Food is SO often discussed first, and unfortunately that's usually because the vet has this "answer" sitting in stacks in his office - "prescription" food. Hills "z" diet is FULL of allergens -- the only reason it "works" is because it breaks the food down into such minute micro-bits that the body processes it differently.
The "shots" work well for some dogs BUT only about 65% of the dogs who get them respond well to them. And the dog has to go thru heck for 18 months while they are starting to be effective.
3-4 is about the age most dogs develop allergies -- and typically it's environmental NOT food. Let me see if I can make it make more sense for you.
There are 4 "types" of allergies:
1. Environmental -- hayfever (pollen, hay, goldenrod, grass, anything green, anything moldy or dusty from outside). Usually they never go away ... but they "worsen" at certain high allergy times of the year.
2. Contact -- it's something in the environment but it's specifically spread by the oil of the plant getting on the skin SOMEHOW. These are typically easy to identify -- belly, feet, 'creases' - but very often the lips and muzzle (because the contact allergen gets on the tongue from licking and that burns the mouth/muzzle). For humans poison ivy is a biggie. Dogs tend to have MORE contact allergens -- St. Augustine sod, night-blooming jasmine, ANY variety of wandering jew, poison oak, poison ivy, and tons of others. Can be something the dog didn't even lay in -- but rather the humans walk thru grass cuttings, get the oil on their shoes, walk into the house and on the carpets, dog lays ON carpet (or touches shoes, pantleg, etc.) and 'contact' is made.
3. Food allergies -- there is a DIFFERENCE between a food intolerance and an allergy. Dog allergies (of all kinds) manifest on the skin. A food allergy will come out pretty fast in the mucus membranes or cause a 'wound' on the skin. But there are certain foods that promote inflammation and that is NOT an "allergy" -- things like chicken and rice tend to be inflammatory foods but they don't cause an 'allergy' -- they just help the body vent an already existing problem. (Statistically only about 27% of all dog allergies are food-related)
4. Flea allergy dermatitis -- it's almost a different category but it's vicious. The dog is actually allergic to the flea SPIT. Yep I'm serious. One *bite* and the affected dog is in misery for months -- it starts at the base of the tail and crawls up the back and down the back legs and eventually to the belly. Crusty sores that cluster together in those mentioned areas first - usually takes pred to relieve it. But it's so toxic to the body ONE bite can result in months of agony.
TYPICALLY when a dog is allergic to one thing it's often allergic to many. And really often it crosses back and forth among all 4 of those things above. Allergy testing can be helpful IF you can uncover some magic high allergen --
I always use the example of a friend of mine with a manchester terrier who was sore and nekkid most of the year. It was easy to see Quincy's allergies were partly seasonal -- he got worse in the Spring and Fall but it never really went away.
But they lived in a house with a dirt basement (dampness, mold), wallpaper (mold, dust mites galore), and had rows of oaks and maples up and down the street. (all major typical allergens).
But they had him tested at Cornell (vet schools rock by the way - they tend to be WAY cheaper than a regular vet on stuff like this and you get cutting edge help). SURPRISE -- he had ONE allergen that was his **worst**
What? VERY rare in dogs. **Feathers**!!!! Yep -- freaking feathers. And ... you guessed it -- these folks slept with feather pillows 24/7 ... and in the fall??? Feather duvets!!!
My friend got hypo-allergenic covers for the pillows and mattresses and suddenly Quincy's allergies were maintainable. he had tons of others but that one that they COULD do something about made his life much easier.
But honestly? That sort of result is rare -- usually the highest allergen is mold or pollen or chlorophyl or .... whatever your house is smack in the middle of. Heck, growing up I suffered every fall and spring-- but the leaves in the fall were the WORST. So I hit 30 and hightailed it to Florida thinking whooo hoooo -- no fall leaves!!
DUMB -- shoot! down here it's "allergy season" 12 months of the year. *sigh* I have worse allergies here than I've ever had before!
Maybe this analogy will help you.
Think of a bucket sitting under a leaky tap. Now it's an old bucket so it leaks a bit from the bottom.
The water dripping in is "allergens". But sometimes it rains and gets in the bucket too (more allergens) ... and the hose drips down in the bucket too (MORE allergens).
As the bucket fills the worse the allergies get. Does it really matter which allergies came from the rain the hose or the tap? Nope.
Sometimes the leak in the bottom ALMOST equals the drip coming in. so the allergies aren't "worsening" nor to they seem unusual. You might even not realize they're there because the level just stays ... level. BUT ... there are allergies there cos they are in the bucket.
At certain times (when the hose is used, when it rains a lot, etc.) the bucket fills up and even overflows. That's like when the dogs skin is SO bad you can't get it under control, it infects, you gotta use antibiotics and pred and you're still losing your mind over it.
But ... all those allergens that combine and flow over the top of the bucket?? Can you even TELL which drops of water came from where? Nope. That's like when allergies get really "bad" - switching food may give SOME relief from SOME of the allergens (like making the hole in the bottom a little bigger??) and it might even help keep the level of the water/allergens IN the bucket more ... well ... level. BUT there are STILL allergens there. They're still keeping the body inflamed and riled up but maybe the food is just taking a little off the top so it doesn't overflow.
My point is this -- food rarely 'cures' allergies. It might help SOME. And you make a tradeoff -- there are nasty carcinogenic preservatives in all of those "allergy" commerical diets the vets love -- which ... cause OTHER problems. And .. that allergy food is expensive.
So ... for MY money I tend to look further -- I like to use the TCVM or homeopathy for allergies. I've had EXTREMELY good luck with homeopathy with both Billy AND me. It's not expensive (and both me and the dog actually go to a homeopath -- a physician who specializes IN homeopathy).. NO sleepy stuff, no steroids ... just relief.
If you want I can teach you about homeopathy -- it's a whole separate branch of alternative medicine -- a homeopathic is NOT a "natural" or something "holistic" -- it's not a naturally occuring substance. It's a whole different modality of the medical arts. Feel free to email me -- I have an article I can send you or I can email or chat with you. I'm not a vet ... just a person who has had extremely bad reactions to a lot of medicines so I've found other methods that work for me.
I will be honest tho -- the one drawback to homeopathy (and again I'm being honest here) - they aren't "convenient'. They aren't pharmaceuticals so there's no such thing as a homeopathic that is a "time-release" thing -- generally you have to take homeopathics 3 times a day. Sometimes more ... and sometimes folks don't want to have to 'give' a dog something several times a day.
They never taste bad, and often dogs think they're a treat (cos they tend to be sweet). But I'll tell you they can sure help allergies.