Recently, some information on alfalfa hay and meal has appeared on the Internet. Several experts are concerned that excess alfalfa hay in the diet may provide too much calcium and protein. However, other authorities disagree with this point of view. There are certainly no controlled studies or published evidence that alfalfa is harmful. My personal opinion is that the use of alfalfa hay as a treat, and alfalfa meal as a pellet ingredient is perfectly acceptable for normal animals (see information below). Caution should be used in accepting information on alfalfa hay that is based on anecdotal reports.

Exotic animal veterinarians do agree on one point: MORE FIBER is needed in the diet of many pets, including chinchillas, guinea pigs, rabbits and especially dwarf rabbits. Many authorities feel these animals benefit from total fiber levels in the diet of 18% OR HIGHER. Old style conventional rabbit pellets were approximately 16% fiber (Hagen pellets are now 18% fiber). Timothy and alfalfa hay varieties (both of which Hagen manufactures) have fiber levels of 30% or higher. Hay is thought to help treat and prevent many of the digestive disturbances and stomach hairballs that rabbits suffer from. However, alfalfa is more palatable (preferred) by all rabbits and rodents. And although it is true that alfalfa is higher in both calcium and protein, due to the 30% fiber content, even if fed free choice the total amount consumed (by weight) is small. However, instead of feeding it free choice, we recommend that a small amount be fed on top of timothy or grass hay to increase its palatability. In any event, because of the grain content in pellets, rabbits and rodents preferentially select it to meet caloric needs, and will always select it to make up the bulk of their diet.

Alfalfa meal is also present in the pellets but this is not relevant as the TOTAL protein and calcium content of the pellet is low.

I have had several veterinarians ask me about the relationship between calcium in the diet and urinary tract stones in guinea pigs and rabbits. Analyses of stones (in Canada) have shown many or most to be "struvite" or magnesium based. At this point, there is no evidence that I am aware of demonstrating a relationship between dietary calcium intake and problematic stone formation. Concurrent urinary tract infections are often found, and until further research is done, it may be premature to conclude that either diet or infection is the cause. Experts have been studying similar problems in the cat much longer and the physiology behind F.U.S. is still unclear.

However, IF a rabbit or guinea pig is currently experiencing crystal or stone formation problems, avoid feeding extra alfalfa. This is a prudent course of action in view of the fact that little research on this subject exists.

It is true that calcification of tissues including the kidneys has often been seen in aged guinea pigs. In a paper published in 1985 in an American publication ("Veterinary Medicine" journal), a review of all renal and urinary tract disease seen at the University of Saskatchewan in guinea pigs presented over a 10 year period, it was speculated that excess vitamin D3 levels might be contained in guinea pig pellets. This is because metastatic calcification is seen in other animals in response to excess vitamin D3. It turned out that many guinea pig pellet manufacturers were adding vitamin D3 in amounts well in excess of what might be considered required. Some manufacturers continue to use levels as high as 4,000 IU D3/kg in guinea pig pellets. (Hagen levels are currently at 1,600 IU/kg).

Both alfalfa and timothy hay can be used with a wide variety of small mammals, including hamsters (who actually eat alfalfa as well as use it in their nests), gerbils, chinchillas, guinea pigs, and rabbits. The leaves and fines from alfalfa have also been offered to iguanas. Cecal fermenters such as rabbits, guinea pigs and chinchillas may have unlimited daily access to timothy hay. Alfalfa hay should be fed in smaller amounts as a treat or appetite stimulant.

Louise Bauck BSc, DVM, MVSc.