Why does my dog excessively lick?
What is ‘excessive’ licking?
“Dogs lick, it’s what they do”. This remark is generally true and the action of licking whether it be for grooming or checking out surfaces in their environment is typically normal behaviour. However, just like anything in life, sometimes normal behaviours can stray into being inappropriate, especially when exaggerated or done too much. The same is true for dogs with licking and it is not unusual to see licking becoming excessive or abnormal for many different reasons.
Some animals will repeatedly lick at themselves in one location, multiple regions or all over their body with enough intensity or duration to result in the loss of fur to varying degrees. Frequently alongside the fur loss or in some instances before hair loss has become noticeable, dogs will start to develop skin lesions.
Alternatively, some dogs will lick at the air or surfaces in their environment which can include other pets or humans in the household. If done continuously, this behaviour could indicate a problem.
What causes excessive licking?
There are numerous potential causes of excessive licking in dogs. The most common causes are:
Parasites (fleas, lice, mites) are one of the most common causes of licking and scratching in domestic pets. Don’t rely on being able to see them with the naked eye. Although they can sometimes be seen, it is not uncommon for them to be missed, even fleas (using a flea comb and not finding any fleas is not a guarantee that fleas aren’t present). Some parasites can only be seen with specific testing and when observed down a microscope.
The most effective way of ruling parasites out is treating all household pets with a vet prescribed anti-parasitic treatment at the recommended interval. Remember, not all products you can buy are made equally and often then don’t cover all the possible parasites that can be a problem; cheap products are a false economy and you may just find yourself spending more money in the long run. Speak to your vet for what they recommend.
Allergic skin disease is very common in dogs and cats. This can be an environmental allergy i.e. an allergy to something your dog comes into contact with in their environment, including certain pollens, dust mites, cleaning products etc. Some environmental allergies can vary in severity between animals and can be worse at different times during the year. For example, irritation caused by outdoor allergens tend to be seen more frequently in the spring/summer months (as with human hay fever).
Alternatively, allergies may be associated with your pet’s diet. Some animals will develop skin irritation associated with something they are eating (common dietary allergies include chicken, beef, lamb, wheat), and can sometimes be seen with associated GI signs (bloating, diarrhoea etc).
A common misconception is that allergies are something you are born with. In reality the most common time for them to develop in dogs is between 6 months and 3 years of age. However, we do see issues arising outside of this timeframe too. Allergies can be complex and involve multiple different allergens (e.g. Atopic Dermatitis).
In some instances, animals will focus on excessively licking at a particular part of their body indicating they are sore or painful in this area. For example, dogs may lick at an area such as over a joint affected by arthritis, or lick at their paw if they have a thorn stuck in it or some other wound. Licking typically won’t resolve until the offending cause is treated.
- Dry skin
Just as humans can suffer with dandruff, so too can dogs. Dandruff is essentially due to dry skin and left to exacerbate it can cause skin irritation for dogs. The origin of dry skin can be associated with a dog’s diet, inappropriate shampoo choices that dry their skin, too frequent bathing, certain parasites and hormonal issues to name a few. Dealing with the underlying cause of the dry skin will help to resolve the licking.
- Skin infections
Skin infections will often cause a dog to lick. However typically skin infections are secondary to other issues such as allergies or self-trauma. If the infection is more than superficial, removing the underlying issue may not be sufficient to resolve the problem. Instead, specific management such as topical cleaning, ointments or in some cases oral antibiotics may be needed.
- Anal gland issues
The anal glands are a pair of glands on the inside of either side of your dog’s anus. They contain secretions involved in scent marking. In some animals the anal glands can become excessively full (impacted) or infected, which can be intensely painful and irritating. As a result, some dogs will lick at their anus (or sides if they are unable to reach their anus). They may also scoot their bottom along the floor and a fishy smell may be noted. This can be a condition exacerbated in animals with underlying skin allergies.
Some animals will lick their lips or ‘lip smack’ if they are feeling nauseous or after vomiting. Causes of nausea/vomiting are a whole different and long blog post! But never-the-less, if you find your dog doing this specific licking behaviour, it’s best you contact your vet for advice.
For some dogs the act of excessive licking can be seen to develop as a response to stress, anxiety or boredom. This type of licking isn’t always isolated to licking themselves. Dogs may be observed licking other surfaces in their environment, other pets, or humans. A good discussion with your vet about home set-up, husbandry and changes may highlight possible issues. Often an effort will be made to exclude other causes of licking first as they tend to be more frequent. Management of behavioural issues may ultimately require seeking the assistance of a trained behaviourist to assess your specific needs.
The possible secondary skin infections that can occur from not addressing the behaviour issues can further increase your pet’s stress levels.
- Dental/oral disease
Dogs may lick their lips (particularly after eating) if they have painful teeth or other oral disease (affecting their gums, tongue or other areas inside their mouth). The best way of assessing this is to have your vet do a dental check. However, remember licking of lips isn’t the only indicator for dental disease, so just because your dog isn’t licking his lips doesn’t mean there aren’t issues there to be addressed.
Why is it a problem?
While there are a number of potential causes of excessive licking. The end result of your dog continuing to lick themselves is the same regardless of the cause. If your pet continues to lick at itself, this will result in skin inflammation. Further increasing the level of irritation in the skin which in turn will elicit more licking. This perpetual loop will continue without intervention. Inflamed skin can result in overgrowth of bacteria/yeasts present on your pet’s skin, resulting in secondary skin infections. If left untreated, it can result in chronic skin damage and even permanent damage to hair follicles, meaning that hair may never regrow even if the licking is eventually stopped.
Don’t forget that some of the causes of licking have effects on your dog beyond just the skin and the licking. If the underlying issues are not addressed it can leave your dog with significant risks to their ongoing health.
What is the treatment?
You can now appreciate there is potentially a lot more to your dog licking excessively than you may have initially considered. The treatment is going to be specific to your dog and what the underlying issue is identified as being. The first step is making an appointment with your vet to discuss the problem. They will take a thorough history and fully assess your pet. Some problems can be identified quickly. However, be patient as further visits and investigation (including examination of samples under the microscope, bloods, allergy testing) may be needed to identify the ultimate cause. Treatments can be one off for some conditions and longer-term for other issues.