1931 



ANNUAL REPORT, 1930 



23 



Tests of Adult Foxes on Board Floors 



Adults. — The above table illustrates the lung-worm tests of ten adult foxes 

 placed on board floors in November, 1928. While only ten foxes are shown, 

 the results are the same for the 32 foxes. Eight of the foxes were finally 

 pelted and a post-mortem examination confirmed the tests and is also recorded 

 in the last column. Positive test is denoted by "-f" and negative for lung- 

 worm eggs by "0." 



Known infected adults were placed in board-floored pens in November, 

 1928. All of the 32 still tested positive in the spring of 1929. Tests during 

 1929 show that some few adults gradually became free of lung worms by 

 November, but the majority were not clean until the spring of 1930. Two 

 foxes still tested positive with a light infection in May, but were both 

 clean by July of 1930. All the adult foxes still on the ranch that had been 

 placed in properly constructed board-floored pens were clean by test in July. 

 1930. This applies only to the foxes continually kept on boards, as one or two 

 foxes when testing clean were placed back in gravel pens and were reinfested 

 within three months. Board floors stop reinfestation but the parasites then in 

 the fox remain alive for some time. All the foxes were clean after a twenty 

 months' continuous period on board floors. Hook-worm infestation is also at a 

 minimum by this method of pen flooring. Examination of the carcasses of 

 numerous foxes pelted this fall show a remarkably light hook-worm infection 

 and no lung worm in foxes kept on board floors. 



Concrete Floors. — Three pens were floored with concrete as an experiment to 

 ascertain its efficiency in parasitic prevention. Pups born in these pens 

 in 1929 were negative for lung worm. In the fall of 1929, a shade roof was con- 

 structed over the pens as they were thought to be rather hot for the foxes. In 

 1930, a total of 11 pups were born to infected foxes in these pens but all were 

 found to be heavily infested with lung worm. Round and hook worms were 

 also present in considerable numbers, which necessitated repeated pilling of the 

 pups. Except for a few cases of round worms, none of the pups raised on board 

 floors has been pilled since the floors were first constructed. Apparently the 

 shade roof prevented the concrete from drying off as rapidly as was necessary. 

 Enough moisture was left in the tiny crevices to give the required degree 

 of dampness necessary for egg development. Perhaps if the concrete had been 

 finished smoothly this would not have been the case. 



Conclusion. — Board floors of proper construction will prevent lung-worm 

 infestation in pups born from infected parents. Adults will in time clean up, 



