Dietary trials with a commercial chicken hydrolysate diet in 63 pruritic dogs

Protein hydrolysate and oil from fish waste reveal potential as dog food ingredients

The increased fish consumption by the growing human population in the world translates into an increase in fish waste. The reintroduction of these fish by-products into food and feed chains presents economic benefits and contributes to counteracting their negative environmental impact. Under this context, the present study aimed to evaluate the effects of the dietary inclusion of fish hydrolysate and oil obtained from fish waste (experimental diet) in substitution of shrimp hydrolysate and salmon oil (control diet) mainly imported from third countries on palatability, apparent total tract digestibility, fecal characteristics and metabolites, blood fatty acid profile, flatulence, and coat quality of adult dogs. A two-bowl test was performed to evaluate palatability by the pairwise comparison between the two diets. A feeding trial was conducted according to a crossover design with two diets (control and experimental diets), six adult Beagle dogs per diet, and two periods of 6 weeks each. The replacement of shrimp hydrolysate and salmon oil with fish hydrolysate and oil did not affect the first diet approach and taste, as well as the intake ratio. Generally, the digestibility of dry matter, nutrients, and energy was not affected by diet, but the intake of digestible crude protein (CP) and ether extract was higher, respectively, with the control and the experimental diet. The higher intake of eicosapentaenoic acid and docosahexaenoic acid with the experimental diet was reflected in a higher content of these long-chain polyunsaturated fatty acids and the omega-3 index of red blood cells, but it did not affect coat quality. The significantly higher intake of digestible CP with the control diet might have contributed to the higher fecal ammonia-N and valerate concentrations. Daily fecal output and characteristics were similar between diets. Overall, results suggest that fish hydrolysate and oil from the agrifood industry might constitute sustainable functional ingredients for dog feeding while adding value for wild fisheries, aquaculture, and fish farming under a circular economy approach and reducing dependence on imports from third countries with a high carbon footprint.

Establishment of clinical criteria for the diagnosis of adverse food reactions in dogs with atopic dermatitis

BACKGROUND

Diagnosis of canine adverse food reactions (AFRs) is based on vague criteria, such as '>50% improvement' during elimination diet trial (EDT) followed by 'deterioration' during provocation test (PT).

OBJECTIVE

The objective of the study was to use predefined criteria to evaluate response during EDT [i.e., Owner Global Assessment of Treatment Efficacy (OGATE) = good-to-excellent] and relapse during PT [i.e., Owner Global Assessment of Challenge Deterioration (OGACD) = moderate-to-severe and/or >100% increase of lesional (Canine Atopic Dermatitis Extent and Severity Index, 4th iteration, CADESI-04) and/or of pruritus (pruritus Visual Analog Scale, PVAS) scores].

ANIMALS

Twenty-nine dogs with atopic dermatitis.

MATERIALS AND METHODS

An extensively hydrolysed diet was fed to all dogs followed, in seven of 11 nonresponders, by a second home-made novel-protein EDT. Dogs responding to either EDT were challenged with their previous diet.

RESULTS

Thirteen (44.8%) dogs were diagnosed with AFRs: at the end of EDT, their OGATE was good (9 of 13; 69.2%) or excellent (four of 13; 30.8%), and both CADESI-04 (46.7%) and PVAS (71.1%) had decreased significantly; at the end of PT, OGACD was moderate or severe in 12 of 13 (92.3%) dogs, and both CADESI-04 (127.9%) and PVAS (181.8%) had increased significantly. Of the 16 dogs without AFRs, 6 (37.5%) responded to the commercial (n = 5) or home-made (n = 1) diet [OGATE = good (three of six) or excellent (three of six)], with significant concurrent reduction of CADESI-04 and nonsignificant reduction of PVAS, yet they did not relapse during PT.

CONCLUSIONS AND CLINICAL RELEVANCE

The proposed (predefined) criteria for the evaluation of response during EDT and deterioration during PT seem reliable and are easily applicable in clinical practice and research.

An open-label clinical trial to evaluate the efficacy of an elemental diet for the diagnosis of adverse food reactions in dogs

BACKGROUND

The diagnosis of cutaneous adverse food reactions (CAFR) in dogs is dependent on a diet trial and provocative challenge.

HYPOTHESIS/OBJECTIVES

To evaluate the efficacy of an elemental diet for the diagnosis of CAFR in dogs.

ANIMALS

Sixty-two client-owned nonseasonally pruritic dogs.

MATERIALS AND METHODS

A prospective, uncontrolled, observational elimination diet trial study. Dogs were fed a commercially available elemental canine diet (Pro Plan Veterinary Diets EL Elemental Canine Formula, Nestlé Purina PetCare Company) for up to eight weeks. Pruritus was assessed using a validated Visual Analog Scale (PVAS), lesions with the Canine Atopic Dermatitis and Severity Index, 4th iteration (CADESI-04) and gastrointestinal (GI) signs with a client questionnaire. All dogs were challenged with their previous diet for up to 14 days. Treats were added from Day (D)7 to D14.

RESULTS

Forty-five dogs completed the study. Eighteen (40%) of these were diagnosed with CAFR and 27 (60%) were diet-nonresponsive (NR). Dogs with CAFR flared on provocative challenges within 14 days. The smallest volume of previous diet that induced a CAFR flare was one teaspoon in two dogs (11.1%). The mean number of days leading to a provocation of clinical signs was 4.88 days. Gastrointestinal signs improved in both groups. Eight of the dogs with CAFR (44.4%) were subsequently maintained on the elemental diet alone.

CONCLUSION AND CLINICAL RELEVANCE

Pro Plan Veterinary Diets EL Elemental Canine Formula is efficacious for the diagnosis of canine CAFR. One teaspoon of the offending diet may induce clinical signs in some dogs with CAFR.

Detection of chicken DNA in commercial dog foods

BACKGROUND

These days the number of potential food allergens is very large, but chicken is one of the most common allergens in dogs. Elimination diet is one of the clinical tools for the diagnosis of allergies and allergy tests are not very reliable. The restriction diet is most commonly carried out by feeding pet foods, relying on the ingredients on the label to select an elimination diet not containing previously eaten foods. Unfortunately, mislabeling of pet food is quite common. The purpose of this study was to determine the absence or presence of chicken DNA using both qualitative and quantitative polymerase chain reaction (PCR) analysis methods in dry and wet maintenance complete pet foods for adult dogs. Results were used to verify the declared composition on the labels.

