If your dog’s post-meal routine involves frantic grass-eating, audible tummy rumbles, or mysterious skin flare-ups, you already know how exhausting the trial-and-error cycle can be. “Sensitive stomach” and “sensitive skin” are more than marketing buzzwords—they’re daily realities that can derail everything from obedience class to couch cuddles. The good news: veterinary nutritionists have spent decades mapping the gut–skin axis, and therapeutic diets such as Hill’s Science Diet Sensitive Stomach & Skin have evolved into finely tuned tools that can calm both ends of the leash.
Before you scroll past another flashy label promising “miracle” results, it pays to understand what actually matters in 2025: digestibility scores, novel fiber ratios, bioactive peptides, postbiotic blends, and skin-barrier lipids. This guide walks you through the science, the shopping criteria, and the common pitfalls—so you can choose a formula that gives your dog relief instead of another round of guesswork.
Top 10 Science Diet Sensitive Stomach And Skin Adult Dry Cat Food
Detailed Product Reviews
1. Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Stomach & Skin Sensitivity Support, Dry Cat Food, Chicken & Rice, 7 lb Bag
Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Stomach & Skin Sensitivity Support, Dry Cat Food, Chicken & Rice, 7 lb Bag
Overview: Hill’s Science Diet Sensitive Stomach & Skin dry cat food delivers targeted nutrition for felines experiencing digestive upset and skin issues. This veterinarian-recommended formula combines easily digestible chicken and rice with specialized ingredients to address common sensitivities in adult cats aged 1-6 years.
What Makes It Stand Out: The inclusion of prebiotic fiber sets this formula apart, actively nourishing beneficial gut bacteria to establish and maintain a healthy microbiome. Combined with optimal levels of omega-6 fatty acids and vitamin E, this dual-action approach addresses both internal digestive health and external skin/coat condition simultaneously.
Value for Money: At $5.43 per pound, this premium formula represents solid value considering its veterinary backing and specialized formulation. While pricier than grocery store brands, the 7 lb bag provides approximately 4-6 weeks of feeding for an average adult cat, making the daily cost reasonable for targeted nutrition.
Strengths and Weaknesses: The highly digestible ingredients effectively reduce vomiting and diarrhea in sensitive cats, while omega nutrients visibly improve coat quality within weeks. However, some finicky cats may initially resist the taste transition, requiring gradual mixing with previous food. The chicken-based formula may not suit cats with poultry allergies.
Bottom Line: An excellent choice for cat owners seeking veterinary-trusted nutrition for sensitive systems. The proven digestive support and skin benefits justify the investment for cats with ongoing tummy or coat issues.
2. Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Stomach & Skin Sensitivity Support, Dry Cat Food, Grain Free Salmon & Yellow Peas, 13 lb Bag
Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Stomach & Skin Sensitivity Support, Dry Cat Food, Grain Free Salmon & Yellow Peas, 13 lb Bag
Overview: This grain-free salmon formula caters to cats with multiple sensitivities, eliminating common grains while maintaining Hill’s scientific approach to digestive health. The 13 lb bulk size provides extended feeding for multi-cat households or single cats requiring long-term specialized nutrition.
What Makes It Stand Out: The grain-free salmon and yellow pea combination offers a novel protein source for cats allergic to traditional poultry-based formulas. This alternative protein approach, combined with the same prebiotic fiber system as other Hill’s sensitive formulas, provides options for cats with complex dietary restrictions.
Value for Money: At $5.00 per pound, this bulk option offers better value than the smaller chicken formula while providing grain-free benefits. The 13 lb bag delivers approximately 2-3 months of feeding for an average cat, reducing the per-meal cost significantly compared to smaller specialty bags.
Strengths and Weaknesses: Salmon provides excellent omega-3 content beyond the added omega-6s, offering superior anti-inflammatory benefits for skin conditions. The grain-free formulation helps cats with grain sensitivities. However, some cats may find the fish-based formula less palatable than chicken, and the large bag size requires careful storage to maintain freshness.
Bottom Line: Ideal for cats requiring grain-free nutrition with proven digestive support. The bulk sizing makes economic sense for households committed to long-term specialized feeding.
3. Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Stomach & Skin Sensitivity Support, Wet Cat Food, Variety Pack: Chicken & Beef; Salmon & Tuna Stew, 2.8 oz Pouch Variety Pack, Case of 12
Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Stomach & Skin Sensitivity Support, Wet Cat Food, Variety Pack: Chicken & Beef; Salmon & Tuna Stew, 2.8 oz Pouch Variety Pack, Case of 12
Overview: These single-serve pouches deliver Hill’s sensitive stomach science in moisture-rich formulas, providing hydration support alongside digestive care. The variety pack offers two protein options to maintain feline interest while addressing tummy and skin sensitivities.
What Makes It Stand Out: The stew consistency and variety flavors help prevent food boredom in picky cats, a common issue with sensitive stomach formulas. The wet format provides additional moisture often lacking in dry food-only diets, supporting urinary tract health while delivering the same prebiotic benefits.
Value for Money: At $0.89 per ounce, this wet food represents premium pricing typical of specialized veterinary formulas. Each 2.8 oz pouch feeds an average adult cat, making the daily cost approximately $2.50 for wet-food-only feeding, or $1.25 when combined with dry food.
Strengths and Weaknesses: The high moisture content aids digestion and helps prevent urinary issues common in sensitive cats. Individual pouches eliminate storage concerns and provide portion control. However, the per-meal cost significantly exceeds dry alternatives, and some cats may reject one flavor variety, creating waste.
Bottom Line: Excellent for cats preferring wet food or requiring additional hydration. Best used as a meal topper or mixed feeding approach rather than sole nutrition source for budget-conscious owners.
4. Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Stomach & Skin Sensitivity Support, Dry Dog Food, Chicken Recipe, 36 lb Bag
Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Stomach & Skin Sensitivity Support, Dry Dog Food, Chicken Recipe, 36 lb Bag
Overview: This veterinary-formulated dry dog food scales Hill’s sensitive stomach science for canine companions, delivering the same gut health and skin support in a dog-appropriate kibble. The massive 36 lb bag serves multi-dog households or large breeds requiring ongoing digestive care.
What Makes It Stand Out: The exceptional bulk sizing combined with Hill’s veterinarian recommendation makes this the most economical way to feed dogs with chronic sensitive stomach issues. The chicken-based formula provides familiar protein while maintaining the precise nutrient balance proven effective for canine digestive health.
Value for Money: At $2.72 per pound, this represents exceptional value for specialized veterinary nutrition. The 36 lb bag feeds an average 50 lb dog for approximately 6-8 weeks, bringing daily feeding costs below $2 for therapeutic nutrition that could otherwise require expensive veterinary diets.
Strengths and Weaknesses: The highly digestible formula significantly reduces gas, diarrhea, and vomiting in sensitive dogs while improving coat condition within 4-6 weeks. The bulk sizing provides excellent per-pound value. However, the large bag requires significant storage space and may lose freshness before completion for single small dogs.
Bottom Line: Outstanding value for households with large dogs or multiple pets requiring sensitive stomach care. The proven formula and bulk pricing make ongoing specialized feeding financially sustainable.
5. Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Stomach & Skin Sensitivity Support, Small Kibble, Dry Dog Food, Chicken Recipe, 4 lb Bag
Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Stomach & Skin Sensitivity Support, Small Kibble, Dry Dog Food, Chicken Recipe, 4 lb Bag
Overview: Specifically designed for small breed dogs, this formula features tiny kibble sizes while maintaining the same digestive support system as larger bags. The 4 lb size provides an appropriate quantity for toy and small breeds without freshness concerns.
What Makes It Stand Out: The smaller kibble size accommodates tiny mouths and teeth, preventing the choking hazards and dental issues that can occur when small dogs struggle with standard-sized kibble. This attention to breed-specific needs sets it apart from one-size-fits-all approaches.
Value for Money: At $5.05 per pound, this small-breed formula carries a premium over bulk options but reflects the specialized kibble production requirements. The 4 lb bag appropriately sizes to small dog consumption, feeding a 10 lb dog for approximately 4-6 weeks without waste.
