What a small dog actually needs
The most common mistake with small breeds is assuming more chews work faster. They don't. ThunderBites Calm + Probiotic, the daily chew this page focuses on, is dosed by body weight, and for a dog 25 lbs and under the label dose is a single chew a day. That one chew carries 1.5 mg melatonin, a meaningful dose for a small dog, so ask your vet before starting, especially for very small dogs, puppies, pregnant dogs or dogs on medication. Doubling up doesn't calm a dog quicker; it just delivers more melatonin and other actives than the dog is meant to have, which can leave a tiny dog groggy or unsettle its stomach.
The second mistake is expecting a switch to flip. These chews are a daily supplement, not a fast-acting sedative. Judge it after 14 days of daily use, not after one storm. The fair test is consistency over those weeks alongside training and environment changes, not a single stressful evening. The chews are for dogs 12 weeks and older; check your dog's age before starting.
Original10 mcg melatonin, 15 mg L-tryptophan, 50 mg chamomile, 25 mg thiamine per chew
- Dose by weight
- Up to 26 lb: 1 · 27–50 lb: 2 · 51–99 lb: 4 · 100+ lb: 6
- How to use
- As needed, 30 min before the stressor
HempSame actives as Original plus 75 mg hemp seed oil and 75 mg hemp seed powder (not CBD)
- Dose by weight
- Up to 26 lb: 1 · 27–50 lb: 2 · 51–99 lb: 4 · 100+ lb: 6
- How to use
- As needed, 30 min before the stressor
Calm + Probiotic1.5 mg melatonin, 30 mg L-theanine, 150 mg ashwagandha, 3 billion CFU per chew
- Dose by weight
- Up to 25 lb: 1 · 26–50 lb: 2 · 51–75 lb: 3 · 76–100 lb: 4
- How to use
- Daily, every day
From ThunderWorks labels (actives listed per 2 chews, shown here per chew). Ask your vet before giving Calm + Probiotic to small dogs, puppies, pregnant dogs or dogs on medication.
Dosing and splitting for tiny dogs
Here is the manufacturer's weight-based dosing for Calm + Probiotic (90-count jar) so you can see where your dog lands. Nearly every small breed sits in the top row.
| Dog weight | Chews per day | Typical small breeds | How long a 90-count jar lasts |
|---|---|---|---|
| Up to 25 lbs | 1 chew | Chihuahua, Yorkie, Maltese, Pomeranian, Toy Poodle | About 3 months |
| 26–50 lbs | 2 chews | Larger Beagles and Cocker Spaniels (many weigh close to 25 lb, so weigh your dog before choosing the band) | About 45 days |
| 51–75 lbs | 3 chews | Border Collie, Bulldog | About 30 days |
| 76–100 lbs | 4 chews | Labrador, Golden Retriever | About 22 days |
Because the chews are soft, they cut in half with a knife or crumble easily into food. For a dog at the very bottom of the weight range, or a fussy eater, mixing a chew into a meal or introducing it in halves over a few days can make it go down more easily. Splitting is about palatability and easing the dog in, not a way to under-dose a calm dog on purpose. If your dog is only a few pounds and you're unsure the single-chew dose is right, ask your vet before adjusting.
Related: Are ThunderBites dog calming chews too hard for small breeds
Which version to buy
ThunderBites comes in different formulas, and they do not share the same calming base. For a small dog, the choice comes down to how you'll use it and whether gut health is also a concern.
- Regular Calming Chews (formerly ThunderWunders, 60 count): chamomile, thiamine, passion flower, ginger, L-tryptophan and 10 mcg melatonin per chew, given 30 minutes before a stressful situation. Dogs up to 26 lb take 1 chew; no more than double in 12 hours. A good fit for occasional events.
- Calm + Probiotic (90 count): a daily chew with ashwagandha, L-theanine, 1.5 mg melatonin per chew, plus probiotics, prebiotics, and postbiotics for digestive support. Worth it if your small dog has soft stools, a sensitive stomach, or you want a daily gut-support routine bundled in.
The calming panels differ. Per chew, Calm + Probiotic has 150 mg ashwagandha, 30 mg L-theanine, 15 mg L-tryptophan, 10 mg chamomile and 1.5 mg melatonin; the regular chew has no ashwagandha or L-theanine and only 10 mcg melatonin (150 times less). The probiotic version featured here also carries 3 billion CFU per chew (6 billion per 2 chews) of probiotics.
Related: ThunderBites probiotic vs regular calming chews which better
What to check before you buy
- NASC seal: ThunderBites is NASC certified. The National Animal Supplement Council seal signals the maker meets quality and labeling standards — a reasonable baseline to look for on any dog supplement.
- Version match: confirm you're ordering the formula you want (plain Calming, 60 count, vs Calm + Probiotic, 90 count), since the jars look similar.
- Flavor and palatability: these are chicken-flavored soft chews, which most dogs take as a treat. If your small dog is an especially picky eater, plan to crumble the first few into food.
- Count and value: the Calm + Probiotic jar holds 90 chews; for a one-chew-a-day small dog that's about a three-month supply.
- Vet check first: if your dog is pregnant, on medication, or has a health condition, clear any new supplement with your veterinarian before starting.
If your small dog's anxiety is mild to moderate and tied to everyday triggers — noises, being left alone, car trips — a once-daily calming chew is a sensible thing to try. Start with the single chew, give it consistent time, and adjust with your vet if needed. It pairs well with other tools like a snug wrap or crate training on rough days.