DOVRINE OR MALADIE DV COIT .21 



As an indication of the counts which may be obtained from healthy horses, the 

 reader is referred to Table VIII. In this table the average findings of Moore, 

 Fischer, Cozette and F. Mier are given, as well as some findings which are a portion 

 of the records of this laboratory. The first three numbers referring to the biological 

 laboratory records are of healthy horses kept under the ordinary conditions of stabling 

 accompanied by work. No. I was a mare used for light driving around Ottawa, and 

 her blood was taken while in harness on a trip to the laboratory. No. 2 refers to the 

 stallion No. 30 (Dick) at the Lethbridge quarantine station, and it is this stallion 

 that has been used in connection with the practical breeding experiments conducted 

 at that station. No, 3 is a gelding attached to ' K ' division of the Royal Northwest 

 Mounted Police, whose blood was taken three hours after arrival at the Lethbridge 

 quarantine station. From the results obtained in case of the horses Nos. 2 and 3, 

 it would appear that the differential blood-count of a horse, even in a range country 

 and feeding on prairie hay, provided it is stabled, will be very similar to that found 

 by the authors above mentioned, which are without doubt records obtained from 

 horses kept under the usual conditions common to a well settled community. 



The counts given as our findings (Nos. 4 to 13 inclusive) are of blood taken 

 from healthy horses kept under range conditions, and indicate that the blood of such 

 animals, even though in perfect health as far as clinical evidence can indicate, pre- 

 sents a marked variation from that which is usually considered normal. These 

 horses were in a district which is and has been free from dourine, and further, were 

 inclosed within a pasture, and were considered as being suitable to supply us with 

 blood smears for purposes of comparison with our many counts of the blood from 

 horses affected with dourine, as given in Table IX. The age of these animals did 

 not seem to occasion any marked variation in the differential counts. 



In Table IX. the first two counts are from blood smears which Dr. Lingard of 

 India was kind enough to supply us; the remainder, however, are of smears taken 

 by myself at the Lethbridge quarantine station and at other points. All of the 

 animals mentioned in this table from which I took smears, save No. 13, were under 

 range conditions at the time of making the blood preparation, having been put 

 through a chute or squeeze for purposes of clinical examination. In a few instances 

 a slight variation in the count from the normal of a particular individual may have 

 been occasioned by the excitement attending their handling. 



A careful study will, however, indicate that there is a marked variation in the 

 differential counts as here recorded. In this connection we have found that the 

 variations noted in cases of dourine are in a large measure due to the stage of the 

 disease. In all cases where the disease is advanced and clinical symptoms are in 

 evidence, the differential blood-count is almost invariably that of the normal animal. 

 In cases of dourine where a strong suspicion of the disease exists, and there is insuffi- 

 cient evidence to warrant the destruction of the animal, the differential blood-count 

 will usually reveal a marked decrease in the poly-morpho-nuclear elements and a 

 decided increase in the lymphocyte groups of cells. While this has been true with 

 our counts there is yet a large amount of work necessary to positively determine the 

 value of this method as an aid to the diagnosis of dourine. 



