Research shows oxytocin—the “bonding hormone”—is released during petting or eye contact and can help boost a pet’s appetite. Appetite regulation in dogs and cats is a multifactorial process involving neuroendocrine signaling, nutrient sensing, and behavioral conditioning. Understanding the physiological drivers of hunger and satiety can help pet owners and veterinary clinicians alike manage weight, understand picky eating, and select the best diets for individual patients. Pet obesity has reached epidemic proportions, with more than 56 percent of dogs and 60 percent of cats currently overweight or obese.1 Conversely, picky eating behaviors can be a struggle for case management for veterinarians.2 Reviewing the hormonal and nutritional mechanisms that govern appetite and using evidence-based diet strategies will optimize nutrition plans for the best health in both dogs and cats. The Control Room: Hypothalamic command of hunger and satiety At the core of appetite control is the hypothalamus, a brain structure that processes signals from key hormones to determine whether a pet should start or stop eating. The cycle of food intake is described as “hunger” or desire to eat, “satiation” or the sense of fullness resulting in meal termination, and “satiety” or the state in between meals in the absence of hunger. The body uses an integration of signals, including hormonal, neuronal, and metabolic, as well as external behavioral and cognitive cues. Between meals, satiety fades with increasing hunger rather than a distinct moment that triggers the next feeding. Ghrelin, secreted by the stomach, primes the system to seek food by activating neuropeptide Y (NPY) and agouti-related peptide (AgRP) neurons while suppressing the action of pro-opiomelanocortin (POMC) neurons in the brain. Ghrelin is a circulating hormone that can increase appetite, food intake, gastric emptying, intestinal transit, and, ultimately, fat storage. In contrast, leptin, produced by fat cells and small intestinal mucosal cells, triggers satiety pathways through POMC neurons, effectively telling the body that energy reserves are sufficient and there is no need to keep eating. Leptin is a hormone that is critical in conserving fat mass for survival and reproduction, but states of obesity can cause leptin resistance. Levels of leptin fall during starvation and correlate with total body fat stores, triggering hunger. Prior to eating, in the “pre-ingestive” phase, even the thought, sound, smell, or first taste of food will activate vagal nerve responses, stimulating salivation, gastric acid secretions, enzyme release, and gut motility.3 With each meal, as food enters the stomach, there is gastric accommodation (expansion of size) and activation of stretch receptors. Meanwhile, gut peptides, such as cholecystokinin (CCK), peptide YY (PYY), and glucagon-like peptide-1 (GLP-1), send satiety signals and begin to slow gastric emptying and modulate hypothalamic responses. The neurotransmitter serotonin (5-HT), which is influenced by dietary tryptophan content, indirectly also plays a role in appetite modulation—especially relevant in stress- or mood-related feeding behaviors4,5 (Table 1). Macronutrient tactics: How Protein, fiber, and carbs influence the game Beyond hormones, nutrients themselves contribute heavily to appetite dynamics. Protein is standout, stimulating satiety signals, such as PYY and GLP-1, and helping maintain lean body mass. Amino acids tryptophan and tyrosine serve as precursors for serotonin and dopamine, which influence central appetite regulation.6 Branched-chain amino acids, such as leucine, have been shown to suppress food intake via nutrient sensing.7 In dogs, higher-protein diets have been linked to reduced voluntary intake during weight loss interventions,8 while cats, as obligate carnivores, demonstrate a strong biological preference for and benefit from protein-rich formulations.9 Dietary fiber, too, plays a pivotal role in appetite regulation.10,11 Soluble fibers ferment in the colon to produce short-chain fatty acids (SCFAs), which can enhance satiety hormone signaling. Insoluble fibers work by increasing gastric volume, slowing transit time, and triggering mechanical stretch receptors in the stomach, further promoting fullness. Fat, though calorie-dense and palatable, surprisingly contributes less directly to satiety unless paired with protein and fiber.12 Additionally, carbohydrate sources matter: complex carbohydrates with low glycemic indices that release glucose more slowly into the bloodstream can stabilize postprandial glucose, prevent large spikes of glucose, and prevent