By Anne Fawcett, BA(Hons) BSc(Vet)(Hons) BVSc (Hons) CMAVA
Unlike dogs and cats, guinea pigs (also known as cavies) are herbivores, adapted to survive entirely on plant material. In fact, they are much better at digesting fiber than rats and rabbits, and are closest to the horse in the way that their gut functions. They have a simple stomach but a very large cecum for digesting fiber. This, coupled with their fast metabolism, means that guinea pigs need to eat almost constantly. In this sense they are pigs by name and pigs by nature.
Because their teeth grow continuously, a high-fiber diet is essential to ensure that the teeth wear appropriately.
Guinea Pig Dietary Tips
Guinea pigs are born fully furred and can eat solid foods within hours after birth. A variety of foods should be provided, because a neonatal or baby guinea pig can “imprint” on a particular food in the first few days of its life — making it reluctant to eat anything else. If this occurs, you can facilitate acceptance of new foods by pairing the guinea pig with an adult guinea pig that eats a varied diet. The juvenile guinea pig will often copy the adult’s eating habits.
Like humans, guinea pigs are unable to manufacture their own vitamin C. Therefore they depend on an adequate dietary intake of vitamin C to meet their needs.
As part of their normal digestion, healthy guinea pigs consume about 40 percent of the fecal pellets they pass, a tendency known as coprophagy. Aside from aiding digestion, this helps maintain a healthy balance of good bacteria or “gut flora” in the digestive system. Normal gut flora is easily disrupted by the sudden introduction of new foods. Introduction of new foods should be performed gradually, by offering small amounts of the food over a few days, and monitoring fecal output. Fecal pellets should remain formed.
Most of the health problems I see in guinea pigs brought to my veterinary practice are due to an inappropriate diet. In many cases, health problems like diarrhea, dental disease, obesity and a range of skin conditions can be avoided by feeding a balanced diet.
It is impossible to overstate the importance of a good diet to the overall well-being of guinea pigs. The daily routine of guinea pigs is centered around food. Feeding a guinea pig isn’t just about providing fuel — a suitable diet enriches the guinea pig’s life, allowing it to graze. Guinea pigs are undoubtedly messy eaters. They enjoy spreading their food around and tend to mix food and water in their mouths. During a veterinary examination it is normal to find a slurry of food in the mouth of a healthy guinea pig. The absence of such a slurry is often a sign that the guinea pig has been off its food.
A balanced guinea pig diet should include vitamin C, good quality hay, leafy greens and vegetables, pellets and water every day.
Vitamin C For Cavies
Guinea pigs are among a very exclusive number of mammals (including humans and some apes) that cannot produce vitamin C (ascorbic acid) within their body. They, therefore, depend on a constant source of vitamin C in the diet.
The average guinea pig requires 10mg/kg of vitamin C per day. Pregnant sows require double at 20 to 30mg/kg. Many guinea pig pellets are supplemented with vitamin C, but over time this can oxidize and break down. Similarly, vitamin C that is added to drinking water is subject to oxidation. Some forms of vitamin C are more stable than others, so it is important to follow the manufacturer’s recommendations for shelf-life and storage.
Vitamin C deficiency, also referred to as scurvy, is characterized by weight loss, an unkempt coat, diarrhea, swollen or painful joints, blood in the urine and weakness. Quite often the skin becomes dry and scaly, with patchy hair loss.
The best way to ensure that your guinea pig receives adequate vitamin C is to provide a balanced diet of greens, carrots and good-quality pellets. Sick guinea pigs may require additional supplementation via injection or dietary supplementation with a product like rosehip syrup.
Multivitamins usually should not be given as these can lead to excessive levels of some vitamins and minerals, such as vitamin D, which can be harmful to guinea pigs. Consult with your veterinarian about using a multivitamin.
Guinea Pig Food: Hay And Grass
Hay and grass should constitute around 80 percent of your guinea pig’s diet. Good quality hay is an important source of dietary fiber and vitamins, such as A and D, as well as a way to ensure appropriate dental wear. It is also essential in preventing boredom. Guinea pigs with a good supply of hay are less likely to develop bad habits like hair-chewing and bar-biting.
