Scratching that itch
The great outdoors is a wonderful place to be with your dog but it can end up with gundogs and pets alike sharing an itch they just have to scratch. Dr Karen Davies looks at the main causes and how to provide relief …
Pets that are excessively itchy are often having an allergic reaction to irritants around them.
These allergens may include pollens, dust mites, foods or contact with specific plants or cleaning products. For this reason, treatments are often based around reducing contact with allergens or improving the health of the skin.
Allergies need to be differentiated from other causes, such as parasites like those that cause mange.
These parasites have two common forms: demodex and sarcoptes.
Demodex is often referred to as puppy mange with the onset of signs typically around the time they approach puberty (i.e. four to five months). Sarcoptic mange is more common in puppies and adult dogs raised in rural regions where they may come into contact with areas where wombats and foxes live.
The result with either form is thick swollen itchy skin and hair loss, secondary infections, and scab formation in severe cases.
Eradicating the mites requires treatment with specific insecticides and may require repeated treatments over a number of weeks.
In the case of sarcoptic mange, reinfestation after coming in contact with another carrier animal is possible. Demodex, however, is only contracted within the first one to two days of life whilst suckling on a carrier mother.
Flea bite dermatitis
Fleas tend to have a season of increased activity during the warmer and drier months, however, when we invite our pets into our homes with central heating etc, we create an artificial environment suited to fleas all year around.
In some dogs, the individual can also be allergic to the saliva of fleas.
Fleas will lay up to 400 eggs a day, which can take up to 180 days to hatch, so one flea can cause a problem for six months.
Flea treatment can take several forms: spot-on products such as Advantage, Revolution or Frontline may not be suitable if your dog is a bit of a water hound, you may be better to choose an oral product like Comfortis, Nextgard or Bravecto. All pets in the household will need to be treated to keep flea numbers minimal.
It is also a good idea to thoroughly wash your dog’s bedding, vacuum your house and any furniture the dog sits on, and consider treating your house with a suitable surface insecticide. Some dogs react drastically to mosquito or fly bites.
Keeping these dogs indoors at night and using insect repellents strategically may be very beneficial.
Allergies and decreasing exposure
In some cases it is possible to decrease exposure to certain allergens. This is most commonly done by stopping the use of new products that may be related to the problem, or by removing problem plants from the animal’s environment.
Some plants that commonly cause dogs to itch include wandering dew (a dark green creeping plant with a purple tinge to the leaves) chives, English ivy, mint plants, liverworts, poison ivy, tree ferns and ginkgo biloba. Other plants release pollen that may affect animals, even at a distance. Some of these are chamomile, chrysanthemum, daffodils, lilies, sunflowers, lavender, marigolds, dandelions, Peruvian lilies and tulips. During the warmer months, the broadbladed grasses that grow tend to have a furry look to them. These little spikes pierce the skin causing irritation (rather than an allergic reaction), however, the symptoms are often the same: red, dry, itchy, traumatised skin.
Many animals are allergic to grains, cereals, and especially animal protein derived from beef, lamb, chicken and pork.
An exclusion diet may need to be trailed, such as Hills z/d or Royal Canin Hypoallergenic. If you prefer to homeprepare, use animal protein derived from a novel source (one that your dog has not had before): fish, horse meat, crocodile and camel are all available these days. Depending on your hunting preference, venison or kangaroo meat may be suitable if your dog has not had it before. It is important that these trials run for a minimum of two to three months and that in this time absolutely no other food, including treats made from other animal protein, is allowed.
Improving the barrier
The epidermal barrier is the part of the skin that helps to keep allergens from interacting with the dog’s immune system. If allergens do not get through this then the dog should not become itchy. In many itchy animals the barrier is defective, allowing allergens through far too easily.
This can be improved by two methods: removing build up and improving hydration.
