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.

2023 AAHA Management of Allergic Skin Diseases in Dogs and Cats Guidelines.

These guidelines present a systematic approach to diagnosis, treatment, and management of allergic skin diseases in dogs and cats. The guidelines describe detailed diagnosis and treatment plans for flea allergy, food allergy, and atopy in dogs and for flea allergy, food allergy, and feline atopic skin syndrome in cats. Management of the allergic patient entails a multimodal approach with frequent and ongoing communication with the client. Obtaining a comprehensive history is crucial for diagnosis and treatment of allergic skin diseases, and the guidelines describe key questions to ask when presented with allergic canine and feline patients. Once a detailed history is obtained, a physical examination should be performed, a minimum dermatologic database collected, and treatment for secondary infection, ectoparasites, and pruritus (where indicated) initiated. The process of diagnosing and managing allergic skin disease can be prolonged and frustrating for clients. The guidelines offer recommendations and tips for client communication and when referral to a dermatologist should be considered, to improve client satisfaction and optimize patient outcomes.

Can pet exposure reduce childhood food allergies?

Georgina Mills discusses new research that explores the link between fetal and early childhood exposure to pets and the risk of developing a food allergy.

Food allergy in dogs and cats; current perspectives on etiology, diagnosis, and management.

Food allergy is a recognized clinical entity in dogs and cats and is an important differential to consider in the workup of a pruritic animal. Food can be a trigger factor for canine atopic dermatitis, and food allergy may coexist with feline atopic skin syndrome. Other clinical signs such as urticaria, recurrent pyoderma, and dorsolumbar pruritus can be seen in dogs, and urticaria, conjunctivitis, and respiratory signs can be seen in cats. In both species, gastrointestinal signs may be present. The pathogenesis in dogs and cats is complex and incompletely understood, which limits the development of reliable diagnostic laboratory tests. The diagnosis currently relies on an appropriately performed diet trial with subsequent provocation. This paper briefly reviews food allergies in people and explores our current knowledge of the disorder in dogs and cats.

Evaluation of the theoretical risk of cross-reactivity among recently identified food allergens for dogs.

BACKGROUND: There is increasing evidence of cross-reactivity between allergens of close or distant species. The A-RISC (Allergens'-Relative Identity, Similarity and Cross-reactivity) index helps evaluate the risk of theoretical cross-reactivity between proteins of the same family among different species. OBJECTIVES: To report the A-RISC indices for several food allergens of dogs between multiple food sources. MATERIALS AND METHODS: We selected several recently characterised food allergens for dogs from fish and chicken (ACTA1, ALDOA, CKM, ENO3, GAPDH, PKM and TPI1), fish (TPM1/2), beef/lamb (PGM1) and corn/potato (WAXY). When quality sequence data were available, A-RISC indices were calculated between multiple animal and plant species that can be used as food sources. For the TPM subunits, A-RISC indices also were calculated with the environmental allergens Bla g 4 and Der f 10, and the Toxocara canis nematode. RESULTS: The A-RISC indices suggest a substantial theoretical risk of cross-reactivity between species for all allergens considered. For TPM, this risk also extends to the environmental and nematode allergens. CONCLUSIONS AND CLINICAL RELEVANCE: There is a high theoretical risk of cross-reactivity between allergens of different species used as food sources. The clinical relevance of these elevated A-RISC indices should be studied further.

Co-fermented cow milk protein by Lactobacillus helveticus KLDS 1.8701 and Lactobacillus plantarum KLDS 1.0386 attenuates its allergic immune response in Balb/c mice.

Milk protein is one of the major food allergens. As an effective processing method, fermentation may reduce the potential allergenicity of allergens. This study aimed to evaluate the therapeutic potential of co-fermented milk protein using Lactobacillus helveticus KLDS 1.8701 and Lactobacillus plantarum KLDS 1.0386 in cow milk protein allergy (CMPA) management. This study determined the secondary and tertiary structures of the fermented versus unfermented proteins by Fourier-transform infrared spectroscopy and surface hydrophobicity to evaluate its conformational changes. Our results showed that different fermentation methods have significantly altered the conformational structures of the cow milk protein, especially the tertiary structure. Further, the potential allergenicity of the fermented cow milk protein was assessed in Balb/c mice, and mice treated with the unfermented milk and phosphate-buffered saline were used as a control. We observed a significant reduction in allergenicity via the results of the spleen index, serum total IgE, specific IgE, histamine, and mouse mast cell protease 1 in the mice treated with the co-fermented milk protein. In addition, we analyzed the cytokines and transcription factors expression levels of spleen and jejunum and confirmed that co-fermentation could effectively reduce the sensitization of cow milk protein by regulating the imbalance of T helper (Th1/Th2 and Treg/Th17). This study suggested that changes of conformational structure could reduce the potential sensitization of cow milk protein; thus, fermentation may be a promising strategy for developing a method of hypoallergenic dairy products.

