A whelping box gives your pregnant bitch a safe, enclosed space to deliver and nurse her puppies. Whether you’re a first-time breeder or experienced, choosing the right box matters — it protects newborns from being accidentally crushed and keeps the whelping area hygienic. Here’s our guide to the best whelping boxes available in the UK for 2026.
Quick Comparison Table
| Whelping Box | Type | Sizes | Puppy Rails | Price |
|---|---|---|---|---|
| Petnap Disposable Cardboard | Cardboard | 24″–48″ | Wooden (included) | £25–£55 |
| Vetfleece Flatpack | Cardboard | 30″–48″ | Chew rails (included) | £30–£60 |
| Warwick Whelping Box | PVC/Wooden | 36″–60″ | Removable aluminium | £120–£250 |
| DIY Wooden Box | Plywood | Custom | Custom | £40–£80 materials |
What Are Puppy Rails (Pig Rails)?
Puppy rails — also called pig rails or anti-crush rails — are horizontal bars fitted around the inside perimeter of the whelping box, raised a few inches off the floor. They create a protected gap where newborn puppies can shelter if the dam rolls over. This is especially important during the first 7–10 days when puppies are blind, deaf, and unable to move away. Any whelping box you buy should have puppy rails, either built in or as an add-on.
1. Petnap Disposable Cardboard Whelping Box — Best Overall
Petnap is the UK’s best-known whelping box supplier, established in 2006. Their disposable cardboard boxes come in sizes from 24″ × 24″ (ideal for toy breeds like Chihuahuas) up to 48″ × 48″ (suitable for Labradors and Golden Retrievers). Each box includes a water-resistant liner and separate wooden puppy rails that slot into pre-cut holes.
The disposable design is the main selling point — after the litter is weaned, you simply recycle the cardboard. This eliminates the risk of pathogens or odours carrying over to the next litter. At £25–£55 depending on size, it’s excellent value for both hobby breeders and Kennel Club registered breeders.
2. Vetfleece Cardboard Flatpack Box
Vetfleece offers a similar concept with a splash-proof coating on the interior walls and integrated chew rails rather than separate wooden pig rails. The flatpack design means it arrives in a compact box and assembles in under 10 minutes. Made from fully recyclable corrugated cardboard with reinforced corners. Available in 30″ to 48″ sizes. Priced at £30–£60, slightly more than Petnap but with the added durability of the splash coating.
3. Warwick Whelping Box — Best Reusable
For breeders who whelp multiple litters per year, the Warwick Whelping Box is a worthwhile investment. Built from wipe-clean PVC-faced panels with removable aluminium puppy rails, it’s designed to last years with minimal maintenance. The front panel drops down for easy dam access, and sizes range from 36″ for medium breeds up to 60″ for giant breeds. At £120–£250, the upfront cost is significantly higher, but it pays for itself after 3–4 litters. Available directly from Warwick or specialist breeding supply shops.
4. DIY Wooden Whelping Box
Many experienced breeders build their own boxes from smooth-sanded plywood, sealed with pet-safe varnish. The advantages are custom sizing and the ability to add features like a removable front panel and adjustable puppy rails. A basic build costs around £40–£80 in materials from B&Q. The main drawback is hygiene — wood is harder to disinfect thoroughly between litters, so seal all joints with waterproof caulk and consider lining the floor with PVC sheeting.
What Size Whelping Box Do I Need?
The general rule is that the box should be 6–8 inches longer and 10–12 inches wider than the dam when she’s lying stretched out. This gives her room to move without stepping on puppies, while keeping puppies contained. Here’s a breed size guide:
| Breed Size | Examples | Recommended Box |
|---|---|---|
| Small (under 10kg) | Chihuahua, Pomeranian, Yorkie | 24″ × 24″ |
| Medium (10–25kg) | Cocker Spaniel, Beagle, Bulldog | 36″ × 36″ |
| Large (25–40kg) | Labrador, Golden Retriever, Boxer | 42″ × 42″ |
| Giant (40kg+) | Great Dane, Mastiff, St Bernard | 48″ × 48″ or larger |
Whelping Box Essentials Checklist
- Vetbed or fleece lining — wicks moisture away from puppies
- Puppy pads — for the first 48 hours under the vetbed
- Heat lamp or heat pad — maintain 29–32°C for the first week
- Thermometer — monitor box temperature
- Scales — weigh puppies daily to track growth
- Clean towels — for drying puppies immediately after birth
Frequently Asked Questions
When should I set up the whelping box?
Set up the box 7–10 days before the expected due date so the dam can get comfortable in it. Place it in a quiet, warm room away from household traffic. Let her sleep in it for several nights before whelping to build familiarity.
Can I reuse a cardboard whelping box?
We don’t recommend it. Cardboard absorbs fluids, bacteria, and odour even through liners. The whole point of disposable boxes is single-use hygiene — simply recycle after the litter is weaned (typically at 6–8 weeks) and start fresh for the next litter.
Do I need puppy rails?
Yes, absolutely. Newborn puppies are at serious risk of being accidentally crushed by the dam during the first 10 days. Puppy rails provide a safe gap around the perimeter where tiny pups can shelter. The Kennel Club and most breed clubs consider them essential equipment for responsible whelping.
Where can I buy whelping boxes in the UK?
Petnap and Vetfleece both sell directly through their websites with UK delivery. Warwick Whelping Boxes are available from their own site and specialist breeding suppliers. You can also find options on Amazon UK and eBay, though we recommend buying from specialist suppliers for quality assurance.