This section is from the book "Sporting Dogs. Their Points And Management In Health, And Disease", by Frank Townend Barton. Also available from Amazon: Sporting Dogs; Their Points and Management in Health and Disease.
Beyond the application of mustard, turpentine, or hot water, blistering agents are not much employed in the treatment of canine ailments.
As a remedy for external use in diseases of the bronchial tubes and lungs, mustard has not, in the author's opinion, any superior.
It can be used either as a paste applied directly to the skin, or in combination with boiled linseed poultices.
In long-haired dogs it is advisable to clip off some of the hair, so as to facilitate the full counter-irritant properties of the mustard.
It requires very little rubbing in, and it is not advisable to repeat the application, unless specially called for.