Based on PubMed | Is daily Omeprazole use safe for chickens, especially laying hens, and are there any health risks or egg/meat withdrawal times to consider?

Daily, chronic omeprazole use is generally not considered safe or routine for chickens especially laying hens because it can alter calcium handling, reduce eggshell quality, suppress appetite, and create uncertain residue risks in eggs and meat. While omeprazole is widely used in humans and some animals for acid suppression, it is not approved for poultry, and there are no established egg or meat withdrawal times for chickens.

Key takeaways

• Not approved in poultry and no established withdrawal times. This means eggs and meat from treated birds may carry unknown residues, and a conservative approach is to avoid consumption during treatment and for an extended, veterinarian‑directed period afterward.
• Potential health risks in chickens: sustained acid suppression can impair calcium solubilization in the gut, lower calcium retention, and reduce eggshell quality in laying hens, and it may reduce feed intake and slow passage of food. ^{[1] [2] [3]}
• Regulatory labels for omeprazole focus on humans, not poultry there is no official guidance for safe use, dosing, or withdrawal in chickens. ^{[4] [5]}

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What omeprazole does in birds

Omeprazole is a proton pump inhibitor (PPI) that suppresses gastric acid production. In chickens, this acid suppression has several downstream effects:

• Calcium solubilization and eggshells: In laying hens, inhibiting gastric acid raises proventricular and gizzard pH, decreases soluble calcium in the gizzard and duodenum, lowers overall calcium retention to a small extent, and reduces eggshell quality. ^{[1] [1]}
• Appetite and weight: Chickens given omeprazole have shown decreased food intake and failure to gain weight, likely related to elevated gastrin levels (hypergastrinemia) that occur when acid is blocked. ^{[2] [6]}
• Gut motility: Omeprazole can delay crop emptying in chicks; adding acid back to the diet reverses this effect, indicating it’s driven by acid suppression. ^[3]

These findings suggest that daily, long‑term omeprazole can undermine key aspects of laying hen health and productivity, particularly eggshell formation and normal feeding behavior. ^{[1] [2] [3]}

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Residues in eggs and meat

• No approved poultry label or residue limits for omeprazole: Without an approved product for chickens, there are no validated withdrawal times for eggs or meat. ^{[4] [5]}
• General principle in laying hens: Many drugs given to hens can leave detectable residues in eggs for days to weeks after treatment stops, underscoring why off‑label use requires strict veterinary oversight and conservative discard periods. ^{[7] [8]}

Because residue behavior of omeprazole in poultry eggs/meat isn’t established in official guidance, the safest course is to avoid human consumption of eggs and meat from treated birds until a veterinarian provides a tailored, extended withdrawal interval based on available pharmacology and risk assessment. ^{[7] [8]}

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Human‑label information doesn’t translate to poultry

Official omeprazole labeling provides safety and reproductive data for humans and common lab animals, but does not set any standards for poultry use or egg/meat withdrawals. ^{[4] [5]} In addition, chronic PPI use in animals can induce hypergastrinemia and related gastric mucosal changes, which have been observed across species and may also occur in birds. ^[6]

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Practical recommendations

• Avoid daily, chronic omeprazole in laying hens unless a poultry veterinarian specifically recommends it for a diagnosed condition, at a defined dose and duration, with a clear plan for egg and meat withdrawal. Potential risks include thinner eggshells, reduced calcium retention, decreased appetite, delayed crop emptying, and unknown residues. ^{[1] [2] [3] [7]}
• If acid suppression is truly needed, discuss alternatives with a veterinarian who is experienced in poultry; they can consider causes (e.g., ulcers, proventricular/gizzard issues), weigh risks, and select the safest therapy and dosing strategy.
• Egg and meat safety: In the absence of established withdrawal times, discard all eggs during treatment and for a conservative period after the last dose as advised by your veterinarian, and avoid slaughter for meat until the same criteria are met. ^{[7] [8]}
• Monitor hen health: Watch for drops in egg production or shell thickness, decreased appetite, weight changes, and abnormal droppings if any acid‑suppressing therapy is used, and report to your vet promptly. ^{[1] [2]}

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Comparison at a glance

Consideration	Laying hens on daily omeprazole	Notes
Regulatory approval	Not approved in poultry	Human labels do not set poultry guidance. [4] [5]
Egg/meat withdrawal time	Not established	Eggs and meat should be withheld per vet guidance. [7] [8]
Calcium handling	Decreased soluble Ca and retention	Can reduce eggshell quality. [1]
Eggshell quality	Reduced	Linked to acid suppression. [1]
Appetite/weight	Decreased food intake and weight gain	Likely via hypergastrinemia. [2]
GI motility	Delayed crop emptying in chicks	Reversed by adding acid. [3]

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Bottom line

Given the lack of approval and established withdrawal times in poultry, and evidence of reduced eggshell quality, altered calcium handling, decreased feed intake, and delayed crop emptying, daily omeprazole is not recommended for laying hens except under direct veterinary supervision with a conservative plan for discarding eggs and withholding meat. ^{[1] [2] [3] [7] [8]}