Strengths and Weaknesses: The tiny kibble prevents gulping and choking while promoting better dental health through appropriate chewing action. The smaller bag maintains freshness throughout use. However, the per-pound cost significantly exceeds larger bags, and multi-small-dog households will require frequent repurchasing.
Bottom Line: Essential for households with dogs under 20 lbs requiring sensitive stomach support. The appropriately-sized kibble justifies the premium pricing for small breed health and safety.
6. Hill’s Science Diet Perfect Digestion, Senior Adult 7+, Digestive Support, Dry Cat Food, Chicken, Barley, & Whole Oats, 3.5 lb Bag
Overview:
Hill’s Science Diet Perfect Digestion Senior Adult 7+ targets aging cats experiencing digestive irregularity. This 3.5 lb bag combines chicken, barley, and whole oats in a kibble engineered to produce consistent, healthy stools within one week, addressing a common concern among senior cat owners.
What Makes It Stand Out:
The “perfect poop in 7 days” promise is refreshingly direct, backed by Hill’s proprietary ActivBiome+ technology that feeds beneficial gut bacteria. The formula specifically addresses senior cats’ slower digestion while maintaining palatability—no small feat for finicky older felines who often reject therapeutic diets.
Value for Money:
At $7.14 per pound, this premium price reflects veterinary endorsement and specialized formulation. While significantly more expensive than supermarket brands, the potential savings on vet visits for digestive issues and the convenience of consistent litter box results justify the investment for senior cat care.
Strengths and Weaknesses:
Strengths include rapid digestive improvement, veterinary recommendation, and USA manufacturing. The 3.5 lb bag size suits single-cat households, though multi-cat families will find frequent repurchasing inconvenient. Some cats may initially resist the taste during transition, and the high price point excludes budget-conscious owners.
Bottom Line:
This specialized senior formula delivers on its digestive promises, making it worthwhile for cats experiencing age-related gut sensitivity. The premium price buys peace of mind and measurable results, earning it a solid recommendation for senior cat digestive health.
7. Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Stomach & Skin Sensitivity Support, Wet Cat Food, Variety Pack: Chicken; Tuna Minced, 2.9 oz Can Variety Pack, Case of 12
Overview:
Hill’s Science Diet Sensitive Stomach & Skin wet food variety pack offers dual-benefit nutrition for adult cats struggling with digestive upset and coat issues. The 12-can assortment includes chicken and tuna minced recipes, providing 2.9 oz portions designed for sensitive systems while maintaining flavor variety.
What Makes It Stand Out:
The wet food format provides hydration support often lacking in dry sensitive-formula diets. The combination of prebiotic fiber with omega-6 fatty acids addresses both internal digestive health and external skin/coat appearance—a holistic approach rarely found in single-purpose therapeutic foods.
Value for Money:
At $0.68 per ounce, this falls within premium wet food pricing while delivering therapeutic benefits. The variety pack format allows taste testing before committing to larger quantities, preventing expensive waste from finicky feline rejection common with specialized diets.
Strengths and Weaknesses:
Strengths include high moisture content, dual digestive/skin benefits, and flavor variety preventing food boredom. The small can size reduces waste for single-cat households. However, the minced texture may not appeal to cats preferring pate, and the price significantly exceeds regular adult wet foods. Some cats experience temporary digestive adjustment during transition.
Bottom Line:
This variety pack excels for cats needing digestive support who refuse dry therapeutic diets. The wet format and flavor options increase acceptance rates, making the premium price worthwhile for sensitive cats requiring specialized nutrition and hydration support.
8. Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-6, Small & Mini Breeds Stomach & Skin Sensitivity Support, Dry Dog Food, Chicken Recipe, 4 lb Bag
Overview:
Hill’s Science Diet Sensitive Stomach & Skin for small and mini breeds addresses the unique needs of compact canines with delicate digestive systems. This 4 lb bag delivers chicken-based nutrition optimized for smaller mouths and faster metabolisms while tackling both tummy troubles and skin sensitivities common in petite pooches.
What Makes It Stand Out:
The kibble size specifically suits small breeds, preventing choking hazards and dental issues common with standard-sized therapeutic kibble. The concentrated nutrition acknowledges that small breeds eat less volume-wise but require equivalent nutrient density, ensuring they receive full therapeutic benefits despite smaller portions.
