The Digestive System of Guinea Pigs

The guinea pig digestion is very complex. Disorders of digestion are usually caused by errors in feeding for these rodents. Find out about all the different stages of the Guinea Pig anatomy that play a role in the digestion process.

The incisors

The incisors are sharp and chisel-like and are used to cut up chunky pieces or food on a stalk. They grow continuously and must be worn down all the time. The teeth should ideally grate against each other when the animal bites off and chews hay and other hard foods.

The incisors are located at the front of the mouth in the centre with two at the top and two at the bottom. It is important to keep them healthy with the correct diet. When choosing to breed, you must be aware of the health of the teeth so that deformities are not passed on.

The molars

Further back in the mouth lie the molars. These also grow continuously. There is one premolar and then three molars one each side, both on the top and the bottom. These crush and grind pieces of food.

Between the molars food gets mixed with saliva and becomes soft. The fluid comes from the salivary glands. Enzymes in the saliva are biocatalysts which start the process of digestion.

The oesophagus

The oesophagus is purely an organ for transportation. Well-chewed food goes from the mouth into the digestive tract. Food mush that has been thoroughly chewed is known as chyme and this is an important part of the digestion process. Drinking water also passes down the pharynx and the oesophagus.

The stomach

In the stomach the digestion process begins and the first components of the food are split away. The food is acidified with hydrochloric acid produced by special cells. Enzymes that decompose proteins start to make use of these proteins in this acidic environment. Hormones from the stomach are sent out as a signal. All hormones are like internal messengers and are sent through the bloodstream.

The stomach muscles, which are all around the stomach, ensure both a thorough mixing of all of the stomach’s contents and that it gets emptied. This process is the passing of the mush of food through the pyloric sphincter into the digestive tract.

The upper small intestine

In the small intestine enzymes and plenty of tissue fluid are mixed with the mush of food so that fluid can be drained off at a later stage.

The pancreas and the liver

After a few centimetres, there are the outlets of the pancreas and the liver. The liver can store excess sugar for a short time in the form of glycogen, apart from that, it is responsible for detoxification. Furthermore, bile which comes from the liver balances out the digestive fluids and changes the environment from acidic to alkaline.

Be aware! As is the case for most vertebrates, the vitally important vitamin C is produced by the liver using ingested food. For this reason, be careful when buying food because guinea pigs, much like humans and apes, can’t synthesise vitamin C inside the body from other substances. Therefore, they rely on getting their vitamin C supply from outside sources.

The pancreas regulates the blood sugar levels and sends out enzymes to break down fat and carbohydrates.

The small intestine

Then the food reaches the small intestine which is where the main part of the digestion process takes place. The extremely active villi transfer the decomposed substances from the food to the bloodstream. Only the elements of the food which have been broken down as far as possible can pass through the intestinal wall and can then be put to good use by the other organs.

The small intestine is where everything that has been digested up to now is transferred to the rest of the organism. An incorrect diet with unsuitable food causes most of the problems in the small intestine so preventative health care with suitable modern pet food products is effective. It is vitally important for these pets! In the mush of food only so called raw fibre is left, this is made up of parts of the plant cell walls from the food.

The appendix

At the intersection of the small intestine and the colon, the appendix branches off. It is like a big fermentation chamber which is filled with lots of specialised bacteria.

The remaining energy must be drawn out of the plant material which is high in raw fibre and roughage and elements of the plant cell walls are extracted, in particular glucose from cellulose. Rapid changes to the composition of the substrate are not tolerated by the appendix. Therefore, changes to the diet should always be undertaken very slowly and gradually, also due to disruption to the small intestine. Only then can the process of fermentation by the appendix run smoothly without generating gas.

The cecum

At the end of this process is the formation of the caecotrophs and sometimes the production of soft caecotrophs in the colon. Together they create soft droppings which are different form the hard pellets which come from the rectum. A protective layer of mucous ensures that this soft substance is directed quickly to the anus. Guinea pigs then eat the droppings which pass once more through the stomach and intestines. From this process, the guinea pig obtains vitamins (predominantly the vitamin B complex) and also important proteins and many active substances.

The large intestine

The intestine behind the area where the small intestine connects to the appendix has the task of recovering the water from the pulp which is already mostly digested but still runny.

In the large intestine there are more bacteria everywhere which, like their counterparts in the appendix, are capable of creating fermentations and metabolic processes. The bacteria make fatty acids from the food remnants available to the cells of the intestine wall. These fatty acids can’t get into the bloodstream from here onwards. The pellets are formed in the rear part of the large intestine.

The rectum

The rectum forms the dry pellets and draws out as much remaining moisture as possible, sometimes guinea pigs will eat these pellets too but that is quite normal. Diarrhoea or constipation can indicate that there is an issue with regulating water due to a problem in the upper sections of the digestive system.

The anus

The anus is the exit for the pellets. These firm excrements contain waste which is not excreted through the kidneys as urine as well as undigested food or surplus nutrients. The anal sphincter marks the end of the digestive tract.