago: Bluetongue and malignant contagious ecthyma in sheep59Besides the noted swelling in lambs, in several sheep in the flock, a swollen and congested tongue was observed (Figure 2), and on labial mucosa there were ulcers with hemorrhage. Due to the swelling of  the tongue, the sheep showed abundant salivation. Necrotic skin and mucosal changes were detected on nostrils which were covered with ulcers in several sheep in the affected flock (Figure 3a). The symptoms were visible on hooves – there were changes on the corium which began with mild swelling of  the fetlock joint. After that, hoof  avulsion was observed, in our case, visible in one sheep. Consequently alterations in hooves resulted in the sheep showing signs of  lameness.  Figure 2. Edema and congested tongueFigure 3. a) Salivation, hyperemia and ulceration of  nostrils in sheep; b) Proliferative and advanced changes in affected sheep; c) Advanced changes in oral cavity, lips and skin (photograph provided by Sonja Nikolić, spec.)Veterinarski Glasnik 2019, 73 (1), 57-6360Diagnosis. Of  the total of  32 sheep, 17 sheep showed signs of  the disease at a different stage (from swellings on head to mouth, tongue and hoof  changes) A total of  15 sheep in the flock and 7 cows from the same farm were seropositive to bluetongue virus by an ELISA test. Whole blood and serum samples were sent to the National Reference Laboratory for Bluetongue Disease, i.e. the Veterinary Faculty in Sarajevo. Additional analysis confirmed the disease, and the presence of  bluetongue virus serotype 4 was confirmed by the European Reference Laboratory.Case 2. Description of malignant form of contagious ecthyma in sheepA malignant form of  contagious ecthyma was described in a small sheep flock at the end September in 2017, in the small village of  Rosulje, Pale.Epizootiological investigation. During clinical examination, the field veterinarian suspected the presence of  contagious ecthyma, but mortality was higher than usual. In the meantime, the carcass of  one dead sheep from the affected flock was delivered to the Veterinary Institute of  Republika Srpska Dr. Vaso Butozan Banja Luka for post mortem analysis. Affected sheep were not treated after the onset of  the disease. According to the information taken from the owner, the following data were recorded: there were no similar symptoms of  the disease in the previous years, there was no direct contact of  the sheep with other flocks, there was no presence of  bluetongue in the flock before, and all sheep were dewormed. The owner applied salt and iodine to treat the wounds of  the affected sheep. Sheep were kept in bad hygienic conditions; these were typically extensive, which is characteristic of  this region. Within 15 days, 33 sheep had died, which constituted nearly 50% of  the flock.Clinical examination. About 90-95% of  the sheep in the flock was affected. There was noticeable general weakness of  ill sheep, somnolence, depression, and visible cachexia. The examined sheep were febrile. Cough was noticeable with evident abdominal breathing. In several ill sheep, diarrhea with a small amount of  fresh blood was observed. Other evident clinical changes included: head swelling, salivation, easily removable scabby lesions on the lips and nostrils. Beneath the scabs there were signs of  fresh bleeding and pus. In the case of  a larger number of  sheep, nasal discharge was clearly visible. Proliferative changes with scabs were visible in the oral cavity of  examined sheep with suppurative and foul-smelling discharge from the nose.Diagnosis. Serologic examination excluded bluetongue. Pathological examination revealed proliferative lesions typical for ecthyma (Figure 3c) with secondary complications: necrotic and suppurative dermatitis and pneumonia. Vacuolar degeneration, epithelial inclusion with secondary necrosis, and lymphocytic infiltration were recorded by histology. Scab samples were sent to the Scientific Institute of  Veterinary Medicine, Belgrade, Serbia, where the presence of  parapoxvirus was confirmed by polymerase chain reaction. Furthermore, Pseudomonas spp. from the lungs of  dead sheep was isolated by routine microbiological examination.STEVANOVIĆ Oliver and NEDIĆ Drago: Bluetongue and malignant contagious ecthyma in sheep61DISCUSSIONBluetongue and contagious ecthyma are sheep diseases that need to be differentiated diagnostically because the measures to be undertaken in the case of  outbreaks of  these diseases are significantly different in Republika Srpska (Bosnia and Herzegovina). On the one hand, bluetongue is regularly reported and eradication in the case of  an outbreak is regulated by legislation, while contagious ecthyma is regularly underestimated. In addition, there are no legally defined measures to control ecthyma. Although bluetongue in this area has been known since 2002 (Nedić, 2002; Đuričić et al., 2002; Mitrović et al., 2004, Đuričić et al., 2004; Velić et al., 2004); significant epizooty occurred in 2016, when this disease caused serious economic losses in sheep farming. One of  the major problems for veterinarians at the time of  the epizooty was to clinically distinguish bluetongue from ecthyma and other diseases (facial eczema, insect bites, etc.) with similar clinical presentation, especially in the initial clinical stages (Sperlova and Zendulkova, 2011).Clinical examination of  diseased sheep in the two described cases of  disease showed differences in the type of  lesions in the oral cavity