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.

Combined prick and patch tests for diagnosis of food hypersensitivity in dogs with chronic pruritus.

BACKGROUND: Previous studies have shown that patch testing with food extracts can assist formulation of elimination diets (ED) in human patients with suspected adverse food reactions (AFR). Little is known about the use of these tests in dogs. OBJECTIVES: To evaluate the effectiveness of a combination of prick and patch testing in current protocols, and food challenge (FC) tests in dogs with AFR. METHODS AND MATERIALS: Prick and patch tests were performed on 21 dogs with chronic, nonseasonal pruritus. Dogs then were fed an ED formulated on the basis of the results. All dogs with improved clinical signs then were challenged with a food to which there had been a positive reaction in the tests. Six dogs subsequently were challenged with a food to which they had been negative on testing. Pruritus Visual Analog Scale (pVAS) and Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI-04) were evaluated on Day (D)0, D30 and D60 of the ED. Sensitivity (SE), specificity (SP), positive (PPV) and negative (NPV) predictive values, and the Kappa (κ)value were calculated. RESULTS: Of the 21 dogs, there was a significant mean improvement in pVAS and CADESI-04 scores in 16 (76%) dogs after D30 (P < 0.01) and D60 (P < 0.01) of the ED. There were no statistical differences between D30 and D60. The combination of tests had SE, SP, PPV, NPV and κ values of 80%, 66.7%, 66.7%, 80% and -0.17, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The combination of prick and patch testing reached high values of SE and NPV. A diagnosis of AFR was made in 76% of the dogs, and test results were useful for the selection of an ED.

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.

Grains on the brain: A survey of dog owner purchasing habits related to grain-free dry dog foods.

Grain-free pet food options abound in the pet food market today, representing more than 40% of available dry dog foods in the United States. There is currently a dearth of information about the factors that contribute to a dog owner's choice of a grain-free dry dog food and if those factors are similar among countries. Therefore, the primary objective of the current survey was to identify the variables that are predictive of a dog owner's choice of a grain-free dry food across North America (Canada and the United States) and Europe (France, the United Kingdom and Germany). The survey consisted of 69 questions, took less than 15 minutes to complete and was distributed virtually via Qualtrics (Qualtrics XM, Utah, USA). A total of 3,298 responses were collected, equally distributed between countries. Multinomial logistic regression was performed in SPSS Statistics (Version 26, IBM Corp, North Castle, New York, USA). Male respondents, people from France, people who ranked the importance of ingredients in a pet food in the lower quartiles and people who do not rotate their dog's diet to provide variety were less likely to select 'no grain' when choosing a pet food. In contrast, people who believe that their dog has a food allergy, follow more than 5 specific dietary routines in their own diet, do not try to include grains in their own diet, get their information about pet food from online resources or pet store staff and look for specific claims on pet food (such as 'no fillers'), were all more likely to select 'no grain' when choosing a pet food. This survey provides insight into the similarities and differences in decision making among dog owners in North America and Europe and should be considered when exploring the effects of grain-free dog foods on canine health and well-being.

Results of food challenge in dogs with cutaneous adverse food reactions.

