Arthritis
Atopy (Inhalant Allergy)
Bufo Toad Poisoning
Cat Home Safety Tips
Collar Hazards
Common Things to Watch for
Dental Disease in Pets
Diabetes
Dog Safety Tips
Feline Heartworm Disease
Mallassezia (yeast) Dermatitis
Reasons to Neuter
Noise Phobia in Dogs
Weight Problems in Pets
Otitis (Ear Infections)
Parvo Virus
Pruritis (Itchiness)
Rabies
Seizures and Epilepsy
Senior Pets
Reasons to Spay
Toxoplasmosis, Cats and Women
definitely one of the most frequent things that I do as a small animal veterinarian. I
would estimate that 75% of the animals that I see in a day have some sort of skin or
ear problem.
One of the most common causes of dermatitis in dogs is "atopy" which is an allergy
to inhaled substances such as pollen, dust and mold spores. When the animal is
exposed to these offending "allergens" the body releases certain chemicals
including histamine that causes the animal to itch.
The disease is an inherited disorder and is common in many of the small terrier
breeds, Beagles, Boxers, Bulldogs, Dalmatians, Lhasas, Pugs, Retrievers, miniature
Schnauzers, Setters, Shi-Tzus and Shar-Peis.
Dogs that are genetically predisposed to developing atopy usually start to show
signs around 1-3 years of age, although some dogs, especially Golden Retrievers
and Shar-Peis, may start to show signs as early as 6 – 12 months of age.
The most common sign of atopy is "pruritis" or itchiness involving the face, muzzle,
ears, paws, abdomen, and groin area. The pruritis may vary in intensity at different
times of the year especially early on in the disease. Most dogs with atopy become
very itchy in the spring and summer months and are less itchy or not itchy at all in
the fall and winter as the degree of pruritis depends on the level of allergens
present in the environment. Usually the condition will get progressively worse and
the dog will exhibit non-seasonal or year-round pruritis as it becomes sensitized to
more and more allergens.
If the animal is not treated appropriately the intense itchiness that it feels causes the
dog scratch, chew and bite itself incessantly. This self-trauma damages the skin
and leads to a host of other problems.
Many dogs develop a concurrent bacterial or fungal skin infection that worsens the
pruritis and causes the dog to itch and scratch even more, further damaging the
skin. Skin infections can present as little red bumps, scabs and a thin hair coat.
Atopy is also one of the most common causes of otitis externa in dogs. The inside
surface of the earflaps and the outer ear canals become red and swollen and the ear
may become infected and stinky. Dogs with otitis externa shake their head and
scratch at their ears a lot and may cry out or become aggressive when touched
around the head.
Because of the constant scratching, biting and chewing on itself, the skin on the feet,
around the eyes and in the armpit and groin regions often times becomes very
thickened and may become pigmented black. Atopic dogs usually have a very thin
hair coat or even bald spots. And they may have very dry, scaly skin and an
objectionable odor that returns soon after a bath.
One of the worst ways to treat an atopic dog, especially one that has had the
disease for a long time and is suffering from secondary problems such as a skin
infection, inflamed ears or swollen feet is to only give it a monthly "itch shot".
This injection is typically a long-acting steroid (such as Depo-Medrol [R]) that has
significant side-effects when given too often. And although it may relieve the itch
for a short period of time it has no effect on the secondary problems that also need to
be treated.
Using a combination of therapies is a much more effective way of treating atopic
dogs and often times brings the disease to a tolerable level for both the pet and the
owner.
If there is a skin infection an appropriate antibiotic must be used. In chronic cases
antibiotic therapy may need to be continued for 6-8 weeks to knock out the
infection. Treating for too short a period of time or using the wrong antibiotic (such
as amoxicillin) will result in treatment failure or a quick return of the infection.
If the dog has otitis externa then appropriate ear care must be done. This includes
gentle cleaning or flushing with an ear cleaner and using medicated eardrops to
reduce the inflammation and heal the infection.
Medicated shampoos that contain chlorhexidene (my favorites are Hexadene [R],
Chlorhexiderm [R], and Malaseb [R]) help to cure both bacterial and fungal skin
infections. I usually recommend bathing every 2-3 days in the beginning and then
less often as the skin heals. Once the skin infection is cured other shampoos that
contain either colloidal oatmeal or antihistamines can be used on a regular basis to
keep the pruritis under control.
A new shampoo called Allermyl [R] is formulated specifically for atopic animals
and promises to be even more effective at relieving skin irritation and itching than
other shampoos.
Bathing an animal, especially large dogs, can be a chore. Often times I have the
owner do "spot baths" such as only washing the feet or the back end of the pet. This
technique is quicker than bathing the whole animal and saves on expensive
shampoos. This makes it easier on the owner and more likely that they will
continue with the treatment plan.
One of the most important goals of treatment is to relieve the animal’s intense
itchiness. Not only is it the compassionate thing to do, it also breaks the self-
trauma cycle and allows the skin to heal. Just using an E-collar, T-shirt, or booties
on the feet to prevent the dog from scratching and chewing on itself is inhumane
and doesn’t address the underlying problem.
Steroids such as prednisone do play an important role in treating atopy and are
very effective at relieving pruritis. However, it is much safer for dogs to receive
oral prednisone tablets rather than the long-acting injectable form. By giving pills
by mouth the dosage can often times be lowered or given every other day thereby
reducing the side effects of these drugs even more. This is especially important
when the pet will need long-term treatment with steroids.
Trimperazine is one of the few antihistamines that actually works in dogs. It is
combined with a small amount of prednisone in the product Temaril P [R]. This
combination is very effective at stopping an itch and I use it quite frequently with
excellent results in small atopic dogs. Unfortunately, it is often prohibitively
expensive to use in large breed dogs.
Fatty Acid supplementation may also help relieve pruritis in atopic dogs. Essential
fatty acids are found in fish oil and flax seed oil and come in 2 forms: omega 3 and
omega 6. Products high in omega 3 fatty acids are thought to be more effective at
relieving itchiness, while higher levels of omega 6 fatty acids are thought to help
animals with dry, scaly skin. Examples of EFA's are "Derm Caps" and "3 V Caps".
In difficult cases or in those animals that are not very responsive to medical
treatment allergy testing and desensitization injections are the next step. Allergy
testing can be in the form of either intradermal skin testing or performed on a blood
sample, and each method has its benefits and drawbacks.
Once it is determined what pollens, grasses and molds the dog is sensitive to, an
"immune serum" is prepared that the owner is taught to inject on a routine basis.
Many dogs respond quite well to this treatment although it may take 6 to 12
months of continued therapy before any improvement is noted.
Because atopy is a genetically inherited disorder there is no cure for it, but with
combination therapy many dogs can lead relatively itch-free lives.