appetite rebound, while simple sugars may disrupt feeding patterns by triggering insulin surges and subsequent recurrent hunger signals.13,14 Photo courtesy Dr. Laura Gaylord Emotional alliances: Behavioral conditioning and the human-animal bond Besides nutrients in food, behavioral issues in dogs and cats, such as anxiety, compulsive behaviors, or attachment-related stress, can significantly influence feeding patterns and appetite, often leading to either excessive food-seeking or food avoidance. These behaviors are deeply intertwined with the human-animal bond, which plays a pivotal role in shaping how pets eat. For example, pets may develop anticipatory behaviors around feeding times, not solely due to hunger but as a response to emotional cues or routines established by their caregivers. These behaviors are often shaped by the dynamics of the human-animal relationship. For instance, for both dog and cat owners, treat feeding is not merely a nutritional act but a form of emotional exchange; caregivers report greater personal satisfaction from giving treats than they perceive their pets experience, reinforcing feeding as a relational behavior rather than a purely physiological one.15,16 The bond itself can reinforce feeding as a social or comforting activity, with pets responding to human attention or emotional states. Research shows oxytocin, the “bonding hormone,” is released in both humans and pets during positive interactions, such as eye contact or petting, and this biochemical feedback loop may enhance a pet’s desire to eat when their caregiver is present.17 Food is an important reinforcer of behavior, with dogs more likely to show preference for food over leisure items when offered a choice in training.18 The emotional comfort pets derive from their human companions can influence their appetite—some may eat more when feeling secure, while others may lose interest in food during periods of separation or stress.19,20 Understanding these behavioral and relational dynamics is essential for managing feeding strategies, especially in pets with anxiety or behavioral disorders. When problem-solving feeding issues, considering behaviors that are either supporting or derailing the nutrition plan is important. It can be advantageous to disconnect the feeding routine from the pet owner in some cases. For both dogs and cats on a weight-loss plan, selecting an automatic feeder may help decrease begging behaviors. Redirecting dogs to a toy or play session when begging occurs may also help reduce excessive treating or overinterpretation of hunger by the pet caregiver. Picky eating problem-solving: Suggestions for clients Set a regular feeding schedule and stick to it – consider feeding 2–3 times per day at the same times. Eliminate ALL treats and snacks—we want reliable hunger for meals and the preferred diet. Some dogs will survive on treats and reject their balanced, appropriate foods. Choose a feeding location that is quiet, free of distractions, separate from other pets or noise. Feed the meal on a paper plate, warm the food slightly to increase aroma, then serve. Allow 20-30 minutes for eating, do not give attention while the food is offered. Resist hand-feeding or coaxing to eat if possible. Once food is consumed, then give lots of praise AFTER eating, not during the eating process. If no food is consumed within 15 minutes, take away the food. A meal can be returned to the refrigerator and offered one more time safely that day or the next morning. After two offerings, discard the food and make a fresh meal. It is okay if one or two meals in one day or the next day are refused (exception to this is for diabetic pets, those that experience hypoglycemia or underweight pets; always check with your veterinarian about repeated food refusals). Some very stubborn dogs will need to learn there are new rules around meals. This may take some time and have a variable course while they adapt. Be patient. Incorporate safe and appropriate exercise into the daily routine. Activity will increase appetite and improve quality of life for every pet. This can support and encourage appetite. Always have an exercise regimen approved by your primary care veterinarian and introduce gradually at the level appropriate for your pet’s current physical condition. Monitor body weight (check one to two times per week). Weight loss should be avoided. If your pet is refusing foods but not losing weight, consider that excess calories are being fed and your veterinarian can advise on reducing meal volumes. MOST IMPORTANTLY: If food refusal is persistent or new clinical signs arise (lethargy, vomiting, diarrhea, etc.), then medical re-evaluation is indicated as soon as possible. Repeat diagnostic testing and alternative medications may be needed to support appetite. For some pets with disease conditions, assisted feeding (feeding tube placement) may be required to overcome a cycle of food refusal and to maintain appropriate food intake. This can be a stress-free and kind way to administer food, medications and hydration. Disease states greatly benefit from assisted feeding including chronic kidney disease, liver diseases, gastrointestinal diseases and others. Many owners choose assisted feeding to support their pet’s comfort and recovery from illness. Strategic feeding: Tailoring diets for life stage and disease Choosing the right diet for a patient also requires consideration of a pet’s age, breed, health conditions, and behavioral tendencies. Puppies and kittens require nutrient-dense meals to support growth, while senior pets will often benefit from lower-calorie, higher fiber foods tailored to manage weight (if prone to overweight body condition) or options tailored to joint or organ health. For pets with chronic conditions—such as diabetes, kidney disease, or gastrointestinal disorders—a therapeutic (prescription) diet should be selected that has consideration for key nutrient levels of concern for each medical condition. As overweight/obesity now affects up to two-thirds of our patients,21,22 however, putting obesity first in our treatment plans should be our mandate in designing nutrition plans. Studies support the use of high-protein, high-fiber diets to enhance satiety and manage weight effectively.23-25 For complex cases or patients with conflicting key nutrients of concern, seeking input from a Board-certified Veterinary Nutritionist is recommended to balance nutrition when managing multiple health conditions along with obesity. How can I support my picky eater when recovering from an illness or introducing a new food? Allow a gradual introduction of any new recipe or food item, as well as any supplements. This is very helpful when transitioning to a new diet. I recommend using the foods that have been eaten well in the past and adding new foods in gradually increasing quantities. Suggested diet transition: 75 percent old diet + 25 percent new diet for three to five days; then 50 percent old diet + 50 percent new diet for the next three to five days, then 75 percent new diet + 25 percent old diet for three to five days, then 100 percent new diet. Some dogs and cats will tolerate foods mixed together, while others may prefer them side by side. Slow the diet transition if there are any concerns about intolerance. Blend or puree foods to accommodate a preference for smooth foods or to reduce the chance of picking out favorite foods and leaving behind the rest. This can be some ingredients or the entire food mixture. Rebels and resisters: Understanding begging and hyporexia In practice, we will see cases that are on either side of the spectrum. Dogs may present with persistent begging behaviors that are challenging for pet parents–we have all had these cases. Leptin resistance, which is often seen in obesity, may occur when the body fails to respond normally to satiety signals.26 Many have behavioral causes or owner attachment issues that can play a role in food-seeking behaviors from both dogs and cats.27 Genetics can also play a role in begging behaviors. In Labrador retrievers, a 14 bp gene deletion in pro-opiomelanocortin (POMC) has been identified with an allele frequency of 12 percent that results in higher body weight, adiposity, and greater food motivation.28 Conversely, for picky eaters, we can struggle maintaining caloric intakes due to a variety of causes, including learned preferences (flavors, textures, shapes), food boredom, environmental stress, negative associations with foods, overfeeding/excessive treating, or from disease conditions or medications needed for disease management that impact appetite (dental, metabolic, etc.). Hyporexia or anorexia can occur in pets with chronic illnesses that are poorly managed or progressive. It is essential to perform a thorough historical, clinical, and physical evaluation—including assessment of body condition score (BCS), muscle condition score (MCS), and a thorough dietary history—in order to differentiate behavioral issues from medical causes. If present, optimally addressing underlying medical conditions is a priority, but also adding management strategies to address behavioral issues is mandatory. This may include setting a routine around feeding (method, location, type, amount) and