Orf is a common viral condition that causes significant welfare and economic problems in UK sheep flocks. Orf can affect sheep of all ages, sexes and breeds. Animals can also carry the disease without symptoms and there is no specific treatment available.
Some flocks experience Orf outbreaks year after year, whilst others have only odd cases infrequently. But often a farm that experiences only a few cases each year will suddenly get an explosive outbreak.
It is important to understand that the disease is difficult to treat effectively – and when you consider the condition can also affect humans with nasty and irritating sores the end result – then prevention of the disease taking hold in a flock is the aim. The main financial losses from Orf are associated with lambs, although ewes will often also show signs. Orf lesions in ewes are usually found on the udder and teats, and the discomfort caused means that the ewe will often not allow a lamb to suckle. As a result, lambs will try and steal milk from other ewes and this spreads infection further. When Orf affects ewes in this way, it results in both chronic and acute mastitis. Ewes suffering with chronic mastitis may lamb the following year with little or no milk due to damage to the teats, but in acute cases the ewe can lose at least half the udder or even die.
Lambs can also die from the disease, but even surviving animals never do as well as unaffected stock and their growth rates and market value can be significantly compromised.
Flocks that have never experienced Orf should maintain disease-free status by carefully selecting replacements from known disease-free premises. But if Orf does break out, you can control the problem with vaccination.
With the introduction of Scabivax Forte there is now an improved vaccine system with a superior formulation that protects against wild strains of Orf. The system also incorporates a durable applicator, which makes it easier to vaccinate animals properly, as well as provide better all round protection against the disease.