Itchiness (Pruritus) Issues
Increased Scratching and Rubbing
If your dog begins to scratch or rub themselves against objects (e.g. furniture or walls) frequently, it may be indicative of allergy related itchy skin. In particular, a common sign is repetitive ear or muzzle scratching using its paws or rubbing its face along the ground, on carpets or against people’s legs.
Ears
Ear inflammation or infection is termed Otitis and the most common form linked to allergies, Otitis external, refers to the painful condition affecting the outer ear/ear canal; this is not the same condition as either Otitis media (middle ear) or Otitis interna (inner ear).
Allergy related infections of the ear flap (pinna) typically arise due to a combination of 2 factors:
- Overproduction of ear wax (cerumen) in response to the allergy by the ceruminous and sebaceous glands located in the external ear canals.
- Skin damage caused by scratching enables microbes, typically fungi e.g. yeast infection, followed by bacteria e.g. Staphylococcus, to infect the area.
Lifting the ear flaps may reveal red bumps and inflammation that can be moist or scabbed if the skin has been broken through excessive scratching. Secondary infections such as these are often characterized by discharge and unpleasant odor, and there is a risk that they can progress deeper into the ear canal. Aside from irritation and pain, ear infections near the ear drum can lead to sensitivity to sound as well as the risk of permanent damage and deafness.
Problems and infections associated with the ears should always be viewed as a possible indicator of allergies. Why? The ears are often the first place allergy symptoms reveal themselves but also, 50% of dogs with allergies may only exhibit ear symptoms!
Muzzle
The muzzle will typically contain clusters of small, red bumps that may not be apparent on casual viewing although larger bumps may be visible. Depending on the breed/fur of dog in question, you may have to inspect the animal carefully to observe allergy-related rashes, irritation or bumps; carefully part the fur at various locations on the muzzle especially on the underside/sides. Remember that the dog may not be feeling its usual self and liable to be less tolerant and patient of handling than normal.
Other locations
Depending on the cause or source of the allergy in question, there is the potential for almost any skin covered area of the body to be affected e.g. back, belly, elbows, groin and sides as well as the genitals and anus. Areas more commonly affected by inhalation (airborne) and ingestion (food) allergies include the eyes, mouth, armpits, abdomen, legs and feet as well as the anus; flea bite allergies have a tendency to affect the hind end more than head or body, forming a triangular symptom-prone region between the middle of back, tip of tail and rear legs.
The range of symptoms associated with allergic skin diseases and related dermatitis vary considerably. As a general guide, unusual areas of reddening (due to inflammation) or discoloration (usually due to repetitive licking by the dog), pigmentation (e.g. older dogs may develop darker areas around the groin), crusty deposits, scaling, loss of hair or bald patches (alopecia) may all be indicative of allergy symptoms. The severity varies considerably between dogs, and although some estimates suggest 4 out of 5 sufferers have some degree of all-year-round itchiness, an individual dog will typically experience waxing and waning of symptoms.
Furthermore, the potential for secondary infections, hot spots, lick granulomas and fever associated with allergies in dogs always needs to be borne in mind. For example, skin inflammation and subsequent damage caused by scratching may allow a secondary yeast infection e.g. Malassezia pachydermatis, to become established producing additional itchiness, discomfort and a noticeable odor. Hot spots are an example of where a secondary bacterial infection e.g. Staphylococcus, develops and pus forms.
If the itch is located in a hard to reach location on the dog or it is particularly distressing, the animal may be seen to exhibit odd behavior. For example, a dog may walk around in repetitive tight circles in what appears to be an attempt to bite its own tail; though comical to watch, it may be the dog’s desperate attempt to alleviate an excessively itchy back or base of the tail caused by a flea allergy. Alternatively, if the affected area is the anal region resulting possibly from a food allergy, the dog may be seen to rub its posterior along the floor in a riding-a-bike motion (bottom scooting). Unfortunately, allergies and scooting can also be associated with irritation, infections and abscesses of the anal sacs.
Increased Licking
The dog may appear to be licking the air, their lips or teeth, or making noticeable smacking/clucking sounds frequently. This can be indicative of the dog attempting to counteract allergy-related itchiness or tingling of the lips, tongue, roof of mouth or back of the throat.
Moreover, frequent paw licking, especially between the webbing of the paws, is a common allergy sign. Sleep disturbances can result if the irritation is significant and the dog may be heard licking itself for extended periods during the night or pacing around its enclosure. Wet areas on its bedding may not be indicative of a soiled bed due to urination but rather excessive salivation through repetitive paw licking.
Do bear in mind though, that aside from ‘classic’ allergy-related itch locations e.g. ears, muzzle, paws etc. any area covered by skin (including the genitals and anus) has the potential to itch and so long as the dog can reach it, excessive licking may be its way of tackling the problem.
Compulsive licking can eventually give rise to lick granulomas which are typically characterized by raised/ulcerated skin especially on the animal’s wrists or ankles.
Increased Nibbling and Chewing
Increased nibbling and chewing of fur, legs and feet/paws/pads is a common sign of dog allergies. As the dog attempts to alleviate the allergy-related itchiness e.g. to food or pollen, such actions can lead to hair loss, or in chronic cases, even bald patches developing in these locations.
In addition, the paws may end up becoming reddened, inflamed or swollen. Sometimes the dog’s lips or pads may suddenly develop areas of pink pigmentation (especially noticeable in darker coated breeds) that result from repetitive nibbling. Again, as with licking, repetitive chewing can impact a dog’s sleep routine making for a miserable time for both dog and owner.
Although loss of hair and scabs may be caused by the actual physical act of nibbling and chewing, the owner should be aware that it may be indicative of an allergy related secondary infection caused by bacteria or fungi.
Increased Shaking
Repetitive shaking of the ear flaps, head or body can indicate an allergy problem. Shaking of the head may resemble the animal trying to rid itself of an insect trapped in its fur or an ear flap, but the cause of this symptom may be allergy-related skin irritation and itchiness. Be aware that frequent head and ear flap shaking can also be indicative of an ear infection.
Itchy and Irritated Eyes
With reference to allergies in dogs, allergic conjunctivitis is either seasonal (e.g. to pollen) or perennial ( e.g. to dust mites or dander), although contact dermatoconjunctivitis can occur in response to the use of eye drops. Allergies can lead to irritation and itchiness around the eyes leading to inflammation and reddening, possible tiny red bumps developing on the eyelids and a tendency for excessive watering of the eyes to occur. Furthermore, chronic allergy conditions may result in a whitish, halo-like appearance extending around the entire lower and upper eyelids. Self-care primarily involves prevention i.e. minimizing dog exposure to the troublesome allergen, whereas treatment may include antihistamines, mast cell stabilizers or corticosteroids depending on the severity of the allergy.
However, it is possible for infective conjunctivitis to develop associated with an allergy related secondary eye infection. Symptoms of this can include liquid on and around the eyes becoming discolored and sticky giving rise to a translucent appearance, the whites of the eyes often become bloodshot and red, and crusty deposits form on the eyelids and fur around and below the eyes. Although the condition may clear by itself within a few weeks aided by simple care e.g. clear away discharge and avoid cross contamination through washing hand afterwards, conventional medical treatment may be required e.g. antibiotics, chloramphenicol.
