Clinical Signs of Hairballs in Cats Fed a Diet Enriched with Cellulose

The normal grooming activity in cats leads to the daily ingestion of hair. Together with food, these ingested hairs can pass through the intestines thanks to peristalsis and subsequently expelled with feces.
Very often, however, the hairs can agglomerate into solid masses in the stomach or intestines and this causes the formation of hairballs also called trichobezoars.
The risk of developing hairballs in cats is increased by longer and thicker coats, as this type of hair agglomerates more easily and in larger boluses, and by a very accentuated treatment behavior by the cat, because the excessive grooming causes the subject to ingest more hair.
Cats get rid of hairballs present in the stomach through vomiting, usually for more voluminous ones, or through the transit in the intestinal tract with consequent excretion with the feces. The clinical signs of hairballs are vomiting, retching and / or coughing. Occasionally, hairballs can cause bowel obstruction, associated with severe clinical signs such as incoercible vomiting, abdominal pain and subsequent anorexia. In severe cases, the treatment of trichobezoars may also require removal by surgery or endoscopy. Treatment of the clinical signs of feline hairballs often involves the use of laxatives and lubricants, but such treatments can interfere with normal digestion and nutrient absorption in the long run, so they are contraindicated in the long run.
The ingestion of a feed containing psyllium husk has been shown to can reduce the severity of the symptoms of hairballs in cats. Psyllium peel is a source of fiber whose ingestion can increase the frequency and intesity of intestinal motility, can delay gastric emptying and leave gastric motor activity unchanged. Psyllium in fact promotes the binding of hair to food particles and therefore increases the quantitative transfer of hair from the stomach to the duodenum, followed by a better transit through the intestine.
The intake of fiber can therefore delay gastric emptying and increase the intestinal transit speed and these effects could antagonize the formation of hairballs. Therefore, it has been speculated that a diet enriched with a preparation rich in insoluble fiber (Arbocel BWW40®: preparation rich in cellulose, which forms a completely insoluble fiber network), would reduce the severity of the clinical symptoms of boluses of hair in cats. In a double-blind and parallel placebo-controlled study, 24 owned cats were used and the clinical signs were assessed by the owners through questionnaires. In both groups, age, body weight and gender distributions were similar for the placebo and the test group. The number of cats with short, medium or long hair was also similar for the two groups. As for the starting values for the mean cough scores they were identical for the test and placebo group, but the scores for vomiting and retching were on average lower for the control cats.
For a period of four weeks, the cats recruited (n = 12 per treatment group) consumed a complete dry food without (control group) or with 4% (w / w) of cellulose (test group). During the test period, the control or test diet was the only source of nutrition.
On a questionnaire, the owners daily recorded the onset of symptoms of hairballs (vomiting, retching and coughing). The starting symptoms were quantified in the form of a severity score, while the symptoms during the study were measured as a daily frequency. Clinical signs were marked by the owners on day 0 (start) and at the end of the first week during which the usual diet was administered. From the start of the second week until the end of the trial, cat owners recorded the number of times they observed vomiting, vomiting and / or coughing on a daily basis.
At the end of this study it was seen that, compared to the control diet, the dietary diet with the addition of 4% of fibers reduced the total incidence of vomiting, retching and coughing by 79, 91 and 70%, respectively, therefore statistically significant especially for vomiting. A particularly significant fact that was also that, in cats with an incidence of vomiting five times for five weeks, the cellulose-containing diet reduced the incidence to one time every five weeks.
Furthermore, it should not be forgotten that test cats had less severe signs of vomiting and retching than control cats, which implies that the beneficial effect of the observed cellulose diet is underestimated rather than overestimated. Finally, it has been seen that the effects of treatment are generally less significant in patients with less severe symptoms.
It is evident that the ingestion of cellulose has led to a delayed gastric emptying, causing the binding of single strands of hair to food particles so as to make more hair pass through the duodenum into small strands, which pass more easily along the intestine. The increase, mediated by cellulose, of the percentage of transit can subsequently favor the excretion of the hair with the feces.
In conclusion, this double-blind, placebo-controlled study shows that a 4% cellulose-enriched diet significantly reduced the clinical signs of hairballs in cats, with a statistically significant reduction in all symptoms examined, especially vomiting. The observed effect can therefore be considered of practical relevance.
Finally, observing the results of this study which involved the dietetic treatment of cats with existing hairball symptoms, it is likely that a diet with added cellulose is also effective in preventing the formation of hairballs, since it would be very useful for cats with an increased risk of developing these (long, thick hair, excessive hygiene, etc.).