by Marc Abraham BVM&S MRCVS

Article courtesy of Barking Heads Meowing Heads

http://www.barkingheads.co.uk/contact/

One of the most common reasons for clients bringing their poorly pets in to my clinic is skin problems. Your dog’s skin, including coat and ear canals, is an extremely good indication of overall health. When skin problems occur, your pooch will often tell you by scratching excessively, and if it can reach, chewing and/or licking affected areas.

With our dogs exposed to so many environmental factors 24/7 it’s no surprise that there’s a wide range of skin problem causes, from external parasites (e.g. fleas, ticks), infections, various allergies, metabolic problems, even stress, or indeed any combination of these.

It’s also worth noting that because of this wide range of causes, dogs of all ages and breeds are susceptible to issues involving skin; but young, elderly, immunocompromised, or dogs living in crowded, stressful environments may be more prone than others.

Symptoms

As well as general signs of irritation e.g. scratching, licking or chewing, there can be so many indications – some more obvious than others – that your dog is suffering from skin disease. Scabs, infections, wounds, redness or inflammation, all depend on not only how active is the problem, but also if these signs are secondary to an original (primary) problem, e.g. Golden Retriever ‘hot spots’ (one particular area where itching is intense) found on their necks (below).

All parts of your dog’s skin can be affected; from round, scaly patches on the face and paws, to dry, flaky or otherwise irritated skin elsewhere. Hair loss and bald patches can often be tell-tale signs of allergies, self-mutilation, even hormonal imbalances, with angry rashes on your dog’s underside commonly indicating a reaction to something they’ve come into contact with, e.g. certain grasses, nettles, etc.

The word ‘lesion’ is commonly used by vets when we assess your dog’s skin, and it means that region in a tissue that’s suffered damage through injury or disease. This can mean anything from an abscess draining pus, to any number of variations of swellings, lumps, bumps, even changes in skin color.

Your dog rubbing its face against furniture or carpet can also be a sign so best get anything abnormal checked out ASAP as these conditions can prove extremely challenging to diagnose, expensive to treat, sometimes requiring long courses of antibiotics, washes, etc.

Causes

With so many potential causes of skin disease any of the following may be enough to cause abnormalities with your dog’s skin and should always be thoroughly investigated. Top of the list – and especially when winter central heating’s turned on – must be fleas; bites and droppings from these pesky insects irritate dog’s skin, with some having an allergic response to flea saliva following a bite.

This ‘flea bite hypersensitivity’ is common with affected dogs (above) displaying itchy lesions on the lower back, tail base, and inner thighs – but can also be more generalized – distribution alone is never diagnostic. Always buy flea treatments from your vet, worm your dog regularly, and in severe cases treat your house with a special spray. Seasonal weather changes may also contribute, like with people, to dry, flaky skin as well.

Other parasites, such as ear mites, can also cause irritation resulting in severe ear infections, accompanied by smelly discharge and intense discomfort. Another burrowing mite called Sarcoptes scabei causes sarcoptic mange, resulting in extreme itching and inflammation similar to an allergic response. All require immediate treatment to alleviate symptoms.

Seasonal allergies are common, characterized by all-over scratching, and maybe due to sensitivity to allergens (allergy trigger factors) like pollen, weeds, dust, mites, trees, mold, or grasses. Particularly affected are specific at-risk dogs with defective skin barriers (allowing increased water loss and allergen penetration), and abnormal immune responses. However, some patients may even be genetically predisposed to inflammatory and itchy allergic skin disease e.g. West Highland White Terriers (below), Labradors, German Shepherds, and Shar Peis.

Another cause of skin disease can be food allergies, developed from a range of common ingredients found in dog foods, such as beef, chicken, wheat, corn, or soy. Even fillers and colorings are seen as ‘foreign’ by your dog’s immune system leading to itching and rashes. Adverse food reactions can invite a response from your dog’s immune system (hypersensitivity) or no response (food intolerances, which can include toxins/histamine release).

Frustratingly, hypersensitivity to food allergens is often indistinguishable from hypersensitivity to other (airborne or contact) allergens. So working out which is the cause – from reactions to food or parasites – is often tricky, and requires careful diagnostic work, including ruling out all other diseases causing itching.

And if all that’s not bad enough for your dog, it’s not uncommon for secondary skin infections to accompany skin allergies, usually bacteria or yeast (e.g. Malassezia), taking full advantage of damaged skin, and totally complicating the picture. Multiple treatments to manage both allergy and infection are often now required.

