History

• According to Drs. Foster and Smith, glucosamine and chondroitin have been used for more than 20 years in Europe to successfully treat osteoarthritis. Many studies on the supplements in Europe have had positive results. However, very few controlled studies have been done in the United States, so these two products have been introduced only recently.
  
  Glucosamine and chondroitin fall under the same category as vitamins, so the FDA does not strictly control them. Because they cannot be patented, big pharmaceutical companies that research these products will not be able to recoup their costs.
  
  

Uses

• Glucosamine and chondroitin are used for more than arthritis relief. According to Drs. Foster and Smith, they also are used for stomach ailments, healing skin wounds and other joint problems. They also are given to dogs after they have had joint surgery to provide relief.
  
  In addition to dogs and cats, horses and humans also benefit from taking glucosamine and chondroitin. Once started, the supplements should be used on a regular basis. Otherwise, the old symptoms and pain will return.
  
  

Source

• Both glucosamine and chondroitin are naturally occurring substances. According to Drs. Foster and Smith, glucosamine is derived from crustaceans. The shells of these creatures contain high amounts of chitin, which produces glucosamine when hydrolyzed.
  
  Chondroitin comes mainly from cow cartilage, but shark and whale cartilage is sometimes used. Usually, cow cartilage is extracted from the trachea rings.
  
  

Function

• Glucosamine and chondroitin work together to protect the cartilage around joints. Your pet's body requires glucosamine as a building block in its process to build and repair cartilage. Chondroitin is required in the process of synthesizing glucosamine and blocks harmful enzymes that destroy cartilage.
  
  Normally, your pet's body will produce enough of these two substances. However, a diet full of processed foods and the degradation that occurs during digestion may make it difficult for your pet to use the glucosamine that she gets from her food.
  
  

Side Effects

• Europe has not reported any side effects from the use of these two supplements. However, dogs have been known to get diarrhea or to vomit if given the supplements on an empty stomach, according to Drs. Foster and Smith.
  
  Glucosamine and chondroitin can be safely used with many other drugs and medications. You should always consult your veterinarian to make sure any products you give your pet will be safe with any medications your pet is taking.