Thank you, Tee. I don't believe that his sniffing represents pathology unless he's become obsessive/compulsive which is described as mood/behavioral disorders characterized by repetitive, invariant, patterned behaviors that are exaggerated in intensity, frequency, and duration given the inciting stimuli (i.e., expressed out of context). The behavior interferes with health and well-being. Earlier in the course you may have been able to stop the behavior, but that may not be the case at this time. Chico Rico may hide (to perform the behavior), become aggressive when you attempt to stop it, or may begin avoiding you.
Consultation with a specialist veterinary neurologist (please see here: www.acvim.org) might be considered. All cases of OCD warrant intervention which is individualized and based on frequency and severity of clinical signs. Treatment is usually a combination of behavioral and environmental modification and psychotropic medication. The goal is to minimize and if possible eliminate bouts of compulsive behavior and the concomitant anxious states that accompany them.
In general, we need to identify and eliminate trigger events/situations. No punishment should ever be used since it can heighten anxiety and worsen the problem. If possible, these pets can be redirected to an alternative and incompatible behavior such as licking food from a toy instead of licking the skin if the redirection doesn't make the pet more anxious. Pets should be calmly rewarded for any spontaneous calm behavior. Keeping a structured daily routine helps decrease anxiety. The most successful medications used in the treatment of OCD in people include SSRIs such as fluoxetine (Prozac) and clomipramine (Clomicalm). Typically, psychotropic therapy is necessary for longer periods of time than other anxiety-based disorders (months to years depending upon severity and how long the disorder has been ongoing). Lifelong medication use isn't unusual in severe cases.
His excessive scratching isn't an expected trigger for obsessive/compulsive disorders but, instead, usually represents an allergic dermatitis. I'll post my entire synopsis of the itchy dog for you so you can see all of the things I need to consider...
Pruritic (itchy) dogs are suffering from an allergic dermatitis in the great majority of cases. Allergies to flea saliva, environmental allergens (atopic dermatitis) such as pollens, molds, dust and dust mites, and foods should be considered. (Paw and extremity licking indicates both atopy and a food intolerance and so it behooves vets to distinguish one from another.) In many instances, a concomitant pyoderma (bacterial skin infection), yeast infection (Malassezia), or mange mite (Demodex or Sarcoptes) might be contributory.
Chico Rico's vet can check a sample of his skin surface microscopically (a “cytology”) for abnormal numbers of bacteria and yeast and skin scrapings can be taken in an attempt to find mites. Pyoderma is treated with a minimum of 3-4 weeks of an antibiotic in the cephalosporin class such as cephalexin (Keflex) and yeast is addressed with ketoconazole for at least a month. Mites are addressed topically, orally, and by injection.
Our dermatologists tell us to apply an over the counter flea spot-on such as Advantage/Advocate, a fipronil-containing product such as Frontline or, preferably, one of the newer prescription products available from Chico Rico's vet to which fleas are less likely to have become resistant even if fleas aren’t seen. Dogs can be such effective groomers so as to eliminate all evidence of flea infestation. Dogs who remain primarily indoors can contract fleas because we walk them in on us and flea eggs and larva can remain viable in your home for months. As the weather warms or you turn on heaters at this time of year, egg hatches are common. If the area between the edge of his rib cage and tail (the “saddle” area) is particularly excoriated, a flea saliva allergy should be the most important differential diagnosis. In severe cases, an anti-allergenic prescription glucocorticoid (steroid) such as prednisone will work wonders for dogs allergic to the saliva of the flea. If you have other pets they may have fleas too but may not be allergic to the flea’s saliva.
Environmental allergies (atopy) are usually initially addressed with prednisone as well. In some dogs an over the counter antihistamine such as clemastine (Tavist) at a dose of 0.025 - 0.75mg/lb twice daily or diphenhydramine (Benadryl) dosed at 1-2mg/lb twice daily (maximum dose of 50 mg at any one time) may be effective. Antihistamines, however, aren’t reliably effective - as you've seen. Adding fish oil to the diet at a dose of 20mg/lb daily of the EPA in the fish oil might synergize with antihistamines to provide better anti-pruritic action. The omega-3 fatty acids in fish oil are antiinflammatory but may take 8-12 weeks to kick in. The new cytokine antagonist oclacitinib (Apoquel) is likely to revolutionize how we address atopic dogs and should be discussed with his vet. Oclacitinib works as well as a steroid without a steroid's adverse effects. The new injectable immunomodulary drug IL-31 (Cytopoint) should also be considered. Please note that atopy, at least initially, should have a seasonality to it while a food intolerance should cause pruritis regardless of the season. Chronically atopic dogs may be pruritic year round.
Food intolerance/allergy is addressed with prescription hypoallergenic diets. These special foods contain just one novel (rabbit, duck, e.g.) animal protein or proteins that have been chemically altered (hydrolyzed) to the point that Chico Rico's immune system doesn't "see" anything to be allergic to. The over the counter hypoallergenic foods too often contain proteins not listed on the label - soy is a common one - and these proteins would confound our evaluation of the efficacy of the hypoallergenic diet. The prescription foods are available from his vet. There are many novel protein foods and a prototypical hydrolyzed protein food is Hill’s Prescription Diet z/d ultra. (I prefer the hydrolyzed protein diets because it avoids the possibility of my patient being intolerant to even a novel protein.) A positive response is usually seen within a few weeks if we’ve eliminated the offending food allergen. Food intolerance can arise at any age and even after our patient has been eating the same food for quite some time.
We need to consider seborrhea in such a patient as well. This is skin disorder of keratinization and maturation. It's a diagnosis of exclusion of the above mentioned skin disorders and can be suggested by skin biopsy.
You also have the option of having a specialist veterinary dermatologist (please see here: www.acvd.org) attend to Chico Rico. You can expect some combination of skin scrapings, cytology, bacterial culture and sensitivity, fungal culture, skin biopsy, intradermal or blood allergy testing, or presumptive hypoallergenic diet trials to be performed.
Please respond with further questions or concerns if you wish.