Dr Sandra Sargent DVM DACVD

www.pittvetderm.comEmail: info@pittvetderm.comPhone: (412) 366-3400

Introduction and definitions Pathogenesis of adverse food reactions Epidemiology Clinical Signs Diagnosis of adverse food reactions Treatment Long term management of animals with adverse food

reactions DCM and “grain free” diets

Skin and GI problems are two of the most commonpresenting complaints

Clinical signs cannot differentiate between atopicdermatitis and food allergy

Diarrhea has many causes, food responsive diarrheais a common cause

Much confusion and contrasting info aboutdiagnosis and management exists whether skinand/or GI issues

Food intolerance vsFood allergy - aka Foodhypersensitivity

Limited to non-immunologic GI disturbances (willnot involve the skin), such as nausea, loose stool or gas.

Causes of food intolerance can include:◦ Food poisoning from toxins in spoiled food◦ Sensitivity to food components (gluten)◦ Absence of an enzyme needed to fully digest a food

(lactase)◦ Irritable bowel syndrome or recurring stress, such

as diarrhea after boarding. Food intolerance can happen after first exposure to

the offending substance.

Abnormal immunologic response to a food antigen and can cause GI signs, dermatologic signs, or both.

Abnormal immunologic response has developed to what should be a safe protein.

Major food allergens (IN PEOPLE) are water-solubleglycoproteins ranging from 10,000 to 60,000 daltonsin size

It is subsequent exposure to the offending allergen that puts the animal over the edge and causes signs ranging from pruritus to vomiting and diarrhea.

Cutaneous signs most common

Adverse Food Reaction (AFR) Cutaneous Adverse Food Reaction (CAFR) Food-Induced Atopic Dermatitis (FIAD)◦ Patients with food hypersensitivity and clinical features

of atopic dermatitis Food associated hypersensitivity Non Food-Induced Atopic Dermatitis (NFIAD) Non-food, non-flea induced atopic dermatitis in cats

What are daltons?

Dalton is defined as 1/12th the mass of a carbonatom, and an average amino acid has a molecular weight (MW) of approximately 135 Daltons.

Average protein has 250 amino acids, soaverage protein has a MW of approximately 34 kDa

Why do we care when discussing food allergies?

Food allergens that elicit immune response are water soluble and heat, acid and protease stable glycoproteins with molecular weight of 10-60 KD. ◦ Considered to be mostly a IgE mediated type 1 reaction Sensitization phase Food antigens encountered by T cells lead to T helper

type 2 reaponse and upregulation of IL-4, IL-5 and IL-13 and class switching of ab prod to IgE

Effector phase Cells with surface Fc-e receptors (mast cells,basophils,

eosinophils)bind food specific IgE and on exposure to food antigens, release inflammatory mediators. Result is angioedema and urticaria

We don’t know if food allergens in dogs and cats range from 10-60 KD as in people

Food specific IgE has been demonstrated and was assumed to indicate clinically relevant type I hypersensitivity ◦ Many studies have failed to show reliable correlation between

serum IgE and clinical exposure to offending allergens ◦ IDT, gastric or colonscopic testing also unreliable ◦ Food induced urticarial and angioedema (as seen in people)

rarely reported ◦ Patch testing with food antigens dogs High negative predictability but positive rxns meaningless

Oral tolerance is the state of local and systemic immune unresponsiveness that is induced by oral administration of innocuous antigen such as food proteins.

Oral tolerance- breakdown may occur due to increasedintestinal permeability and dysbiosis Severe intestinal disease such as parvo, parasitism

could cause in animals

Oral tolerance to food protein O Pabst & A M Mowat, Mucosal Immunol Vol 5 pages232–239 (2012)

Protein allergens present in both animals andplants

In animals, serum albumin is the mostcommon allergenic protein◦ Serum albumin is heat labile◦ The reason it is possible to be allergic to raw or

under-cooked meat and not allergic to well-cookedmeat important point for clients wanting to feed raw

Common dietary allergens ◦ Most reported allergens are beef, dairy, wheat, lamb, eggs, soy and

chicken, not because these are inherently allergenic but because they are common in OTC pet foods.

