By Tyler Carmack, DVM, CVA, CVFT, CTPEP, CHPV, CVPP

A senior dog that turns away from a favorite kibble, or a geriatric cat that no longer bothers to walk to their food dish, is rarely simply being picky. In geriatric and palliative care patients, inappetence is rarely about calories alone; it is a symptom and can often be a signal of pain, nausea, or physical/emotional distress that deserves the same diagnostic attention as any other clinical finding. Treating the underlying driver, rather than the loss of appetite in isolation, is what separates a pet that merely survives longer from one that genuinely enjoys the time it has left.

Why aging and dying pets stop eating

A complex interplay of hypothalamic signaling, gastrointestinal comfort, and disease-related biochemistry regulates appetite. In cancer patients, cachexia is driven by inflammatory cytokines, such as IL-1 and IL-6, along with emerging mediators like GDF-15 and activin A, which act centrally to suppress hunger while simultaneously accelerating muscle catabolism, a process that calorie supplementation alone cannot reverse.^1,2 Chronic kidney disease, hepatic disease, and chronic pain conditions add their own layers: uremic toxins cause nausea, osteoarthritis makes the walk to the feeding area unappealing, and the stress of a declining body can flatten the drive to eat entirely.

This means the first step in an appetite workup for any pet, particularly a senior or hospice patient, should not be reaching for an appetite stimulant, but ruling out and treating pain, nausea, dental disease, and GI ulceration. A cat with unaddressed degenerative joint disease or a dog with dental pain will not respond reliably to pharmacologic appetite support until the discomfort itself is managed.

Pharmaceutical support

Once reversible causes are addressed, several medications have evidence base for appetite support:

• Mirtazapine remains the most studied option. It antagonizes serotonergic 5-HT2A/2C and 5-HT3 receptors, and presynaptic alpha-2 receptors, increasing norepinephrine and serotonin release in a way that reliably stimulates appetite.

Placebo-controlled crossover trials in cats with chronic kidney disease showed improved appetite, weight gain, and reduced vomiting frequency with both compounded transdermal and oral formulations, and an FDA-approved transdermal product is now labeled specifically for weight loss associated with feline CKD.³

In dogs, mirtazapine's effect appears milder but still measurable: dogs treated with it were significantly more likely to resume voluntary eating and lost less weight than untreated controls in retrospective and placebo-controlled work.

• Capromorelin is a ghrelin-receptor agonist and the first FDA-approved appetite stimulant for dogs, later also approved for cats.⁴ In a randomized, masked, placebo-controlled trial in healthy beagles, capromorelin increased food consumption by roughly 60 percent over baseline compared with a decline in the placebo group, with good tolerability.⁵
• Maropitant targets the emetic center via NK-1 receptor antagonism and is the first FDA-approved veterinary antiemetic.⁶ While it is highly effective for vomiting, its effect on nausea specifically is less consistent; cats with CKD given maropitant showed reduced vomiting without a corresponding rise in appetite in some studies, suggesting it is best used as an adjunct rather than a substitute for a dedicated anti-nausea agent.⁷
• Ondansetron, a 5-HT3 receptor antagonist, may in fact be a more effective option when nausea itself, rather than active vomiting, is causing appetite suppression. A 2022 pharmacokinetic and clinical study documented measurable anti-nausea effects with intravenous ondansetron in hospitalized dogs showing clinical signs of nausea,⁶ a widely used antiemetic in veterinary oncology for chemotherapy-associated nausea. Because ondansetron has poor and variable oral bioavailability in dogs, it is best given by injection. It is used off-label, as no ondansetron formulation is FDA-approved for veterinary patients. In hospice cases where nausea rather than overt vomiting appears to be the dominant driver of inappetence, combining or rotating a 5-HT3 antagonist such as ondansetron with maropitant may offer broader coverage than either drug used alone. Analgesics, such as NSAIDs (whose long-term use in cats is now guided by updated consensus recommendations),⁸ gabapentin, or opioids (depending on the diagnosis), are frequently the highest-yield intervention in arthritic or cancer-pain patients, since unmanaged pain suppresses appetite more reliably than almost any other single factor.

Nutritional and supplement strategies

Omega-3 fatty acids (EPA/DHA) have anti-inflammatory and anti-cachectic properties that may help preserve lean muscle mass in cancer patients, though evidence in veterinary oncology is still evolving.

Calorically dense, highly palatable recovery or renal diets, slightly warmed to enhance aroma, can help patients with a diminished sense of smell, which is common in older and sick pets.

B-vitamin supplementation is reasonable in anorectic cats, since prolonged inappetence itself can create deficiencies that further blunt appetite.