RESULTS

Eleven out of fifteen (73%) dog foods were produced as declared by the manufacturer, two of which showed the presence of chicken protein as stated on the label. The remaining nine foods contained amounts of chicken DNA below 1%, consistent with declarations that no chicken was added in the composition. Four of tested dog foods (27%) were not produced consistently with the declaration on the packaging. Two dog foods (one dry and one wet) did not contain the claimed chicken protein. In two foods the addition of chicken DNA was detected at the level of over 2% and almost 6%, respectively.

CONCLUSIONS

In this study, we focused on one of the most commonly undeclared animal species on the label-chicken protein-and performed DNA analyzes to investigate possible contamination and mislabeling. The results showed some inaccuracies. However, most of them are trace amounts below 1%, which proves compliance with the label. Our results showed that undeclared animal species can be as common as missing an animal protein declared on the label. The conducted research indicates that both dry and wet analyzed foods should not be recommended as a diagnostic tool in elimination tests, because it may result in false negative results. Over-the-counter maintenance foods for dogs should not be recommended for the diagnosis and treatment of food hypersensitivity.

A Descriptive Study on the Extent of Dietary Information Obtained during Consultations at a Veterinary Teaching Hospital

Simple Summary

The majority of dogs with chronic idiopathic gastrointestinal (GI) disease are diet-responsive. We retrospectively evaluated what dietary information was gained when dogs were presented with chronic GI signs to either our Gastroenterology (GE) (n = 243) or Internal Medicine (IM) (n = 239) Service between 10/2017 and 01/2020. Referral documents mentioned the previously fed diet in 53/131 (40%) GE and 14/112 (13%) IM referrals. No dog had received more than one diet trial from the referring veterinarian. Diet trials had been performed in 127/199 (64%) GE and 56/156 (36%) IM dogs prior to presenting to our teaching hospital. The diet fed at the time of consultation could be named by 106/199 (53%) GE and 40/156 (26%) IM dog owners. Data on response to subsequent newly prescribed diets were available from 86 GE dogs and 88 IM dogs. A positive response to diet was noted in 50/86 (58%) GE and 26/88 (30%) IM dogs. A further 23/35 (66%) GE dogs and 12/21 (57%) IM dogs responded positively to a second diet trial, and 4/9 GE dogs (44%) and 6/7 (86%) IM dogs responded positively to a third diet trial. In conclusion, obtainable dietary information was infrequent. Positive response is still possible after initial diet failures. Further studies are now needed to determine if collecting complete dietary information at the time of consultations could lead to an increased percentage of diet-responsive disease.

Abstract

The majority of dogs with chronic idiopathic gastrointestinal (GI) disease respond to diet. So far, no study has assessed how much dietary information is obtained during consultations. We retrospectively evaluated what dietary information was available from dogs presenting to our Gastroenterology (GE), and Internal Medicine (IM) Service between 10/2017 and 01/2020. Data from 243 dogs presenting for first GE consultations were compared to 239 dogs presenting with chronic GI signs for first IM consultations. Referrals comprised 131 (54%) GE dogs and 112 (47%) IM dogs. Referral documents specified the previously fed diet in 53/131 (40%) GE and 14/112 (13%) IM dogs. No dog had received more than one previous diet trial for chronic GI signs. Irrespective of referral status, diet trials had been performed in 127/199 (64%) GE, and 56/156 (36%) IM dogs. The specific diet fed at the time of consultation could only be named by 106/199 (53%) GE and 40/156 (26%) IM dog owners. Data on response to subsequent newly prescribed diets were available from 86 GE dogs and 88 IM dogs. A positive response to diet was noted in 50/86 (58%) GE and 26/88 (30%) IM dogs. A further 23/35 (66%) GE dogs and 12/21 (57%) IM dogs responded positively to a second diet trial, and 4/9 GE dogs (44%) and 6/7 (86%) IM dogs responded positively to a third diet trial. In conclusion, overall dietary information gained from referring veterinarians and owners was often incomplete. More dietary information could be gained during GE consultations compared to IM consultations for chronic GI signs. A positive response to diet can still be seen after two diet failures. Further studies will help to ascertain if the percentage of diet-responsive GI disease increases when more complete dietary information is obtained at the time of consultations.

Successful nutritional control of scratching and clinical signs associated with adverse food reaction: A randomized controlled COSCAD'18 adherent clinical trial in dogs in the United States

Background

Adverse reactions to food are a common dermatological condition in dogs, requiring nutritional intervention using a novel or hydrolysate protein‐based food.

Objective

To evaluate a therapeutic food containing egg and phytonutrients in dogs with food allergies using an activity monitor and core outcome set for canine atopic dermatitis (COSCAD'18) guidelines and in a controlled double‐masked, multicenter, prospective clinical trial.

Animals

Adult dogs with a history of adverse food reaction as diagnosed by a food elimination trial were recruited from general practices.

Methods

After a 21‐day baseline period, dogs were randomized to test or positive control (hydrolyzed protein) food for 21 days. Owner (pruritus visual analog score [PVAS], coat quality, food acceptance, and satisfaction) and veterinarian (canine atopic dermatitis lesion index [CADLI], physical examination) assessments were completed on days 0, 21, and 42. Dogs wore a collar‐mounted activity monitor to record scratching and shaking behavior throughout the study. Statistical analysis included within‐group comparison to baseline and between‐group comparison at study end using a significance threshold of alpha = 0.05.

Results

At the end of the treatment period, all results were similar between groups for CADLI, PVAS, owner satisfaction, activity, and questionnaire data. Scores for hair dullness, brittleness, amount of dandruff, feces quality, and food acceptance were positive and not statistically different between groups.

Conclusions and Clinical Importance

The therapeutic test food was well‐accepted and efficacious in managing signs of adverse reactions to food compared to baseline as well as compared to the positive control food.

Successful nutritional control of scratching and clinical signs associated with adverse food reaction: A randomized controlled COSCAD'18 adherent clinical trial in dogs in the United Kingdom

Background

Adverse reactions to food are a common dermatological condition in dogs, requiring nutritional intervention using novel or hydrolysate protein‐based foods.

Objective

To evaluate a therapeutic food containing egg and phytonutrients in dogs with food allergies using an activity monitor and core outcome set for canine atopic dermatitis (COSCAD'18) in a controlled double‐masked, multicenter, prospective clinical trial.

Animals

Adult dogs with a history of adverse food reaction as diagnosed by a food elimination trial were recruited from general practices.

