FILARIASIS OF DOGS,.

New Zealand Journal of Agriculture, Volume VI, Issue 1, 15 January 1913, Page 34

FILARIASIS OF DOGS,.

C. J. Reakes,

D.V.Sc., M.R.C.V.S.

The value of the quarantine system as applied to imported animals was well demonstrated in a recent case which occurred in Auckland. A dog brought from one of the Pacific islands was found, while undergoing detention at the quarantine - station, to be affected by the condition termed filariasisin other words, to be harbouring in its system parasitic worms of the class termed Filaria. A popular term for the particular affection present in this case is “ heart-worm,” the parasites being present in the heart itself (see photograph). The

mature worms are of considerable size, one taken from the heart of this particular dog being 7 in. in length, and, as will be gathered from the photograph, several of these . were present, all being located in the right ventricle. Outwardly the animal showed no indication of sickness or of. any trouble whatever, and the presence of the parasites was only determined by the fact that, as a proper precautionary measure, a small quantity of blood was obtained during life and

subjected to microscopical examination. This clearly demonstrated the presence in the blood of the parasite in a very early stage of its existence. The presence of the parasitic disease being thus proved, the animal was destroyed, and a post-mortem examination conclusively confirmed the opinion previously formed.

The particular parasite responsible for this condition is named Filaria immitis. It affects dogs in many parts of the world, particularly in India, China, Japan, the Pacific islands, and the southern States of America. Cases are also stated to have been met with in Denmark, Italy, . Germany, and France.

So far as is known only one case has been met with previously in ■ New Zealand, and in this particular instance, which occurred several years ago, it is impossible to ascertain whether the dog was an imported one or not. Although dogs infested with these parasites do not show, in the majority of cases at least, any signs by which their presence can be told by the ordinary observer, it has been noticed that symptoms of circulatory interference can often be detected. Thus, lameness of one hind leg, with wasting of its muscles, and even partial paralysis. This has been noticed in animals of the Great Dane breed. Owing to the parasites interfering with the circulation of the brain, fainting and convulsions may occur, and often the animal may become dull and snappish. Emaciation and weakness are generally seen in the later stages.

Some Bacteriological Effects of Liming (lowa Agric. Expt. Sta., Research Bull. No. 2). —The effects of applications of ground limestone on cropyields, the total number of bacteria in the soil, and the number of bacteria of certain groups were determined, and an attempt was made to correlate the three phenomena. The ground limestone was carefully mixed with three different lots of soil in pots at the rates of |, 1,2, and 3 tons per acre, and the pots were kept at approximately uniform temperature and moisturecontent throughout the experiment. After the lapse of a month the soils were sampled, the sampling being repeated three times at intervals of two or three weeks; at each sampling the number of bacteria was estimated. It was found that the applications of limestone had resulted in an increase in the number of bacteria in the soil, and the increase was almost proportional to the amount of limestone applied up to 3 tons per acre. In all cases the largest percentage of gain in bacteria was shown at the first sampling. At subsequent dates differences occurring in all the soils, both treated and untreated, obscured to a greater or less extent the differences due to liming. The applications of limestone were also found to increase the ammonifying, nitrifying, and nitrogen-fixing powers of the soil, the increases in each case being found to be almost proportional to the weight of limestone given. In the case of crop-yields the smaller dressings had little effect, but with the 2-ton and 3-ton applications the crop was materially increased. The nitrogen-content of the crop was . increased to . a much greater extent than the weight of the crop itself. -