Common questions, answered honestly.

We dispatch from inside the EU and ship internationally with tracked delivery — including the UK, EU, US, Canada, Australia, and most other countries. Every order includes a tracking number so you can follow it to your door.

United Kingdom and European Union: 3–7 business days. United States and Canada: 7–14 business days. Australia and New Zealand: 7–18 business days. Rest of world: 7–21 business days. We dispatch within 1 business day of order.

Flat £4.99 tracked international shipping, regardless of destination. Single-box orders sit below the typical import-VAT thresholds in most destinations, so customs charges are rare. Where local duties apply, they remain the customer's responsibility — see the Shipping page for details.

You have 30 days from delivery to request a return for a full refund. Buyer pays return shipping. If the box arrives damaged or never arrives, we replace it at our cost — contact us with your tracking number.

Checkout is handled by our payment partner. You'll be redirected to complete payment securely outside this site. Major credit/debit cards and PayPal are accepted.

Yes — loyalty and multi-box discounts are available. Get in touch and we'll sort out a price for your order size. Breeders, multi-pet households, and rescue organisations: contact us for bulk pricing.

You'll receive a tracking number by email within 1 business day of order. Use the Order Tracking page or the tracking link in your dispatch email.

No. Biheldon is an intestinal wormer only — it contains no insecticide. To treat fleas you need a separate product, typically a spot-on (Frontline, Advantage) or an oral isoxazoline (NexGard, Bravecto). You can use a flea product and Biheldon on the same day for most pets, but stagger by 24 hours if your pet has a history of sensitivity to either.

No. Lungworm (Angiostrongylus vasorum) is transmitted by slugs and snails and is now endemic across much of the UK. Treating lungworm requires a prescription product containing milbemycin oxime (Milbemax) or moxidectin (Advocate, Bravecto Plus), given monthly in at-risk areas. If you suspect lungworm — persistent cough, breathing difficulty, unexplained bleeding, lethargy — see a vet immediately.

Consult your vet first. Both praziquantel and pyrantel embonate have a good safety record in pregnant and lactating animals (pyrantel embonate is poorly absorbed; praziquantel is FDA category B in humans). However, dosing during pregnancy is a clinical judgement and depends on stage of pregnancy, other medications, and your vet's protocol. Do not self-medicate a pregnant pet.

Praziquantel acts within hours — it causes near-instantaneous paralysis of tapeworms on contact, and dead worm segments are typically passed in the stool within 24–48 hours. Pyrantel embonate paralyses roundworms and hookworms within the same window, and worms are then expelled by normal gut peristalsis. You may not see worms in the stool at all if the parasite load was low — that is normal and does not mean the treatment failed.

No. Biheldon is imported as an EU-authorised veterinary medicine and supplied directly to pet owners — no UK vet prescription is required for purchase. The active ingredients (praziquantel and pyrantel embonate) are themselves NFA-VPS class in the UK supply chain when sold by domestic brands like Drontal Cat.

Re-dose with the same amount, ideally with a small amount of food. Both active ingredients begin to be absorbed within 30 minutes, but a tablet that comes back up whole or partially dissolved is unlikely to have delivered a full dose. If vomiting persists beyond the first dose, stop and contact a vet — persistent vomiting is rarely caused by the wormer itself and usually points to a separate issue.

Both active ingredients have a high safety margin. Reported side effects are rare and almost always mild and transient: occasional GI upset (soft stools, mild nausea, reduced appetite) for 12–24 hours after dosing. Serious side effects are very uncommon. If your pet shows any unusual behaviour, lethargy, persistent vomiting, or signs of an allergic reaction (facial swelling, hives, difficulty breathing) after taking Biheldon, stop further dosing and contact your vet.

Yes. Biheldon tablets are scored on both sides so they can be split into halves or quarters for accurate dosing of pets under 10 kg. See the dosing table for the exact split by body weight. Split tablets can be stored in the blister pack for the next dose, ideally used within 28 days.

Puppies from 4 weeks of age (and weighing enough for at least a quarter-tablet) can use Biheldon. The puppy schedule is every 2 weeks until 12 weeks old, then every 3 months. Kittens can use Biheldon from approximately 6–8 weeks of age, once they reach ~1.5 lb (700 g) body weight. Do not use earlier than this — both products are licensed from these ages in their UK equivalents (Drontal Cat, Drontal Puppy Suspension).

ESCCAP UK recommends a minimum of four times a year (every 3 months) for adult dogs and cats with outdoor access. Push to every 2 months — or monthly — if your pet hunts, eats raw food, lives with young children or anyone immunocompromised, or you live in a high-Echinococcus area (parts of Wales, Hebrides). Puppies and kittens need worming more often during their first 12 weeks of life.