Regular washing is important for itchy dogs. Shampooing helps remove allergens from the coat and rinsing helps re-hydrate the barrier. Mediderm is a good shampoo that does this but also contains antibacterial and antifungal properties. Start washing your dog twice a week to start with, decreasing the frequency as
your pet itches less. Make sure you soak your dog in Mediderm for at least five minutes for the active ingredients to work.
Moisturising (conditioning) also helps to rehydrate the barrier. For a small dog about a 5-cent-piece-sized puddle of shampoo is sufficient and should be massaged over the dog’s coat in the direction of fur growth only. This should then be rinsed very thoroughly for a minimum of five minutes. This step is very important. Then a conditioner may be applied. In some cases, it can be left on, or you may need to rinse briefly.
Good product choices for this are Aloveen or Nutriderm. These conditioners may also be used in-between washes as a lotion.
Providing nutrients to the skin
Omega three and six are powerful antioxidants that can be used to help in reducing inflammation. Scientific studies seem to suggest that fish oil is poorly absorbed. Oral supplements such as Megaderm, and special skin and coat foods, including Royal Canin Skin Support, are available and can be very effective. Some dogs are not very good at transporting and converting oral nutrients into the products required by their skin. For this reason, preparations that can be applied topically have been developed, these include: the Nutriderm conditioner (outlined above) and Essential 6 spot on treatments. Essential 6 treatment helps to normalise oil production in the coat, deodorise, fight dandruff and decrease non-seasonal hair loss. It also provides antioxidants and improves the skin barriers to decrease itching.
Modifying the immune systems response
When all else fails or when symptoms become very severe we may need to prescribe drugs that modify the immune response.
Old medicine used corticosteroids and they act to dampen the body’s attempts to fight the allergens it encounters. The result is a reduction in inflammation and itching. Short term, the most common side effect is an increase in thirst, whereas long-term use of steroids is best avoided if at all possible as it may lead to the development of some diseases: mainly diabetes and Cushing’s disease as well as marked weight gain.
The decision to use steroids long term is something that must be decided between you and your vet. Animals on long-term steroids should ideally have regular blood profiles run to detect any abnormalities as early as possible.
More recently, newer drugs with a much more specific method of action and therefore greater safety for your pet, have become available. Apoquel is the newest of these drugs and only interacts with the hormones produced in the skin itself during the inflammatory process. It does not interfere with the animal’s whole immune system or other organs, like cortisone and other immune modifying medications.
We do on occasion use antihistamines developed for humans. Ask your vet if this would be appropriate for your pet, and a dose rate.
Sometimes dogs will scratch to the point they create an open wound that may become infected. Your veterinarian may feel that antibiotics are necessary. If so, it is important that the whole course is completed. If stopped too early the wound may get worse or recur. Hot spots
Hot spots or pyotraumatic dermatitis are triggered by moisture and usually occur where the coat is thick, as this traps moisture. This environment encourages bacteria to multiply and produce toxins that irritate the skin. This causes severe itch that results in self-trauma causing a wound to appear very quickly. Hotspots may appear overnight and can become very large; they are also susceptible to fly strike and usually require treatment. To prevent them from re-occurring we need to stop the humid environment from arising. This may involve clipping the dog’s coat short and regularly drying problem areas. The most common cause of hot spots are flea bites, so make sure your flea control is up to standard.
Green-lipped muscle capsules, various plant oils (coconut, safflower, sunflower and linseed) and tumeric all have well recognised benefits.
Green-lipped mussels are available from Paws as a capsule. For oils, the dose for a medium-size dog is 5 mm per feed.
Tumeric paste recipe: Mix 1/2 cup tumeric powder and 1 cup of water into a paste and place over a low heat until thickens, then add 1/4 cup coconut Oil and 1 1/2 teaspoons of fresh ground black pepper. Stir well, then place into a container (glass is best) and keep in the fridge.
Give 1/4 teaspoon per 5 kg body weight once daily. Introduce slowly as may cause diarrhoea at first.