This section is from the book "The Dogs Of Great Britain, America, And Other Countries. Their Breeding, Training, and Management in Health and Disease", by John Henry Walsh (Stonehenge). Also available from Amazon: The Dogs Of Great Britain, America And Other Countries.
Though very often fatal among highly-bred animals, phthisis or consumption has not been noticed by writers on dog diseases, neither Blain, Youatt, nor Mayhew making the slightest allusion to it I have, however, seen so many cases of tubercular diseases in the dog, that I cannot doubt its existence as an ordinary affection. Furthermore, I know that hundreds of canines die every year from it I have seen the tubercules in almost every stage of softening, and I have known scores of cases in which a blood-vessel has given way, producing the condition known in the human being as spitting of blood.
The symptoms of consumption are, a slow insidious cough, without fever in the early stage, followed by emaciation, and ending, after some months, in diarrhoea, or exhaustion from the amount of expectoration, or in the bursting of a blood-vessel. This last is generally, the termination in those dogs that are kept for use, the work to which they are subjected leading to excessive action of the heart, which is likely to burst the vessel. In the latter stages there is a good deal of constitutional fever, but the dog rarely lives long enough to show this condition, being either destroyed as incurable, or dying rapidly from loss of blood or diarrhoea. Treatment is of little avail. Though the attack may be postponed, the disease cannot be cured, and no phthisical animal should be bred from. Cod-liver oil is of just as much service as in the human subject, but, as before remarked, it can only postpone the fatal result. It is therefore not well to use it except in the case of house pets. The dose is from a teaspoonful to a tablespoonful three times a day.