13UKEAU OF ANIMAL INDUSTIiY. 559 



taiuly lias more in its favor tban the opposite. A few, especially amoug 

 tlic, Freucli, adhere to the belief of its couiiiiuiiieability. 



Tlu; life history of these luuj?-worms may be summarized brielly as 

 foHows: The adult sexually mature worms iu the trachea aud brouchi, 

 or alveoli {P.sendolius oris puImonaJis), ])roduce a large luuuber of o\a, 

 which fiually set free living embiyos. These are discharged with the 

 mucus and probably enter some invertebrate as a mediate host to uii- 

 dejgo further devclopuieut. When taken into the stomach of lh(.' liuid 

 host, through the food and drinking water, thej migrate back to the 

 pharynx and thence into the air passages, where they assume the adult 

 form aud set up constant irritation leading to bronchitis. Ruminants 

 nufy be more readily affected in this way, because the food is ivturned 

 to the mouth and with it any embryos which are thus at liberty to enter 

 the trachea and brouchi through the larynx. 



TEEATJIENT. 



Preventive mcosuycs. — The most important jihase of treatment is un- 

 doubtedly the adoption of rules for the prevention of the spread of the 

 disease. These rules will vary according as we believe the disease di- 

 rectly communicable from one animal to another or not. Presumptive 

 evidence leans towards the latter view, but it will be safest to remove 

 the sick from the healthy, if that be possible. This will i)revent the 

 contamination of the stables and pastures with the mucous discharges 

 that are known to contain the parasites. The latter, if not immediately 

 dangerous, are potentially so, and when their development is completed 

 the places where the embryos have been <leposited may become potent 

 sources of evil. In large herds, where strict attention cannot be given 

 to preventive measures, destruction of the diseased animals aud anni- 

 hilation of the lungs aud other diseased organs and products by tire or 

 some chemical agent is without doubt the safest aud most profitable 

 course in the end. 



On contaminated pastures the parasites are probably taken up in spring 

 and early summer. The disease in lambs nuiy be avoided either by 

 keeping them in the stables or by giving them plenty of water to drink 

 before they are driven to pasture, so that they will not be forced to seek 

 the stagnant pools, the usual abode of parasites. Some food may be 

 given with the water. 



It is thought by some that there is much risk in pasturing lambs or 

 calves on old jiastures after adult stock, aiul that it is advisable to keej) 

 theiu on young grasses and on high ground. 



Spinola advises, iu addition, the use of anthelmintic substances for 

 lambs in spring and early summer which act injuriously on the para- 

 sites in the stomach. A favorite formula of his, which has found its 

 way into most veterinary works, is the following: 



Wormwood and calamns root, each 2 pounds. 

 Tansy root, burnt bones. (animal cliarcoal?), each 1 pound. 

 Sulphate of iron, 3 ounces. 



Make into a powder and mix with ground oats as a lick, each lamb to receive about 

 one-half ounce. 



Finally, in adopting preventive measures, the destruction of the para- 

 site must be the chief end in view, and while this is being done suscepti- 

 ble animals must be kept away from places where the parasites are sup- 

 posed to be. With these two rules constantly in mind the disease may 

 be kept in check. All fodder soiled by discharges should be burnt, in- 

 fected stables carefully cleaned ; pastures should be drained to remove 

 all stagnant pools; stieams of running water should be kept perfectly 

 pure. 