Another condition affecting dogs is ringworm, a highly contagious fungal infection resulting in inflammation, scaly patches, and hair loss. Due to its high potential for spread ringworm also needs to be treated immediately to avoid other pets and people in the household from becoming victims.

Stress or boredom can cause skin disease too. Your dog may lick their skin (especially legs – above) excessively for many reasons. Some will lick as a coping strategy for stress, as well as when not given adequate opportunity for physical or mental stimulation. Metabolic or hormonal problems can also cause changes in skin color, coat consistency, thickness, even distribution.

Finally, certain grooming products e.g. shampoos, can irritate your dog’s skin. Be sure to only use dog-friendly grooming products, and ask your vet if you suspect any products are responsible.

Diagnosis

Identifying the many underlying causes of skin disease is not always straightforward, so visit your vet as soon as you notice any abnormality in your dog’s skin or hair, or if they begin to excessively scratch, lick and/or bite areas on their fur.

Your vet will obtain a detailed history and perform a thorough physical examination, perhaps even some diagnostic tests in order to identify the cause of symptoms. Tests may include a skin biopsy, skin scrapes, hair plucks and/or coat brushings for flea dirt (feces of fleas – below) or ringworm, microscopic examination of hair and skin for presence of parasites or infection, allergy testing (may recommend diet change), even blood tests to assess your dog’s overall health.

Food allergy diagnosis can usually only be made by response to a novel or ‘hydrolyzed’ protein diet, with treatment by avoiding offending allergens. Diagnosis is based on history, clinical signs, and response to treatment, but other concurrent allergic skin diseases may also need to be addressed as multiple allergies co-existing in one patient is not uncommon.

Once diagnosis is certain, some owners may want to pursue specific testing (intradermal allergy/serological testing) to reveal which allergens are responsible; and is also required for owners wanting to pursue allergen-specific immunotherapy – but is not mandatory – as many forms of treatment are symptomatic and don’t require identification of allergens concerned.

Treatments

As expected with so many causes, there is a wide range of treatments available, including antibiotics, antifungals or anti-itching topical products/medications e.g. shampoos, dips, creams, or spot-on products (to prevent and treat parasites). Shampoos are useful in many cases, and also help treat specific secondary infections, reduce allergen load in the coat, and improve skin barrier function.

Like all disease prevention, a healthy balanced diet is important to help maintain healthy skin and coat e.g. Barking Heads Bad Hair Day. Dietary supplements containing essential fatty acids are extremely useful, reducing skin inflammation, enhancing skin’s role as a barrier; hence very useful in chronic treatment of skin allergies, but can often take a couple of months before positive effects are noticed.

Steroids (e.g. prednisolone) are useful drugs for the short-term management of allergic disease in animals that have seasonal disease or for acute flare ups, producing rapid reductions in itching; with short acting courses being more favorable than long term. Steroids may be dispensed as tablet or topical treatments e.g. ear drops, eye drops, creams, ointments, and sprays.

Most steroids, both ingested orally or absorbed through the skin when applied topically, can lead to side effects, such as eating/drinking more, leading to weight gain. Longer term, every other day tapering therapy is recommended only in patients that cannot be managed using other drugs, with fewer side effects which may include diabetes mellitus, skin thinning, and liver changes.

Sadly, safer antihistamines e.g. piriton, aren’t nearly as potent as steroids, with some animals only responding when multiple drug combinations are trialed – if any response at all. On a positive note side effects from antihistamines are rare, although drowsiness may be seen (which in itself can reduce scratching at night).

Prevention

Good management of canine skin disease may involve regular visits to your vet, and is generally divided between treatment of acute flare-ups and managing the chronic disease. All dog owners should try to use natural, dog-friendly hypoallergenic soaps, and shampoos. Regular brushing prevents matting of hair, carefully checking skin, paws, and ears at every grooming session.

Feed a healthy, balanced diet e.g. Barking Heads Bad Hair Day, without fillers or artificial ingredients. Vets may also recommend dietary supplements. Treat for fleas and worms, as well as regularly cleaning and vacuuming your home (remembering to always throw away the bag!) Reduce likelihood of stress try by providing calm living conditions for your dog using artificial pheromone or oral calming natural products if indicated.

Some forms of skin disease can be extremely difficult to cure, with pets often requiring lifelong medication. Despite treatment, most patients still suffer from occasional flare-ups of disease and often have secondary infections which need treatment in addition to allergy management. Occasionally referral to a veterinary skin specialist may be of benefit to discuss multiple treatment options and better control.