Dental Disease in Rabbits and Guinea Pigs

Rabbits and guinea pigs share a trait that makes them prone to a distinctive form of dental disease: all their teeth, not just the incisors, grow continuously throughout life. When wear fails to match growth, malocclusion follows, and the resulting spurs and overgrowth can cause pain severe enough to stop an animal eating entirely.

Continuously Growing Teeth and Why They Fail

Both species have hypsodont, open-rooted cheek teeth that erupt continuously to compensate for the grinding wear of a fibrous diet. Chewing tough grass and hay requires a wide lateral jaw movement that wears the teeth evenly; diets dominated by soft pellets or muesli encourage a narrower, up-and-down chewing motion that leaves the teeth insufficiently worn.

Unworn teeth keep growing, and because the crowns are constrained by the jaw, this pushes molars out of alignment, producing sharp enamel spurs on the cheek teeth that lacerate the tongue and cheek. Incisor overgrowth follows a similar logic and, left untreated, can curl into the lip or opposite jaw, while root elongation in guinea pigs can also cause visible facial swellings or exophthalmos from pressure on the eye socket.

Diet as the Root Cause

• Dropping food from the mouth or selective eating of soft items only
• Excessive drooling that mats fur under the chin (guinea pig 'slobbers')
• Reduced faecal pellet size or fewer caecotrophs being eaten
• Facial swelling, particularly under the jaw or below the eye
• Weight loss despite food still being present in the enclosure

Because these are prey species that mask pain, dental disease is frequently well advanced by the time an owner notices reduced eating; subtle clues like smaller droppings, matted chin fur or a preference for softer foods often precede outright anorexia by days to weeks.

Spotting Dental Pain Before Weight Loss Sets In

A conscious oral exam with an otoscope can reveal incisor malocclusion and obvious spurs, but full assessment of the cheek teeth almost always requires sedation, since these species' narrow mouths and reflex jaw clamping obscure the caudal molars in an awake animal.

Skull radiographs in at least two views, or CT where available, assess root elongation, tooth root abscessation and bone changes that a visual exam cannot detect, and are particularly important in guinea pigs presenting with facial swelling or exophthalmos where an underlying tooth root abscess is a common cause.

Oral Examination and Skull Imaging

Treatment addresses the immediate mechanical problem in the mouth as well as the dietary cause, since burring teeth without fixing husbandry guarantees recurrence.

• Burring of cheek tooth spurs under general anaesthesia using a dental burr
• Incisor trimming or, for recurrent cases, incisor extraction
• Analgesia and syringe feeding of critical care formula during recovery
• Treatment of any concurrent tooth root abscess, often requiring surgical debridement

Burring, Extraction and Long-Term Management

Long-term management centres on diet: unlimited grass hay or fresh grass should be the majority of the diet for both species, with pellets limited to a small measured portion and muesli-style mixes avoided entirely, since selective feeding on the sweet components worsens the underlying wear problem. Fresh water and daily fibrous vegetables support both dental wear and gut health.

Animals with a history of malocclusion typically need recheck dental exams every 4-8 weeks initially, since regrowth is inevitable given the open-rooted anatomy; owners should monitor weight and faecal output weekly as an early proxy for recurrence between visits.

When to seek help urgently

• Complete refusal to eat for more than 12-24 hours
• Visible facial swelling or discharge from the eye or nose
• Persistent drooling with matted, wet fur under the chin
• Sudden dramatic weight loss over just a few days

Every animal's mouth and bite pattern differs, so this information is a general guide only; have your rabbit or guinea pig examined by your own vet if any of these signs appear.