◦ Dogs Beef, dairy, chicken and egg

◦ Cats Beef, fish, dairy and chicken

Most pets are allergic to animal proteins◦ Glycoproteins: 10-70 kDa ?◦ Gluten allergy is extremely RARE Irish Setter and NO cats

◦ Allergy to specific Grain is RARE

Usually a protein Carbohydrates on their own are poorly immunogenic. They

covalently attach to proteins to form glycoproteins.

The glycan portion of mammalian glycoproteins is generally not immunogenic and are common to most mammals

Therefore the mammal's own immune system develops tolerance to these carbohydrate moieties.

Conversely, non-mammalian glycoproteins that are dissimilar to the mammal's own glycoproteins, can induce the formation of IgG and sometimes IgE antibodies.

Literature supports the notion that carbohydrate epitopes, on their own, do not contribute significantly to the induction of allergic reactions.

They bind weakly to IgE antibodies and have been termed as cross reactive carbohydrate determinants. These epitopes cause confusion in in-vitro IgE testing through nonspecific cross-reactivity.

Coincident with the rising trends in food allergy prevalence in people, there has recently been reports of anaphylaxis induced by carbohydrate epitopes.

Two distinct groups of carbohydrate epitopes, each with unique characteristics and geographical distribution

◦ Anaphylaxis and acute allergic reactions related to the carbohydrate galactose-α-1,3-galactose (α-Gal) epitopethat are present in the monoclonal antibody, cetuximab and red meat have been described where tick bites have been found to be the primary sensitizer.

◦ Another carbohydrate inducing anaphylaxis is galacto-oligosaccharides in commercial milk formula which has been described in the several Asian populations including Singapore. The latter is unique in that the allergen is a pure carbohydrate.

Develops in adults w/o a history of foodallergies

Lone-star tick ingests the carbohydratefrom a mammalian non-primate

Upon biting a human,transfers carbohydrate

Classic late to delayedallergy symptomsdevelop to red meatsand pork

A single allergen may induce more than onesymptom, with more than one immune mechanism, atmore than one reaction time

◦ i.e. Chicken may induce immediate IgE pruritus,late phase IgG and IgE erythema and then delayedangioedema

◦ What about cooked vs raw chicken? See Abstract to follow

Goal was to compare the IgE reactivity with raw, cooked and/or processed meat, fish, milk and wheat.

Cooking reduced the IgE sensitization to meat from 45 to 19% and to fish from 81 to 40%.

Milk processing into cheese and yoghurt decreased this IgE sensitization from 65 to 31 and 13%

The processing of wheat into bread and pasta reduced this sensitization from 100 to 58 and 83%, respectively.

Although IgE sensitization does not equate to clinical allergy, our results suggest that feeding raw food might be more allergenic and should be avoided.

http://vetnutrition.tufts.edu/2016/01/important-information-you-could-be-misreading-on-the-pet-food-label/

http://vetnutrition.tufts.edu/2017/01/food-allergies/

http://vetnutrition.tufts.edu/2018/06/a-broken-heart-risk-of-heart-disease-in-boutique-or-grain-free-diets-and-exotic-ingredients/

https://www.wsava.org/nutrition-toolkit

Critically appraised topic on adverse foodreactions of companion animals

Ralf S.Mueller, Thierry Olivry & Pascal Prélaud Open Access 6 review papers Everything you always wanted to know about food

allergies but were afraid to ask….

Prevalence of AFRs in dogs and cats unclear Owners report very common but this is based on very

weak evidence Confirmation require detailed work up hindered by

poor client compliance Cats◦ 0.22-6% cats with cutaneous signs◦ 17-22% with GI signs

Dogs◦ 7.6-25% (both immunologic and non-immunologic◦ 50-60% chronic enteropathies respond to diet

Elimination-provocation dietary trials remain the standard of care to diagnose CAFRs in dogs and cats.

Currently no consensus on the duration of elimination diet trials that would permit the highest sensitivity of diagnosis of CAFR in companion animals.

Results: Best evidence available suggests that, by 5 weeks in dogs and 6 weeks in cats after starting an elimination diet, more than 80 % of patients had achieved a remission ofclinical signs of CAFR.

