Blood sampling for food allergies, any merit at all?

RE: Blood sampling for food allergies, any merit at all?

David Bentley — Wed, 10 Nov 2021 14:45:27 GMT

It’s only an 80% predictive value. You do have to test each protein source in turn. Insect based diets are a great idea, but once they go mainstream they won’t be considered a “novel” protein. I do know of one dermatologist who is a Diplomate that uses Vetruus Solo Vegetal as a food trial diet. It’s 100% vegetarian but I don’t know who novel all the different sources are.

RE: Blood sampling for food allergies, any merit at all?

Julie Innes — Wed, 10 Nov 2021 13:56:06 GMT

I thought blood tests for environmental allergies could potentially be useful, but for food allergies were fairly useless. Anything we have sent to dermatologists have been immediately put on food trials, so I feel if they don't use the tests they probably aren't really worth doing.

Really surprised @beats not seeing food allergy dermatitis, though- we see a huge amount, especially since the arrival of the doodledoos/ cockapoos/ maltichons etc etc. Anything I see with itchy ears/ face less than 1 year old I immediately suspect food allergy.

They are a nightmare, though! Owners do NOT want a diagnosis that requires them to do anything, they want you to tell them, and you can't!! But I tell them if it IS a food allergy they will be back (moaning!) at me every 2-3 mths until something changes! It's amazing how many of these dogs I see back regularly for ears, then I meet them at the supermarket and realise I haven't seen them in ages "Oh, we changed his diet and his ears have been great since!" (Like I have been advising since 2015, but A Man Up The Park swears by X food, so they took his advice...) No matter, dog cured!

RE: Blood sampling for food allergies, any merit at all?

Neil Wheadon — Wed, 10 Nov 2021 08:43:56 GMT

[quote userid="5408" url="~/001/veterinary-clinical/small-animal/dermatology/f/discussions/30059/blood-sampling-for-food-allergies-any-merit-at-all/233876#233876"]is an 80% predictive value for the negatives, so if a food allergy has been established using an elimination diet then I suppose if the owner wants to spend £300[/quote]

So would it be a good starting point to select a specialist diet? My experience of feeding trials is that they are never complied with, people just don't seem to get the fact that nothing else can be fed.

There's also a suggestion that we should be considering insect based diets for animals (global warming) Would these diets be useful as a starting point as I don't expect many commercial diets have these in them.

Neil

RE: Blood sampling for food allergies, any merit at all?

David Bentley — Wed, 10 Nov 2021 08:20:44 GMT

I don't do blood allergy tests. Far too many false positives, but the is an 80% predictive value for the negatives, so if a food allergy has been established using an elimination diet then I suppose if the owner wants to spend £300, if they then want to do provocative testing to see what food is tolerated, a good starting point would be those neagtives.

RE: Blood sampling for food allergies, any merit at all?

Beats — Tue, 09 Nov 2021 21:12:35 GMT

My thoughts = I'm not interested any adverts of food allergy tests. It's a bit like flea allergy testing: it could only possibly make it harder for me to get the owner to do what I want them to do.

My further thoughts = food-induced skin allergy appears ridiculously rare in my experience. I thought for years I was just missing these cases, now I think no I am actually not seeing them.

When doing a food trial (usually for GI reasons, occasionally still for skin reasons), I use Royal Canin Anallergenic in an adult dog most of the time as my first choice and am very happy with it, rarely needing to go to a second choice. In a juvenile dog, I have a bit more bother, but tend to try a locally-sourced (nightmare these days) novel-protein/novel-carb diet.

For cats on the other hand, I recommend feed turkey/chicken/white fish only for a week to see if the GI signs resolve. If they do, then try introducing a selected cat food.

RE: Blood sampling for food allergies, any merit at all?

Julian Earl — Tue, 09 Nov 2021 20:50:13 GMT

That was/is my understanding as well. The alletrgic reaction ocCurs at the level of the intestinal mucosa , not systemically and exclusion-diets are the only way forward in my humble opinion!

Also the tinned prescriptio diets are unreliable due to the stabiisers and additives introduced n the tinning-proces!

HTH?