It can, especially if you give more than a few pieces on day one. The combination of novelty (a new food the gut microbiome is not accustomed to) and richness (high protein and fat density) can cause loose stools in the first 24–48 hours. Starting with 1–3 small pieces and increasing gradually over a week typically avoids this.
In this article
Why first-time reactions happen
Dogs have gut microbiomes — communities of bacteria in the intestinal tract — that are adapted to their current diet. When a novel food is introduced, especially one that is nutritionally different from the current diet, the microbiome needs time to adjust. Bacteria that are efficient at processing beef liver protein develop over time; introducing a lot of liver all at once before those bacteria are established can result in incomplete digestion and loose stools.
This is the same reason that transitioning dog foods is always recommended as a gradual process over 7–10 days. A treat is lower volume than a full diet transition, so the adjustment is less pronounced — but it still exists for particularly rich foods like freeze-dried liver.
How long does the adjustment take?
For most dogs, the first-use GI reaction (if any) resolves within 24–48 hours and does not recur with ongoing regular use at appropriate amounts. The gut microbiome adapts quickly to a consistent new food source. After 1–2 weeks of regular small-amount use, the same dog who had loose stools on day one is typically using the treat with no issues at all.
Dogs who continue to have GI symptoms after 2 weeks of careful use (1–2 pieces per day) are showing something more than a microbiome adjustment. In those cases, true intolerance or allergy is more likely and warrants vet consultation.
The right introduction protocol
Day 1–3: one or two small pieces (or the equivalent in crumbles) once per day. This is genuinely just a taste introduction, not a training session. Watch for any loose stool or vomiting in the 24 hours after.
Day 4–7: increase to 3–5 pieces per session, two sessions per day if training. Normal stools confirm tolerance so far.
Day 8–14: move to your target training use level. If you plan to use 20–30 pieces per training session, increase gradually over this week rather than jumping to full training volume.
This protocol is conservative — most dogs will show no reaction even with larger amounts on day one. But for dogs with known GI sensitivity, a history of food reactions, or smaller body weight, this pacing prevents problems before they start.
When first-time upset is a warning sign
Vomiting within 30 minutes of the treat (versus loose stools 6–24 hours later) suggests the stomach is rejecting the food, not the lower GI having a processing issue. Vomiting on first exposure is more likely to predict ongoing intolerance than delayed loose stools.
Facial swelling, hives, or difficulty breathing within 30 minutes is an allergic reaction requiring immediate veterinary attention. This is rare but real. If this happens, do not reintroduce the treat.
What to do if first-use causes problems
Stop the treat for 48–72 hours until stools normalize. Then try again with a much smaller amount — literally one pinch of crumble, not a full piece — and observe for 24 hours. If that goes well, increase very slowly over 2 weeks. If even crumble amounts cause consistent GI symptoms, this treat is not the right choice for your dog and a vet consultation about food sensitivity is appropriate.