Methods

After a 21‐day baseline period, dogs were randomized to test or positive control (hydrolyzed protein) food for 21 days. Owner (pruritus visual analog score [PVAS], coat quality, food acceptance, and satisfaction) and veterinarian (canine atopic dermatitis lesion index [CADLI], physical examination) assessments were completed on days 0, 21, and 42. Dogs wore a collar‐mounted activity monitor to record sleep, scratching, and shaking behavior throughout the study. Statistical analysis included within‐group comparison to baseline and between‐group comparison at study end using a significance threshold of alpha = 0.05.

Results

At the end of the treatment period, all results were similar between groups for CADLI, PVAS, owner satisfaction, activity, and questionnaire data. Scores for hair dullness, brittleness, amount of dandruff, feces quality, and food acceptance were positive and were not statistically different between groups.

Conclusions and Clinical Importance

The therapeutic test food was well‐accepted and efficacious in managing signs of adverse reactions to food compared to baseline as well as compared to the positive control food.

The usefulness of a hydrolysed fish and rice starch elimination diet for the diagnosis of adverse food reactions in cats: an open clinical trial

BACKGROUND

Diagnosis of adverse food reaction (AFR) is based on an eight week elimination diet (ED) and is confirmed by relapse upon re-challenge with the previously fed diet. Hydrolysed EDs are commonly used for this purpose.

OBJECTIVE

To evaluate the commercially available hydrolysed fish protein and rice starch ED Farmina UltraHypo (FUH) for the diagnosis of feline AFR.

ANIMALS

Thirty-two nonseasonally pruritic cats.

METHODS AND MATERIALS

Pruritus was assessed with a new dual Visual Analog Scale, lesions with the Scoring Feline Allergic Dermatitis scale and Quality of Life with a validated questionnaire on days 0 and 56. Short-acting corticosteroids or oclacitinib were permitted during the first six weeks. Cats showing 50% pruritus and/or lesional improvement were separately challenged with their prior diet, fish and rice. Cats not responding to the study diet were fed another hydrolysed diet for two months.

RESULTS

Twenty-five cats completed the ED: four dropped out due to vomiting and/or diarrhoea, one owing to low palatability and two were lost to follow-up. In 17 cats, pruritus improved by >50% and these underwent dietary challenges. Of these, nine reacted to their prior diet and/or fish and/or rice and were diagnosed with AFR, while eight did not relapse (and a diagnosis of AFR was considered to be doubtful). Of the eight cats in which pruritus did not improve, four underwent a second ED with no improvement.

CONCLUSION AND CLINICAL IMPORTANCE

FUH may be a useful ED for the diagnosis of feline AFR, even in cats reacting to fish or rice.

Food antigen-specific IgE in dogs with suspected food hypersensitivity

OBJECTIVE

Knowledge of cross-reactions in food-sensitive dogs will influence the choice of elimination diets and the long-term management of those patients. The objective of this study was to evaluate food allergen-specific IgE tests of suspected allergic dogs for concurrent positive reactions as possible evidence for cross reactions between allergens.

MATERIAL AND METHODS

Results of serum IgE tests from 760 suspected allergic dogs submitted to 2 laboratories were evaluated statistically. After the tested allergens were grouped by their phylogenetic relationship, odds ratios as well as a sensitivity analysis of the odds ratios were performed to evaluate if concurrent positive IgE results to 2 allergens occurred more often than expected.

RESULTS

Within related allergen pairs 27% (laboratory 1) and 72% (laboratory 2) of the pairs could be considered as associated. For the unrelated allergen pairs only 6.8% and 10.6% of the analyzed pairs were considered associated respectively. Strong correlations were shown in the group of ruminant allergens, especially beef and lamb, and grain allergens. High rates of concurrent reactions were also detected in the poultry group, especially between chicken and duck, as well as between pork and ruminant allergens, and soy and grain allergens.

CONCLUSION

As our results showed not only correlations within related but also between non-related allergens, the possible relevance of carbohydrate moieties as well as panallergens for canine hypersensitivities warrants further study. Further investigations are necessary to distinguish co-sensitization from cross-reactions and determine the clinical relevance of food-specific IgE reactivity.

CLINICAL RELEVANCE

Due to possible cross reactivity related allergens, especially beef and lamb as well as grain allergens, should not be used for an elimination diet to avoid false results.

Use of the Health Belief Model to identify factors associated with owner adherence to elimination diet trial recommendations in dogs

OBJECTIVE

To use the Health Belief Model to identify factors associated with owner adherence to elimination diet trial (EDT) recommendations by veterinarians for dogs with suspected cutaneous adverse food reactions (CAFRs).

SAMPLE

192 owners of dogs prescribed an EDT between April 1, 2012, and April 1, 2017.

PROCEDURES

Owners of dogs prescribed an EDT to diagnose CAFRs were identified through review of medical records from a single veterinary dermatology specialty practice. Identified owners were invited to participate in an anonymous online survey that was developed on the basis of the Health Belief Model. Multivariable logistic regression was used to evaluate associations between potential predictor variables and 100% adherence to EDT recommendations.

RESULTS

665 owners were invited to participate, and 192 (28.9%) completed the survey. Of the 192 respondents, 77 (40.1%) reported 100% adherence to EDT recommendations, and 115 (59.9%) reported < 100% adherence. Results indicated that the odds of owners reporting 100% adherence to EDT recommendations were significantly decreased by owner perception of barriers (adjusted OR [OR_a] = 0.86) and were significantly increased by owner knowledge regarding diets and CAFRs in dogs (OR_a = 1.30) and by self-efficacy or confidence in performing an EDT as directed (ORa = 1.18).

CONCLUSIONS AND CLINICAL RELEVANCE

Findings indicated that most prescribed EDTs were not followed strictly. Interventions to help owners reduce perceived barriers, increase self-efficacy, and improve related knowledge could improve adherence to EDT recommendations and, thereby, increase the diagnostic utility of EDTs.

Critically appraised topic on adverse food reactions of companion animals (9): time to flare of cutaneous signs after a dietary challenge in dogs and cats with food allergies

BACKGROUND

At this time, elimination diets followed by oral food challenges (OFCs) represent the "gold standard" for diagnosing skin-manifesting food allergies (FA) in dogs and cats. Regrettably, there is no clear consensus on how long one should wait for clinical signs to flare after an OFC before diagnosing or ruling-out a FA in a dog or a cat.