Increasing the diet trial duration to 8 weeks leads to a complete remission in more than 90 % of dogs and cats with CAFR.

Conclusions: For diagnosing CAFRs in more than 90 % ofdogs and cats, elimination diet trials should last at least 8 weeks.

Dogs◦ Age of onset: <1yr, > 6 yr, Any age really◦ Nonseasonal pruritus◦ Breed predispositions? GSD, WHWT,Pug,RR◦ % concurrent with AD?

Cats◦ Age of Onset: 4-5 years (3 mo-11 years) Nonseasonal pruritus % concurrent with AD?◦ Also possible for the effects of a food allergy to be low or below the

“itch threshold” and only observe flares of pruritus with the addition of environmental allergens during high pollen seasons.

Yep, clear as mud

No specific clinical signs, can’t differentiate from other allergic skin diseases

Peak incidence < 1 year Non seasonal pruritus +/- otitis Pruritus, erythema, secondary self trauma Otitis- 50%, may be only sign Ears and rears?

Pododermatitis- canine atopic dermatitis, cutaneous adverse food reaction, demodicosis, deep pyoderma

Follicular “cyst” rupture incites a persistent, immune-mediated, pyogranulomatous foreign body reaction to free keratin and hair liberated from the ruptured hair follicles

Repeated rupture of the follicular “cysts” results in fistulous tract formation, which drains into the dorsal interdigital space. The presence of this dorsal clinical lesion gives

the impression that the lesions originate thereThey are not actually cysts but furuncles

Urticaria Vasculitis Erythema multiformae Generalised erythroderma Nail disease Perianal fistulas Zinc-responsive dermatosis conjunctivitis

Perianal Fistulas/Furunculosis

Zinc Responsive Dermatosis and Food Allergy

Vomiting, abdominal discomfort, flatulence, frequent defecation, borborygmi

Concurrent GI and skin 6-44% of dogs Diarrhea and increased frequency most common Positive correlation with number of bowel movements and

pruritus

Breed predispositions◦ Irish setters- inherited hypersensitivity gliadin and

glutenin; reversible with gluten free diet

◦ Border terriers- Canine epileptoid cramping syndrome, responds to gluten free diet

◦ Soft coated Wheaten terriers- protein losing enteropathy caused by AFR

Incidence- 1-6% of dermatologic diseases No breed predisposition – Siamese? Age of onset- 3 months-11 years NONSEASONAL PRURITUS Concurrent skin and GI in 10-15%

Four Cutaneous Reaction patterns-◦ NONSPECIFIC- food, flea, atopic Self induced alopecia Miliary dermatitis Head and neck pruritus Eosinophilic plaques, granulomas, indolent ulcers

Do we really know anything about allergies in cats?????

Task for on Canine Atopic Dermatitis◦ Evidence supports re-evaluation of historic separation of

CAFR and AD◦ CAFR may manifest as AD in some patients◦ Food components may trigger flares in AD in those dogs

hypersensitive to such allergens ◦ Some dogs (and cats?) may have both environmental and

food triggers for their pruritus ◦ May appear to not respond to food trial or have only partial

response◦ Complicates diagnosis

History, History, History!◦ Lack of seasonality◦ Age of onset?◦ Variable or no response to anti-pruritic therapies◦ Ectoparasitism treated/ruled out

Clinical signs◦ Not just “ears and rears”◦ Cant really differentiate from AD based on clinical signs

What is the next step??

Resolve infections first 8 plus weeks of novel protein or

hydrolyzed diet Challenge with old diet, other proteins Reasons for lack of responseFailure to resolve infectionsLack of client compliance

WHY IS THIS SO HARD?

It cant be the food, I already changed their diet …10x

But I feed…….◦ grain free◦ natural◦ organic◦ food from the best company in the world◦ the pet store recommended it◦ it has the best reviews on Chewy, Whole Dog

Journal, Dogs Naturally magazine etc

Why do I have to do a prescription diet?◦ The companies that make the food vets recommend

are the devil◦ Vets get paid by those companies to recommend

those diets◦ Vets don’t know anything about nutrition◦ The lady at the pet store is an expert and

she said those foods willkill my dog◦ Those diets are

too expensive…..

