Brief version of what to know before walking from April onwards: ticks in long grass, adders on heaths and dunes, blue-green algae in still water, grass seeds in paws and ears, and heatstroke any time it's over 20°C. Most are easy to avoid once you know they exist; a couple are genuinely serious.
Here's a practical run-through of the hazards you'll actually encounter on UK walks between April and September. Not everything's a crisis, but a few of these can kill a dog quickly, so they're worth knowing about.
1. Ticks
The most common hazard, and the easiest to manage.
When: April to October, peaking late April–June and again in September–October.
Where: Anywhere with deer, sheep, or long grass, woodland, moorland, country parks, even some urban green spaces.
The risk: Most tick bites are uneventful, but a small percentage transmit Lyme disease, babesiosis, or other infections. UK risk is much lower than mainland Europe, but real.
Prevention:
- Spot-on or oral treatments (Frontline, Bravecto, Nexgard), most kill ticks before they can transmit disease
- Tick collars (Seresto, Foresto)
- Check your dog after every walk in tick country, feel through the coat, focusing on head, ears, neck, armpits, groin
If you find one: Use a tick twister or fine tweezers, get close to the skin, twist or pull steadily. Don't use vaseline, hot matches, or alcohol. Watch the bite site for 4–6 weeks. (We've got a full removal guide separately.)
2. Adders
The UK's only venomous snake, and underrated as a hazard.
When: April to September, mostly on warm sunny days when they're basking.
Where: Heathland, sand dunes, moorland, and chalk grassland. Common in places like Surrey heaths, the New Forest, Norfolk and Suffolk coasts, North Yorkshire moors, parts of Wales and Scotland.
The risk: Adder bites are rarely fatal to adult dogs but cause significant pain, swelling, and occasionally serious complications (particularly in small dogs). The bite usually happens on the face or front legs when a dog investigates a snake hidden in heather or grass.
Prevention:
- Stay on paths in heathland during warm weather
- Don't let dogs charge into heather, gorse, or bracken in spring/summer
- If you see an adder, walk back the way you came calmly, don't try to move it
If your dog is bitten:
- Carry them if possible (movement spreads the venom)
- Keep them as still and calm as you can
- Get to a vet immediately. This is an emergency. Don't wait to "see how they do".
- Symptoms: rapid swelling around the bite, two puncture marks, lethargy, drooling, sometimes collapse
Vets stock antivenom and most dogs make a full recovery if treated promptly. Don't delay.
3. Blue-green algae
The hazard that genuinely kills dogs, and the one most owners don't know enough about.
When: Late spring through autumn, anytime water is warm, still, and nutrient-rich. Worst in hot dry summers.
Where: Still or slow-moving freshwater, ponds, lakes, reservoirs, slow canal sections, even some park ponds. Looks like green or blue-green paint slicks, scummy foam, or pea-soup discoloration on the water surface.
The risk: "Blue-green algae" is actually cyanobacteria. Some species produce toxins that damage the liver and nervous system. Dogs can die within hours of drinking contaminated water or licking it off their fur. This isn't dramatic, multiple UK dogs die from this every summer.
Prevention:
- Don't let your dog drink from or swim in any still freshwater between May and October. Bring water from home.
- Look for warning signs at popular spots, but assume nothing if there are none, as algae blooms can appear in days
- Avoid water with green scum, foam, or unusual discoloration, but note that not all toxic algae is visibly obvious
- Rinse your dog if they've been in any natural water
If you suspect exposure:
- Take them to a vet immediately. Don't wait for symptoms.
- Symptoms: vomiting, diarrhoea (often bloody), lethargy, drooling, seizures, collapse, often within 1–2 hours
There's no antidote. Treatment is supportive. Speed matters.
This is the hazard that should change your behaviour the most. Salt water (sea swimming) is fine. Fast-flowing rivers and streams are usually fine. Still freshwater in summer should be considered guilty until proven innocent.
4. Grass seeds (foxtails)
Less dangerous, but very common and surprisingly nasty.
When: May to August.
Where: Anywhere with long, dry grass that's gone to seed.
The risk: Grass seeds are arrow-shaped, barbed at one end, pointed at the other. They work their way into a dog's body and don't come back out:
- Paws — typically between the toes. The dog limps and licks the foot. Seeds can migrate up the leg and abscess.
- Ears — sudden head-shaking and pawing at one ear after a walk in long grass. Seeds in the ear canal usually need vet removal.
- Eyes — squinting and watering after a walk. Vet visit immediately.
- Nose — sudden violent sneezing fits, sometimes nosebleed.
