Rabbit and Guinea Pigs - their teeth grow continuously

Rabbits and guinea pigs have quite different teeth to humans and most other mammals. For most of us, our teeth stop growing fairly early in our lives, and the teeth you have as a young adult are the teeth you will have for the rest of your life. The teeth of rabbits and guinea pigs on the other hand continue to grow for life. These critters have a diet of fibrous plant material which requires lots of chewing, and hence wear and tear on the teeth. To stop the teeth grinding down, they constantly grow throughout their life. 

This continued dental growth works very well in the wild to make sure their teeth are always well formed and ready for use, but it is unfortunately common to see pets that are fed an inadequate diet resulting in reduced use of the teeth. These teeth continue to grow, and eventually can become much longer and taller than normal, a condition called dental malocclusion. This affects their ability to eat properly, and in severe cases can prevent the pet properly closing the mouth, resulting in discomfort, pain and if severe, starvation.

Signs of dental problems 

The most clear sign of dental malocclusion is, as the condition suggests, overgrown teeth. If you hold your rabbit or guinea pig gently and lift their lip the front teeth (incisors) will look very long and spindly, and in some cases may be bent or not properly meet up. In marked cases the pet will not be able to fully close their mouth, and the lips may be open at all times. Quite often they will have wet lips and chin from saliva staining and drooling, and there may be a bad smell from the mouth. This will prevent the pet from eating properly and you may notice weight loss and lethargy, and in severe cases the teeth can press back into the gums and jaw, resulting in swelling and pain on the face and sometimes watery eye discharge.

How can you can prevent dental malocclusion?

Dental malocclusion is painful and it significantly affects a pet’s quality of life, but with a little care it can be easily prevented. The first step is proper nutrition. Many owners make the mistake of feeding only a commercial pellet diet, believing it is a complete source of nutrition. These diets are good in that they usually contain vitamins, minerals, protein and energy, but they should only make up ten percent of a rabbit or guinea pig diet at most. This is sometimes compounded by the fact that the pellets are usually delicious, and they will definitely be eaten before more healthy foods such as hay and vegetables. I like to think of pellets as powerbars or cookies - fine in small quantities but not something you should eat all day.

What should I feed my rabbit and guinea pigs?

Rabbits and guinea pigs should have the majority of their diet as hay (approximately 75%), with 15% vegetables and the occasional piece of fruit, and less than 10% of their diet should be pellets. There are a number of different types of hay, but the best for rabbits and guinea pigs is either Timothy, Grass, Orchard and Oat hay. Alfalfa hay can be fed in small amounts but is much higher in calories. Hay should always be available in your rabbit or guinea pig’s pen, and you’ll notice that they spend a lot of the day chewing. In addition to grinding their teeth down and keeping their mouth healthy, hay is also excellent roughage that aids digestion, promotes healthy intestinal bacteria and nourishes the gut.

75% hay, 15% vegetables, some fruit, less than 10% pellets

Vegetables are an excellent source of vitamins and minerals, and are also tasty and enjoyed by most guinea pigs and rabbits. Green, leafy vegetables such as lettuce, spinach, parsley and kale with raw some raw carrots are an excellent staple, along with smaller amounts of broccoli and cauliflower. They can also have the occasional small piece of apple, mango or banana, but too much can cause stomach upset, so be careful. Rabbits and guinea pigs should never be fed onions, garlic, rhubarb, peas, potatos or beans, or any seeds that could get stuck such as cherry seeds. 

If you are concerned that your rabbit or guinea pig may have overgrown teeth I’d recommend you speak to a vet familiar with small critters. In mild cases a change in diet may be enough, but if the teeth are too overgrown they may need to be trimmed back before the rabbit or guinea pig can properly chew. Don’t worry, this isn’t as difficult as it sounds in most cases, but it does need to be done by someone with expertise in the area. 

Dental malocclusion is probably the single most common issue I see in pet guinea pigs and rabbits, and it can significantly affect their quality of life, to the point of being life threatening if severe. It is easily prevented with a little care and knowledge, and treatment is also usually very successful.