ON THERAPEUTICS. 
193 
to employ setons duriug debility, unless there should be a 
tendency to the formation of abscess, in which case the pu¬ 
rulent diathesis may be diverted to a portion of the body not 
important in its relations, and so the vital organs be pro¬ 
tected ; or in that state of the system where the blood is 
diseased (cachaemia), setons act beneficially, if we may judge 
from the amount of effete matter excreted. But it must be 
remembered that tonics and stimulants and dietetics will be 
necessary meanwhile to support the animal under the constant 
drain, which will increase the debility, even although the 
fluids removed be largely mixed with noxious matter. 
In acute diseases setons are less objectionable than blisters, 
as they occasion much less excitement. On the other hand, 
their action is not developed so rapidly, nor do they affect 
the nervous system so markedly. Their influence being more 
direct upon the circulation of the part, they are most effec¬ 
tive when applied close to the seat of disease. Thus, in acute 
“sore throat” we have found setons under the larynx to be 
very useful, and also in cerebral congestion. 
In acute laminitis, frog setons are sometimes found to be 
effectual, although the destructive character of the malady 
forbids us to hope for much benefit from any kind of treatment. 
In subacute or chronic disease, this form of counter-irri¬ 
tation is of undoubted value in cases of lameness from splint 
or spavin, especially those of old standing. In articular 
lameness, in chronic or subacute laminitis, in navicular dis¬ 
ease, setons act by producing a diversion and establishing a 
new action in the vicinity of the disease. 
In cases of suddenly arrested discharges and in the treat¬ 
ment of malignant growths setons establish a new outlet 
for the diseased secretions, and are so far derivative in their 
action. 
As prophylactics, setons or rowels are very popular 
during the prevalence of epizootics, as pleuro-pneumonia, 
nor is it unreasonable to presume that the production of a 
certain irritation in one part of the body may lessen the ten¬ 
dency to a similar condition in another and more vital portion. 
Experience is in favour of the practice, which theory certainly 
does not positively condemn ; besides, in epizootic affections 
the blood is invariably diseased before any local effects are 
developed ; the action of the seton will, in this view of the 
matter, be advantageous, always on the understanding that 
the loss sustained by the system be compensated for by a 
nutritious diet. 
Firivg .—All counter-irritants differ in degree only; the 
general phases of their action we have seen to be— First , a 
