11 Drugs for Small Animal Dermatology

Antibiotics for Canine Pyoderma

• The most common isolate in canine pyoderma is Staphylococcus pseudintermedius.
• Empirical therapy includes cephalosporins like cephalexin (q12h), cefpodoxime (q24h), and cefovecin (subcutaneous injection).
• Antibiotics are generally well-tolerated, with the most common side effect being GI-related.
• Giving antibiotics with food can reduce GI disturbances.
• Bacterial culture and susceptibility testing is recommended for poor response to empirical antibiotic therapy, recurrent skin infections, history of past antibiotics, deep skin infections, or Methicillin-Resistant Staphylococcus history.

Oclacitinib

• Oclacitinib is a synthetic Janus Kinase inhibitor.
• It inhibits pruritogenic and inflammatory cytokines that depend on JAK enzymes.
• Apoquel® is approved for allergic dogs over 1 year old.
• Zenrelia is another recently available JAK enzyme inhibitor.
• Oclacitinib has a fast onset of action, with efficacy seen within days.
• Follow label directions: twice daily for 2 weeks, then once every 24 hours.
• Some dogs may experience increased pruritus when decreasing from twice daily to daily dosing.
• Oclacitinib has been used in allergic cats, but it is not labeled for cats.

Oclacitinib Side Effects

• Oclacitinib is generally well-tolerated
• Occasional GI effects can occur.
• Mild decrease in leukocytes is possible, requiring initial blood work and periodic monitoring.
• It can increase susceptibility to infections like demodicosis, pyoderma, and fungal infections.

7-Year-Old MC DLH Cat Case

• A 7 year old MC DLH cat presents with non-seasonal pruritus that waxes and wanes.
• The cat failed a diet trial to assess food allergies and responds to oral prednisolone liquid.
• The cat can take Atopica® (cyclosporine), which is labeled for cats, in oral solution because the owner cannot give pills, only liquid.
• Allergy testing and immunotherapy are not options, and topical antipruritic shampoos are difficult to use.
• Cytopoint™ cannot be used in cats, and Apoquel® is only labeled for dogs.
• Chewable Apoquel® can be used off-label if the owner understands, and the cat is monitored whilst taking it.

Cyclosporine

• Cyclosporine is an immunosuppressive medication.
• It inhibits cutaneous allergic inflammation by blocking T-cell activation and inhibiting cytokine production and release.
• Atopica® and Cyclavance™ are labeled for atopy in dogs and cats
• A 4-week trial is needed to assess efficacy.
• Atopica® (Novartis) and Cyclavance™ (Virbac) are brand name options
• Generic forms can be tried, but bioavailability may vary.
• Micro-emulsified forms are absorbed more readily.
• Taper doses to every 48 to 72 hours as necessary.

Cyclosporine Side Effects

• GI disturbances.
• Immunosuppression.
• Papillomatosis.
• Psoriasiform lichenoid-like dermatosis.
• Gingival hyperplasia.
• Potential drug interactions like increased plasma levels of cyclosporine if administered with a drug that suppresses the P-450 enzyme system.

4-Year-Old French Bulldog with Pemphigus Foliaceus

• A 4 year old French Bulldog with Pemphigus Foliaceus has been treated with prednisone by RDVM.
• The dog developed a new skin lesion while taking steroids and presents with alopecic, thickened, firm/hard, crusted, dorsal skin
• The dog developed calcinosis cutis from the steroids being administered

Calcinosis Cutis

• Calcinosis cutis involves the deposition of calcium salts in the dermis
• It can result from spontaneous or iatrogenic Cushing’s disease
• It can occur from steroids administered to treat the PF.
• Individual variation exists in developing calcinosis cutis when taking steroids.
• It can occur with prolonged topical steroid use.
• Treatment: decrease and eliminate the steroids, control the PF with other medication, in this case cyclosporine.

Anti-Canine IL-31 Monoclonal Antibody

• Lokivetmab (Cytopoint™) is an anti-canine IL-31 monoclonal antibody.
• IL-31 transmits the sensation of itch
• It targets and neutralizes" IL-31 through subcutaneous injection.
• It is generally administered monthly, but frequency may vary depending on the response

Cytopoint™

• Cytopoint™ is generally well-tolerated.
• Possible transient pain with injection and transient lethargy can occur.
• It is expensive, especially in large dogs.
• It is generally compatible with other medications.

Steroids Use

• Steroids decrease inflammation and pruritus.
• They are needed for inflamed ears and swollen ear canals in otitis externa cases.
• The use of steroids can lead to iatrogenic Cushing’s syndrome, increased secondary infections, and demodicosis
• Avoid long-acting injectables for steroid use, especially in dogs.
• Lowest alternate-day prednisone/prednisolone dose for maintenance therapy, or every 3-4 days for triamcinolone or dexamethasone should be used.
• Avoid long-term management unless other medications are ineffective
• Cats generally require higher doses than dogs.
• Injectable therapy may be needed if owners cannot orally medicate cats.
• Different steroids can be tried in cats, such as triamcinolone.
• Combining steroids with fatty acids, antihistamines, and topical therapy may allow for a lower steroid dose.

Steroid Side Effects

• Polydipsia, polyphagia, and polyuria.
• Infections.
• Cutaneous atrophy and seborrhea.
• Steroid hepatopathy.
• Behavioral changes and lethargy.
• Diarrhea.
• GI ulceration.
• Adrenal gland suppression.

Topical Therapy

• Shampoos can remove allergens, reduce debris and scale, provide antipruritic, antibacterial, anti-yeast, and moisturizing effects.
• Shampoos help to restore a healthy skin barrier by containing fatty acids and ceramides.
• Rinses and conditioners can be rinsed off or left on and not rinsed.
• Sprays, lotions, and creams are best for localized areas.
• Otic products are also used in topical therapy.
• Topical therapy is used for Superfical pyoderma, Bacterial overgrowth, Yeast dermatitis, Dermatophytosis, Pruritus, Seborrhea, Sebaceous adenitis, Discoid lupus, Dry skin, Focal lesions and Otitis externa