What is better for ticks — a spot-on or a tablet?

For ticks, oral isoxazoline tablets (Bravecto, NexGard, Simparica, Credelio) are more effective: they work systemically and kill the tick when it bites, before most disease transmission can occur. Spot-ons work on the skin surface and also offer a repellent effect. For fleas, both formats are highly effective.

How often do you apply a spot-on?

Standard spot-ons last 4 weeks. Some premium products (Vectra 3D, Advantix) also last one month. Apply to the back of the neck where the dog cannot lick it off. Frequent bathing or swimming can reduce effectiveness.

Are isoxazoline tablets safe for dogs?

In 2018 the FDA issued an alert about rare neurological side effects (tremors, seizures) in some animals — the incidence is very low. Dogs with a history of epilepsy or neurological conditions should be discussed with a vet before prescribing. In healthy dogs the safety profile is good.

Is a collar enough protection on its own?

The Seresto collar (8 months) or Scalibor (3–6 months) provides solid continuous protection. It may fall short in very high-tick-burden areas or for dogs that swim frequently. In those cases, combining with a spot-on or tablet is recommended.

Spot-On vs Tablets: Which Parasite Prevention Is Best for Your Dog?

The Four Formats and How They Work

Spot-on (pipette)

Concentrated liquid applied directly to the skin at the back of the neck. It spreads through the lipid layer of skin and coat. Mechanism: contact kill when the parasite touches the skin or coat. Some also have a repellent effect (Advantix, Vectra 3D). Typical duration: 4 weeks. Effectiveness can be reduced by frequent bathing or swimming.

Oral tablets (isoxazolines)

Distributed throughout the body via the bloodstream. Mechanism: the parasite dies when it bites the dog — the tick absorbs the active ingredient while feeding. Key advantage: very high efficacy; ticks die before most pathogens can be transmitted. Duration: 1 month (afoxolaner/NexGard, sarolaner/Simparica, lotilaner/Credelio) or 3 months (fluralaner/Bravecto). Unaffected by bathing or rain.

Collars

Release active ingredients continuously onto skin and coat. Advantage: months of uninterrupted protection (Seresto 8 months, Scalibor 3–6 months). Limitation: distribution may be uneven in very thick coats; effectiveness can reduce if the collar is frequently wet.

Combinations

In high-risk areas or during summer, many vets recommend combining formats: oral tablet (maximum acaricidal power) + collar or spot-on with repellent effect. This combination provides the most comprehensive protection.

Quick Comparison

Format	Fleas	Ticks	Repellent	Duration	Water resistance
Standard spot-on (Frontline)	✅	✅	❌	4 wks	Reduced by bathing
Premium spot-on (Advantix, Vectra)	✅	✅	✅	4 wks	Reduced by bathing
Tablet (NexGard, Simparica)	✅	✅✅	❌	1 month	Not affected
Tablet (Bravecto)	✅	✅✅	❌	3 months	Not affected
Collar (Seresto)	✅	✅	✅	8 months	Slightly reduced

Which Format for Which Situation

Dog that swims or bathes frequently: oral tablet — unaffected by water.
High tick burden area / summer: oral tablet + collar or repellent spot-on for combined protection.
Dog travelling abroad: ask your vet about destination-specific parasites (leishmaniasis, heartworm) — additional protection may be needed.
Puppy under 8 weeks: most products have a minimum age — always ask a vet first.
Dog with epilepsy or neurological history: discuss isoxazolines with your vet before use.
Want to forget about it for months: Bravecto oral (3 months) or Seresto collar (8 months).

Log your dog's parasite prevention in Purzi — product name, application date and next due date. You will never miss a treatment, which matters most in summer when the risk is at its peak.