Many different types of hay are available. Most guinea pigs enjoy a variety of hay, so mix it up a little. Grass hays (timothy, oat, wheat and ryegrass) and legume hays (alfalfa and clover) are suitable. For healthy, adult guinea pigs, grass hay is preferred, because legume hay is high in calcium and, if fed over a long period, can lead to the formation of urine stones (uroliths).
Always store hay in a dry area as it rapidly grows mold when it becomes damp. Ingestion of moldy hay can lead to diarrhea and other gastrointestinal upsets.
Fresh grass is a great source of fiber, protein, vitamins and minerals, and guinea pigs love eating it. Grass should be free from chemicals or pesticides. Freshly cut grass can be fed, but lawn clippings should be avoided as these are often already fermented and may lead to diarrhea.
If your guinea pig has not eaten fresh grass in awhile, introduce small amounts gradually to allow its gut to adapt.
Guinea Pig Food: Pelleted And Mixed Diets
Commercially available guinea pig food comes in the form of pellets and mixes. These provide an excellent source of vitamins and minerals, but not all products are equal.
Mixes are typically made up of seeds, cereals, hay, nuts, fruit and vegetable matter. Some mixes contain foods that guinea pigs are unable to digest, such as nuts and dried fruits, and should be avoided. Seed-based diets are high in fat and low in fiber. Guinea pigs fed entirely on seed-based diets inevitably develop obesity and dental disease.
Pellets are high in calories and should only make up around 5 to 10 percent of your guinea pig’s diet. The most suitable pellets are high in fiber (at least 16 percent) and low in protein. Commercial rabbit foods are not suitable for guinea pigs as they tend to be low in vitamin C, high in vitamin D and often contain anti-coccidial agents, which can make guinea pigs extremely unwell.
Guinea Pig Food: Veggies And Greens
Guinea pigs enjoy eating a variety of vegetables and herbs. Part of the fun of feeding guinea pigs is in selecting a range of fresh vegetables for them to eat. Every guinea pig has different preferences, usually established in the first few weeks of its life. In fact, adult guinea pigs are neophobic and tend to avoid trying new foods. That is why it is important to offer young guinea pigs a variety of foods from an early age.
The rule is moderation. Too much of any one vegetable leads to an unbalanced diet. Suitable vegetables include bok choy, choy sum, celery, carrots, spinach, Brussels sprouts, broccoli and cabbage. Guinea pigs often enjoy carrot and celery tops, too.
Suitable herbs include parsley, coriander, mint and basil.
Fresh vegetables should be fed daily. To reduce the risk of bacterial contamination and pesticide exposure, always rinse vegetables well before offering to your guinea pig.
Fresh, Clean Water
Guinea pigs require fresh, clean water daily. They have a habit of tipping over and soiling in open water bowls. Sipper bottles are preferable as they minimize contamination, but not all guinea pigs take to a sipper bottle.
Observe all new guinea pigs to ensure that they are able to reach and drink from the sipper bottle. If you have any doubt, supply an alternative water source (usually in a bottom-heavy container to reduce the risk of tipping). Sipper tubes should be placed high enough above the bedding that wicking and leaking of water onto bedding is avoided, but low enough for all guinea pigs in the enclosure to reach.
Provide two sipper bottles per enclosure to ensure a constant water supply if one sipper tube becomes blocked. This is not an uncommon occurrence, as guinea pigs often spit balls of grass up the sipper tube, causing a blockage. When cleaning the sipper bottle, always clean the tube with a pipe cleaner to ensure all grass is removed.
The normal daily water intake for guinea pigs is 100ml/kg, but there is enormous variation. Guinea pigs may obtain a large amount of their water requirement in their fresh vegetable ration.
h2>Happy Tummy, Happy Guinea Pig
Guinea pigs that enjoy a high-fiber, balanced diet spend the majority of their time grazing and produce well-formed fecal pellets. They are bright, active and interested in their surroundings and their companions. They will often “wheek” in anticipation of their next meal, and tend not to waste time in munching any available fare. There’s nothing like the sound of a guinea pig contentedly munching on leafy green vegetables — a true sign that the way to a guinea pig’s health and happiness is through its stomach!
Excerpt from the annual magazine Critters USA, 2013 issue, with permission from its publisher, Lumina Media