eliminating or setting limits on treats. In many cases, adding flavor enhancers as toppers or broths, warming the food, and providing some flexibility or options is required (Table 1). Flavor meals with a small topper addition (with your veterinarian’s approval): Sweet: pancake syrup, honey, fruit purees, fruit-flavored baby foods, yogurts. Savory: cottage cheese, meat or vegetable baby foods, low-fat gravies (turkey, chicken or pork; onion/garlic free), low-sodium chicken, beef or vegetable broth (onion-/garlic-free), bone broths, tuna juice, salmon juice, clam juice. Save juices from cooking meats and use them to flavor meals. If fat restriction is needed, cool these liquids in the refrigerator and skim away the fat layer that congeals on the surface before adding to meals. Other: parmesan cheese, nutritional yeast, bonito flakes, tomato powder (cats), or Purina Fortiflora probiotic or Purina Hydracare. Use gravies or sauce from canned cat foods, tuna/salmon water, broths. Create a broth by pureeing a well-liked canned food and adding extra water. Store in the refrigerator (three days) or freeze portions in ice cube trays. Generally, avoid high protein, high fat or high sodium foods or dilute with added water. Again, always confirm food toppers as appropriate with your veterinarian or consult with us. If your pet is on a hypoallergenic feeding trial, you will need to stick with novel proteins (and possibly also carbohydrate sources). Pharmacologic power-ups: Tools for appetite intervention When nutrition and behavior modification are not enough to improve cases with persistent hyporexia, pharmacologic support may be indicated. Capromorelin is a ghrelin receptor agonist approved for dogs and cats, which directly stimulates hunger pathways.29,30 Mirtazapine is a 5-HT2A, 5-HT2C, 5-HT3 and H1 receptor antagonist with appetite-enhancing and anti-nausea effects.31 Cyproheptadine is another appetite stimulant option that has antihistaminic and anti-serotonergic properties that may increase food intake.32 Use of dronabinol, a synthetic form of tetrahydrocannabinol (THC) used for appetite stimulation in humans with cancer or chemotherapy-associated nausea, may have application for dogs (Table 2). Following the rise in use in human medicine, GLP-1 agonists, such as semaglutide, are now being explored for companion animal use in obesity management. A slow-release implantable device to deliver a GLP-1 agonist was studied in cats.33 Another company (Better Choice Health) has plans to study delivering GLP-1 drugs in the form of treats and toppers as another tool to combat obesity in pets. A key limitation remains the cost of these medications, but these may decline over time as competitors enter the market. Using therapeutic nutrition in combination with pharmacologic interventions is key, however. Like human medicine, sustaining a healthy body composition will be essential to disease prevention and improving the health and longevity of our dogs and cats while we work to reverse obesity.34 Photo courtesy Dr. Laura Gaylord Appetite in context: Winning with tailored nutrition Ultimately, appetite management will rely on assessing each pet as an individual to determine what aspects of the pet treatment plan can be improved to help manage appetite better–medical, behavioral, and nutritional. Appetite support is not solely about suppressing or stimulating hunger; it is about understanding each patient’s unique needs, decoding the signals in the body, and aligning nutrition and medication with physiology and behavior. By utilizing this insight, a multi-modal plan can be tailored to each pet as an individual. Whether addressing chronic overeating or coaxing meals from reluctant pets, the path to success lies in using all available information, noting what areas need improving, and then fully enlisting the support of the pet owner. Let the games begin—with the right tools, science is always in our corner. Laura B. Gaylord, DVM, DACVIM (Nutrition), is an independent consultant and the owner/founder of Whole Pet Provisions, PLLC, a nutrition consulting company established in 2016, which offers veterinary nutrition consulting to pet owners, veterinarians, the pet food industry, and pet supplement companies. Dr. Gaylord offers homemade diet recipe formulation and commercial diet consultations through her business for pet parents and their veterinary teams. References German AJ, Woods G, Ward E, Churchill J. 'We should adopt new definitions for clinical obesity in companion animals'. Vet Rec. 2025;196(5):197–8. Johnson LN, Freeman LM. 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