Why is my dog itchy?
This is a common question for our vets here in Broome and the following information has been put together by one of our vets Dr Farand Thompson who has a keen interest in getting to the bottom of skin conditions in pets.
Working as veterinarians in general practice we see a lot of animals for skin disease and can understand how frustrating, time consuming and complicated treatment can be; both for the owners and us as veterinarians. Especially when it often isn’t always easily fixed and diagnosis of the underlying condition can be challenging, time consuming and financially straining on owners.
As skin disease can encompass various aetiological agents, and diagnosis and treatment can require lots of information and various medications the following is designed to try and emphasise the important treatment goals when dealing with skin disease for your pet.
It is not normal for your animal to have repeated skin infections, ear infections and feet infections; this suggests there is an underlying cause; most likely allergic skin disease.
Why is my pet itchy?
There are multiple reasons that can cause your pet to itch. It can include, insects, plants, and allergic reactions to washes, soaps, chemicals or cleaning materials. However in regards to underlying allergic skin disease it is broadly categorized into 3 main areas: Fleas, ticks and mites, Adverse Food Reactions (Food Allergy) and Atopic Dermatitis. Finding out which is impacting on your animal often requires treatment trials to rule one out before we can progress to the other; there is no specific test.
What is best to rule out whether fleas, ticks, mites or parasites are troubling my pet?
Starting and maintaining your pet on good, consistent flea and tick control is required for an insect exclusion trial and is always the first category to be excluded when working up your pet’s skin condition. Even if you don’t see fleas on your animals consistent treatment is recommended as it can take as little as 1 bite to cause your dog to itch for 72 hours. Additionally if it fixes your pets condition or reduces your reliance on other medications it’s a win. The typical pattern of flea allergy is scratching and chewing at the tail base, back legs and body sides.
If its not fleas or ticks what else could it be?
If we have performed an insect exclusion trial and your animal is still having issues the next exclusion will be Food Allergies and or Atopic Dermatitis.
What is food allergy or an adverse food reaction?
Recent data predicts that there is a 15-20% incidence of food allergy among our pets. It is often to either a protein and or carbohydrate source that your animal has had repeated exposure to. This includes diets that they have been on for their entire life. We often suspect food allergies if we have some gastrointestinal signs (vomiting, loose stools, anal gland issues) in conjunction with signs of skin disease; foot licking, chronic ear infections, rashes on the belly, armpits, groin, face.
How do I rule out if my animal has Food Allergy?
Unfortunately the only way is to perform a food trial. In this trial your pet is fed ONLY ONE specific diet for 8 weeks. The goal is to identify if your animal is allergic to a specific type of protein or carbohydrate that they have already been exposed to.
The easiest way is to either use a specific formulated diet (Hill’s z/d or Royal Canin Hypoallergenic/ Anallergenic) for food allergy trials or select a novel protein and carbohydrate that you pet hasn’t been exposed to. For the latter make a list of all the protein types (pork, chicken, turkey, beef, lamb, etc.) and carbohydrates (potatoes, pasta, rice) that they have been exposed to and choose something novel to them.
If anything else is fed during this 8 weeks the test will be for nothing and we cannot confidently exclude that your pet doesn’t have a food allergy.
This is because you may be exposing them to something they have already had causing them to react.
What is atopic dermatitis (AD)?
If the insect and food allergy trials haven’t helped your pet then they likely have AD. AD is multifactorial but can be viewed as sensitivity to environmental allergens; trees, grasses, house mites, plants, etc.…
Most cases of AD occur between 6 months to 3 year of age. Animals typically itch on their face, ears, paws, groin and armpits and AD is often a progressive disease that worsens over time. It involves a combination of skin barrier dysfunction, secondary infections and immune system dysregulation.
How can I manage atopic dermatitis?
As it comes in varying severities, management can include having to manage seasonal flare-ups in the hotter months to needing specific strategies in place for the entire year. Unfortunately we are not always able to cure animals or achieve 100% remission rates but the goal of therapy is to have them comfortable, controlled and to prevent chronic skin changes (these can worsen clinical disease and make control a lot more difficult). Management relies on recognising when an animal is flaring and intervening before it becomes quite severe. Shampoos, conditioners and various oral medications help us to achieve this.
What is allergy testing?
Allergy testing is also an option where we try and identify which specific environmental allergens our pets are allergic to and try and desensitize them with a vaccination. This often requires specialist referral and a successful response occurs when we can reduce the dose and dose frequency of current medications. As previously stated this is not a test to confirm AD or rule out food allergy in your pet. It is useful for management of AD once we have a suspected diagnosis of AD
The Goal of Treatment
As mentioned previously allergic skin disease can be extremely frustrating and a cure is often not possible. However by using some of the following medications and strategies we aim to help to make our pets more comfortable and prevent severe instances of allergic skin disease.
1. Treat Secondary infections and Primary inflammation
In the initial stages we need to try and undo and reduce the number of factors impacting on the animal. We often need to treat the secondary infections, aid the skin barrier and prevent further trauma.
