The name furballs or hairballs (more technically trichobezoars) is a bit of a misnomer. All rabbits ingest hair when grooming and the main problem is actually lack of long, indigestible fibre in the diet which means there is not enough long fibre to create an open ball of food in the stomach. This leads to a condition known as ‘gut stasis’. Small, dry droppings strung together with fur are a warning sign that your rabbit is at risk. Feed plenty of good hay and make sure the rabbit is drinking enough water. Remember their natural diet is grass which has a high moisture level. Sometimes water bottles get blocked and an owner fails to notice.
Although particles of chewed grass or hay are 5mm long, the fibre in pellets is cut much smaller and there is little fibre in grains and biscuits. These produce denser balls which makes it harder for the stomach acid to penetrate and kill any bad bacteria. In addition, the shorter the fibre, the slower the process through the gut. Instead of taking 4 hours as in the case of grass or hay, fibres 3mm or less can take over 14 hours to pass through the rabbit. The time taken for food to be processed is known as ‘transit time’.
Long transit time leads to dehydration of the food ball. All food balls contain hair from normal grooming which is simply passed in the faeces. When the food ball dehydrates however it can lead to the formation of fur balls. Fur balls are even more likely if the rabbit is obese, inactive and doesn’t drink enough water. The average rabbit takes in 10% of its bodyweight in water every day.
Traditional remedies include liquid paraffin, the enzymes papain and bromelain and pineapple juice but they cannot break down hair so any success with these is more likely to be from hydration in the case of pineapple juice, speeding up the gut (liquid paraffin) than breaking down the proteins in the food ball.
Veterinary treatment involves rehydration, drugs to speed up gut motility and possible surgery.
Make sure your rabbit always has a supply of good quality hay and fresh water available at all times.