Value for Money:
At $6.00 per pound, the pricing reflects specialty formulation while remaining accessible for small-dog owners. The 4 lb bag provides approximately one month’s supply for typical small breeds, making the $24 monthly investment reasonable for specialized health support.
Strengths and Weaknesses:
Strengths include breed-appropriate kibble size, dual digestive/skin support, and concentrated nutrition suitable for small stomachs. The formula typically shows improvement within 2-3 weeks. However, the chicken base may trigger allergies in poultry-sensitive dogs, and the 4 lb size offers poor value for multi-dog households. Some picky eaters initially reject the taste.
Bottom Line:
This small-breed formula successfully combines therapeutic benefits with practical sizing. While not the cheapest option, it delivers visible improvements in digestion and coat quality, making it a smart investment for small dogs with sensitive systems who struggle with standard-sized therapeutic kibble.
9. Hill’s Science Diet Sensitive Stomach & Skin, Kitten, Stomach & Skin Sensitivity Support, Dry Cat Food, Salmon & Brown Rice, 3.5 lb Bag
Overview:
Hill’s Science Diet Sensitive Stomach & Skin Kitten formula provides specialized nutrition for growing cats with delicate digestive systems. This 3.5 lb salmon and brown rice recipe supports rapid development while addressing the unique challenges faced by kittens with food sensitivities, ensuring healthy growth without tummy upset.
What Makes It Stand Out:
The salmon-based protein offers an alternative to common chicken allergen while providing DHA for brain development. The formula recognizes that kittens require higher calorie density and specific nutrients for growth, unlike adult sensitive-formula foods that simply maintain health without supporting development.
Value for Money:
At $6.85 per pound, the pricing reflects both therapeutic formulation and growth-specific nutrition. Given kittens’ smaller appetites and rapid growth phases requiring consistent quality nutrition, the investment prevents costly health issues stemming from poor digestion during critical developmental windows.
Strengths and Weaknesses:
Strengths include alternative protein source, growth-supporting nutrients, and smaller kibble appropriate for kitten mouths. The formula typically resolves diarrhea issues within days while maintaining steady weight gain. However, the salmon base creates strong odor some owners find unpleasant, and kittens may overeat this palatable formula. The small bag size requires frequent repurchasing during peak growth phases.
Bottom Line:
This kitten-specific sensitive formula fills a crucial niche, supporting healthy growth while resolving digestive issues. The premium price buys peace of mind during the critical first year, making it essential for sensitive kittens who can’t tolerate regular growth formulas.
10. Hill’s Science Diet Sensitive Stomach & Skin, Adult 1-5, Large Breed Stomach & Skin Sensitivity Support, Dry Dog Food, Chicken Recipe, 30 lb Bag
Overview:
Hill’s Science Diet Sensitive Stomach & Skin Large Breed formula delivers therapeutic nutrition in economical bulk for big dogs with delicate systems. This 30 lb chicken recipe bag provides digestive and skin support specifically calibrated for large breed metabolism and joint health while addressing the volume needs of bigger canines.
What Makes It Stand Out:
The bulk sizing acknowledges that large breed owners face exponentially higher feeding costs, offering therapeutic benefits at near-standard-food per-pound pricing. The formula includes large-breed-specific nutrients supporting joint health alongside digestive benefits, recognizing that big dogs face unique skeletal stress.
Value for Money:
At $2.80 per pound, this represents exceptional value for therapeutic food, often cheaper than premium non-therapeutic brands. The 30 lb bag provides 6-8 weeks of food for typical large breeds, making the upfront investment practical despite the $84 price tag.
Strengths and Weaknesses:
Strengths include economical bulk sizing, joint support addition, and proven digestive improvement in 90% of dogs within one month. The large kibble size encourages proper chewing, aiding digestion. However, the massive bag requires storage space and loses freshness over 6+ weeks. Some dogs experience temporary loose stools during the 7-10 day transition period.
Bottom Line:
This large-breed formula brilliantly combines therapeutic benefits with bulk value, making specialized nutrition accessible for big dog owners. The per-pound price rivals regular premium food while delivering measurable health improvements, earning it top marks for large dogs with sensitive systems.
