Zylkene 75 mg by Vetoquinol contains alpha-casozepine, a substance derived from cow's milk protein. It gently reduces anxiety in cats and dogs during moves, travel, vet visits, loud noises and the arrival of new people or animals. The 75 mg strength is for cats and dogs up to 10 kg — one capsule a day. Zylkene doesn't cause drowsiness: the animal stays active but calmer. It works best when started in advance, 1–2 days before a stressful event.
What it is and who makes it
Zylkene is made by Vetoquinol (France), a large veterinary company. It isn't a medicine but a nutritional supplement: alpha-casozepine resembles the substance that helps newborns relax after feeding on milk. It comes in three weight-based strengths: 75 mg (cats and dogs up to 10 kg), 225 mg (dogs of 10–30 kg) and 450 mg (dogs of 30–60 kg). Each pack holds 10 capsules.
When it helps
| Situation | How to give it |
|---|---|
| Travel, vet visit, grooming | Start 1–2 days ahead and give on the day |
| Fireworks, thunderstorms, sirens | Start 1–2 days before the expected noise and continue throughout |
| Moving, renovation, a new pet or baby | A course for the whole adaptation period |
| Stress-related marking and house soiling | A course alongside fixing the cause, on your vet's advice |
How to give it
- One 75 mg capsule a day for a cat or a dog up to 10 kg.
- Give the capsule whole, or open it and mix the powder with a little food or a treat.
- For predictable stress, start 1–2 days ahead; for long-term situations, give it as a course.
- Combine with changes in the environment: a hiding place, quiet, a stable routine, pheromones.
Pros
- No drowsiness. It doesn't sedate or switch your pet off — it stays itself.
- Gentle action. A natural milk protein component; a supplement, not a drug.
- Easy to give. The capsule can be opened and the powder mixed into food.
- For cats and dogs. The same 75 mg capsule suits cats and small dogs.
- Can be combined. Works alongside pheromones and behaviour training.
Cons and what to keep in mind
- Individual effect. Some animals respond quickly, others less so.
- Not for severe phobias. Panic, aggression or self-injury need a vet and possibly prescription medication.
- Start in advance. A capsule given during the fireworks helps less than a course started 1–2 days earlier.
- Milk protein allergy. Discuss it with your vet for animals with this allergy.
Who it suits
Cats and small dogs that fear travel, the carrier, the vet or loud noises, or react anxiously to changes at home. More about calming aids and how to help your pet during sirens and fireworks is in calming aids for dogs and cats. What to pack for air-raid alerts is in an emergency kit for cats and dogs. Other supplements are in vitamins and supplements.
What to do alongside Zylkene
The supplement takes the edge off, but the best results come from combining it with the right conditions. Get your pet used to the carrier in advance, give it a hiding place in a quiet room, keep feeding and walks on schedule, and don't scold it for being afraid. For cats, a pheromone diffuser works well; for dogs, gradual exposure to scary sounds in a calm setting.
Verdict
Zylkene is a gentle, safe helper for predictable stress: travel, vet visits, fireworks and moves. It doesn't replace a vet for serious fears, but for most everyday situations it's a convenient aid without drowsiness. The key is to start early and choose the right strength for your pet's weight.
Frequently Asked Questions
How quickly does Zylkene work?
Many owners see an effect within the first days, which is why it's recommended to start 1–2 days before a stressful situation and give another capsule at the usual time on the day itself.
Can Zylkene be given long-term?
Yes, for long periods of stress (moving, adaptation) it's given as a course; agree the duration with your vet.
Does Zylkene cause drowsiness?
No, it has no sedative effect.
Which strength for a 15 kg dog?
Dogs of 10–30 kg take the 225 mg strength — one capsule a day.
