Oleum canis evening primrose oil is extracted from the seeds of the evening primrose a medicinal and ornamental plant it contains a high content of essential fatty acids and can help to strengthen your dogs natural defences this oil is particularly rich in gamma linolenic fatty acids which are polyunsaturated omega 6 fatty acids that have a beneficial effect on helping to reduce inflammation oleum canis evening primrose oil can also be given to your dog both orally and externally to soothe