The importance of topical therapy for pets should not be underestimated.
The importance of topical therapy for pets should not be underestimated. Whether for routine bathing, or to aid in the treatment of diseased skin, veterinary technicians can contribute significantly to a pet's well being and quality of life by recommending appropriate products. When recommended or prescribed by the veterinarian, the veterinary technician can add value to the product by explaining its proper use to the client. When selected for appropriate conditions and used correctly, topical products are more likely to be of benefit. Veterinary practices often miss the opportunity to take the lead in recommending and dispensing shampoo therapy for their patients. When the veterinary team makes a concerted effort to recommend an appropriate product for each pet, both the pet and the practice will benefit.
Topical therapy formulations include shampoos, conditioners, lotions, and ointments (including creams and gels). They may be applied through bathing, rinsing, spraying, or rubbing. The frequency and duration of therapy must be specified. Clearly, there are many choices to be made when prescribing or recommending topical therapy. A basic understanding of the pharmacology of topical therapy can help in making those recommendations.
The epidermis, the outer layer of skin, consists of the stratum corneum, stratum granulosum, stratum spinosum, and stratum basale. As the epidermis matures, from the stratum basale outward, the cells undergo significant changes. By the time they reach the stratum corneum (approximately 21 days later), the cells are flattened, highly keratinized and there is a significant water-insoluble component. These properties have a significant impact on the types of molecules that can penetrate the skin surface.
It is important to emphasize the importance of contact time to the pet owner, in order to hydrate the skin and provide sufficient time for active ingredients to have their desired effects. Ten minutes is often recommended.
Commonly used shampoo ingredients can be loosely categorized as moisturizing agents (hygroscopic or emollient), anti-inflammatory agents, antimicrobials, or anti-seborrheics. Hygroscopic ingredients help draw water into the skin, while emollients are meant to replenish surface lipids and trap moisture in the skin. Anti-inflammatory and antipruritic agents may include antihistamines, glucocorticoids, or oatmeal extracts. Antimicrobial ingredients may be directed at bacteria, fungi and/or yeast, and include chlorhexidine, acetic acid, boric acid, sulfur, benzoyl peroxide, salicylic acid, triclosan, ketoconazole, miconazole, and others. Anti-seborrheic ingredients include sulfur, salicylic acid, benzoyl peroxide, and coal tar. Benzoyl peroxide is a strong de-greasing agent and will affect the efficacy of spot-on flea products that concentrate in the sebum.
For normal dogs, a moisturizing shampoo (e.g. DermaLyte, DermaPet) and conditioner are recommended for regular bathing. The choice of shampoo for dogs with skin disease will depend largely on the etiology and types of lesions present. For allergic skin diseases (atopic dermatitis, flea allergy dermatitis, and food hypersensitivity) without significant pyoderma, an anti-inflammatory shampoo and conditioner are recommended (e.g. DermAllay, DermaPet; EpiSoothe, Virbac). When pustules, epidermal collarettes, and moist pyoderma are the primary features of the skin disease, a shampoo with antibacterial properties (MalAcetic, DermaPet; Hexadene, Virbac) should be chosen. When follicular flushing activity is also desired, benzoyl peroxide shampoos (DermaBenSs, DermaPet; Pyoben, Virbac) are selected. These are also the shampoos of choice for demodectic mange or for very greasy dogs with seborrhea. For Malassezia dermatitis and dermatophytosis, shampoos, rinses and wipes with miconazole or ketoconazole are good choices.