RESULTS

We searched two databases on October 23, 2019 to look for specific information on the time for a flare of clinical signs to occur during OFCs after elimination diets in dogs and cats with skin-manifesting FAs. Altogether, we reviewed the study results of nine papers that included 234 dogs and four articles containing data from 83 cats. As multiple OFCs could be done in the same patient and not all animals included were subjected to an OFC, we were able to compile 315 and 72 times to flare (TTF) after an OFC in dogs and cats, respectively. When regrouping all cases together, about 9% of dogs and 27% of cats exhibited a flare of clinical signs in the first day after an OFC; 21% of dogs and 29% of cats had such relapse by the end of the second day. The time needed for 50 and 90% of dogs to exhibit a deterioration of clinical signs (TTF50 and TTF90) was 5 and 14, respectively; in cats, these times were 4 and 7 days, respectively. By 14 days after an OFC, nearly all food-allergic patients from both species had had a relapse of clinical signs. These results are limited by the likely under-reporting of flares that occur on the first day immediately following an OFC, the time in which IgE-mediated acute allergic reactions typically develop.

CONCLUSION

Veterinary clinicians performing an OFC need to wait for 14 and 7 days for more than 90% of dogs and cats with a skin-manifesting FA to have a flare of clinical signs, respectively.

Serum IgE and IgG responses to dietary antigens in dogs with and without cutaneous adverse food reactions

BACKGROUND

It is suspected that many canine cutaneous adverse food reactions (CAFR) are true immunological hypersensitivities; however, few specific dietary allergens have been identified.

OBJECTIVE

To compare serum immunoglobulin (Ig)E and IgG reactivity to specific food antigens in privately owned dogs with and without CAFR.

ANIMALS

Eighteen adult dogs with nonseasonal pruritus recruited from a hospital population.

METHODS AND MATERIALS

Dogs were fed an extensively hydrolysed poultry-based diet exclusively for 12 weeks. Serum was collected at the beginning of the trial. Canine atopic dermatitis extent and severity index and pruritus Visual Analog Scale scoring were performed at the beginning and end of the trial. Immunoblotting was performed to identify IgE and/or IgG binding to specific proteins in beef, egg, milk, chicken, pork, soy and wheat extracts.

RESULTS

A CAFR (defined as an unequivocal relapse of pruritus after dietary challenge) was diagnosed in 10 dogs, with 60% relapsing when fed chicken-based diets. Binding of subjects' IgG to almost all proteins in all extracts was seen regardless of reported dietary history. Few proteins were exclusively or predominantly bound by IgE in CAFR dogs. Exceptions included a 42 kDa band (chicken), a 52 kDa band (beef), a 46 kDa band (beef and milk) and a poorly defined high molecular weight protein or proteins (beef and milk).

CONCLUSION

This study demonstrated three protein bands and a poorly defined band predominantly recognized by sera from dogs with CAFR relative to non-CAFR dog sera. Almost all proteins were bound by IgG in all dogs, suggesting prior exposure to unreported foods.

Critically appraised topic on adverse food reactions of companion animals (6): prevalence of noncutaneous manifestations of adverse food reactions in dogs and cats

BACKGROUND

Many reports describe the cutaneous signs of adverse food reactions (AFR) in the dog and cat. However, various non-cutaneous clinical signs are less well described. Our objective was to systematically evaluate these non-cutaneous signs of AFR in small animals.

RESULTS

We searched two databases (MEDLINE and Web of Science) for pertinent references on non-cutaneous signs of adverse food reactions. Among 117 and 764 articles found in the MEDLINE and Web of Science databases, respectively, we selected 47 articles that reported data related to non-cutaneous clinical signs of AFR. Gastrointestinal signs, symmetrical lupoid onychitis, conjunctivitis, sneezing, and anaphylaxis were reported to be associated with AFR in dogs and gastrointestinal and respiratory signs, conjunctivitis, and hyperactive behaviour in cats. In Border terriers with paroxysmal gluten-sensitive dyskinesia, an underlying AFR should be considered. Of these clinical signs diarrhoea and frequent defecation were most frequently reported to be diet-responsive in dogs; in the cat, these were vomiting and diarrhoea.

CONCLUSIONS

An elimination diet should be considered early in the work-up of dogs and cats with chronic vomiting and diarrhoea. Other non-cutaneous signs occur less commonly because of AFRs.

Cross-contamination in canine and feline dietetic limited-antigen wet diets

Background

Adverse food reactions (AFRs) are defined as abnormal responses to an ingested food or food additive. Diagnosis and treatment of AFRs consist of the complete elimination of these ingredients in the dietary trial. Previous studies have demonstrated the presence of undeclared ingredients in commercial limited-antigen dry food diets that can compromise the results and efficacy of dietary elimination trails. The aim of this study was to assess a selection of commercial canine and feline dietetic limited-antigen wet foods for the potential cross-contamination of animal proteins from origins not mentioned on the label.

Results

Eleven canine and feline dietetic limited-antigen wet foods (9 novel animal protein foods, 1 vegetarian and 1 hydrolyzed) were analyzed by polymerase chain reaction (PCR) to detect the presence DNA of animal and vegetal origins. PCR analysis confirmed the contamination of 6 of the 11 (54.5%) limited-antigen wet diets with undeclared animal protein. One of these 6 diets was solely composed of animal protein sources completely unrelated to those declared on the label. None of the foods containing horse meat or fish were contaminated, and neither were the vegetarian or the hydrolyzed food products. Moreover, the results show that had zoological class primers only been used to check for cross-class contaminations, as are generally used in the pet food industry for in-house checks, the apparent contamination rate would have been significantly underestimated: less than 20% (3/11), instead of the actual rate of 54.7% using species-specific primers.

Conclusion

This study reveals a high rate of cross-contamination in dietetic limited-antigen wet canine and feline foods, as previously described for dietetic dry limited-antigen foods (reported to be more than 80%). These results add new fuel to the discussion about the potential causes underlying the failure of elimination diets, since animal protein contaminants may actually be present in the commercial dietetic limited-antigen diets. AFRs may therefore occur as a result of inadequate practices in the pet food industry.

An open label clinical trial to evaluate the utility of a hydrolysed fish and rice starch elimination diet for the diagnosis of adverse food reactions in dogs

BACKGROUND

The diagnosis of adverse food reaction (AFR) is based on an eight week elimination diet (ED) and is confirmed by relapse upon re-challenge with the previously fed diet. Hydrolysed EDs are commonly used for this purpose.

