There is a lot of mythology out there about food allergies. The recent concern about the potential risks of grain-free diets is only an issue at all because such diets became wildly popular with no evidence that grains were a problem in the first place. A lot of folks blame grains for allergies and other health problems, but there’s no real evidence this is true, and these ingredients probably play a fairly minor role in food allergies in dogs and cats.
Other myths about food allergies include the idea that changing diets can cause them (actually, prolonged exposure is usually needed to develop a sensitivity), that raw foods are less allergenic (nope, only more likely to give you a food-borne illness), and that you can use blood, hair, or saliva tests to diagnose food allergies (sorry, a limited ingredient diet trial is the only way to do this). This last misconception is perpetuated despite evidence from human medicine that it is not true because, quite frankly, it makes people money.
I’ve previously discussed an example of this quackery, Jean Dodds’ Nutriscan allergy testing system. In her book, Dr. Dodds provides many citations to support her claim that this is a legitimate test, but a cursory look at these shows they don’t make that case at all. And there are unpublished reports from at least one allergy specialist that suggest the test is not merely inaccurate but completely useless nonsense:
One veterinary dermatologist has performed her own uncontrolled test of Nutriscan, with Dr. Dodds’ knowledge and permission, and found it entirely unreliable. Twelve samples were submitted for testing in a blind manner, from dogs with known food sensitivities based on dietary testing, dogs with environmental allergies, dogs without allergic disease, and one sample of tap water. All samples including tap water, environmental allergy dogs, and normal dogs showed reactivity to beef, corn, milk and wheat. Some samples showed reactivity to soy. In some cases, these obviously false results would have led to recommendations against diets which actually helped these dogs.
Granted, this is essentially an unpublished anecdote, so while it counters the anecdotes Dodds and others put forward for Nutriscan, it is not published scientific research. Now, however, a different allergy test, using saliva and hair samples to identify allergies, has failed the same test as spectacularly as Nutriscan purportedly did.
Coyner K, Schick A. Hair and saliva test fails to identify allergies in dogs. J Small Anim Pract. October 2018. doi:10.1111/jsap.12952
Our study demonstrates that hair and saliva testing fails not only to identify allergic dermatitis in dogs, but fails to differentiate between animal and non-animal samples, providing essentially identical results, regardless of the origin of the sample.
These authors submitted not only hair and saliva from dogs with known allergies and dogs without allergies, but also fake hair samples from stuffed animals and water (in place of saliva). All of the samples tested positive for some allergies, and there was essentially no difference between the results and random chance.
Saliva and hair tests for food allergies are a scam and a waste of time and money.
Finally a study to prove it’s a scam..
from dogs with known food sensitivities based on dietary testing, dogs with environmental allergies, dogs without allergic disease>>>>> how was environmental allergy dx made? A lot more to dog skin allergy than elevated IGE that blood allergy testing measure.
The samples submitted for an atopic dog were from a dog diagnosed with atopy based on IDST and food trial:
“The allergic dog was a 3-year-old, female spayed Labrador retriever. The diagnosis of food allergies had been obtained using an elimination food trial followed by single ingredient food challenges. Intradermal allergy testing had identified allergic reactions to multiple environmental allergens”
Exactly as you say, I changed my dog’s food to grain-free kibble due to a allergy blood test, many years ago. He was miserable at the time, very itchy and with alopecia. Hydrolyzed kibble wouldn’t help him, only steroids would. The vet then suggested the blood test… And this is what frustrates me, being a suggestion of the vet… He tested allergic to A LOT of things (basically, he could only eat pork and fish as protein sources). I’ve found it a little weird, but I didn’t bother, because the diet change to grain-free pork- or fish-based foods worked. Now I see it was just luck. Basically, I did an elimination diet based on a false test, but I got lucky and eliminated the right ingredients! Ahah Anyway, he is now on a homemade diet, after the FDA warning about grain-free diets. Will think about designing him a few new recipes with other protein sources, now I know the test is unreliable…
Does it give totally random results or just false positives? If the negatives are correct, it can still be useful to select foods.
It gives positive results for some antigens for all samples, real and fake, and the pattern of which antigens are positive and which negative appears to be random, so it can’t guide clinical management.
