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An Urban Experience
Tip two:
A search for obvious underlying disease is indicated in almost every ALD case
Investigation of infectious or neoplastic factors:
A number of infectious conditions may be complicated by significant secondary self-trauma. Examples include dermatophyte kerions, demodicosis and deep fungal infections (Pythium, phaeohyphomycosis, Blastomyces, etc.). Mast cell tumors may be associated with the elaboration of pruritogenic factors, while other tumors may be associated with discomfort and secondary self- mutilation. Skin scrapings and dermatophyte cultures should be performed at the initial visit, but may fail to demonstrate deeply sequestered organisms. Biopsy for histopathology and culture (bacterial, fungal, +/- Pythium, Lagenidium) is appropriate for large or chronic lesions.
Identify sources of pain:
Patients may lick at the skin over arthritic joints, foreign bodies, wound sites (including tumors) or at locations of prior trauma. An orthopedic examination is easy and quick to perform on the initial visit, and may be helpful to identify painful joints or bones. In persistent cases, imaging (radiographs, CT, MRI, ultrasound) may help
to reveal the presence of orthopedic abnormalities or foreign bodies.
Investigate the possibility of neuropathic disease:
Neurologic issues such as disk herniation, degenerative myelopathy and nerve damage/impingement may all trigger an unpleasant sensation and the desire to lick or chew. Other conditions that potentially could be associated with neuropathic pain / neuropathy include hypothyroidism, syringomyelia and caudal occipital malformation syndrome. A complete neurologic examination should be performed at the initial visit. Persistent disease (or the presence of other neurologic abnormalities) may warrant advanced imaging (MRI) or neurology referral. Alternately, gabapentin (see below) may be of benefit in some of these patients.
Allergic skin disease workup:
Flea allergy, food allergy and atopic dermatitis have all been associated with the development of ALD. Typically, patients will demonstrate ALD in addition to more “classic” signs of allergy, such as pruritus, pododermatitis and otitis. However, anecdotal reports exist in which allergic patients have only demonstrated ALD. Aggressive flea control is always indicated. Food allergy elimination diet trials may be implemented once the bacterial component is at least somewhat under control. Intradermal or serologic testing is usually performed last, unless the history strongly suggests this differential.
Behavioral investigation:
While boredom, isolation and separation anxiety can certainly be associated with the development of these lesions, it has been my experience that behavioral / psychological issues are not usually the primary problem. Nonetheless obtaining a thorough history is important as psychological stress can contribute to the persistence of the issue. Relevant questions would include the amount of time that the patient spends confined or alone, addition or loss of human or animal family members, whether overcrowding or inter-dog aggression has
been a problem and whether the dog’s routine (timing, location, quality) has recently changed.
Tip three:
Symptomatic therapy
In my hands, symptomatic medical therapy of ALD has been of limited benefit. I do believe that it helps in many cases (especially early or less severe disease), but I think it works best as a treatment ADJUNCT, not as the sole means of treatment.
Topical therapy:
1. Fluocinolone / DMSO 8ml plus flunixin 3ml: Apply to lesion twice daily
2. Bitter apple 2 parts / liquid HEET 1part: Apply to lesion twice daily
3. Bitter apple: isopropyl alcohol, water, bitter extract
4. Liquid HEET: 0.25% capsacin, 15% methyl salicylate, 3.6% camphor, acetone, alcohol
Systemic therapy:
1. Gabapentin: 10-20 mg/kg three times daily. May be especially effective if neuropathic pain is suspected. Some sources will increase as far as 30mg/kg if necessary.
2. Clomipramine: 1-3mg/kg once daily. May require 2-4 weeks for full effects
3. Amitriptyline: 1-2 mg/kg twice daily, +/- hydrocodone 0.25mg/kg two to three times daily.
4. Fluoxetine: 1-2mg/kg once daily. May require 2-4 weeks for full effects.
5. Doxepin: 2-4mg/kg twice daily.
6. Oclacitinib: 0.4-0.6mg/kg twice daily for two weeks, then once daily. May be most effective for patients with underlying allergic skin disease.
Miscellaneous therapy:
1. Laser ablation: Laser treatment can be used to gradually resurface chronic, severely fibrotic lesions. The point is not to try to remove the lesion entirely as it is to decrease the amount of sequestered fibrous tissue, hair and bacteria so that antibacterial treatment
may be effective. This is generally reserved for lesions that remain fibrotic and proliferative despite appropriate protection and antibiotic therapy.
1. Angus JC, Canine Acral Lick Dermatitis. North American Veterinary Dermatology Forum; 2010; Portland, Oregon

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