Introduction
Orf virus (OV) belongs to genus Parapoxvirus and family Poxviridae and causative agent of papular dermatitis in sheep and goat also known as scabby mouth, sore mouth and contagious ecthyma. Typically OV lesion progress from erythema to macule, papules, vesicles, pustules and scab, which are mostly located around the mouth, on the teats of nursing ewes or around coronets. The shed scab contains high titer of stable virus, which if kept dry, can remain infectious long enough to sustain outbreak of disease. Sever outbreak can occur in naive herd, in which lesion are extensive and proliferative and do not regress spontaneously. The disease is more sever in nursing lambs due to developing lesion and animal die due to starvation and thirst. During outbreak ,morbidity can approach 100% while morbidity is usually less then 1%. However mortality can increase by 20%~50% as a result of secondary bacterial infection, stress, immunosupression or concomitant disease and may exceed 90% in case of malignant orf (Hosamani et al., 2009, Kitching et al., 2004). The diagnosis is generally based on clinical signs, which are typical, but can be confused with other vesicular diseases sheep. These include foot and mouth (Watson, 2004), bluetongue, sheep and goat pox (Kitching et al., 2004). Other diseases that resemble orf include papillomatosis (Smith et al.,2002), staphylococcal dermatitis and dermatophilossis (Smith et al., 2002). Rapid and accurate differential diagnosis is therefore necessary, not only allows to adopt control measures for animals but also prevents zoonotic chances. This may have negative effect on the profitability of small animal industry.

Case Presentation
On February 2, 2014, an approximately 1 year old, 30 kg sheep (Kajle) was presented at Department of Clinical Medicine and Surgery University Of Agriculture Faisalabad Pakistan. Upon arrival animal was examined physically. Animal have hemorrhagic papules, vesicles and pustules to multifocal necrotic scabs at commissure of the lips, medial canthus of right eye, coronet and pastern region. Animal have 105 temperature, heart rate was 70beats/minute and respiration 20 breath/minute. Animal was dehydrated, emaciated and have dull appearance. History reveals that animal was off feed from last two days. According to owner they have lost 2~3 animals with the same condition before this and there was history of keeping this animal with those that died. Owner use home made medicine to cure this but zero response. After physical examination, history, presence of lesion and sign and symptoms it was diagnosed to be a case of orf.

Treatment
Following treatment was given and animal show positive response and recovered with in 7 days. Amoxicillin (injection Amoxi- vet ICI), Infusion Ringer-Lactate, fly repellents (BIPP bismuth iodoform paraffin paste) on daily basis and injection Ivermectin.

Discussion
Contagious ecthyma also called contagious pustular dermatitis, ecthyma contagiousm, and scabby mouth with world wide distribution that affects sheep, goats, wild artiodactyls and man. The causative agent is double –stranded DNA virus. Virus gains entry through abraded skin and replicates in epidermal cells. Skin lesion progress in an orderly fashion through multiple stages. Infection is confined to the squamous epithelium and may involve the oral cavity, eye lids, teats, and coronary band, subsequently predisposing affected animals to secondary infections. Residual skin lesion are not ineffective once the scab falls off, but substantial amounts of infective virus are shed within scab which can remain infective in the environment for years. Although it is generally accepted that orf is endemic in Pakistan, the extent of problem is unknown. It is postulated that the underestimation of importance of orf can be attributed to the fact that it is not a controlled or notifiable disease. As a result there is little or no data available recorded by veterinary authorities and no surveillance programmes on orf virus are running in Pakistan. Autogenous vaccine is mostly used and that procedure can further add a risk for transmission, as the scab used for autogenously prepared vaccine contain live virus that can survive for a long time in the environment. Furthermore scratching the scab from infected animal possess a risk of zoonotic transmission, which is usually more for those who are in close contact with infected animal. There are several vaccines commercially available for Orf which contain virulent. The purpose of vaccine is to produce a lesion at the vaccine site, thus inducing immunity, this also causes virus shedding and can contribute to maintenance of infective virus with in environment.

References
D.E. Anderson, and D.G. Pugh, 2002, Diseases of the intgumentry system, In: Sheep and Goat Medicine, D.G. Pugh, Ed., W.B. Saunders Company, Philadelphia, Pa, USA, 1st edition, pp.203-204
http://dx.doi.org/10.1016/B0-72-169052-1/50010-7

Hosamani M., Scagliarini A., Bhanuprakash V., Mclnnes, C.J. and Singh R.K., 2009, Orf: An update on current research and future perspectives, Experts Reviews, 7(7): 879-899

Kitching R.P., 2001, Orf, In: J.A.W. Coetzer and R.C. Tustin, (eds), Infectious diseases of livestock, 2nd edn., Oxford University Press, Cape Town, pp.1282-1286

Smith G.W., Scherba G., Constable P.D., Hsiao V., Behr M.J. and Morin D.E., 2002, Atypcial parapoxvirus infection in sheep, Journal of Veterinary Internal Medicine, 16: 282-292
http://dx.doi.org/10.1111/j.1939-1676.2002.tb02371.x

Watson P., 2004, Differential diagnosis of oral lesion and FMD in sheep, In Practice, 26: 182-191
http://dx.doi.org/10.1136/inpract.26.4.182