Several studies in the past 10 years have used enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) tests on OTC pet food ingredients against label claims

Foods labeled to be soy-free and beef-free tested positive for both.

In another study, PCR or microscopy analysis, or both, identified discrepancies in the results compared with the ingredients listed on label. The ingredients listed on the label matched those found in testing in just two of the 12 diets. Cross-contamination is allowed within reason in pet food

manufacturing and is unavoidable even under good processing practices

L’Hocine L, Boye JI, Munyana C. Detection and quantification of soy allergens in food: study of two commercial enzyme-linked immunosorbent assays. J Food Sci2007;72:C145-C153.

Raditic DM, Remillard RL, Tater KC. ELISA testing for common food antigens in four dry dog foods used in dietary trials. J Anim Physiol Anim Nutr(Berl) 2011;95:90-97.

Ricci R, Granato A, Vascellari M, et al. Identification of undeclared sources of animal origin in canine dry foods used in dietary elimination trials. J Anim PhysiolAnim Nutr (Berl)2013;97 (suppl):32-38.

Please don’t just tell your clients just toeliminate beef and chicken or to feed an overthe counter limited ingredient diet in order torule out a food allergy

At least not without a good explanation ofwhy that won’t rule out a food allergy

When they come to see me, they are thenupset because “but my vet told me to feedxyz over the counter diet…. And I have toexplain why the trial needs repeated

SORRY BUT ELIMINATION DIETS ARE GOLD STANDARD

What about the tests for hair and saliva I can doonline or at the pet store ?

SORRY BUT ELIMINATION DIETS ARE GOLD STANDARD

Choose ingredients based on dietary history and use diets that only contain ingredients to which the animal has not been previously exposed

Easier said than done

Serum tests for food-specific IgE and IgG, intradermal testing with food antigens, lymphocyte proliferation tests, fecal food-specific IgE, patch, gastroscopic, and colonoscopic testing were evaluated.

Testing for serum food-specific IgE and IgG showed low repeatability and, in dogs, a highly variable accuracy. In cats, the accuracy of testing for food-specific IgE was low.

Negative patch test reactions have a very high negative predictability in dogs and could enable a choice of ingredients for the elimination diet in selected patients. The best diagnostic procedure to identify AFRs in small

animals remains an elimination diet with subsequent provocation trials.

Numerous tests purport to measure saliva or serum immunoglobulin levels specific to various foods for evaluation of adverse food reactions. No validation exists on their utility in diagnosing AFR.

Objective: To test dogs without historical or active clinical signs of eitherdermatological or gastrointestinal manifestations of AFR with two commonly used commercial serological assays (A and B) and one saliva assay (C).

We hypothesized that (1) assays would yield positive results despite lack of clinical disease and (2) positive results would correlate with prior food exposure.

Thorough medical and diet histories were obtained from 30 asymptomatic dogs

Fourteen foods common to all three assays were evaluated. Results were classified into positive or negative responses to each food. All 30 asymptomatic dogs had at least one positive response to a food. One or more dogs tested positive to 14/14 (100%), 12/14 (86%) and 14/14 (100%) foods in assays A, B and C, respectively.

There was no predictable concordance between positive responses and historical food exposure. The results suggest that serological and saliva test results do not correspond to clinical evidence of AFR and overdiagnosis of AFR is likely if these tests are used in lieu of a strict elimination diet trial.

Abstracts of the North American Veterinary Dermatology Forum 26–29 April 2017 Orlando, FL, USA

This study investigated the accuracy of a saliva-based testfor food-specific IgA and IgM and an ELISA serum test for food-specific IgE.

Group 1 (n = 11) included dogs with previously diagnosed and controlled AFR; group 2 (n = 15) comprised dogs with allergic dermatitis at the beginning of their ED; and group 3 (n = 16) was composed of clinically healthy research dogs.

Saliva samples were collected from all groups and blood samples from group 1 and group 3. The results of clinical re-challenges with individual food components were compared with the test results. Specificity, sensitivity, positive and negative predictive values and likelihood ratios were determined.

