Dog Shampoos: The Function of Common Ingredients
Veterinary & Aquatic Services Department, Drs. Foster & Smith

Many shampoos have been developed to treat a variety of skin conditions in dogs and cats. Understanding the function of the various ingredients may appear daunting. The following table should help you understand why certain ingredients are included in a shampoo. This information can help you, with consultation from your veterinarian, select the right one for your pet's skin condition.
INGREDIENTS COMMENTS
INSECTICIDALS For treatment and prevention of fleas, ticks, and some types of mange
   Pyrethrin  
   Pyrethroids, such as permethrin DO NOT USE ON CATS
   Carbaryl Good if sensitive to pyrethrin
ANTISEBORRHEIC For removal and prevention of scales, and in some cases to remove excess oils
For seborrhea oleosa Characterized by scales and excess oils
   Sulfur Removes scale and crust, and reduces scale production
Antibacterial and antifungal
Reduces itching
Works best when used with an equal concentration of salicylic acid
   Salicylic acid Removes scale and crust, and reduces scale production
Reduces itching
Antibacterial
Works best when used with an equal concentration of sulfur
   Refined Tar Most potent ingredient to reduce scale production
Reduces itching
Degreases
Can be irritating
DO NOT USE ON CATS
   Selenium sulfide Removes scale and crust, and reduces scale production
Antibacterial and antifungal
Degreases
Can be irritating to scrotum and mucous membranes
Best to limit its use to yeast infections and severe oiliness
Must leave on at least 10 minutes for antifungal activity
DO NOT USE ON CATS
   Benzoyl peroxide Removes scale and crusts
Can dry out the skin
Excellent degreaser, and flushes out hair follicles
Antibacterial
For seborrhea sicca Characterized by dry scales
   Sulfur Removes scale and crust, and reduces scale production
Antibacterial and antifungal
Reduces itching
Works best when used with an equal concentration of salicylic acid
   Salicylic acid Removes scale and crust, and reduces scale production
Reduces itching
Antibacterial
Works best when used with an equal concentration of sulfur
ANTIPRURITIC For relief of itching due to conditions such as atopy and other allergies
   Colloidal Oatmeal Reduces inflammation
   Hydrocortisone Produces minimal side effects when compared to oral steroids
   Aloe vera  
   Pramoxine hydrochloride Topical anesthetic
   Diphenhydramine Antihistamine which decreases inflammation
   Menthol Has cooling and anesthetic effect
   Sulfur Removes scale and crust, and reduces scale production
Antibacterial and antifungal
Reduces itching
Works best when used with an equal concentration of salicylic acid
   Salicylic acid Removes scale and crust, and reduces scale production
Reduces itching
Antibacterial
Works best when used with an equal concentration of sulfur
   Cool water rinses  
ANTIBACTERIALS For treatment of bacterial infections such as pyoderma, folliculitis, and impetigo
   Benzoyl Peroxide Removes scale and crusts
Can dry out the skin
Excellent degreaser, and flushes out hair follicles
Antibacterial
   Chlorhexidine Higher concentrations may be irritating or dry out the skin in some animals
   Povidone Iodine  
   Triclosan Low potency
   Ethyl Lactate Flushes follicles, has some degreasing activity
   Sulfur Removes scale and crust, and reduces scale production
Antibacterial and antifungal
Reduces itching
Works best when used with an equal concentration of salicylic acid
Can help prevent Staph infection
ANTIFUNGALS For treatment of ringworm and yeast infections
   Miconazole 2% Less expensive than ketoconazole
   Chlorhexidine 2-4% Some activity against yeast, less against ringworm
Higher concentrations may be irritating or dry out the skin in some animals
   Povidone Iodine Not as effective, can cause irritation
   Ketoconazole 2% Highly effective
   Selenium sulfide 1% Removes scale and crust, and reduces scale production
Antibacterial and antifungal
Degreases
Can be irritating to scrotum and mucous membranes
Best to limit its use to yeast infections and severe oiliness
Must leave on at least 10 minutes for antifungal activity
DO NOT USE ON CATS
EMOLLIENTS Add oils to skin
   Almond Oil  
   Corn Oil  
   Cottonseed Oil  
   Coconut Oil  
   Olive Oil  
   Peanut Oil  
   Persia Oil  
   Safflower Oil  
   Sesame Oil  
   Lanolin  
   Mineral Oil  
   Paraffin  
EMULSIFIERS Help distribute emollients
   Cetyl Alcohol  
   Laureth-5  
   Lecithin  
   PEG-4 dilaurate  
   Stearic acid  
   Stearyl alcohol  
HUMECTANTS Rehydrate skin
   Carboxylic Acid  
   Lactic Acid  
   Urea  
   Sodium Lactate  
   Propylene Glycol  
   Glycerin  
   Polyvinylpyrrolidone  
SPECIAL FORMULATIONS Microscopic particles which can be made to contain a number of ingredients; they adhere to the skin and hair and slowly release their contents
   Novosomes® Release contents over 7-10 days
   Spherulites® Release contents over 8 days
 

 
References and Further Reading

Campbell, KL. Shampoos in veterinary dermatology. Proceedings of the 2000 American Veterinary Medical Association Convention. Salt Lake City, Utah; 137-138.

Kwochka, KW. Shampoos and moisturizing rinses in veterinary dermatology. In Bonagura, JD (ed.) Current Veterinary Therapy XII. W.B. Saunders Co. Philadelphia, PA; 1992: 590-595.

Rees, CA. Noninsecticidal veterinary shampoo components. The Compendium on Continuing Education for the Practicing Veterinarian. 1999: 55-64

Rees, CA. Noninsecticidal shampoo therapy. Veterinary Medicine. 1998 (October): 899-904.

Scott, D; Miller, W; Griffin, C. Muller and Kirk's Small Animal Dermatology. W.B. Saunders Co. Philadelphia, PA; 1995: 190-203.

   Click here for the web viewable version of this article.

Click here to email this article to a friend.


Copyright © 1997-2014, Foster & Smith, Inc. All Rights Reserved.
Reprinted from PetEducation.com.