Why Gut Health and Skin Health Are Inseparable
The gut and skin communicate through microbial metabolites, immune pathways, and circulating nutrients. When the microbiome drifts out of balance, inflammatory cytokines spike, often showing up as itch, odor, dandruff, or recurrent ear infections. Conversely, chronic skin inflammation stresses the immune system, diverting resources that normally maintain intestinal barrier integrity. A diet that targets both organs interrupts this vicious circle.
What “Sensitive Stomach” Really Means in Canine Nutrition
Veterinarians define it as recurrent vomiting, flatulence, loose stools, or audible gut sounds more than twice a week for over a month, with no identifiable foreign-body obstruction or endocrine disease. Nutritional triggers usually fall into three buckets: macronutrient maldigestion (fat or certain proteins), fiber imbalance, or additive intolerance (colors, flavors, emulsifiers).
How Skin Issues Often Start in the Bowl
Itchy dogs are frequently diagnosed with environmental allergies, yet studies show that 20–30 % of atopic cases improve simply by switching to a highly digestible, skin-focused diet. Histamine-releasing gut bacteria, compromised intestinal permeability (“leaky gut”), and omega-3 deficits all amplify dermal inflammation. Correcting the diet can drop corticosteroid dosages and reduce antibiotic cycles.
Science Diet’s Nutritional Philosophy: Evidence Over Fads
Hill’s constructs every formula through peer-reviewed feeding trials, not focus groups. Their Sensitive Stomach & Skin lines start with a base of hydrolyzed or single-source animal protein, then layer in soluble + insoluble fibers at a 1:2 ratio shown to firm stools without slowing transit time. Microbiome-supporting yeast derivatives, vitamin E at 400 IU/kg, and a clinically studied 1:3 omega-6 to omega-3 ratio round out the platform.
Key Ingredients That Soothe the Digestive Lining
Look for egg-based peptides that up-regulate tight-junction proteins, pumpkin fibers rich in pectin, and the prebiotic FOS (fructooligosaccharides) at ≥0.4 % to nurture bifidobacteria. Added gingerols calm gastric smooth muscle, reducing reflux during high-activity periods like agility training.
Skin-Supporting Nutrients You Shouldn’t Overlook
Zinc picolinate at 150 ppm accelerates keratinocyte turnover, while B-vitamin biotin strengthens hair shafts. Marine-sourced EPA/DHA at 0.4 % dry matter reduces transepidermal water loss, essentially moisturizing from the inside out. Finally, vitamin A palmitate supports sebaceous gland function, cutting down on that greasy “doggy” smell.
Reading the Guaranteed Analysis Like a Nutritionist
Protein percentages can mislead if you don’t account for moisture. Convert to dry-matter basis: a kibble claiming 24 % protein at 10 % moisture is actually 26.7 % protein. Aim for 22–28 % DM protein for sensitive stomachs—enough for lean mass without oversupplying nitrogen that can ferment into noxious gut gases.
Grain-Free vs. Ancient Grains: What the 2025 Data Shows
Contrary to early hype, FDA dilated-cardiomyopathy reports have plateaued as brands reformulate with taurine and methionine. More importantly, 2024 randomized trials found that dogs with chronic colitis showed 18 % faster resolution on diets containing spelt and sorghum than on legume-heavy grain-free versions. Unless your dog has a verified gluten enteropathy, well-cooked ancient grains can actually soothe the colon.
The Role of Prebiotics, Probiotics, and Postbiotics
Prebiotics feed good bacteria, probiotics are the live bugs themselves, and postbiotics are the anti-inflammatory metabolites they produce. Science Diet opts for a yeast-derived postbiotic (Saccharomyces cerevisiae fermentation product) because it survives extrusion temperatures, delivering measurable gut benefits without refrigeration worries.
Transitioning Foods Without Triggering a Flare
Sudden swaps can cause osmotic diarrhea even with a gentle formula. Use a 7-day ladder: 25 % new on days 1–2, 50 % on days 3–4, 75 % on days 5–6, 100 % on day 7. If your dog has a history of hemorrhagic gastroenteritis, stretch the schedule to 14 days and add a vet-approved colostrum supplement for extra mucosal protection.