Forty-one dogs completed the study. There was a total of 163 re-challenges.

Sensitivity, positive predictive value and likelihood ratio, specificity, negative predictive value and likelihood ratios were unsatisfactory for both tests

No clear difference in the number of positive reactions between the allergic dogs and healthy dogs from a research population.

Based on these results, the saliva test for food specific IgA and IgM and the ELISA serum test for food specific IgE were not reliable to diagnose adverse food reactions in dogs.

Until more data are available, elimination diets remain the reference standard in the diagnosis of this disease.

How can I possibly only feed this diet for 2months?

I already tried a prescription diet from my vet- for 2weeks, then fluffy wouldn’t eat it

I couldn’t stand not giving treats It was Christmas My grandmother came to visit….

No diets are completely “hypoallergenic”’ Dogs and cats can be allergic to pretty much

any protein or carbohydrate ingredient that canbe found in pet food

No evidence that continually changing(rotating) diet ingredients prevents foodallergies, but it definitely can limit diet choicesto try to diagnose them

http://vetnutrition.tufts.edu/2017/01/food-allergies/

Step 1: Choose the trial diet

Step 2: Start the diet trial and treat infections

Step 3: Follow up by phone one week later

Step 4: Check patients progress with a recheck examafter 6 weeks

http://veterinarymedicine.dvm360.com/diagnosing-food-allergies-dogs-and-cats-bring-your-case-trial

Step 1 : Choose the trial diet◦ There is no foolproof, works-every-time test diet. ◦ Choosing the best diet to feed a suspected food-allergic

patient requires choosing a diet: 1) that consists of proteins the patient has not been

exposed to 2) that has minimal chance of cross reactions with

previously fed proteins some patients allergic to beef will cross-react or show

clinical signs when exposed to other ruminants, chicken may cross react with duck or turkey

3) that is palatable to the patient 4) that the owner is able and willing to feed. Giving a

treat option will improve compliance

www.serenegy.com

Royal Canin- Remember all RC limited ingredient diets contain hydrolyzed soy including the duck, venison and rabbit◦ Only ones that are really novel protein are

Canine Selected Protein Adult KO

Canine Selected Protein Adult PW

Hill’s D/D- salmon, venison, duck aren’t novel any more Purina DRM- Dermatologic Management Naturals is brewers rice,

trout and oat

Blue Buffalo Veterinary Diet – NVD NP- alligator

Rayne clinical nutrition- variety of novel proteins

REMEMBER some patients allergic to beef will cross-react or show clinical signs when exposed to other ruminants, chicken may cross react

with duck or turkey, etc

In humans, cross‐reactive clinical allergy has been reportedbetween three chicken and fish meat proteins: beta‐enolase, aldolase A and parvalbumin.

Objective: To evaluate if IgE cross‐reactivity betweenchicken and fish also existed in the dog using sera from dogs with suspected allergic skin disease and with IgEagainst chicken and fish.

Methods: Sera were analysed by ELISA andimmunoblotting with chicken, white fish (haddock and cod) and salmon extracts.

Results :Out of 53 archived canine sera tested by ELISA against chicken, white fish or salmon, 15 (28%), 12 (23%) and 26 (49%), respectively, had elevated IgEagainst one, two or all three of these extracts.

Mass spectrometry identified nine cross‐reactive proteins All of these have been reported previously as fish,

shellfish and/or chicken allergens for humans. Conclusions and clinical importance : Whether any of

these newly identified IgE cross‐reactive chicken–fish allergens is the cause of clinical allergy needs to be determined in dogs reacting to at least two of these

common food sources.

Purity of prescription diets

◦ Are the label claims accurate?◦ What are the major veterinary prescription diets doing to prove

this? ◦ What is the potential for meat protein cross-reactions?

Ruminants? Poultry? Fish?

Objective: to determine if: 1) four over-the-counter (OTC) dry dog foodscarrying a ‘made with no soy’ claim and 2) seven veterinary therapeutic dry dog foods designed for food elimination trials were suitable for a canine soybean elimination trial.

