For dogs and cats that exhibit digestive difficulties such as loose stools, additional supplements can help support the health of the intestinal lining. 

Probiotic supplements can aid in re-establishing the healthy bacteria needed by your pet’s digestive system.  You can give human probiotic supplements to dogs and cats, just adjust the dosage to your pet’s weight, (usually ¼ capsule for cats, and ½ – 2 capsules for dogs).

L-glutamine is an amino acid that is critical for maintenance of proper intestinal metabolism, structure and function.  Most health food stores carry several brands of L-glutamine.  Again, adjust dosage to your pet’s weight – keeping in mind that most suggested dosages on the bottle are for a 120-150 lb human. 

Slippery Elm is a useful herb for detoxification and intestinal support as it both soothes and tones tissues while drawing out and eliminating toxins.  You can make a gruel out of the powder or purchase a tincture (preferably glycerin based). 

Always consult a veterinarian when your dog or cat shows signs of any illness.  When more serious causes have been ruled out, however, a diet change may be just what is needed to alleviate chronic itching or digestive troubles. 

Resources:

Natural Veterinary Medicine by Susan G. Wynn and Steve Marsden

Herbs for Pets by Gregory L. Tilford and Mary L. Wulff