WOW! This article really useful for me. I confused for choosing the hair care and allergies care information what would be the best for everything. But review this article my confusion has cleared. Thanks a lot for sharing such an informative article about Hair and Saliva Test for Allergies and I’m sure most people can take notes from this article. One thing most people lack experience while aware of Allergies. Well, this post will give me much good ideas for allergies care. Thanks and keep it up…….
Thanks so much, been reading these articles all afternoon since I found your blog.
Can you explain what (if any) differences there are between blood testing for environmental allergies and blood testing for food allergies/intolerance?
I understand why blood testing for food is worthless, but I’m not sure I understand why blood testing for environmental allergies doesn’t fall under the same banner? Or do they? Doesn’t an elevated IgG response to environmental allergens just mean exposure also and not an allergic reaction?
I have a constantly scratching GSD which my vet has had a blood test done on for environmental allergens and said that the results show an allergic response to grass, weeds, moulds and mites.
Apparently an additional blood test will reveal exactly which grass, weeds etc. are the ones responsible – from that they can then produce vaccine shots which might help.
At the same time, I am wondering if there are food intolerances to consider…she gets fed a raw diet at the moment and is a fairly wide variety of different proteins (we buy Nature’s Menu items). Also, I’m now thinking that food elimination testing should have been done prior to the environmental allergen testing and that hasn’t been done.
Blood testing for immunoglobulins cannot be used to diagnose atopy (environmental allergy) because, as you point out, it only indicates exposure to the antigen. Blood testing doesn’t show that a particular antigen is causing clinical signs. However, when a clinical diagnosis of atopy is made (based on clinical signs, ruling out flea and food allergies, response to therapy, etc.), blood testing may be useful in identifying antigens which are triggers for symptoms and in guiding immunotherapy. However, the evidence for this in dogs is not strong, and such testing may not always be worthwhile. Here is an evidence-based. summary of blood testing for allergies.
You might be interested in a second, larger study that examined a different company (Glacier Peaks Holistics), and found similar, if not more damning results:
Bernstein JA, Tater K, Bicalho RC, Rishniw M. Hair and saliva analysis fails to accurately identify atopic dogs or differentiate real and fake samples. Vet Dermatol. 2019
Not only could the system not differentiate atopic from healthy dogs, but it could not identify fake fur samples as “non-biological”. Furthermore, the results were so clearly skewed towards particular “allergens” and triggers (regardless of the source of the sample), that it suggests a systematic bias, rather than just “random number generating”.
Thanks Mark! I saw this study, but not until after my Feb. 2019 column in VPN on the subject (which had to be written and submitted in December, 2018). It’s great to see such stark confirmation of the uselessness of these tests, though I despair of convincing followers of Dr. Dodds and other proponents of such testing that it is bogus. 🙁
i have been seeing an integrative wellness vet to help with my dogs scratching, I had a phone consult with a deva Khulsa on the internet who writes articles and books, who diagnosed my morkie with maladezia. she had the black in the ears and flea like pepper flecks on her hot spots. My normal vet was treating with apaqual and i didnt care to remain on it due to all the internet scare about it. we treat the ears with zymox optic ear, and did muscle test to see she has a grain (yeast) and chicken and beef allergy. so i feed her freeze dried or raw pork, turkey, lamb venison, duck etc. and stay away from all chicken and beef and grains. I just switched to a closer vet so i didnt have to drive 45 min each way and she suggested a nutriscan saliva test. I was hestitant to hurry and order and decided to contact my old vet and they said they dont really tell you correct information, any more than muscle testing can. So then i googled and saw your information. I am confused as to why my dog has this maladezia (not sure if she really has this, no one has really diagnosed what she is itching from) but my dog will be more itchy during the season changes she still has some black flecks in her skin and likes to be scratched on her back but sometimes more than others she wants to be scratched. what test will tell me what is causing this yeast on her skin or whatever it is. that is what i want to know how or what it is and to clear it once and for all. being 2 years on raw food and shampoo with young living only and now a new one from the vet that helps better than young living. no grains etc she should be cured by now on top of taking things to cleanse the liver every 6 months etc.