Method: A 100 gram sample of each test diet plus a soy positive and negative control diet were submitted for ELISA testing to an outside independent food laboratory. The ELISA test is quantitative for soy flour protein concentrations between 2.5 and 25 ppm. The positive control diet contained >25 ppm soy protein antigens and the negative control < 2.5 ppm soy.

Results: Three of the four OTC ‘no soy’ claiming diets were positive for soy antigen; two contained >25 ppm. Four veterinary therapeutic diets had less than the lower detectable limit of soy protein. Two veterinary therapeutichydrolyzed soy diets were positive (>2.5 ppm): one diet had a natural flavor (with a soy carrier) contained >25 ppm soy and the other diet contained 4.6 ppm with no soy ingredients listed.

Study done in 2011

Hydrolyzed diets◦ Remember talking about Daltons?◦ Is the average molecular weight small enough? Options – soy, chicken, salmon, feather

NVD HF- 2000 Daltons RC Ultamino - <1000 Daltons Royal Canin HP- < 10,000 Hill’s Z/D - < 3000 Purina HA: vegetarian- <11671 Purina HA: Chicken flavor- <11671

BLUE NVD HF*

Primary Protein Sources

salmon hydrolysate

Protein (g/100kcals) 7.19Primary Carbohydrate 

Sources) potatoesFat (g/100kcals) 3.69

Lifestage maintenance

** Purina also has HA with hydrolyzed chicken

A recent study in 10 dogs known to be allergic tochicken protein resulted in four of 10 dogs flaringwhen fed a hydrolyzed chicken-liver based diet, butnone of the dogs flared when fed a very finely hydrolyzed diet consisting of poultry feathers.

A randomized, double-blinded crossover trial testing the benefit of two hydrolysed poultry-based commercial diets for dogs with spontaneous pruritic chicken allergy.

Bizikova P Olivry T Vet Dermatol. 2016 Aug;27(4):289-e70

Recently a hydrolyzed salmon diet has been madecommercially available and provides another feedingoption. Additional clinical trials and field experienceare needed, but samples submitted by onedermatologist to an independent laboratory performingELISA testing found no trace of poultry, beef, pork,soy or dairy products.

Conflicting studies on the effectiveness of hydrolyzed diets◦ 10% to 40% of patients allergic to the basic protein continue

to show clinical signs on a hydrolyzed version of the same protein.

Commercial options include hydrolyzed soy, chicken, feathers and salmon.◦ None of these proteins are necessarily novel.◦ The degree of hydrolysis can vary◦ Presumably, the greater the hydrolysis and the smaller the

resulting protein or amino acid, the better the chance a food allergic patient will improve.

Best to try and choose a hydrolyzed diet to which the patient has had little or limited exposure to the parent protein.

Objectives: study the recognition of standard and variably hydrolyzed poultry extracts by sera from dogs and cats with elevated chicken-specific serum IgE.

Methods: Forty sera from dogs and 40 from cats with undetectable, low, medium or high serum levels of chicken specific IgE were tested by ELISA on plates coated with the positive controls chicken, duck and turkey meat extracts and the negative controls beef meat (dogs) or wheat (cats).

Plates were also coated with a non-hydrolyzed chicken meal, and mildly- or extensively-hydrolyzed poultry feather extracts.

Results: The frequencies of dogs with positive IgE against the various extracts were: chicken meat: 100%, duck and turkey meats: 97%, beef meat: 3%, non-hydrolyzed chicken meal: 73%, mildly-hydrolyzed poultry feathers: 37% and extensively-hydrolyzed poultry feathers: 0%. For cats, these respective percentages were (with wheat replacing beef as a negative control): 100, 84, 97, 7, 7, 0 and 0%.

ELISA done on plates coated with chicken, duck or turkey meats with or without inhibitors. ◦ The median inhibition percentages after incubation with the non-hydrolyzed

chicken meal were ~22%, with the mildly-hydrolyzed poultry feathers: 14–22%, and those with the extensively-hydrolyzed poultry feathers: 5 to 10%; the last inhibition level was similar to that of the beef meat negative control.

Conclusions: These results suggest that an extensive—but not partial—hydrolyzation of the poultry feather extract is necessary to prevent therecognition of allergenic epitopes by poultry-specific IgE

Objective :To evaluate a commercially available hydrolysed fish protein and rice starch ED for the diagnosis of AFR.

