Effect of Miscanthus Grass As a Dietary Method to Aid Hairball Control in Cats

Feline grooming habits can lead to accumulation in the stomach and formation of masses (trichobezoars) hairballs that are regurgitated. Some pet food companies have created diets intended to force the concretion into the intestines, primarily by supplementing large quantities of insoluble fiber like cellulose. Miscanthus grass (M), possesses a similar content of insoluble fiber and may be an alternative for this purpose. Therefore, the objectives of this study were to determine the effects of M on hairball passage in cats. Experimental diets were composed of 90% basal ration and 10% of either M or rice flour (C). Cats (12 American Shorthair) were individually fed one of the two extruded diets for 16 days of adaptation then feces were collected for 5 days. Hair masses were washed from feces, counted, and total hair weight, and fecal dry weight were quantified. Hair masses were sorted by their length and diameter (extra small: <10.0 mm x <5.0 mm, small: 10.0 - 20.0 mm x 3.5 - 6.5 mm, medium: 20.0 - 30.0 mm x 4.0 - 7.0 mm, large: 30.0 - 40.0 mm x 4.5 - 8.5 mm, and extra-large >40.0 mm x >5.0 mm). Treatments were fed as a switch-back design and data were analyzed using the GLM procedure in SAS (v. 9.4) with means were separated by significant alpha (5%). Total dry fecal weight was greater for cats fed M than C (P<0.0001; 112.99 vs. 66.71, respectively). There was a tendency for less total fecal hair mass per gram of dry feces (P=0.0712), and fewer fecal hairball counts per gram of dry feces (P=0.1082) for cats fed M. However, hairball size (P=0.2431) total fecal hairball weight (P=0.2541), and total fecal hair weight (P=0.3027) did not differ between treatments. The addition of M lead to some improvement in gastrointestinal management of hair in short-hair cats not otherwise predisposed to hairball. Use of predisposed animals, long-hair cats, the use of a larger number of animals, and (or) larger fiber particle size may increase differences among the treatments. In conclusion, M decreased hairball size and total fecal hair mass per gram of feces, which could be an indication of increased ability of cats to eliminate hair masses through fecal excretion and reduce their regurgitation in a home setting.