Dog Keeps Itching? Possible Causes and Treatments

How is the cause of dog itching diagnosed?

Finding the cause of itchiness in dogs needs a logical, systematic process and it can take time. Your vet may be able to give your dog some symptom relief while the process gets started. The diagnostic process will involve some or all of the following:

1. Clinical exam: Your vet will look at where your dog is itching the most, as these patterns can point to causes. For example, fleas tend to congregate around the head and neck and the base of the tail. 
2. Hair samples, swabs and skin scrapes: These will check for fungal and bacterial infections and some of the microscopic mites.
3. Food elimination trial: Your vet may suggest a special diet for a period of time to see if your dog has a food allergy. There are two main types of foods used for these:
   1. Hydrolysed protein: As most food allergies are to protein sources, your vet may use a hydrolysed food. This means that the proteins in the food have been broken down into pieces that are too small for the body to recognise as proteins but that the body can still use. These foods are good because, in theory, any dog with any allergy can eat them. This makes for an easy approach, especially if you don’t know what your dog’s feeding history is.
   2. Novel protein sources: These foods rely on knowing what your dog has been exposed to before. You feed your dog foods containing proteins they haven't been exposed to previously, such as venison or duck.
   If you do a food trial, it’s essential that you do not feed them anything else during that time. For intestinal food allergies the trial may only last 3-4 weeks, but for skin disease this can be up to 12 weeks.
4. Skin and blood tests for atopy: Your vet may suggest intradermal skin testing or blood tests to find out exactly what your dog is allergic to.

How is dog itchiness treated?

This will, of course, depend on the cause. You will likely need to resort to one or more of the following:

• You may find just keeping up to date with parasite control is enough for fleas or mites.
• Your vet may recommend medicated shampoos, anti-inflammatories, and possibly topical lotions if the skin is badly damaged in places. 
• For dogs with food allergies, you can either stick with the special food or gradually try other foods to try to identify the exact offending ingredient. This can be time consuming and most pet parents find it easier to keep their dog itch free on the dietetic food.
• In case of atopy, once you know what your dog is allergic to, you may be able to avoid those allergens, but often there are multiple culprits and it can be difficult. You could try desensitisation. This involves a special, tailor-made ‘vaccine’ for your dog's allergies which gets periodically injected. This starts at tiny amounts and becomes more and more concentrated to allow the body time to acclimatise and stop being allergic. It doesn’t work for all dogs but can be a big help, even if you don’t get a total cure.
• Foods that help skin in general. There are many diets available that have ingredients that are designed to repair the skin barrier and reduce inflammation. These can be great for any itchy dog and especially helpful for dogs with atopy.
• Omega fatty acid supplements. These can help reduce inflammation and may help as part of an overall treatment plan. If your dog is on a skin diet, you almost certainly won’t need to supplement these, as special skin diets are often high in omega fatty acids, but always check with your vet.

Remember, some dogs unfortunately have multiple problems, so you may need a combination of these therapies to get the best result for your dog.

Visit your vet

As you can see, there are many reasons for dogs to be itchy, but the two most common reasons are parasites and allergies. Regardless of the reason, seek veterinary attention right away when you notice your dog scratching. Don't give any medications prior to your veterinarian's examination and instruction. You could delay diagnosis and worsen your dog’s problems.

Itchy skin is unpleasant for everyone concerned, and it can be time-consuming and costly to get to the bottom of it. But with patience, understanding and strong collaboration between you and the team at your veterinary clinic, many dogs and their owners can find great relief and lead happy lives.

Dog itching FAQs

Why does my dog keep itching but has no fleas? 

Sometimes you may not see fleas, but they may still be in the house. If fleas are not the cause, it could be other parasites, infection, food allergy or atopy. It’s best to see a vet if your dog is itching all the time.

Is it normal for my dog to scratch all the time? 

No. All animals, like humans, will get the odd itch, but if your dog is always itchy or has hair loss, scabs or inflamed skin, you need to see a vet.

Can food cause my dog to itch constantly? 

Yes. Food allergies can cause intensely itchy skin as well as gut symptoms like diarrhoea and vomiting.

What can I give my dog to stop itching at home? 

Don’t try to treat your dog at home without the say-so of your vet. You may delay diagnosis and worsen your dog’s skin problems.

How do I know if it’s allergies or parasites? 

You may see parasites, but some are microscopic, and allergies need careful veterinary diagnosis. It’s best to see your vet rather than try to diagnose your dog at home.

Reviewed by Karen Shenoy, DVM.