Dogs do occasionally scratch, but if it’s frequent, incessant or distressing then something is amiss. Some dogs will lick or nibble rather than scratch. Many do this in private so watch out for red, sore skin, bald patches, or brown saliva staining where the fur has been licked.
Itching (technically called pruritus) is a sign, not a diagnosis or specific disease. It’s probably the most common reason for owners to take pets to the vet’s, making up a large proportion of our consultations.
Fleas are elusive and VERY common. In warmer weather, flea eggs develop into adults quicker. It’s important to carry out the following steps before discounting these critters.
How to check your dog for fleas
They move fast and hide well, especially in thick or dark coats, so are hard to find. Adults are 5% of the population. The rest exist as eggs, larvae and pupae within the environment. As one flea can lay 40-50 eggs per day, there don’t need to be many adults to start a problem, so not finding a flea doesn’t rule out fleas. Only in heavy burdens can you find them with ease.
Using a comb look for the dark gritty specks of flea faeces, often around the tail base and neck. These specks, when placed on dampened cotton wool, form a red tinge due to blood content.
I’ve used a flea treatment; could it still be fleas?
Flea treatments need to have effective ingredients and be applied regularly. Breaks in protection allow fleas to feed and lay eggs in your home. Given 95% of their lifecycle resides in the environment, effective home treatments mustn’t be forgotten during an outbreak.
There’s a baffling array of flea products out there containing different active ingredients. Products bought from shops or online may have not been tested rigorously for safety and efficacy. Get advice from your vets, especially in the face of an outbreak. In addition, veterinary treatments are often combined with ingredients to prevent other parasites like ticks or lungworm. They can help you pick a treatment that looks after your individual needs and lifestyle risks.
Many flea treatments need fleas to bite before being killed. If your dog is allergic to flea bite saliva (flea allergic dermatitis), you don’t need many fleas for your dog to itch. As one flea can bite up to 400 times a day, a few can cause lots of irritation.
The itch is localised; what could this mean?
Look closely for any wounds, matts, foreign bodies such as splinters, or insect or tick bites. If your pet is scratching only its ears you’ll need a vet to look down the ear canals, checking for inflammation, infection or foreign bodies such as grass seeds.
My dog is scratching all over; what could this be?
The most common causes of itching are parasites, infections, and allergies.
We have already covered the most common parasite; the flea. There are also many types of…
Some can be easily seen with a microscope, others are more difficult to spot, and most are not visible with the naked eye. Sarcoptic mites usually cause intense itching and scabbing on the ears, chest, elbows and hocks. They are infectious, spread by other dogs or foxes, and affect humans.
A predominantly rabbit mite (Cheyletiella) less commonly affects dogs. It’s spread by wild rabbits or other dogs. It appears like ‘walking dandruff’ and can cause itching if the dog is hypersensitive, although usually doesn’t. These mites will not live on humans but may cause skin irritation.
Demodex mites cause hair loss and scaling which can be local or general and, in certain forms, cause itching. The mite is not infectious to other animals or humans. If a secondary skin infection occurs, with severe cases this will cause intense itching.
If everything else has been ruled out, your dog is most likely suffering from an…
Allergic skin disease.
Contact allergies aren’t common but can occur with a new shampoo or washing powder, for example. Think if you have changed anything recently.
Flea allergy dermatitis, which is common as mentioned, with lesions typically affecting the rump, back and neck.
The other two broad types are:
- Canine atopic disease (“Atopy” or “Atopic Dermatitis”): a reaction to environmental allergens like pollen causing seasonal signs, or house dust mites causing all-year signs.
- Cutaneous adverse food reaction (“Food Allergy”) is due to an allergic reaction to certain foods, that usually occurs all year round.
They have very similar signs so are hard to tell apart. Many dogs suffer a mixture of allergies, complicating things further. Usually, skin changes and itching are generalised, affecting the tummy and face more often, but can be local. Food allergies are more likely if your dog is less than 1 year old, but can happen at any age. They cause gut signs in one third of dogs. Atopy usually starts between 6 months and 3 years old.
Your vet may discuss starting a strict elimination food trial if an adverse food reaction is suspected.
Allergic skin diseases cannot be cured, only managed, and cause immense frustration for owners as well as being time consuming and costly, as management is lifelong.
These may involve yeasts or bacteria, and usually happen due to poor skin barrier function from an underlying allergic skin disease. It may be the first sign that your dog has allergic skin disease. Bacterial infections often appear in humid areas of the body like the ears, feet and groin as circular scaly patches, pimples or oozing sores but can be general. Yeast infections tend to be more greasy and generalised and can affect ears. These infections cause intense itching so need treatment but the underlying allergy mustn’t be ignored. Prevention of infections is important for long-term management of allergic skin diseases.
Common things occur commonly so make sure all animals and the house are up-to-date with a safe, effective and recommended flea treatment. If the itch doesn’t settle then a vet visit will be required.