OBJECTIVE

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

ANIMALS

Fifty nonseasonally pruritic dogs.

METHODS AND MATERIALS

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. Antimicrobial treatments were permitted during the first four weeks, and corticosteroids and oclacitinib during the first six weeks. Dogs showing at least 50% pruritus improvement were separately challenged with their prior diet, fish and rice.

RESULTS

Thirty eight dogs completed the ED, four were dropped out due to worsening clinical signs, three to low palatability and five were lost to follow-up. 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 diet seemed to be a useful ED for the diagnosis of AFR, even in dogs allergic to fish or rice.

Comparing immediate-type food allergy in humans and companion animals-revealing unmet needs

Adverse food reactions occur in human as well as veterinary patients. Systematic comparison may lead to improved recommendations for prevention and treatment in both. In this position paper, we summarize the current knowledge on immediate-type food allergy vs other food adverse reactions in companion animals, and compare this to the human situation. While the prevalence of food allergy in humans has been well studied for some allergens, this remains to be investigated for animal patients, where owner-reported as well as veterinarian-diagnosed food adverse reactions are on the increase. The characteristics of the disease in humans vs dogs, cats, and horses are most often caused by similar, but sometimes species-dependent different pathophysiological mechanisms, prompting the specific clinical symptoms, diagnoses, and treatments. Furthermore, little is known about the allergen molecules causative for type I food allergy in animals, which, like in human patients, could represent predictive biomarkers for risk evaluation. The definite diagnosis of food allergy relies-as in humans-on elimination diet and provocation tests. Besides allergen avoidance in daily practice, novel treatment options and tolerization strategies are underway. Taken together, numerous knowledge gaps were identified in veterinary food allergy, which need to be filled by systematic comparative studies.

Evaluation of canine adverse food reactions by patch testing with single proteins, single carbohydrates and commercial foods

BACKGROUND

Adverse food reaction (AFR) is an important differential diagnosis for the pruritic dog. It is usually diagnosed by feeding an elimination diet with a novel protein and carbohydrate source for eight weeks followed by subsequent food provocation. A previous study demonstrated that patch testing dogs with foods had a high sensitivity and negative predictability for selection of elimination diet ingredients.

HYPOTHESIS/OBJECTIVES

The aim of this study was to investigate patch testing with proteins, carbohydrates and dry commercial dog food in dogs to determine whether there was value in patch testing to aid the diagnosis of canine adverse food reaction.

METHODS

Twenty five privately owned dogs, with confirmed AFR, underwent provocation trials with selected food antigens and patch testing.

RESULTS

For proteins, carbohydrates and dry dog food the sensitivity of patch testing was 100%, 70% and 22.2%, respectively; the negative predictive values of patch testing were 100%, 79% and 72%. The positive predictive values of patch testing for proteins and carbohydrates were 75% and 74%, respectively.

CONCLUSION AND CLINICAL IMPORTANCE

This study confirmed that patch testing may be useful for the selection of a suitable protein source for an elimination diet in dogs with suspected AFR, but not as a diagnostic tool for canine AFR. Results for proteins are more reliable than for carbohydrates and the majority of positive patch test reactions were observed with raw protein. Patch testing with commercial dog food does not seem to be useful.

Critically appraised topic on adverse food reactions of companion animals (3): prevalence of cutaneous adverse food reactions in dogs and cats

BACKGROUND

The prevalence of cutaneous adverse food reactions (CAFRs) in dogs and cats is not precisely known. This imprecision is likely due to the various populations that had been studied. Our objectives were to systematically review the literature to determine the prevalence of CAFRs among dogs and cats with pruritus and skin diseases.

RESULTS

We searched two databases for pertinent references on August 18, 2016. Among 490 and 220 articles respectively found in the Web of Science (Science Citation Index Expanded) and CAB Abstract databases, we selected 22 and nine articles that reported data usable for CAFR prevalence determination in dogs and cats, respectively. The prevalence of CAFR in dogs and cats was found to vary depending upon the type of diagnoses made. Among dogs presented to their veterinarian for any diagnosis, the prevalence was 1 to 2% and among those with skin diseases, it ranged between 0 and 24%. The range of CAFR prevalence was similar in dogs with pruritus (9 to 40%), those with any type of allergic skin disease (8 to 62%) and in dogs diagnosed with atopic dermatitis (9 to 50%). In cats presented to a university hospital, the prevalence of CAFR was less than 1% (0.2%), while it was fairly homogeneous in cats with skin diseases (range: 3 to 6%), but higher in cats with pruritus (12 to 21%) than in cats with allergic skin disease (5 to 13%).

CONCLUSIONS

Among dogs and cats with pruritus and those suspected of allergic skin disease, the prevalence of CAFR is high enough to justify this syndrome to be ruled-out with a restriction (elimination)-provocation dietary trial. This must especially be considered in companion animals with nonseasonal pruritus or signs of allergic dermatitis.

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

BACKGROUND

Hydrolysed protein diets are used to diagnose and treat dogs with cutaneous adverse food reactions (CAFR). Little is known about what proportion of dogs hypersensitive to the native protein would react to its hydrolysed form.

OBJECTIVES

To determine the clinical allergenicity of hydrolysed poultry feather (RCU) and chicken liver diets (HZD) in dogs with chicken induced CAFR.

METHODS

In this randomized, double-blinded, crossover trial, ten dogs with chicken induced CAFR were selected after a positive oral challenge to chicken meat and a negative one to corn. Test diets were fed for 14 days separated by a 14 day wash-out period. Owners rated pruritus daily with a Visual Analog Scale (PVAS). The challenge was ended if a flare in pruritus occurred (i.e. PVAS ≥5/10).

RESULTS

The median PVAS scores before feeding RCU and HZD were 0.9 and 1.7, respectively (Wilcoxon signed rank test, P = 0.46). Pruritus scores increased significantly after feeding HZD (Friedman's test, P < 0.001) but not after feeding RCU (P = 0.895). None of the dogs fed RCU, but four dogs fed HZD (40%), were withdrawn after a flare in pruritus developed (Fisher's test, P = 0.04). The maximal PVAS score was significantly higher after HZD (median: 4.7) compared to RCU (2.5) (Wilcoxon signed rank test, P = 0.01). One dog in each group was withdrawn due to diarrhoea.