Methods: In Fifty nonseasonally pruritic dogs, Pruritus was assessed with a Visual Analog Scale, lesions with the Canine Atopic Dermatitis Lesions Index and quality of life with a validated questionnaire on days 0 and 56. Dogs showing at least 50% pruritus improvement were separately challenged with their prior diet, fish and rice.

Results: Thirty eight dogs completed the ED

In 24 dogs, pruritus improved by >50% and 22 underwent dietary challenges. Of these, 15 reacted to their prior diets and were diagnosed with AFR, whereas seven did not relapse (and a diagnosis of AFR was considered to be doubtful)

Five dogs reacted to fish and four to rice. Of the 14 dogs in which pruritus did not improve, some underwent a second ED and others were successfully treated for atopic dermatitis.

Conclusion and clinical importance: The hydrolysed fish and rice dietseemed to be a useful ED for the diagnosis of AFR, even in dogs

allergic to fish and rice

Step 2: Start trial and resolve infections

Food allergic dogs get same infections as atopic dogs If not resolved, will obscure response to food Don’t forget your minimum derm data base!◦ Scrapings for mites, cytology for infections, fungal culture

Treat infections for the first month◦ Antibiotics, antibacterial topical treatments◦ Look for yeast! When in doubt treat

Treat pruritus- ok to use apoquel or cytopoint, may help Its easy to figure out what helped after the fact if a correct trial is

done

Rule out scabies and fleas even if not present◦ Easy peasy- give a Bravecto at the start of the trial!

Don’t forget the flavored Heartgard/Interceptor Use Revolution or non flavored HG tabs

Don’t use flavored antibiotics What about flavored nutraceuticals, NSAIDS etc No protein containing supplements

A 2014 study examined whether there was soy, pork and beef antigens in flavored OTC products and medications.

Three OTC products and four veterinary therapeutics were tested using ELISA for the presence of soy, pork and beef antigens, in addition to positive and negative controls.

All the OTC products tested produced ELISA results in agreement with their ingredient lists, but the veterinary therapeutic products did not agree with ingredient lists or product inserts because of other ingredients that need not be listed.

Parr JM, Remillard RL. Common confounders of dietary elimination trials contain the antigens soy, pork, and beef. J Am Anim Hosp Assoc 2014;50:298-304.

Train your nurses to go through the details Have a good handout http://veterinaryteam.dvm360.com/client-handout-understanding-food-

allergy-dogs

Don’t just hand them a bag of food and send them outthe door!

It’s the small stuff that can screw it up◦ Nothing else can be fed- food supplements, flavored

medications, flavored chew toys, treats Step 3: Phone progress reports- need a cheerleader Step 4: RECHECK,RECHECK RECHECK

Explain what hydrolyzed means!◦ Client thinks its ok to feed chicken or fish when on

hydrolyzed diet using those proteins Doesn’t understand the concept that “nothing

else can pass their lips” Absolutely cannot comply with the no treat

rule- so give them some treat options!! Not asking clients how they give meds◦ No cheese, peanut butter, lunch meat, PILL

POCKETS etc Not giving them anything in writing

Owners fed the patient an appropriate test diet butcontinued to feed treats.

Small children at home dropped food that thepatient ate.

Unsupportive family members in the home gavethe patient non-elimination diet food because theydidn’t think it would make a difference.

The patient snuck a few bites from another dog’sfood bowl.

The patient received medication or supplementswith beef- or pork-based additives or flavoring.

What symptoms are we monitoring?◦ Pruritus◦ Erythema

What about?◦ Gastrointestinal◦ Recurrent superficial bacterial pyoderma◦ Malassezia dermatitis◦ Chronic otitis◦ Recurrent anal sacculitis

When infections are resolved, stop antibiotics After 4-6 weeks, try to stop apoquel, cytopoint if using Avoid challenging if too many other variables Winter in north east best time to challenge Remember food may just be another trigger so even partial

response important How to challenge?

If you want to prove that the pet is food allergic, pet must fed everything that he/she was receiving when most itchy, former diet as well as treats.

