I did a lot of research about hairball in rabbits after Poppy passed away last year. One of such work is this article which I sent to a local rabbit rescue. After sitting in my harddrive for over a year, I saw it again today and thought I might share this with the rest of the world in hope that somebody will find this useful. So here it is attached below.
The medical use of pineapple for rabbits
There are many myths circulating around the internet regarding the health benefit of pineapple for rabbits, especially for hairballs. So I did some research of my own using medical journals and trustworthy sources.
It seems that bromelain, the actual enzyme in question, is most abundant in the stem of the pineapple, the center part that we throw away. Fresh pineapple are best as the enzyme can be denatured once frozen or processed.
Although there are no definitive evidence that bromelain intake helps with hairball or GI stasis in rabbits, there are other positive results. They are summarized below.
From the study of [1], it seems that bromelain is good for diarrhoea. The effect is that it will reduce intestinal fluid secretion, which is the real cause of death from diarrhoea as patients literally excrete out all their nutrients and water.
From [2] and [3], these could be the direction to extrapolate that bromelain helps with hairball. They suggest that bromelain has mucolytic and digestive properties. So it’ll dilate the mucus coating of the GI tract as well as helping to breakdown proteins. The Ontario Rabbit Education web site [4] implies that the mucus is the source of the obstruction as it’s like adding gel with hair. However, if the hairball is big enough to obstruct motility on its own, then reducing the mucus coating would have the adverse effect of removing a protective layer of the GI tract and could pose other health issues as the it grinds with the hair. The risk is location dependent as thickness of the GI tract decreases further along. So the use of bromelain during GI blockage is risky and not advised.
Lastly, [5] concludes that bromelain acts as an agent to complement tumour therapy because of its metastasis efficacy. And they also suggest that it accelerate wound healing.
These attributes of bromelain apply to human and other pets as well. In summary, eat some pineapple if your rabbit have diarrhoea, receiving tumour therapy, or wounded. And be careful of feeding your rabbit pineapple during GI blockage.
References:
[1] T.L. Mynott, et al., Bromelain prevents secretion caused by Vibrio cholerae and Escherichia coli enterotoxins in rabbit ileum in vitro, Gastroenterology, 1997.
[2] A. Bernkop-Schnürch, et al., The Use of Auxiliary Agents to Improve the Mucosal Uptake of Peptides, Medicinal Chemistry Reviews-Online, 1994.
[3] G. S. Kelly, Bromelain: A Literature Review and Discussion of its Therapeutic Applications, Alernative Medicine Review, 1996.
[4] http://www.ontariorabbits.org/health/healthinfo8.htm
[5] H.R. Maurer, Bromelain: biochemistry, pharmacology and medical use, Cellular and Molecular Life Sciences, 2001.
[6] K. Suzuku, et al., Experimental study of the effects of bromelain on the sputum consistency in rabbits, Nippon Yakurigaku Zasshi, 1983