CONCLUSIONS

The hydrolysed poultry feather diet did not induce pruritus flares in dogs allergic to chicken in contrast to the hydrolysed chicken liver diet that led to pruritus flares in 40% of these dogs.

Owner assessment of pruritus and gastrointestinal signs in apparently healthy dogs with no history of cutaneous or noncutaneous disease

BACKGROUND

Determining the cause of pruritus relies on establishing the pattern of abnormal pruritus. The presence of gastrointestinal (GI) disease has also been helpful in determining the cause of pruritus. No study has systematically evaluated typical GI signs and pruritic behaviours in apparently healthy dogs.

HYPOTHESIS/OBJECTIVES

To evaluate owners' perceptions of pruritus and GI signs in apparently healthy dogs, and determine if age, breed, activity, diet or supplements affected these signs.

ANIMALS

Three hundred and fourteen apparently healthy dogs ≥ 12 months old with an unremarkable physical examination and no history of pruritus, otitis, skin/hair disease, metabolic or GI disease were enrolled.

METHODS

Thirty one veterinarians enrolled dogs after establishing their pruritus visual analog scale (PVAS) score and faecal consistency score (FCS); owners completed a comprehensive online survey regarding GI signs, possible pruritic behaviours, ear cleaning and sneezing.

RESULTS

A PVAS score of ≤ 1.9 was recorded in 87.6% of dogs and the FCS was 2-3 in 94.9% of dogs. PVAS was positively correlated with paw licking/chewing, facial/muzzle rubbing, head shaking and sneezing. Scooting was positively correlated with sneezing. Over 96% of dogs had 1-3 bowel movements (BM) per day. Age was positively correlated with facial/muzzle rubbing, sneezing, coprophagia and borborygmi. The number of walks/day was positively correlated with paw licking/chewing, head shaking, sneezing, number of BM/day, coprophagia, belching, flatulence and borborygmi.

CONCLUSION AND CLINICAL IMPORTANCE

A standard method of asking relevant questions was developed and the frequency of GI signs and many behaviours that may indicate pruritus in apparently healthy dogs was established.

Food-specific serum IgE and IgG reactivity in dogs with and without skin disease: lack of correlation between laboratories

BACKGROUND

Despite conflicting data on their utility and no reports on interlaboratory reproducibility, serum food-specific antibodies are commonly assayed in first-opinion canine practice.

HYPOTHESIS/OBJECTIVES

To determine both the variability of test results between two laboratories and the frequencies and magnitudes of food reactivity in dogs of different disease status.

ANIMALS

Sera were obtained from eight dogs with cutaneous adverse food reaction (Group A), 22 with nonfood-induced atopic dermatitis (Group B), 30 with an allergic/inflammatory phenotype (Group C), 12 with miscellaneous skin diseases (Group D) and nine healthy dogs (Group E).

METHODS

Paired sera were submitted to two laboratories (A and B) for assays of food-specific IgE and IgG antibodies.

RESULTS

Numbers of positive IgE and IgG tests determined by each laboratory in Groups A, B, D and E were comparable (Group C not included). Significant differences in the magnitude of IgE reactivity between groups for each allergen were seen only for lamb (Laboratory A, P = 0.003); lamb reactivity in Group D exceeded Group E (P = 0.004) but was comparable between all other groups. Agreement (kappa statistic) between the two laboratories' tests was 'moderate' for one antigen (potato IgE), 'fair' for four (corn IgE, rice IgE and IgG and soya bean IgG), 'slight' for eight (six IgE and two IgG) and 'less than chance' for the remaining six antigens (three IgE and three IgG).

CONCLUSIONS AND CLINICAL IMPORTANCE

These laboratories' tests appear to have dubious predictive clinical utility because they neither correlate nor distinguish between dogs of different disease status.

Perianal pruritus in dogs with skin disease

BACKGROUND

Perianal pruritus has been reported in dogs with anal sac disease but not in healthy dogs. Some authors describe it as typical of allergy, but there is little evidence in support of this.

HYPOTHESIS/OBJECTIVES

The aim was to investigate the association between perianal pruritus and canine atopic dermatitis (CAD), adverse food reaction (ARF) and other skin diseases in dogs.

ANIMALS

Two hundred and fifty privately owned dogs with skin disease and without anal sac disease.

METHODS

The presence or absence of perianal pruritus, macroscopic and cytological evaluation of the perianal skin surface and the macroscopic appearance of anal sac contents were assessed. Chi-square and Fisher's exact tests were performed to compare the frequency of perianal pruritus with the clinical diagnoses and with clinical and cytological parameters.

RESULTS

Perianal pruritus was seen in 39 of 75 dogs with CAD, in 29 of 57 dogs with ARF and in only 24 of 118 dogs with other conditions. The frequency of perianal pruritus in dogs with CAD and/or ARF was significantly higher than that in dogs with other diagnoses (P < 0.0001). No other disease was significantly associated with perianal pruritus. Perianal pruritus was significantly associated with signs of perianal alopecia, erythema, excoriations, lichenification and hyperpigmentation; it was not associated with the presence of bacteria or yeasts or with anal sac impaction.

CONCLUSIONS AND CLINICAL IMPORTANCE

Perianal pruritus was seen more frequently in dogs with AFR/CAD than with other dermatological diseases. This is the first study to evaluate perianal pruritus in dogs with skin disease and without anal sac disease.

Identification of undeclared sources of animal origin in canine dry foods used in dietary elimination trials

Failure to respond to commercial limited antigen diets can occur in dogs kept on a dietary trial for the diagnosis of adverse food reaction (AFR). The aim of this study was to assess twelve canine dry limited antigen diets (eleven novel protein diets and one hydrolysed diet) for potential contamination by ingredients of animal origin not mentioned on the label. The validity of the two methods adopted for the detection of such food antigens was also evaluated. Each dietary product was analysed by microscopy analysis using the official method described in Commission Regulation EC 152/2009 with the aim of identifying bone fragments of different zoological classes (mammalian, avian and fish) and by polymerase chain reaction (PCR) for the identification of DNA of animal origin. Discrepancies between the results obtained by PCR and/or microscopy analysis and the ingredients listed on pet food packages were found. Only in two pet foods did the results of both analyses match the ingredients listed on the label. In the remaining ten samples, microscopy detected bone fragments from one or two unpredicted zoological classes, revealing avian fragments in six of ten samples followed by those of fish in five of ten and mammalian fragments in four of ten. In two samples, microscopy analysis identified a contamination that would have otherwise passed unobserved if only PCR had been used. However, PCR confirmed the presence of all the zoological classes detected by microscopy and also identified the DNA of an additional unexpected zoological class in two samples. Dogs might fail to respond to commercial limited antigen diets because such diets are contaminated with potential allergens. Both PCR and microscopy analysis are required to guarantee the absence of undeclared animal sources in pet foods. Before ruling out AFR, a novel protein home-made diet should be considered if the dog is unresponsive to a commercial regimen.

