Dog allergies are a vicious cycle.
One symptom causes another, which causes the first symptom to worsen.
If you’ve had a pet with allergies, you know there’s always more than one instigator.
Always more than one issue.
Allergies are one of the most frequent conditions I see in my clinic.
Here are some of the questions about dog allergy medicine I hear over and over- I hope you learn something from them!
1. What Are Secondary Infections?
Secondary infections, most frequently yeast and/or bacteria, result from dog allergies and intensify the signs associated with allergies.
Managing secondary infections is a critical part of treating canine skin allergies.
For dogs with superficial pyoderma, at least 3 weeks of an appropriate antibiotic is recommended.
If deep pyoderma is present, 4-8 weeks of antibiotics may be necessary.
A good antibacterial shampoo scrubbing will assist in resolution of the infection.
If Malassezia dermatitis is present, topical therapy alone or in conjunction with systemic antifungal therapy should be utilized.
2. What Are the Best Topical Treatments?
Cool water baths with oatmeal shampoo decrease itching by soothing the skin and washing away inflammatory mediators and potential allergens.
Colloidal oatmeal is a safe and relatively effective antipruritic.
Topical anesthetics are also available and may have temporary antipruritic effects.
Pramoxine has been the topical anesthetic of choice in veterinary medicine.
Pramoxine is usually combined in shampoo or rinses with colloidal oatmeal.
Colloidal oatmeal products, with or without additional ingredients, are most useful for mild pruritus.
Lime sulfur (LymDyp®, DVM Pharmaceuticals)
Lime sulfur is a very effective, nonsteroidal antipruritic.
Because it is applied as a rinse and allowed to dry on the animal, it provides residual
Lime sulfur is safe for use in both dogs and cats.
In addition to its antipruritic effects, lime sulfur is antiparasitic and antifungal.
Topical corticosteroids are very effective antipruritic drugs and are commonly used in the treatment of canine seasonal allergies.
3. Which Products Contain Corticosteroids?
CortiSoothe® (Virbac) is a 1% hydrocortisone containing shampoo with a colloidal oatmeal base.
Capex® shampoo (formerly known as F/S Shampoo) contains 0.01% fluocinolone acetonide.
Genesis Topical Spray® (Virbac) is a 0.015% triamcinolone spray, approved by the FDA for generalized use in the itching dog.
In a blinded, placebo-controlled study of 103 dogs with pruritus of various causes, 67% showed significant reductions in erythema, pruritus, and eruption over 28 days.
In that study, hematological and biochemical results of treated dogs did not change significantly over the course of treatment.
In a separate study, the product was demonstrated to be effective for symptomatic treatment of flea allergy dermatitis in the dog.
This product is intended for generalized use over short periods of time (28 days or less) as an alternative to oral or injectable corticosteroids.
4. What About the Home Remedy Benadryl?
Benadryl is an antihistamine.
Histamine is a potent inflammatory mediator released by activated cells and may be a major initiator of itching in the dog.
For that reason, antihistamines have been recommended to alleviate itching.
The most common allergy medicines for dogs are Benadryl and Hydroxyzine.
Because first-generation antihistamines readily cross the blood-brain barrier, they may lead to increased sedation.
Benadryl commonly sedates dogs.
Significant improvement has been seen in up to 30% of patients.
Tricyclic antidepressant (TCA) drugs, amitriptyline, and doxepin have also been recommended in the dog for control of itching.
5. What Are the Doses of Antihistamines for Dogs?
- Diphenhydramine (Benadryl) 2.2 mg/kg q 8 hrs.
- Hydroxyzine HCl (Atarax) or pamoate 2.2 mg/kg q 8 hrs.
- Chlorpheniramine (Chlor-Trimeton) 0.2-0.8 mg/kg q 8 hrs.
- Clemastine fumarate (Tavist) 0.05-0.1 mg/kg q 12 hrs
- Loratidine (Clariton) 10 mg/dog q 24 hrs
- Cetirizine (Zyrtec) 5-10 mg / dog q 24 hrs
- Amitriptyline (Elavil) 1-2 mg/kg q 12 hrs.
- Doxepin (Sinequan) 1-2 mg/kg q 12 hrs.
6. Can I Use Fish Oil?
Fatty acid supplements are beneficial in the management of canine allergy symptoms.
Numerous veterinary and over-the-counter products are available.
Very few products have been critically evaluated in good, scientific studies.
Additionally, a double-blinded, placebo-controlled study using high doses of marine fish oils (180 mg EPA and 120 mg DHA per 10 # body weight) has been published.
In this study, treated dogs had significantly less pruritus and alopecia, and significantly better hair coat quality than placebo-treated dogs.
Some diets have been fortified with essential fatty acids.
Essential fatty acids must be incorporated into the cell membrane before they can affect a change in the inflammatory cascade, so it may take up to eight weeks before improvement is noted.
Side effects due to fatty acid supplements are rare, but may include pancreatitis, weight gain, diarrhea, flatulence, and fish-breath.
In addition, high doses of fatty acids may affect platelet aggregation, so use in dogs with known coagulation problems is contraindicated.