Mediterranean Pet Safety: Preventing Leishmaniasis and Heartworm on the Road

For those in a rush to hit the road, here is the executive summary of what you need to know this season.

• Sandflies are tiny: Standard campervan mosquito nets will NOT stop them. You need 0.6mm mesh or treated nets.
• Geography has changed: As of 2026, sandfly pockets are confirmed as far north as Paris and Southern Germany. Do not assume 'North' means safe.
• The 'Double Defense' Rule: Repellency (to stop the bite) + Internal Prevention (to kill the larvae). You need both.
• Dusk and Dawn: These are high-risk times. Walk your dog when the sun is high or fully set, avoiding the twilight hours.
• Vaccines: The third-generation Leishmaniasis vaccines available in Europe offer better protection than older models, but they do not replace repellents.

To defeat the enemy, you must understand their tactics. These are not just 'bugs'; they are vectors for systemic diseases that can shorten your dog's life.

The Sandfly (Leishmaniasis Vector)

Unlike mosquitoes, sandflies do not hum. They are silent, erratic fliers, and they are tiny-about a third of the size of a mosquito. They thrive in arid, dry environments but need moisture to breed, often found in stone walls, cracked earth, and rural gardens.

The Mechanism: When an infected sandfly bites your dog, it deposits Leishmania protozoa. This attacks the immune system, kidneys, and skin. It is difficult to cure and expensive to manage.

The Mosquito (Heartworm Vector)

Heartworm (Dirofilaria immitis) is transmitted by various mosquito species, including the aggressive Tiger Mosquito which is now common across Southern Europe.

The Mechanism: Larvae enter the bloodstream through a bite, migrating to the heart and lungs where they grow into foot-long worms. This causes heart failure and lung disease. Unlike Leishmaniasis, Heartworm is easier to prevent with monthly tablets but dangerous to treat once established.

If you are using travel guides from 2023 or 2024, throw them out. The data is obsolete. As we settle into 2026, climate shifts have expanded the habitat for both vectors.

RVT Tip: If you are wintering in Spain or Portugal (a popular vanlife choice), protection must be maintained 12 months a year. The insects do not hibernate if the temperature stays above 10°C (50°F).

As a Veterinary Technician, I categorize protection into two distinct layers: Repellency (The Shield) and Intervention (The Cleanup). You cannot rely on just one.

Layer 1: Repellency (The Shield)

The goal here is to stop the bite from happening. If the sandfly doesn't feed, it can't transmit the disease.

• Scalibor Collar Europe: Still the gold standard for sandflies. The Deltamethrin spreads across the lipid layer of the skin.
  • Pros: proven efficacy against sandflies (approx. 95%), lasts 5-6 months, water-resistant.
  • Cons: Can be toxic to cats (keep separated), some dogs develop skin reactions.
• Seresto Collar: excellent for fleas and ticks, but check the packaging. In some markets, the claim for Leishmania reduction varies. It acts by repelling the fly, but Deltamethrin (Scalibor) historically has stronger data for sandflies specifically.
• Spot-Ons (Advantix / Vectra 3D): These contain Permethrin. They repel mosquitoes and sandflies brilliantly.
  • Frequency: In high-risk zones, we now recommend applying every 3 weeks rather than 4, as efficacy dips towards the end of the month.
  • Warning: Permethrin is FATAL to cats. If you have a mixed van household, this is a major risk.

Layer 2: Intervention (The Cleanup)

If a mosquito bites, we need to kill the larvae before they reach the heart.

• Milbemax / Milbactor: Oral tablets containing Milbemycin.
  • Protocol: Must be given every 28 days precisely.
  • Bonus: Also treats intestinal worms (hookworm, roundworm) and acts as part of the requirement for the Animal Health Certificate when returning to the UK (for tapeworm).

The Vaccine Question

In 2026, the LetiFend and CanLeish vaccines have seen updates.

• Efficacy: They do not prevent infection 100%, but they drastically reduce the likelihood of the dog developing severe clinical disease.
• Recommendation: If you are spending more than 4 weeks in the Mediterranean, vaccinate. Combine this with a collar. Do not use the vaccine as a standalone shield.

Chemicals are great, but physics is better. Creating a 'safe zone' inside your van is critical for sleeping soundly.

1. Upgrade Your Screens: Standard fly screens on Dometic or Seitz windows often have holes around 1.2mm x 1.2mm. A sandfly is roughly 1.5mm-3mm long but can navigate surprisingly small gaps. For true safety, you need sandfly-proof mesh (often called 'midge mesh' in the UK), which has a tighter weave (at least 600 holes per square inch).

2. The Fan Strategy: Sandflies are terrible flyers. They cannot navigate strong air currents. A high-velocity fan (like a MaxxFan set to 'intake') pointed at the sleeping area creates a turbulent barrier that insects struggle to penetrate.

3. Parking Hygiene:

   • Avoid: Old stone barns, piles of organic debris, and damp, wind-protected corners. This is where sandflies breed.
   • Seek: Open, breezy hilltops or coastal spots with a strong onshore wind.

4. Elevated Sleeping: Sandflies are 'hoppers' rather than strong fliers. They tend to stay close to the ground (under 1-2 meters). If your van has a pop-top or a high fixed bed, your dog is marginally safer than if they sleep on the floor.

Despite our best efforts, nature finds a way. Knowing the symptoms can save your dog's life.

Early Signs of Leishmaniasis

• Skin lesions: Patches of hair loss (alopecia), especially around the eyes (spectacles), nose, and ear tips.
• Dermatitis: Dry, flaky skin that doesn't heal.
• Weight loss: Despite a normal appetite.
• Long nails: Abnormally fast nail growth (onychogryphosis) is a classic 'tell'.

Early Signs of Heartworm

• Cough: A dry, lingering cough, especially after exercise.
• Lethargy: Unwillingness to go for walks.
• Breathing difficulty: Rapid or shallow breaths.

The 2026 Vet Visit: If you have been traveling in the Mediterranean, ask your home vet for a Leishmania titre test and a Heartworm antigen test 6 months after you return. It can take that long for antibodies to show up. A negative test immediately upon return can be a false negative.