Secondary infections (yeast and bacterial) really complicate allergic skin by continuing to disrupt the skin barrier and by causing your animal to itch more and more. Antibiotics or topical therapy with antibacterial and anti fungal washes can be useful for dogs with large areas affected. Topical eardrops are also used if ear infections are present.
The shampoos and conditioners (leave on moisturisers) can also be useful in trying to improve the skin barrier by soothing, reducing scale and crusts and by helping with fighting and preventing secondary infections.
Low dose and short courses of corticosteroids or Apoquel are often used to reduce how itchy your pet is by targeting inflammation and the body’s immune response to the allergic stimulus. It helps to lessen further trauma, which complicates allergic skin disease and allows your animal to be more comfortable.
2. Try and identify an underlying cause to your pets allergic skin disease
Remove possible sources of allergy; specific plants, shampoos, chemicals. Perform insect and or food elimination trials. Allergy testing.
If we can identify a cause to your pet’s condition we can prevent the severity of disease, reduce reliance on various medications or identify high-risk times of year, locations, etc.
3. Prevent or reduce severity of reoccurrence of allergic skin disease
Once we have treated and cleared secondary skin infections we will try and wean your animal off some of their medications and switch to medications used to prevent and control relapses of allergic skin disease; this relies on your ability to identify early stages of relapse and intervening as necessary; shampoos, conditioners and topical steroids or Apoquel are most commonly used. Reversing some of your pets chronic skin changes are an important part of reducing relapse as well.
What are some of the medications I am being prescribed and why?
Corticosteroids (Steroids) tablets and or an injection: These are often prescribed and can be effective in reducing itching and inflammation. Long-term use can often by associated with undesirable side effects, however at the appropriate dose and application they are a cheaper alternative to other medications
Apoquel: Works like Corticosteroids by influencing the body’s immune response responsible for causing the allergy but with less of the undesirable side effects of corticosteroids. However, is a lot more expensive. Depending on cost restrictions this medication is proving especially useful in managing atopic dermatitis with fewer side effects.
Cytopoint: is an injection that controls itch due to allergic or atopic dermatitis for 4 to 8 weeks. Cytopoint blocks signals that trigger allergic itch, so the constant scratching can stop, and red irritated skin can heal.
Antibiotics: As mentioned above it is important to reduce and remove secondary infections that are complicating your animals allergic skin disease.
Malaseb Shampoo: This is an antifungal and antibacterial wash. When used correctly (it must be applied and left on the skin for 10-15 minutes before rinsing) it is effective in preventing and treating secondary infections associated with allergic skin disease. Overuse can cause the skin to dry out so it’s often paired with a leave on conditioner/moisturiser.
Pyohex Conditioner: Useful as a leave on antibacterial conditioner/ moisturiser. Helps in treating and preventing reoccurrence of secondary infections
NOTE: When used effectively topical medications have been shown to be as effective as oral antibiotics over a 7-day period.
Cortavance Spray: This is a steroid spray. Once secondary infections have been controlled it can help to prevent flare-ups of repeat infections or inflammation. As it is a topical steroid it isn’t as potent as oral medications in regards to side effects. Its use relies on recognising early stages of disease (inflammation; redness, itchiness), as its effectiveness once secondary infections have developed will be impaired. Tends to be uses as a maintenance medication.
Nexgard: Very effective in the treatment and prevention of mange and insect allergies: – fleas and ticks. Used ONCE per month. All animals at a household should be treated.
NOTE: Not used for cats; they need to also be treated with an alternative product.
Dermotic, Easotic, Canaural eardrops: medicated eardrops used to treat and remove infections associated with ear infections
Otoflush: an ear cleaner used to remove debris, dirt and products associated with ear infections; allows the medicated eardrops to work more effectively.
May be used as a maintenance to prevent the reoccurrence of ear infections; used 1-2 times weekly as required.
Antibiotic Cream: an antibacterial cream that is a combination of a steroid, local and low dose steroid. Effective for localised areas of infection and inflammation.
Elocon Steroid Lotion: This is a more potent topical steroid cream that is used to try and reverse chronic skin changes such as thickening and darkening of your pets skin. Ideally it will not be used long term and will be stopped once we are happy with the response. It is sometimes used as a maintenance cream to reduce inflammation and prevent relapse.
Fish Oil / Omega Magic Supplementation: Fish oils are used to help maintain a healthy skin barrier. They have anti-inflammatory properties and can help promote healthy hair growth. Skin barrier is important in the prevention of secondary infection. Excessive scale and damaged hair follicles/ shafts can worsen pets with allergic skin disease. 1000mgs per 10kg of bodyweight is a good starting dose
Hills Derm Defence Diet: Unlike the diets for food allergies that use novel proteins or hydrolysed proteins, the derm defense food is aimed at environmental atopic dermatitis and includes the correct balance of omega 5’s and histaguard complex to reduce reactions to allergens.
If you have any concerns or questions regarding your animal please feel free to contact The Broome Veterinary Hospital 0891921319 to organise an appointment.