A randomized, open-label, positively-controlled field trial of a hydrolyzed protein diet in dogs with chronic small bowel enteropathy

BACKGROUND

Hydrolyzed protein diets are commonly used to manage canine chronic enteropathies (CE), but their efficacy has not yet been critically evaluated.

HYPOTHESIS

A hydrolyzed protein diet is superior to that of a highly digestible (control) diet in the management of CE in dogs.

ANIMALS

Twenty-six dogs (18 test diet, 8 control diet) referred for investigation and management of naturally occurring chronic small intestinal disease.

METHODS

Randomized, open-label, positively controlled trial. After a full diagnostic investigation, which included endoscopy, dogs were assigned either to the test diet or control diet on a 2:1 basis (test:control). Cases were re-evaluated 3 times (at approximately 3, 6-12 months, and 3 years). Outcome measures included response of clinical signs (complete, partial, none), change in severity of signs (based upon clinical disease activity index; canine inflammatory bowel disease activity index [CIBDAI]), change in body weight, and need for other therapy.

RESULTS

There were no significant differences in baseline characteristics (eg, signalment, body weight, and duration of clinical signs), and histopathologic severity between test and control diet groups. However, despite randomization, CIBDAI was significantly higher in the test diet group (P=.013). Most dogs had responded by first evaluation, with no difference between groups (P=.87). However, significantly more dogs on the test diet remained asymptomatic at both the second (P=.0012) and third (P<.001) re-evaluation, and the decrease in CIBDAI was significantly greater (P=.010).

CONCLUSIONS AND CLINICAL IMPORTANCE

A hydrolyzed protein diet can be highly effective for long-term management of canine chronic small bowel enteropathy.

Clinical efficacy of a novel elimination diet composed of a mixture of amino acids and potatoes in dogs with non-seasonal pruritic dermatitis

There has been a need for improvement of the elimination diet used for diagnosis of adverse food reaction (AFR) in dogs. Recently, a novel elimination diet composed of a mixture of amino acids and potatoes was developed. We evaluated the efficacy of the elimination diet for diagnosis of AFR in dogs. Twenty dogs that were suspected to have allergic dermatitis were enrolled in a 2-month food elimination trial using the diet. Before and after the trial, the clinical symptoms were evaluated based on the change in canine atopic dermatitis extent and severity index (CADESI), pruritus score and medication score. Of the 20 dogs, 15 completed the food elimination trial. The remaining 5 dogs were removed from the trial because of diet unpalatability, skin disease progression or diarrhea. On the basis of evaluation of the clinical scores, we observed that the clinical symptoms improved in 11 of the 15 dogs that completed the food elimination trial. Provocative challenge was performed in 10 of the 11 dogs that showed improvement in their clinical symptoms. Of the 10 dogs, 7 were diagnosed as having AFR against food ingredients such as pork, beef, chicken and wheat because their skin symptoms reappeared after intake of these ingredients. The results of the food elimination trial and the provocative challenge indicated the usefulness of the novel elimination diet for diagnosis of AFR.

A systematic review of the evidence of reduced allergenicity and clinical benefit of food hydrolysates in dogs with cutaneous adverse food reactions

Several hydrolysate-based diets have been commercialized for helping diagnose or treat dogs with cutaneous adverse food reactions (CAFR). This systematic review was performed to examine the evidence in favour of reduced immunological and clinical allergenicity of hydrolysates in dogs with CAFR. Citation databases, meeting abstracts and article bibliographies were scanned for relevant citations, and companies were contacted to provide unpublished reports. Eleven studies relevant to this study were identified. Some evidence of reduced serum IgE binding to a soy hydrolysate (1 study) and decreased intradermal test reactivity to hydrolysed proteins (three studies) was found. In four reports, the feeding of dogs suspected of having CAFR with hydrolysate-based diets reduced or eliminated clinical signs in a variable proportion of subjects. The percentage of dogs with CAFR that still reacted to these hydrolysate-based diets could not be assessed, however. Importantly, up to 50% of dogs with CAFR enrolled in three controlled studies exhibited increases in clinical signs after ingesting partial hydrolysates derived from foods to which they were hypersensitive. In conclusion, the limited number of studies undertaken point to reduced - but not eliminated - immunological and clinical allergenicity of hydrolysate-based commercial diets. A variable proportion of dogs with CAFR will exhibit a worsening of clinical signs when fed partial hydrolysates. Clinicians must weigh the clinical benefit of these diets versus their high cost and low risk of reduced appetence or gastrointestinal sign development. At this time, hydrolysate-containing diets are probably best used in dogs suspected not to be hypersensitive to their individual components.

Development of an owner-assessed scale to measure the severity of pruritus in dogs

Assessment of pruritus is critical in dermatological history taking, both for initial diagnosis and for monitoring treatment. Various methods of assessing pruritus in the dog have been described but none have been validated. In this study, four different pruritus scales were initially assessed: a 0-5 numerical scale; a scale containing six categories of pruritic behaviours; a scale with six basic descriptors of severity; and a visual analogue scale with severity descriptions at either end. One hundred and sixteen owners were asked to grade their dog's pruritus with each of the four scales given to them in a randomized order, and asked which they thought was easiest to use, which was most accurate in assessing their dog's pruritus level, and which two scales they would combine to make a superior scale. Pruritus scores from different scales were highly correlated with each other, but scores were significantly higher with the severity and numerical scales compared to the behaviour scale. Based on the clients' responses, a new scale was developed that combined features of the behaviour and severity-based scales with the visual analogue scale. When tested on 166 different owners, 98% thought it was easy to use and accurate in assessing their dog's pruritus level. In 44 dogs, independent scores obtained by two owners were highly correlated (R = 0.8; P < 0.0001), confirming the scale's repeatability. The new scale proved to be an easy and repeatable method for owners to determine the severity of pruritus in their dog.