Simple palatability tools are often underused. Meal toppers, low-sodium warmed broths, and lickable purees can increase voluntary intake largely by boosting aroma and moisture rather than by changing nutrient content. Commercial lickable toppers are widely used by veterinary teams as a low-effort appetite motivator and hydration aid in senior and hospice cats, given their high moisture content and minimal chewing requirements. They also double as an easy vehicle for hiding oral medication. There is little independent efficacy data for these specific products, so they are best presented to clients as a way to improve the odds a patient will eat something rather than as a clinically proven appetite stimulant. Probiotics have somewhat stronger supporting evidence, though the benefit shown to date is for gastrointestinal comfort rather than appetite directly: a randomized, placebo-controlled trial in shelter cats and dogs found probiotic supplementation reduced episodes of diarrhea compared with placebo.⁸

Since ongoing GI upset is itself a common driver of inappetence, a probiotic that improves stool quality and gut comfort may indirectly support more consistent eating in patients with concurrent GI disease.

Assisted feeding (syringe or feeding tube) has its place, but should be approached cautiously in hospice patients: forced feeding of an actively dying or severely nauseated animal can cause aversion, aspiration, and distress that undermines quality of life rather than supporting it. The goal in hospice nutrition is comfort and voluntary intake, not meeting a caloric target.

Complementary techniques, including acupressure

Acupuncture and acupressure are increasingly used as adjuncts in integrative palliative protocols. Unlike many complementary modalities, a few specific points have controlled trial data in veterinary patients, though results are point-specific and mixed.

Stomach 36 (ST-36), located on the lateral hind limb just below the stifle, is traditionally regarded as the master point for the stomach and GI tract and is commonly used to support digestion and appetite in debilitated patients, though its veterinary evidence base remains largely observational.

Pericardium 6 (PC-6), located on the palmar forelimb just proximal to the carpus, has the strongest controlled-trial support of any point used for nausea and vomiting. In a randomized clinical trial of 222 dogs, electroacupuncture at PC-6 reduced morphine-induced nausea and vomiting as effectively as maropitant or acepromazine and significantly better than a sham acupoint or saline.⁹ That benefit has not been replicated across every trigger, however: targeted acupuncture at PC-6 and ST-36 failed to reduce nausea or sedation in dogs receiving intravenous lidocaine infusions,¹⁰ and PC-6 aquapuncture did not reduce the incidence or severity of dexmedetomidine-induced vomiting in cats.¹¹

Taken together, this suggests PC-6's antiemetic effect is most reliable for opioid-triggered nausea specifically, rather than general nausea, although there are many anecdotal reports of success.

Shan Gen, a calming point located on the midline of the nasal bridge where the fur meets the hairless nose leather, is commonly used by veterinary acupuncturists to help coax a reluctant patient into taking the first bite. It lacks controlled trial data specific to appetite, but it is non-invasive, low-risk, and easy for caregivers to learn and perform at home. Gentle, sustained digital pressure at any of these points for 20-30 seconds, repeated a few times daily, is reasonable to teach clients as a comfort measure.

Practitioners should present acupressure as a complement to diagnosis-driven medical management rather than a replacement for it and should be transparent that evidence quality varies substantially by point and by the underlying cause of nausea.

Teaching acceptance early: An investment in future comfort

Much of the difficulty in medicating or feeding a geriatric or hospice patient traces back to a lifetime of never having been exposed to variety. Practices should actively counsel owners of healthy puppies and kittens to introduce a range of food textures, temperatures, and forms (i.e., wet, dry, pâté, shredded, broth) and to periodically practice low-stress "mock" medicating, an empty pill capsule tucked into a treat, gentle handling of the mouth and paws, and short desensitization sessions paired with food rewards. This cooperative-care and Fear-Free approach, built on gradual desensitization and counterconditioning, produces adult and senior animals that are far more resilient when illness eventually narrows their food preferences or requires daily medication.¹² A cat that has only ever eaten one flavor of dry kibble for 12 years is a much harder patient to support through inappetence than one that has learned to accept a variety of textures from kittenhood.

Supporting dignity through the whole course of disease

Consensus hospice and palliative care guidelines frame appetite support within the broader concept of the "unit of care," the patient and caregiver together, reminding practitioners that success in hospice nutrition is not measured only in grams of food consumed but in comfort, communication, and the quality of the time that remains.^16-18 Appetite loss in an aging or dying pet is rarely a simple problem with a simple fix. It requires ruling out pain and nausea first, applying pharmaceutical and nutritional tools thoughtfully, considering complementary techniques like acupressure as adjuncts rather than solutions, adapting the physical environment to the patient's changing body, and, ideally, having built a foundation of food and handling flexibility years earlier, while the patient was still young and well.

Tyler Carmack, DVM, CVA, CVFT, CHPV, CPEV, CVPP, is the director of Hospice and Palliative Care for the Caring Pathways family of practices. She founded Hampton Roads Veterinary Hospice, an AAHA-accredited end-of-life practice, and has practiced hospice and palliative care exclusively since 2011. Dr. Carmack has served on the Board of Directors of the International Association for Animal Hospice and Palliative Care (IAAHPC) since 2016, in various roles, including serving as president in 2020 and 2025.

References

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