BACKGROUND: Elimination diet trials and food challenge tests remain the gold standard for diagnosing cutaneous adverse food reaction (CAFR) in dogs. However, food challenge tests are difficult to perform owing to a lack of definite information on expected clinical signs and the time frame within which they develop after challenge. OBJECTIVES: To report the results of the food challenge test carried out in client-owned dogs under observation. METHODS AND MATERIALS: A retrospective evaluation of the medical records of dogs presenting with pruritus was performed. Skin infections and/or parasites were treated before inclusion in the study. Dogs that underwent an elimination diet with clinical improvement and relapse with food challenge tests were included in this study. A pruritus Visual Analog scale score was recorded as an index of pruritus before and at the end of the elimination diet trial before challenge. The onset of time to relapse of clinical signs and the body sites affected after food challenge testing were recorded by the owners. RESULTS: We examined the medical records of 310 dogs with pruritus. Of these, 46 dogs with a diagnosis of CAFR were enrolled in this study. Significant clinical improvement was observed after the elimination diet trial (P < 0.0001). All dogs exhibited pruritus, and none exhibited anaphylaxis after food challenge testing. Among these dogs, 60.9% developed pruritus within 12 h of food challenge. Notably, 23.9% of the dogs developed pruritus within 3-6 h. The limbs exhibited the highest frequency of pruritus (56.5%), followed by the face (26.1%). CONCLUSIONS AND CLINICAL RELEVANCE: This study is the first to report details of the time to onset of clinical signs and body site affected after food challenge testing in dogs. These results will assist veterinarians and dog owners in the decision-making process regarding food challenge testing.

Sensitivity and specificity of a shortened elimination diet protocol for the diagnosis of food-induced atopic dermatitis (FIAD).

BACKGROUND: The gold standard to diagnose food allergy in dogs is an eight week elimination diet trial (EDT) followed by a re-challenge. A recent study demonstrated that a shorter EDT is possible if prednisolone is administered initially. HYPOTHESIS/OBJECTIVES: The goal was to evaluate the sensitivity and specificity of the EDT based on the number of relapses after prednisolone discontinuation. In addition, the aim was to determine whether the initial treatment length or the replacement of prednisolone with oclacitinib would influence the outcome. ANIMALS: Eighty-seven dogs with atopic dermatitis. METHODS AND MATERIALS: Dogs were fed an elimination diet and treated with either prednisolone or oclacitinib for two to three weeks. Relapsing dogs were treated a second time. In the absence of a relapse after two weeks off medication, dogs then were challenged. Dogs never achieving two weeks off treatment without relapse received the regular EDT. RESULTS: Fifty-eight of 87 dogs completed the study. Thirty-nine of 58 dogs received prednisolone; 21 of these were diagnosed with FIAD and had no relapse (n = 14), one relapse (n = 6) or two relapses (n = 1). Nineteen of 58 dogs received oclacitinib; 11 of these were deemed food-allergic and had no relapse (n = 7) or two relapses (n = 4). The initial treatment duration did not influence the outcome. The threshold of one relapse or less for the diagnosis of FIAD was associated with a sensitivity of 95% for prednisolone and 63% for oclacitinib. The specificity was 100% for both drugs. CONCLUSION AND CLINICAL IMPORTANCE: Initial prednisolone or oclacitinib use in EDT shortens the time to diagnosis of FIAD.

Feline allergic diseases: introduction and proposed nomenclature.

BACKGROUND: Feline allergic diseases present as challenging problems for clinicians, not least because of the number of reaction patterns of the feline skin, none of which are specific for allergy. Furthermore, there is some controversy over the nomenclature that should be used in their description. OBJECTIVES: To review the literature, assess the status of knowledge of the topic and the extent to which these diseases could be categorized as atopic in nature, and make recommendations concerning nomenclature. METHODS: Atopic diseases in humans and cats were researched. A comparison then was made of the essential features in the two species. RESULTS: There were sufficient similarities between human atopic diseases and the manifestations of feline diseases of presumed allergic aetiology to justify the use of "atopic" to describe some of the feline conditions affecting the skin, respiratory and gastrointestinal tract. However, none of the allergic skin diseases showed features consistent with atopic dermatitis as described in man and the dog. CONCLUSIONS AND CLINICAL IMPORTANCE: The term "Feline Atopic Syndrome" (FAS) is proposed to encompass allergic diseases of the skin, gastrointestinal tract and respiratory tract, and "Feline atopic skin syndrome" (FASS) proposed to describe allergic skin disease associated with environmental allergies. We are not aware of any adverse food reactions in cats that are attributable to causes other than immunological reactions against the food itself. We therefore propose an aetiological definition of "Food Allergy" (FA) to describe such cases.

Clinical signs and diagnosis of feline atopic syndrome: detailed guidelines for a correct diagnosis.