Prevention:
- Avoid long dry meadows in peak grass-seed season, especially with fluffy/feathered breeds (Spaniels, Cockapoos, Setters)
- Trim feathering on paws and around ears in summer
- Check between toes after every walk, feel for swelling or look for a small entry wound
- Wipe down ears, eyes, and muzzle after walking in long grass
If you suspect a grass seed: Don't dig at it. Vet visit. Removal usually requires sedation, especially if it's already migrated.
5. Heatstroke
The hazard that kills the most UK dogs every year.
When: Anytime over ~20°C, especially over 24°C. Worse in humidity.
Where: Anywhere, but particularly in cars (even briefly), on tarmac, in poorly ventilated rooms, on long walks at the wrong time of day.
The risk: Dogs cool themselves mostly by panting, which is much less effective than human sweating. A dog can go from "panting" to "in serious trouble" in under 15 minutes on a hot day. Brachycephalic breeds (Pugs, French Bulldogs, Bulldogs, Shih Tzus) are dramatically more vulnerable.
Prevention:
- Don't leave dogs in cars. Ever, in summer. "Just five minutes" is how dogs die.
- Walk early morning (before 8am) or late evening (after 8pm) in hot weather. Skip walks if it's properly hot, a missed walk won't hurt them.
- Test pavement with the back of your hand, if you can't hold it for 5 seconds, it's too hot for paws.
- Always carry water on summer walks
- Avoid running, fetch, or any sustained exercise in heat
- Brachycephalic breeds shouldn't be walked at all in genuinely hot weather
Signs of heatstroke:
- Heavy panting that doesn't slow down
- Bright red gums, drooling
- Lethargy or stumbling
- Vomiting
- Collapse
If you suspect heatstroke:
- Move to shade immediately
- Pour cool (not ice-cold) water over them, especially neck, armpits, groin
- Offer water but don't force it
- Get to a vet immediately, even if they "seem fine again"
The "cool first, transport second" advice has been confirmed by recent research. Get them cooling down on the spot, then drive.
6. Bee and wasp stings
When: May to September.
Where: Anywhere there are flowers or flying insects.
The risk: Most stings are like ours, painful, briefly swollen, fine in a day. Stings to the mouth, throat, or eyes are more serious and can cause swelling that obstructs breathing.
If your dog is stung:
- One sting on a leg or paw, usually fine to monitor. Cool compress helps.
- Sting to the face, mouth, or throat, vet visit. Especially if breathing changes.
- Multiple stings, vet visit.
- Any sign of allergic reaction (hives, vomiting, collapse), emergency.
7. Sunburn
Yes, dogs get it.
Where: Pink-skinned areas, bellies (white-coated dogs), nose tips, ear edges, especially in short-coated breeds (Boxers, Whippets, hairless breeds).
Prevention: Pet-safe sunscreen on exposed pink skin during long sunny outings. Avoid midday sun.
8. Salt water and rough sea
A short note. Salt water itself isn't dangerous in small amounts, but a dog who drinks lots of seawater will likely have very dramatic vomiting and diarrhoea ("beach diarrhoea"), occasionally needing fluids.
Rough sea is more dangerous, strong currents, undertows, and waves that look fine until your dog is 100m offshore. Many dogs die in the sea each year, particularly inexperienced swimmers chasing balls.
A general rule for warm-weather walking
If you're not sure whether something's safe, water, terrain, the temperature, assume it's not, and walk somewhere else. There's almost always another walk that's clearly safe; you don't need to gamble on the marginal one.
What to put in your summer dog walking bag
- Water bottle and collapsible bowl
- Tick twister
- A clean towel
- Spare poo bags (you always need more)
- A first-aid wipe or two
- Your vet's number saved on your phone
That's the lot. Most summer hazards are entirely avoidable once you know about them.
FAQs
Is it safe for my dog to swim in lakes and ponds in summer? Generally no, risk of blue-green algae is real and rising. Stick to fast-flowing rivers, salt water, or paddling pools.
What temperature is too hot to walk a dog? Loose rule: above 24°C is risky for most dogs. Above 28°C is risky for any dog. Brachycephalic breeds shouldn't be walked above ~20°C.
Are adders aggressive? No, they're shy and try to escape. Most bites happen because a dog stuck their face in the heather where the snake was hiding.
My dog ate something on a walk, what do I do? Photo it if you can, and call your vet or the Animal PoisonLine (a paid VPIS service for owners). For mushrooms, plants, fruits, and any human food, assume it's worth a phone call.
Are most UK summer walks actually safe? Yes. The point of this guide isn't to make you nervous, it's to make you informed about the few hazards that actually matter. 99% of summer walks are fine.