22 DEPARTMENT OF GAME AND FISHERIES No. 9 



and risk the spreading of snuffles to other parts of the rabbitry. Following 

 outbreaks any rabbits suffering from sore hocks or any does that repeatedly 

 fail to raise healthy young should be eliminated. 



Board Floors for the Prevention of Lung Worm 



Board floors were first constructed in twenty pens at the Experimental 

 Fur Farm in November, 1928. By that time, tests of the foxes showed that 

 lung-worm infection was increasing and if left unchecked would likely become 

 a serious problem. Periodical tests for the presence of parasites are carried out 

 regularly as routine work at the farm. Preliminary tests of the first pups 

 born from infected parents kept on board floors were so conclusive that twenty- 

 four additional double pens were remodelled and board-floored in November, 



1929. Of the fifty fox pens at the farm, all are now board-floored with the 

 exception of three concrete and three gravel pens, which are kept especially 

 for experimental work with parasites. 



Construction. — First experiences show that the floor should be built with a 

 decided slope and with the lumber laid lengthways with the slope. Boards 

 should be straight-edged and laid close together. In time, the warping and 

 shrinkage will leave a slight crack between the boards. Rapid and perfect 

 drainage is thus provided. The floor should have a 6-inch drop in each 20 feet 

 and should be so constructed as to leave plenty of space, at least 13^ to 2 feet, 

 between it and the ground. This allow^s space for a good circulation of air 

 under the floor and assists in the rapid drying out of the floor after a heavy rain. 

 Most parasitic eggs require a certain amount of moisture for their development. 

 It is the lack of moisture on properly constructed board floors that stops the 

 lung-worm eggs from developing. 



Four of the pens were floored in 1928 with lumber resting on 2- by 4-inch 

 scantlings laid on the gravel bottoms of old pens. These pens were later found 

 to be useless in the prevention of lung worm. Pups born here were found to 

 be just as badly infested as those from infected parents born on dirt or gravel 

 pens. Apparently the floor was too close to the ground and the moisture kept 

 the floors in a state of dampness sufficient for parasitic development. Such 

 floors do not dry out as rapidly after rains as is necessary. 



Pups. — In 1929, a total of 53 pups were born to known infected foxes 

 that had been placed in board-floored pens in November, 1928. These pups 

 were raised to maturity on boards and showed consistently negative tests for 

 lung-worm eggs throughout the entire year. Some of these pups were pelted 

 that December and contained no lung worms. An exception is noted of twelve 

 additional fox pups that were born from infected parents kept in the renovated 

 pens where the floors were laid too close to the ground as mentioned above. 



Thirty-nine pups were born to infected parents kept on board floors in 



1930. They were also negative in every case for lung-worm eggs. These pups 

 also showed a marked decrease in hook-worm infestation. Very few pups showed 

 any hook-worm eggs throughout the entire four tests performed during the year. 

 A number of these pups were pelted in December and autopsies revealed very 

 few cases of hook worms and no lung worms, but round worms were still present 

 in the pups that had not been wormed. Board floors do not appear to be of 

 any appreciable value in preventing round worms. 



