Sores around the mouth, refusing food, and contagious: what could it be?

Crusting and ulcers around a guinea pig’s mouth with loss of appetite may be stomatitis, also called infectious stomatitis. Early signs are redness of the lips, tongue, upper jaw, and oral mucosa, with drooling and reduced or no appetite, leading to weight loss and poor nutrition, and even death in the end. It may be caused by improper feeding or by the mouth being cut by a sharp object. Once these signs appear, treat with iodine glycerin, antibiotics, and vitamins: first rinse the mouth and skin around it with saline or iodine glycerin, wipe away discharge, then apply a layer of iodine glycerin, and afterward spray an anti-inflammatory oral spray inside; if severe, also give oral anti-inflammatory medicine, applying twice daily until improvement. During treatment remember to supplement vitamin B2 to speed healing of ulcers and mucosa.