Common Conditions that Cause a Dog to Scratch

Whilst attending a Breeder Education Seminar in November 2013 we were treated to a very informative talk by Mrs Susan Paterson, a specialist in veterinary dermatology, practising at Rutland House Referrals, St Helens Merseyside []. Sue gave an excellent lecture on the most common incidents of dogs/puppies scratching, the likely causes and how often these conditions can be treated by owners and do not require veterinary treatment. The following article is based on notes taken during that lecture and the subsequent question and answer session with full credit going to Sue Paterson for the contents and information. This is not an exhaustive list, but merely the more common conditions that dog owners come across and naturally, if as an owner you are not sure of the cause, veterinary advice should always be sought, particularly before administering any treatment that may cause harm to your dog. The causes of dogs scratching can be placed into the following 5 categories:

  • Ectoparasites: Cheyletiella, Demodex, Fleas, Sarcoptes
  • Infections: Impetigo, Dermatophytosis, Malassezia
  • Allergy: Food, atopy
  • Congenital Disease: Zinc responsive disease, Ichthyosis, Primary Seborrhea
  • Immune Mediated Disease: Juvenile Cellulitis

For the purposes of this article we will only concern ourselves with the first 3 categories listed above as they are typically the conditions that can be dealt with at the early stages by most dog owners, without the need for veterinary intervention (whereas congenital diseases and immune mediated diseases are definitely the realm of the veterinary specialist). Sue Paterson went on to state that she now treats over half her patients with topical treatments such as shampoos and powders, rather than medication such as antibiotics and steroids. She was concerned that many general practice vets prescribe these medications all too readily and that such medication is often ‘overkill’ for these minor conditions. In addition, the excessive prescribing of antibiotics, much as with humans, is now causing problems when treating dogs as ever increasing stronger drugs are now having to be used due to overuse for minor conditions and also more drug-resistant strains of bacteria appearing.

Many of these conditions can be avoided and/or treated with a balanced diet, good hygiene around the home, some basic supplements and natural remedies and the diligence of owners. A basic dog treatment kit at home could consist of the following:

  • Malacetic shampoo/ Cider vinegar (loads of uses and a great antiseptic)
  • Frontline spray/spot on treatment
  • Coconut oil - best natural antifungal)/ Manuka Tea tree oil/ Aloe vera gel
  • Topical powder treatment such as Thornit (but use Cleanaural or Otodine for cleaning ears)
  • Antihistamine (such as cetirizine based)


Fleas Fleas are a common problem for most warm blooded animals and particularly domestic pets. If your dog or puppy is scratching and appears itchy then usually fleas are the first thing to check for and they can be seen either by checking through the dogs coat or by combing through the fur and onto a piece of paper. Fleas vary in size from 1/12 to 1/6 inch in length and they can jump several inches vertically and up to 16 inches horizontally. They thrive in warm conditions such as on the dog itself, also on the dog’s bedding and the areas where the animal typically walks. The adult fleas feed on the blood of their host (in this case your dog) and they then lay eggs and these eggs can hatch in as little as 2 days and become flea larvae, which look like maggots. The larvae feed on the faeces of the adult fleas, which contains undigested blood and then the larvae form cocoons, from which new adult fleas emerge in 1-2 weeks. This cycle means that for every adult flea you can see there will be many more eggs, larvae and cocoons that you cannot see and so all of the environment must be treated and not just the dog itself. There are many products on the market to treat fleas and they come in tablet, pipette (spot on), powder and spray forms. Brand names such as Frontline and Effipro will be familiar to many of us and are typically Fipronil based treatments (Eliminall and Flevox are other popular brands), whereas Comfortis tablets are Spinosad based and only target fleas rather than other parasites. Whatever product you decide upon remember to treat all areas of the dog’s environment including bedding, carpets, floors, collars and leads and furniture. Repeat applications of products may also be required to eliminate all of the emerging larvae and adult fleas during different stage of the cycle.

Demodex Demodex is a type of mite that lives in the skin of its host and so it cannot be seen with the naked eye, but it can cause a severe reaction in dogs and particularly in young puppies. The demodex mites block the pores of the skin and when you part the fur back and look at the skin it often looks like little blackheads/spots to the naked eye. The mite is actually part of the normal fauna of the dog and so is always present in small numbers on a healthy animal, but when demodex exceeds normal levels the results can be very dramatic with large patches of affected skin and a lot of fur loss. In severe cases the infestation can become so bad that the dog does not respond to treatment, resulting in the dog being euthanized, but this is the exception rather than the norm and usually dogs are treated very successfully and never suffer a repeat of the infestation. Treatment for demodex is fairly straight forward, once the mite has been identified, but in order to do so skin scrapings must be taken to confirm the presence of the demodex mite. Scrapings must be done prior to any steroidal treatment being administered, otherwise the scrapings will be useless. Treatment of demodex is typically done with either Aludex which is an Amitraz based product and is a topical wash applied to the dog’s skin. Panomec is another alternative treatment for demodex and it has Ivermectin as its active ingredient. Ivermectin is not commonly given to dogs and is typically used for livestock treatment and as such it is injected into the animal on a dosage according to body weight. Therefore this treatment should only really be considered in severe cases and should be on vet recommendation only.