BACKGROUND: Feline atopic syndrome (FAS) describes a spectrum of hypersensitivity disorders characterised by highly diverse clinical presentations including skin, gastrointestinal and respiratory systems. Among these disorders is feline atopic skin syndrome (FASS), in which hypersensitivity is typically associated with environmental allergens, although food allergy may coexist. Involvement of other organ systems (e.g. asthma) also may occur. Because of its highly heterogeneous clinical presentation, diagnosis of FASS can be challenging. OBJECTIVES: A subgroup of the International Committee on Allergic Diseases of Animals was tasked to summarise the most current information on the clinical presentations of FASS and to develop diagnostic guidelines. METHODS AND MATERIALS: Online citation databases and abstracts from international meetings were searched for publications related to feline allergic conditions. These were combined with expert opinion where necessary. RESULTS: A total of 107 publications relevant to this review were identified. Compilation of these data enabled development of a detailed description of the clinical features of FASS and development of guidelines focusing on systematic elimination of other skin conditions with similar clinical characteristics. As allergen tests are frequently used by dermatologists to support a clinical diagnosis of FASS, a brief review of these methodologies was also performed. CONCLUSIONS AND CLINICAL IMPORTANCE: In a similar way to atopic dermatitis in dogs, FASS is a clinical diagnosis based on the presence of compatible clinical signs and exclusion of other diseases with similar clinical features. Elimination or exclusion of fleas/flea allergy, other parasites, infections and food allergy is mandatory before reaching a diagnosis of FASS.

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.

IgE reactivity to fish allergens from Pacific cod (Gadus macrocephalus) in atopic dogs.

BACKGROUND: IgE reactivity to fish allergens in atopic dogs, which are used as models for food allergy, has not been elucidated to date. We investigated IgE reactivity to crude extracts and purified allergens derived from the Pacific cod (Gadus macrocephalus) in atopic dogs to identify the allergenic proteins of cod. RESULTS: The levels of specific IgE to crude cod extracts were measured in the sera of 179 atopic dogs, including 27 dogs with cod allergy, using enzyme-linked immunosorbent assay (ELISA). Specific IgE to crude cod extracts were present in 36 (20%) of the 179 atopic dogs and in 12 (44%) of the 27 dogs with cod allergy. The allergens in crude cod extracts were analyzed by ELISA, immunoblotting, and liquid chromatography-tandem mass spectrometry. In allergen component analysis, IgE reactivity to tropomyosin and enolase was observed in the sera of dogs with cod allergy. IgE reactivity to parvalbumin, collagen, and tropomyosin was evaluated using the sera of atopic dogs that tested positive for specific IgE to crude cod extracts. Among the 36 dogs with IgE reactivity to crude cod extracts, 9 (25%), 14 (39%), and 18 (50%) dogs tested positive for specific IgE to parvalbumin, collagen, and tropomyosin, respectively. CONCLUSIONS: The IgE reactivity to cod allergens observed in dogs was similar to that in humans, and this finding further supports the use of atopic dogs with fish allergy as a model for fish allergy in humans.

IgE sensitivity to Malassezia pachydermatis and mite allergens in dogs with atopic dermatitis.

In this study, dogs with atopic dermatitis were separated into non-food-induced atopic dermatitis (NFIAD) group (n = 15) and food-induced atopic dermatitis (FIAD) group (n = 37) based on an elimination diet test. IgE reactivity for crude Malassezia pachydermatis (M. pachydermatis) and house dust mites (HDM) allergen extracts was investigated in the two groups using fluorometric enzyme-linked immunosorbent assay (ELISA) and intradermal skin test (IDST). Nine (60%) of the 15 dogs in NFIAD group and 6 (16%) of the 37 dogs in FIAD group showed specific IgE for M. pachydermatis (Mann-Whitney U-test, P < 0.01). By immunoblotting analysis, the pooled serum samples from dogs with IgE for M. pachydermatis showed IgE reactivity for 50 kDa protein of M. pachydermatis. Twelve (80%) of the 15 dogs in NFIAD group and 8 (22%) of the 37 dogs in FIAD group showed specific IgE for HDM (Mann-Whitney U-test, P < 0.01). In addition, the dogs in NFIAD group significantly show a positive IDST to M. pachydermatis and HDM extracts compared with the dogs in FIAD group. The results suggest that dogs with NFIAD are at increased risk of becoming sensitized to the normal commensal organism M. pachydermatis compared with dogs with FIAD, perhaps co-sensitization occurred due to an HDM protease antigen's, Der f 1 and/or Der p 1, proteolytic activity related epidermal skin barrier defects. Treatment to limit skin colonization may thus be especially important in NFIAD.

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.