and lips. The main noted differences were proliferative changes in lips and oral mucosa in the case of  the malignant form of  contagious ecthyma, which is understandable, given the epitheliotropism of  the parapoxvirus. These signs were not seen in the case of  bluetongue, but rather, swelling and hyperemia of  oral mucosa and nostrils that could turn into bleeding and necrosis in the late stage of  the disease were observed. Swelling and congestion due to changes in tongue blood vessels are typical in cases of  bluetongue, giving a clinical pathognomonic sign. Similar clinical and pathological changes have been described in Montenegro during an outbreak of  bluetongue (Pejović, 2016).Changes in the tongue are also possible in contagious ecthyma, but they are proliferative, and later, they turn into scabs. Scabs can spread from the lips to the surrounding skin of  the face, which was evident in our case. The scabs can easily be removed from the skin, leaving shallow erosions that become doorways for secondary bacterial infections. Consequently, suppurative and necrotic lesions occur in these places. If  the sheep in the flock are immunocompromised, the mortality rate can rise, and in the literature this is called the malignant form of  contagious ecthyma (Scagliarini et al., 2012). The mortality for contagious ecthyma can be over 50% (Scagliarini et al., 2012). Generally, contagious ecthyma has a lower mortality rate than bluetongue, but due to similar clinical phases, veterinarians sometimes do not submit samples for laboratory confirmation, which is not recommended in areas endemic for bluetongue. Although contagious ecthyma often occurs, there is not enough data on this disease in Republika Srpska and Bosnia and Herzegovina, and it is not possible to assess losses in the case of  outbreaks. Advanced complications of  contagious ecthyma in the sheep from Pale were a consequence of  bad farming practice and inadequate treatment. Clinical examination is essential and always helpful in making a final diagnosis. It is also necessary to revise the procedure for laboratory diagnosis of  contagious ecthyma and Veterinarski Glasnik 2019, 73 (1), 57-6362bluetongue in the Republic of  Srpska. Unfortunately, in bluetongue endemic areas, serological techniques are insufficient, because a significant number of  animals in the population will have been previously exposed to infection (Sperlova and Zendulkova, 2011). In this case, the disease must be confirmed using molecular techniques. Given the large number of  diseases that can be mistaken for bluetongue, practioners should insist on laboratory testing and, thus, reduce the possibility of  diagnostic errors.Authors contributions:OS described outbreaks of  Bluetongue and Malignant Orf  in Bosnia and Herzegovina. OS and DN drafted manuscript.Competing interests:Authors declare that they have no competing interestsREFERENCESNedić D. 2002. Veterinarsko-epidemiološka sitauciјa u Republici Srpskoј i sviјetu, 2001-2002. Zbornik radova, Osmo savјetovanje veterinara Republike Srpske – Uvodni referat, 7-8.Đuričić B., Pavlović M., Laušević D., Nedić D., Radenković-Damјanović B. 2002. Bluetongue - mere suzbiјanja i kontrole bolesti. Zbornik referata i kratkih sadržaјa Simpoziјum, četvrti Јugoslovenski epizootiološki dani, 84-94.Mitrović N., Nedić N. D., Marić Ј., Santrač V. 2004. Epizotiološka situaciјa bolesti plavog јezika u 2002-2003 godini u Republici Srpskoј. Zbornik kratkih sadržaјa 10. Godišnje savјetovanje veterinara Republike Srpske, 61-62.Đuričić B., Nedić D., Laušević D., Pavlović M. 2004. The epizootiological occurrence of  bluetongue in the central Balkans. Veterinaria Italiana, 40 (3), 105-107.Velić L., Velić R., Bajrović T., Dukić B., Čamo D. 2004. Bluetongue in Bosnia: comparisons of  competitive enzyme-linked immunosorbent assay and standard agar gel immunodiffusion tests. Veterinaria Italiana, 40(4), 562-563.Pejović N. 2016. Nalaz karaktirističnih patomorfoloških promjena kod ovaca sa malignom groznicom ovaca, Doktorska disertacija, Poljoprivredni fakultet, Univerzitet u Novom SaduSperlova A., Zendulkova D. 2011. Bluetongue: a review. Vet Med-Czech, 56(9), 430-452.Scagliarini A., Piovesana S., Turrini F., Savini F., Sithole F., McCrindle C.M. 2012. Orf  in South Africa: endemic but neglected. Onderstepoort Journal of  Veterinary Research, 79(1), 1-8.STEVANOVIĆ Oliver and NEDIĆ Drago: Bluetongue and malignant contagious ecthyma in sheep63KLINIČKA PREZENTACIJA BOLESTI PLAVOG JEZIKA I MALIGNOG OBLIKA ZARAZNOG EKTIMA KOD OVACA: OPIS SLUČAJEVASTEVANOVIĆ Oliver, NEDIĆ Drago Kratak sadržajBolest plavog jezika i zarazni ektim su bolesti ovaca koje imaju sličnu kliničku sliku te ih je teško razlikovati na osnovu ispoljavanja kliničkih znakova. U praksi, detaljan klinički pregled ovaca je potcenjen i retko se sprovodi. U radu su prikazani klinički slučajevi bolesti plavog jezika i maligne forme zaraznog ektima. Detaljno su opisane razlike u kliničkoj slici kod ova dva oboljenja i postupak postavljanja kliničke dijagnoze koja je neophodna za primenu efikasnih mera suzbijanja bolesti.Ključne reči: ovce, bolest plavog jezika, zarazni ektim, klinička prezentacija

Klinička prezentacija bolesti plavog jezika i malignog oblika zaraznog ektima kod ovaca - opis slučajeva

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Klinička prezentacija bolesti plavog jezika i malignog oblika zaraznog ektima kod ovaca - opis slučajeva

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