The effects of inulin supplementation of diets with or without hydrolysed protein sources on digestibility, faecal characteristics, haematology and immunoglobulins in dogs

Dogs with food allergy are often treated by giving a diet with hydrolysed protein sources. Prebiotics might also be successful in prevention and treatment of allergic disease through their effect on the colonic microflora, analogous to studies on probiotics in allergic children. The present study was set up to investigate the effect of supplementing inulin (IN) to commercial hypoallergenic dog diets on apparent nutrient digestibility, faecal characteristics, haematology and Ig in dogs. Supplementation of 3 % IN did not affect faecal pH, food and water intake and urine production. Compared with the intact protein diet with a limited number of ingredients (L), the diet with a hydrolysed protein source (H) resulted in an increased water intake (P<0·001), which could be due to the osmotic effect of free amino acids. Faeces production was increased by IN due to increased faecal moisture content. Increased faeces production on the H diet was mainly due to a higher DM excretion. Subsequently, the apparent digestibility coefficient (ADC) of DM was lower in the H diet group. A similar result was noted for ADC of diethyl ether extract and crude ash. The ADC of crude protein was higher in the H diet group, whereas IN decreased the ADC of crude protein. Differences in the ADC of crude protein among the different diets disappeared after correction for a higher faecal biomass, except for the dogs fed the L + IN diet. Total faecal IgA concentrations were lower in the H group (P<0·05) because of lower antigenic stimulation of hydrolysed protein, which implies that hydrolysed protein is really hypoallergenic. The present study indicates that the use of hydrolysed protein diets for canine food allergy treatment can affect digestibility and that combination with IN affected apparent protein digestibility but not IgA response.

A retrospective analysis of case series using home-prepared and chicken hydrolysate diets in the diagnosis of adverse food reactions in 181 pruritic dogs

The purpose of this retrospective study was to compare home-prepared and chicken hydrolysate diets in the diagnosis of canine adverse food reactions (AFR). Seventy-two dogs were fed home-prepared diets and 109 were fed hydrolysate. Owners chose the type of diet at presentation, and ingredients of home-prepared diets were selected depending on each dog's dietary history. Ectoparasitic infestations and microbial infections were treated during the trials. Cutaneous and gastrointestinal signs and pruritus scores were recorded before starting the diet, 6 weeks into the trials and after provocation with the original diets. AFR was diagnosed if pruritus resolved during the trial and recurred on dietary provocation. The dropout rate was lower for home-prepared diets although not statistically significant (18.1% home prepared; 24.7% hydrolysate, P=0.377). AFR alone was diagnosed in 10 dogs (17%) using home-prepared diets and in 15 (18.3%) fed the hydrolysate. Gastrointestinal problems were more frequent in dogs with AFR than in dogs without AFR (P=0.001). Another 11 dogs (18.6%) in the home-prepared diet group and 20 (24.4%) in the hydrolysate diet group had AFR concurrent with other pruritic diseases, mainly atopy. The similar frequencies of AFR diagnosis in the two groups (P=0.837 AFR; P=0.416 concurrent AFR) indicate that the chicken hydrolysate diet may be a valuable alternative to home-prepared diets in the diagnosis of canine AFR. Prospective cross-over studies are warranted to confirm these findings.

Hydrolyzed Protein Diets for Dogs and Cats

The primary aim of a hydrolyzed protein diet is to disrupt the proteins within the diet sufficiently to remove existing allergens. Published assessment of hydrolyzed protein diets includes physiochemical and immunologic assays as well as nutritional and clinical feeding trials. Potential problems include poor palatability, hypoosmotic diarrhea, and a reduced nutritional value, although persistent allergenicity is the most significant. The primary indications for a hydrolyzed protein diet are use in elimination trials for the diagnosis of adverse food reactions, and the initial management of inflammatory bowel disease. Initial studies of hydrolyzed diet efficacy are encouraging. Consideration of the source ingredients should be given when using hydrolyzed protein diets in elimination feeding trials because antigenic sites may not be fully destroyed.

Canine atopic dermatitis: validation of recorded diagnosis against practice records in 335 insured Swedish dogs

A cross-sectional study of insured Swedish dogs with a recorded diagnosis of canine atopic dermatitis (CAD) was performed. In order to validate the correctness of this specific diagnosis in the insurance database, medical records were requested by mail from the attending veterinarians. All dogs with a reimbursed claim for the disease during 2002 were included in the original study sample (n = 373). Medical records were available for 335 individuals (response rate: 89.8%). By scrutinizing the submitted records it was determined that all dogs had been treated for dermatologic disease, and that 327 (97.6%) could be considered to have some allergic skin disease. However, as information regarding dietary trial testing was missing in many dogs the number that were truly atopic could not be determined. The clinical presentation and nature of test diet for dogs with or without response to dietary trial testing was compared for a subset of 109 individuals that had undergone such testing. The only significant difference between these two groups was that the proportion of dogs with reported gastrointestinal signs was higher in the group that subsequently responded to a diet trial. In conclusion, the agreement between the recorded diagnosis in the insurance database and the clinical manifestations recorded in the submitted medical records was considered acceptable. The concern was raised that many attending veterinarians did not exclude cutaneous adverse food reactions before making the diagnosis of CAD.

Immunologic responses against hydrolyzed soy protein in dogs with experimentally induced soy hypersensitivity

OBJECTIVE

To assess whether dogs with experimentally induced type I hypersensitivity against soy protein would respond to soy hydrolysate and develop cutaneous or gastrointestinal tract reactions after intradermal and oral challenge exposure.

ANIMALS

12 naïve Beagle pups (9 sensitized and 3 control dogs).

PROCEDURE

9 dogs were sensitized against soy protein by administration of allergens during a 90-day period. After the sensitization period, serum concentrations of soy-specific IgE were determined and an intradermal test was performed to confirm the dogs were sensitized against soy protein. An intradermal challenge test and an oral challenge test with native and hydrolyzed soy protein were conducted on 6 sensitized and 2 control dogs.

RESULTS

High serum concentrations of soy-specific IgE and positive results for the intradermal test were observed for the 9 sensitized dogs after completion of the sesitization process. Sensitized dogs challenge exposed with hydrolyzed soy protein had a reduced inflammatory response after intradermal injection and no clinical response after an oral challenge exposure, compared with responses after intradermal and oral challenge exposure with native soy protein.

CONCLUSIONS AND CLINICAL RELEVANCE

Soy-sensitized dogs did not respond to oral administration of hydrolyzed soy protein. Thus, hydrolyzed soy protein may be useful in diets formulated for the management of dogs with adverse reactions to food.