Sarcoptes (scabies)

The Sarcoptes mite (more commonly known as scabies) is extremely itchy and can cause severe symptoms in dogs and especially puppies. The mites burrow into the skin of the host and form tunnels inside the skin, where they lay eggs which in turn hatch out larvae. Foxes are typical carriers of scabies and can also succumb to its worst effects. The mites cause severe irritation and make the dog scratch profusely causing fur loss and a lot of trauma to the skin, so secondary infections are common place. If left untreated a scabies infestation can spread across the dog’s entire body causing horrific damage to the skin and total fur loss, but usually the symptoms are spotted by owners in the earlier stages and one of the key signs of Sarcoptes is fur loss around the perimeter of the ears. Dogs with scabies are usually treated with products such as Advocate or Stronghold, but treatments need to be repeated every 2 weeks for a total duration of 6 weeks in order to eliminate the adult mites, the nymphs and the larvae and to break the life cycle of the Sarcoptes.


Cheyletiella are yet another revolting looking mite and they live in the top layer of the skin and feed on the skin’s keratin. However, unlike Demodex or Sarcoptes, these mites lay their eggs on the host’s hair follicles and so they can be seen with the naked eye and are fairly easy to detect. As with fleas, the owner should use a comb to part the fur and then comb the fur from the root to the end and allow the contents of the comb to drop onto a piece of paper. The reason for this mate being commonly referred to as ‘walking dandruff’ should then become very obvious! Treatment for dogs with Cheyletiella is typically done with Fipronil based products such as Frontline spray (see above section on fleas), but other topical treatments can also be used including sulphur based shampoos.


I have decided to include a short section at this point about ears and also to dispel a common myth that many ear irritations found in dogs are caused by ear mites. Sue Paterson stated categorically in a discussion after her talk that she frequently sees dogs in her clinic that were misdiagnosed as having ear mites – she states that ear mites are actually quite rare and usually the dog has an allergy issue. Another interesting aspect to treating dogs with ear irritation is the over-prescription of medicated ear drops/cleaners. Often a vet will prescribe Canaural drops or Surolan to treat nothing more than a waxy ear. These proprietary ear medications contain 3 things; a broad spectrum antibiotic, a targeted antibiotic and a steroidal anti-inflammatory. Therefore they are not suitable as a general ear cleaner and frequently, depending upon the cause of the ear irritation, vets actually want to use just one of the 3 medicated ingredients and not the other 2. Sue Paterson recommends either Cleanaural or Otodene for general maintenance cleaning of ears as they do not contain any antibiotic or steroids. She also strongly discouraged owners from using powder in dogs’ ears, particularly down the ear canal as these can actually make ear conditions worse; the natural mechanism of a dog’s ear transports foreign bodies and irritations upwards and out of the inner ear to the outer ear, but powders can coagulate in the inner ear and form a ‘plug’ which stops this natural mechanism from working. If you still use a powder such as Thornit in the ear, (which I would strongly recomend you don't now having attended this seminar), then please ensure that the powder is rubbed into the skin of the ear flap and does not drop down the ear canal.



Impetigo is a mild skin infection that affects the surface of the skin and is usually seen in puppies and dogs under 12 months of age. The infection occurs in between the pores rather than in the pores of the skin themselves and typically shows as pus filled blisters on the underside of the dog (but can also be seen on other parts of the body). Like many infections the rash itself is not difficult to eliminate, but it does cause the dog to itch and left untreated the dog or puppy can then abrade the skin and go on to cause pyoderma which will need more aggressive antibiotic treatment. Therefore dogs and puppies should be checked regularly for any signs of skin irritation. The impetigo rash can be successfully treated with shampoos such as Etiderm, Malasseb, Paxcutol and Malacetic. Initially bathe the area with the shampoo twice a week for 2-3 weeks and also identify the cause of the flare-up so check bedding and the dog’s environment for unsanitary conditions.


