Border disease of sheep and goats in Saudi Arabia

Border diseases is one of viral diseases that affect sheep and goats causing economic losses worldwide. The present study was intended to explore the existence of border disease infection in sheep and goats in two regions at the north of Saudi Arabia. Collected serum samples were 624 from 155 sheep and 217 goats in Hail and 144 sheep and 108 goats in Rafha regions at the north of Saudi Arabia. Antibodies against pestivirus were examined in collected sera using competitive ELISA. Overall found pestivirus antibodies were 18.4%. Sheep showed the highest sero-prevalence (20.7%). Within localities highest seroprevalence was seen in Rafha region. Obtained results points to the circulation of border disease infection in sheep and goats in the northern part of Saudi Arabia. © 2020 Published by Innovative Publication. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by/4.0/)


Introduction
Border disease virus (BDV)is one of viral diseases which affect the animal production. BDV, bovine viral diarrhea virus (BVDV) and classical swine fever virus (CSFV) are classified in the family Flaviviridae. 1 BVDV can infect sheep and goats; border disease is known to affect sheep and goat production negatively by losses due to stillbirth, weak offspring. 2 Border disease is existing all over the world, Antibodies were reported in different countries; In Iraq, 47% of sheep and 16% of goats tested positive. 3 In Turkey 68% of tested sheep were positive. 4 Existence of BDV or BVDV antibodies with variable prevalence rates were documented, in India, 5 Sudan, 6 Austria 7 Serbia. 8 In Saudi Arabia very scares work was undertaken to investigate the existence of BVDV and/ or BDV in sheep and goats. Antibodies against BDV and/or BVDV were detected in sheep and goats, in Al-Ahsa region 24% of sheep and 3% of goats were found to be positive for BDV antibodies. 9 more recent study reported the presence of pestivirus antibodies in cattle sera in north, east, west and central regions of Saudi Arabia. 10 This study was carried out to explore the presence of antibodies against pestivirus in sheep and goats in the northern region of Saudi Arabia.

Study area
Two regions in the north of Saudi Arabia were selected for the study, Hail and Rafha ( Figure 1).

Collection of samples
Serum samples (n = 624) were collected from sheep (n = 155) and goats (n = 217) in Hail and sheep (n = 144) and goats (n = 108) in Rafha. Sera were collected randomly from clinically healthy animals in the slaughterhouses and some farms. Blood from jugular vein was drawn, centrifuged and sera were kept at -20 o C till tested.

Discussion
Pestivirus including BVDV and BDV are known as significant viral causes of infectious diseases affecting domestic animals leading to great economic losses. 2 Border disease in sheep and goats had been extensively reported around the world. In the present study antibodies to pestivirus were found in 18.4 % of 624 examined sheep and goat sera at the north of Saudi Arabia. Unlike a previous work in camel sera, 11 highest prevalence rate was found in Rafha which was not expected as Rafha is a small town with very scares animal production facilities.
The detected pestivirus prevalence in sheep (21%) was similar to a previous report (23.7%) in the eastern region of the country 9 as well as many countries. It was 23% in 22% in India 5 22% in Austria, 12 18% in Japan, 13 19% in Turkey. 14 Reported prevalence of pestivirus is variable in different countries. The detected prevalence in this study is higher than that presented in may reports, it was only 0.3% and 0.5% in Australia and Denmark, 15  However far higher prevalence of pestivirus in sheep were reported, 45% in Turkey, 20 68% in Algeria 1 as well as in Turkey, 21 75% in Turkey. 22 This discrepancy is most probably due to the management system, where in USA and Europe strict sanitary and hygienic measures are adopted.
The overall results showed that sheep had higher prevalence rate than goats which is in agreement with the picture reported in different countries, although prevalence in goats was slightly higher than in sheep in Hail region which is unusual and may be due to the collection of samples from highly infected flocks. Existence of antibodies to pestivirus or specifically BDV in sheep and goat sera was confirmed in different countries, in most of the reported cases sheep were found to be highly affected than goats. Pestivirus antibodies were found in% of sheep, 17% of oats in India, 5 18.7% in sheep, 6.5% in goats in Chile, 23 64% in sheep, 18% in goats in Bulgaria, 24 39% in sheep, 15% in goats in Sudan; 6 50% in sheep, 3% in goats in Turkey, 25 13% in sheep, 12% in goats in Nigeria, 26 47% in sheep, 16% in goats in Iraq. 3 The results obtained in this study confirmed the high prevalence of pestivirus infection in small ruminants in the country, this raise the need for more detailed study to investigate the prevalence of this viral infection in different areas of the country. Such research beside the molecular characterization of the circulating virus is highly recommended to aid in the control measures of this economically important disease.

Acknowledgments
My thanks and gratitude is directed to my colleagues at Rafha and Hail for samples collection and to my colleagues, Prof. Dr. Yahia Hassan Ali and Dr. Muaz Magzoub for assistance in the Lab work.

Source of funding
None.

Conflict of interest
There is no any conflicts of interest exist.