The floatation method with zinc sulfate solution was applied to eggs of five species of canine intestinal parasites. The rate of floatation determined by it ranged from 56 to 79% for eggs of Trichuris vulpis. It reached 95% for eggs of Toxocara canis. It ranged from 13 to 64% for eggs of Gnathostoma spinigerum, from 43 to 91% for eggs of Ciphyllobothrium erinacei, and from 0 to 86% for eggs of Metagonimus yokogawai.
A total of 100 apparently healthy mongrel dogs supplied by the dog retention station were examined serum-chemically for 24 components to establish a screening method of dogs for experimental use. As a result, 7 components, tatol serum protein, cholesterol, creatinine, cholinesterase, GOT, GPT, and potassium were considered to be effective for this purpose. Screening by these components revealed ethat 25 of 63 dogs free from microfilariae could be used for a longterm experiment without any pretreatment, and that 4 of 37 dogs harboring microfilariae could be used for such experiment after anthelmintic treatment. The other dogs were presumed to be unfit for experimental use, since they were affected with some disorders of heart, liver, or kidney.
From 1971 to 1973 Ryu's R. M. A. T. was applied to examination of leptospiral antibodies in house and stray dogs. The average positive rate of antibody, against Leptospiraicterohaemorrhagiae in three cities of the Shikoku region was 12.2%. The sera of 66 of 250 stray dogs (25.4%) in Takamatsu-shi were positive against L. icterohaemorrhagiae and L. canicola, while 10 stray dogs in Matsuyama-shi were negative against both species. Of 90 house and 20 stray dogs, one house dog was positive against L. australis A, 2 house 3 stray dogs were positive against L. pyrogenes in addition to L. icterohaemorrhagiae and L. canicola. None were positive against L. autumnalis, L. hebdomadis, and L. grippotyphosa. The positive rate was higher in house male dogs (17.7%) than in house bitches (6.8%) and in stray male dogs (30.5%) than in bitches in stray bitches (21.2%). Only one of 410 vaccinated house dogs showed a positive reaction. The positive rate was much higher in house dogs under 6 years old than in those over 6 years old. It was the lowest in summer and the highest in winter.