Unfortunately, you’ve been giving a lot of misinformation. Allergies are complex and often challenging to control, but Malessezia yeast is often a secondary opportunistic infection, not the primary cause, and it can be part of the normal microbiome in dogs which overgrows due to changes in the skin from allergies. Muscle testing is complete quackery and can tell you nothing about food allergies, and as you see from this article neither can the Nutriscan test. Food allergies are rarely due to grains, though the can occur, and the only reliable way to test for them is an elimination diet using a hydrolyzed protein diet followed by challenges with specific protein sources. Raw diets have no proven benefits for dogs with allergies, and they have significant health risks. Many dogs have environmental allergies rather than or in addition to food allergies, and so skin problems may continue even if we are feeding an appropriate diet.
All of this is to say you really need to find a qualified veterinary dermatologist and get some legitimate medical help rather than the nonsense being sold by folks like Dr. Khalsa and Dr. Dodds.
Take your dog to a veterinary dermatologist for exam, testing, diagnosis and effective treatment options.
And if you were referring to Young Living essential oils, please cease using it, there’s no evidence whatsoever that it is effective for skin allergens, nor is it safe! (not to mention the sordid history of it’s proprietor and an MLM scam to boot).
I’ve been reading Dr. Dodd’s website information about the Nutriscan testing. She explains numerous times that the test is for food sensitivities, not allergies and true food allergies are rare. She also writes that to determine allergies requires a different kind of testing. People should read all of the information and understand it before calling it one thing or another.
She may say this, but she is wrong. There is no evidence to support the claim, and there are clear study results showing such tests, including hers, don’t work. The distinction is mesaningless here because both claims are equally specious.
My dog waa diagnosed with IBD @ one year old after a biopsy of her GI tract. After many months of steroids, metronidazole and Hydrolyzed protein canned food and HP kibble as a training treat she still has poop that is inconsistent. Sometimes it looks “normal” then it is a weird color and/or mushy. We give her nothing else except her food, and the hydrolyzed protein food. I was told she would have to eat this food forever as it is the only food her body would tolerate. I am wondering if there is something in her food that is causing her to have this mushy poop. Anyone have a similar issue??
PS. My dog also scratches her ears and bodt alot and bites her paws. All bloodwork was “normal” as of april 2020.
Dr Dodds is very clear that her test ONLY tests for IgG and IgM saliva reactions to food ingredients. She is not claiming to test for allergies, which involve different immunoglobulin responses and more severe and immediate reactions.
Also, I will never be convinced that ultra processed ingredients, no matter how well nutritionally balanced, are better for any living being than properly balanced whole food ingredients!
Well, “I will never be convinced” makes it clear that yours is not a belief based in science or evidence, so it is not surprising that the clear evidence tests like this are worthless doesn’t concern you. It is quite disingenuous to suggest Dr. Dodds is making limited claims for this test when she and all the Hemopet marketing very clearly state that the test is “proven” to identify food intolerance or sensitivities and can “can greatly improve the quality of your pet’s life and longevity.” She is literally promising longer life as a result of using this test! It would be nearly impossible to find a better example of deceptive quack marketing.
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Hi everybody ,,,I Live in Greece and I have an Irish setter who had ibd 9years now,,,I made him blood tests for food intolerance twice and become more intolerance every year I most protein and other foods,,I fed him hydrolysed z/d and one novel protein every time also tools metronidazole,,,now I have huge problem because hills change the ingredients of the food and he cannot eat it,,,I tried every hydrolysed canned food like soya,,,only 4 are in the market,,,any ideas???
The only I know is that those dogs with ibd cannot live without hydrolysed protein food and changing food so I am wondering why one company think of making hydrolysed single protein with one or two ingredients fully hydrolysed,,,I have tried everything in the whole world for him,,,I read every day in the whole world for people who has dogs with ibd and don’t know what to do,,,I think food companies didn’t care for those dogs to live,,,that’s my opinion but animals are not things to buy another,,,really I am very sad about that,,,we have many many foods but only 5 in the whole world with few ingredients and hydrolysed protein and only 2 without soya!!!
Not a vet, here, but I would rule out internal parasites including giardia and coccidia. Both can be very hard to get rid of and both are in the environment if your dog is near other dogs, such as daycare, dog parks, etc. Internal parasites can cause intermittent mushy stools. Also, talk to your vet about prebiotics and probiotics. There are a number of good options available.