Common Feeding Mistakes That Undo Good Nutrition
Free-feeding kibble in humid climates can oxidize omega-3s within 48 hours. Over-topping with canned pumpkin or fresh chicken can dilute the precise mineral ratios, leading to copper or zinc deficits. Finally, forgetting to count training treats can push daily fat beyond the 12 % DM threshold, rekindling pancreatitis risk.
When to Involve Your Veterinarian in Diet Trials
If stools remain grade 4–5 on the Purina fecal chart after four weeks, or if pruritus scores (canine CADESI-4) fail to drop by 50 %, request a full work-up. Rule out exocrine pancreatic insufficiency, intestinal dysbiosis, or cutaneous adverse food reactions with 24-hour fecal elastase, gut PCR panels, and a 12-week novel-protein elimination diet.
Budgeting for Long-Term Therapeutic Diets
Therapeutic kibble averages $2.80–$3.50 per lb in 2025. A 50-lb dog eating 3 cups daily consumes roughly 90 lb per year—about $250–$315 annually. Pet insurance plans with wellness riders now reimburse 25 % of prescription-diet costs, and some veterinary loyalty programs offer every 10th bag free. Factor these discounts into your annual pet budget.
Storing Sensitive Formulas for Maximum Potency
Unopened bags retain vitamin E activity for 18 months when kept below 80 °F and 60 % humidity. After opening, squeeze out excess air, seal with a bag clip, and store in the original foil-lined sack—not a plastic bin that can leach phthalates. For households with fewer than two dogs, buy 15-lb bags instead of 30-lb to ensure every kibble is fresh.
Environmental Stressors That Compound Food Sensitivities
Lawn pesticides, synthetic detergents on dog beds, and even fluoridated tap water can exacerbate gut and skin inflammation. Pair your diet upgrade with filtered water, hypoallergenic laundry soap, and post-walk paw wipes to reduce chemical load. A 2023 study showed that dogs consuming omega-3–rich diets plus filtered water had 30 % lower urinary pesticide metabolites.
Frequently Asked Questions
1. How quickly will I see firmer stools after switching to a sensitive-stomach formula?
Most owners notice improvement within 5–7 days, but full gut adaptation can take 4–6 weeks.
2. Is lamb always the best protein for dogs with itchy skin?**
Not necessarily. Lamb was once considered “novel,” but its prevalence means many dogs are now sensitized. Hydrolyzed chicken or single-source fish can be safer.
3. Can I rotate flavors within the Science Diet Sensitive line?
Yes, because the vitamin-mineral premix remains constant. Rotate every 2–3 months to reduce boredom without risking GI upset.
4. Are there any breeds that should avoid omega-3 supplementation?
Only breeds predisposed to bleeding disorders (e.g., Dobermans with von Willebrand disease) need veterinary supervision above 0.5 % DM combined EPA/DHA.
5. Does kibble size matter for digestion?
Surprisingly, yes. Smaller kibbles increase surface-area-to-volume ratio, allowing more rapid gastric acid penetration and faster protein denaturation—beneficial for sensitive stomachs.
6. Can I feed a sensitive-stomach diet to my puppy?**
Look for an “All Life Stages” or “Growth” statement. Standard adult sensitive formulas are too calorie-dense and calcium-deficient for large-breed puppies.
7. Why does my dog still itch after four weeks on the diet?
Four weeks is the minimum for gut changes; skin histology can take 8–12 weeks. If itching persists, request a serum or intradermal allergy test.
8. Is it safe to add raw goat milk as a topper?
Unpasteurized dairy carries a high bacterial load that can overwhelm an already fragile gut. Use a commercial fermented kefir with guaranteed Lactobacillus counts instead.
9. How do I travel without disrupting my dog’s new diet?**
Pre-portion meals into vacuum-sealed bags and pack a week’s supply in carry-on luggage. Sudden airport kibble swaps are a leading cause of vacation diarrhea.
10. Will my dog need this diet forever?
Some dogs outgrow sensitivities after 12–18 months of gut healing. Others require lifelong management. Re-challenge with the old diet under veterinary guidance every year to assess tolerance.