The most common cause is too many treats at once. Freeze-dried beef liver is nutritionally dense — high in protein, fat, and vitamins — and overwhelming the GI tract with too much at once causes loose stools or gas. The fix is almost always reducing quantity, introducing slowly, and breaking pieces into smaller bits for training sessions.
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The most common cause: too much at once
A single piece of Stewart freeze-dried beef liver is roughly 4 calories. That sounds trivial, but the protein density (60%+ dry matter) and fat content (10%+ dry matter) are much higher than a typical commercial biscuit. When a dog receives many pieces in a short period — say, 30 pieces during a long training session — the GI tract receives a rich, concentrated load it cannot process efficiently.
The result is osmotic diarrhea: the intestines pull water in to dilute the richness, and stools become loose or watery within 6–24 hours. This is not a reaction to a harmful ingredient — it is a volume problem with a very rich food. Most dogs recover fully within 24–48 hours with a brief fast and bland food.
Less common causes
True protein sensitivity or allergy to beef: some dogs have genuine immune reactions to beef protein. This presents as diarrhea, gas, vomiting, skin itching, or ear inflammation. If symptoms persist even with small amounts — 2–3 pieces — and resolve only when you stop the treat entirely, beef sensitivity is worth investigating with your vet.
Transitioning too quickly: dogs whose gut microbiome is accustomed to a low-variety diet sometimes react to any novel food, even in small amounts. The reaction typically resolves after 1–2 weeks as the microbiome adapts, if the new food is genuinely tolerated.
Batch-specific contamination: extremely rare, but any pet food product can occasionally have a manufacturing issue. If multiple dogs in the same household develop symptoms from the same bag simultaneously, or if symptoms are severe (bloody diarrhea, fever, lethargy), stop using that specific bag and contact the manufacturer with the batch code from the packaging.
Distinguishing a portion problem from an allergy
Portion problem: symptoms appeared after a large quantity was given; symptoms resolve within 48 hours of stopping the treat; dog has no ongoing issues with small amounts; other foods in the diet are unchanged and causing no problems.
Likely allergy or sensitivity: even small amounts (1–3 pieces) cause consistent symptoms; symptoms include itching, ear problems, or skin reactions in addition to GI symptoms; symptoms resolve only when the treat is eliminated completely and do not return when the treat is reintroduced in small amounts — wait, that last one is backwards. True allergy: small amounts reliably cause symptoms; elimination causes relief; reintroduction reliably causes symptoms again.
How to reintroduce after a problem
After the GI upset resolves (stools back to normal, dog eating well), wait 48 hours before trying the treat again. Then start with one small piece broken into 4–5 bits, spread across a training session. Observe for 24 hours. If stools remain normal, you can gradually increase over the next 1–2 weeks to your target training use level. This gradual reintroduction distinguishes a portion problem (dog tolerates small amounts fine) from an intolerance (any amount causes symptoms).
When to contact a vet
Contact your vet if: diarrhea contains blood or is black and tarry (which can indicate GI bleeding); vomiting is severe or frequent alongside diarrhea; the dog shows lethargy, loss of appetite, or abdominal pain; symptoms last more than 48–72 hours without improvement; or the dog is a puppy, senior, or has a known health condition that makes GI illness higher risk.