This infection is extremely itchy and therefore can cause the dog or puppy to scratch and abrade their skin and the resulting trauma can lead to nasty bouts of pyoderma. Malassezia is a yeast that is commonly found on a dog’s skin and inside its ears, but some dogs can end up with an overgrowth of the yeast and it can cause widespread trauma to the skin in a similar way to a systemic Candida infection. Typically dogs that are stressed or have a compromised immune system can fall foul to malassezia. Initially it starts in areas such as the feet, inbetwen the toes and pads and also inside the ears and then it spreads to other areas of the body. The yeast likes warm, damp areas to breed and multiply so any parts of the dog that do not get as much airflow to them can be a site for malassezia. The skin of the dog becomes itchy, oily, scaly and has a greasy odour to it, with fur loss and reddening of the skin too. Certain breeds do appear to have a genetic predisposition to this infection and West Highland White Terriers are one of those breeds who can suffer horrendous bouts of malassezia. Treatment needs to be two-fold and treat both the external and internal symptoms, much in the same way as a candida infection. The external rash symptoms can be treated topically with shampoos such as Malasseb and even T-Gel (human shampoo, but ensure it is diluted down), but another effective bath is sulfurated lime, also sold as Lime Sulfur Dip. Sue Paterson recommends bathing every day for the first week, then every 2 days, then every 3 days and so on until the rash disappears and then just be aware and check for any signs of reoccurrence and a weekly maintenance bath will also help prevent the problem coming back. The internal aspect of the infection should also be treated by amending the dog’s diet to exclude any grains and also supplementing the animal with a strong probiotic and an anti-fungal such as coconut oil or olive leaf extract. Dermatophytosis – Ringworm

Ringworm is another common infection and is fungal in nature and invades the hair and hair follicles and produces round rings of hair loss with crusty, scaly skin in the centre and a red ring around the outer edge. It is usually seen in puppies and young adult dogs and is not a particularly itchy condition to being with, but secondary infection can be an issue if the ringworm is not treated and the dog goes on to cause trauma to the skin. However, ringworm is sometimes diagnosed by mistake when actually the lesions are localized Demodex or infected hair follicles, so care must be taken when analysing the lesions and if in any doubt, seek veterinary advice. Treatment for dermatophytosis is similar to other fungal infections and topical treatment with shampoos, sulfurated lime or Nizoral should be utilised to clear up a first stage infection, but again, if secondary infection has occurred through trauma then antibiotic treatment may also be required.


Food Allergy

Allergies in dogs seem to be more common than ever before and the symptoms can present in very similar ways to parasites and infections. Also, some dietary issues can contribute to other conditions such as systemic candida and malassezia and therefore diet plays a large part in the well being of our dogs and puppies. The first step in diagnosing a food allergy is to rule out other causes of reaction, particularly parasites and infections, to ensure that a correct diagnosis can be made, as many of these conditions can have visually similar symptoms. Once these have been ruled out, many vets often then suggest blood tests in an attempt to identify the allergen responsible, however Sue Paterson considers these tests to be at best inconclusive and at worst a very expensive waste of time and money! Therefore Sue recommends the second stage as being the trial of a restricted diet whereby the dog is given only a specialist food, usually one containing hydrolised protein, for 3-4 weeks. If any dog is referred to her consultancy practice without having been trialled on such a diet first, she sends the owners away to do exactly that. There are several such proprietary diet foods on the market, made by different manufacturers, but a homemade diet could also be used, so long as the protein sources as less common such as duck,rabbit, or fish being of choice. Such a homemade diet must also not include grains, but certainly a carbohydrate such as potato could be incorporated, there are indications that rice is now casuing reactions too. Understandably, many owners may choose to trial a BARF or raw food diet at this stage and often see improvements in the dog’s condition, but again, less common protein meats should be used.

Atopic Dermatitis

Atopy is a common allergy condition seen by vets and dermatology consultants and typically presents in several parts of the dog’s body and often is an overall rash with hair loss and red, inflamed skin. One consultant defines the conditions as “an inherited pruritic skin disorder characterised by the production of allergic antibodies to environmental allergens”. Atopic dogs have a differing skin structure to non-atopic dogs and their skin allows allergens to penetrate and cause a reaction. In most cases the dog will display symptoms in at least 2 areas of the body, but in 10% of cases the dog will only have symptoms in its ears, but often the dog will chew its feet and rub its face and scratch its ears. Atopy is further complicated as it often presents with a secondary condition such as bacterial or fungal infections as well, such as malassezia. Once again, diagnosis is made by first ruling out other causes such as parasites and infections. Although atopy is an incurable disease, much can be done to control and eliminate the symptoms and therefore improve the dog’s quality of life. On a basic level, minor cases of atopy can be managed using antihistamine (now available from most supermarkets and chemists without prescription) and natural supplements such as evening primrose oil, starflower oil and salmon oil or with proprietary products such as Yumega. For more advanced cases there have been great strides made in the field of immunotherapy, whereby a vaccine is created for the dog and targets that dog’s specific allergens.

The Bonaforte Regime

Interestingly we have very few skin conditions, allergies or ear problems in the kennel. There is obviously no scientific proof but our diet of Bonaforte's Complete coupled with 20ml of olive oil daily seems to keep them in good condition. We also add some coconut oil to their diet too and worm on a very regular basis.