Molar points: In addition to their incisors, rabbits, guinea pigs and chinchillas have cheek teeth or molars, which are not visible without some sort of medical instrument. These cheek teeth are open-rooted and therefore grow continuously throughout their lives (figure 1.1). When the teeth are aligned properly, normal eating and chewing of high roughage foods, due to their fibrous consistency (i.e., timothy hay or orchard grass) will help control growth.
(Fig. 1.1: Capello V, et al: Rabbit and Rodent Dentistry Handbook. Zoological Education Network, 2005. www.exoticdvm.com)
These animals chew in what can be described as a circular motion. The mandibular premolars/molars (bottom cheek teeth) grind against the maxillary premolars/molars (top cheek teeth) as the animal chews. If the teeth are not aligned properly (maloccluded), the areas of the teeth that do not have an opposing surface (i.e., opposite tooth) to grind against points/spikes will develop. These points/spikes will grow into and over the tongue on the bottom arcade of teeth, and will grow into the cheeks on the upper arcade, causing ulcers/wounds that are painful (figure 1.2).
Causes, signs, and treatment of molar malocclusion: Rabbits, guinea pigs and chinchillas can start having trouble with molar teeth from a very early age, but it usually occurs over the age of 3 yrs. Early symptoms can be associated, but not limited too, insufficient Vitamin C (in guinea pigs), roughage in the diet and poor genetics. Most significantly in rabbits, the selective breeding for particular traits (color, size, shape, etc.) subsequently altered the traditional shape of the skull, therefore, preventing the teeth from coming in properly.
The most common presentation of possible molar issues are decrease in appetite, decrease in quantity and physical size of fecal pellets, audible teeth grinding, excessive drooling, and discharge from eyes and nose (figure 2.1).
(Fig. 2.1: signs of eye discharge and excessive drooling)
Keeping them on large amounts of roughage (i.e., timothy hay or orchard grass) will help delay the teeth overgrowth. Unfortunately, animals with molar problems need to be anesthetized in order to safely trim and/or filed (done with the aid of an endoscope). This in combination with frequency can make it a fairly expensive procedure as it could be necessary every 4-16 weeks (figure 2.2).
(fig 2.2: Procedure)