If he/she is food allergic, the itch should resume within 3-5 days of the dietary changes. If this occurs, he/she should go back on the prescription diet immediately until the itching resolves again.

If you want to determine specifically what the pet is allergic to, individual protein and carbohydrate sources such as chicken, eggs, beef, dairy, corn, wheat and soy can be fed at two week intervals to see what the trigger for the itching is.

Alternatively, many people choose to leave their pet on the prescription diet

Does not appear to be just an issue with grain-free diets. Suspected diets, “BEG” diets – boutique companies, exotic

ingredients or grain-free diets. The apparent link between BEG diets and DCM may be due to

ingredients used to replace grains in grain-free diets, such as lentils or chickpeas, but also may be due to other common ingredients commonly found in BEG diets, such as exotic meats, vegetables, and fruits.

Not all pet food manufacturers have the same level of nutritional expertise and quality control, and this variability could introduce potential issues with some products.

Exotic ingredients have different nutritional profiles and different digestibility than the typical ingredients that have been evaluated in numerous feeding trials

Most dogs being diagnosed with DCM do not have low taurine levels.

Some owners continue to feed a BEG diet butsupplement taurine thinking that this will reducetheir risk for heart disease.

More than 90% of Tufts patients with DCM inwhich taurine has been measured have normallevels (and the majority are eating BEG diets).

Some of these dogs with DCM and normal taurinelevels improve when their diets are changed.

Without Taurine deficiency◦ May be reversible with diet change with or without

diet supplementation◦ Possible causes Absolute deficiencies of other nutrients Altered bioavailability of certain nutrients due to

nutrient-nutrient interaction Inadvertent inclusion of cardiotoxic ingredients

Recommendation is to change the diet to onemade by well established manufacturer thatcontains standard ingredients and followsWSAVA guidelines

Twenty-three of 24 dogs diagnosed with taurine deficiency and dilated cardiomyopathy were fed diets that were either grain-free, legume-rich, or a combination of these factors. None of these diets were feeding trial tested using Association of American Feed Control Officials (AAFCO) procedures.

Twenty-three of 24 dogs had significant improvement in their echocardiographic parameters and normalization of taurine concentrations following diet change and taurine supplementation. Nine of 11 dogs diagnosed with congestive heart failure (CHF) had resolution of their congestion at follow-up with five no longer requiring diuretic therapy and four tolerating diuretic dose reduction by >50%.

Certain diets and diet characteristics were associated with the development of taurine deficiency. Taurine deficiency and dilated cardiomyopathy in golden retrievers is likely multifactorial, including a combination of dietary, metabolic, andgenetic factors

The group of 24 golden retrievers diagnosed with DCM and low taurine concentrations, were fed a total of nine different pet food brands (and a total of thirteen different varieties)

All diet labels included a complete and balanced claim substantiated by formulation to meet the AAFCO Dog Food Nutrient Profiles; none had undergone feeding trials for nutritional adequacy.

No baseline diets met the recommendations of the World Small Animal Veterinary Association (WSAVA) Global Nutrition Committee

15/24 dogs were fed diet 1, Acana Pork and Squash- Champion Pet Foods

Twelve of 13 diets were grain-free, and 10/13 diets contained legumes within the first five ingredients listed

What do you tell your clients?

https://www.wsava.org/Guidelines/Global-Nutrition-Guidelines

Journal of the American Veterinary Medical Association December 1, 2018, Vol. 253, No. 11, Pages 1390-1394

Diet-associated dilated cardiomyopathy in dogs: what do we know?Lisa M. Freeman DVM, PhD; Joshua A. Stern DVM, PhD; Ryan Fries DVM; Darcy B. Adin DVM; John E. Rush DVM, MS

https://ccah.vetmed.ucdavis.edu/sites/g/files/dgvnsk4586/files/local_resources/pdfs/ucd-diet-and-dcm-handout.pdf

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0209112

Taurine deficiency and dilated cardiomyopathy in golden retrievers fedcommercial diets

https://www.wsava.org/wsava/media/arpita-and-emma-editorial/selecting-the-best-food-for-your-pet.pdf

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