Necrotic rhinitis is an uncommon, sporadic disease of young pigs characterized by suppuration and necrosis of the snout, arising from wounds of the oral or nasal mucosa. Confusion exists in the literature because of the use of the misnomer “bullnose” to also describe atrophic rhinitis (see Atrophic Rhinitis in Pigs).
Signs include swelling and deformity of the face, occasionally hemorrhage, snuffling, sneezing, foul-smelling nasal discharge, sometimes involvement of the eyes with lacrimation and purulent discharge, loss of appetite, and emaciation. Generally, only one or two pigs in a herd are affected.
The facial swelling usually is hard, but incision reveals a mass of pinkish gray, foul-smelling necrotic tissue, or greenish gray tissue debris, depending on the age of the lesion. The nasal and facial bones become involved, and facial deformity may be marked.
Prevention is directed toward avoiding injuries to the mouth and snout, improving pig processing techniques, and improving sanitation. When the disease occurs repeatedly, needle teeth should be clipped carefully.
If the condition is advanced, treatment may not be advisable. Early surgical intervention and packing the cavity with sulfonamide or tincture of iodine may be useful. In young pigs, sulfamethazine given PO is of value.