Leptospirosis is a bacterial infection dogs pick up from water and soil contaminated by wildlife urine. Risk rises in Delta each autumn as rain refills ditches and sloughs. Early signs are vague: low energy, poor appetite, vomiting, sore muscles or increased drinking. It can affect the kidneys and liver, so early veterinary attention matters.
Why September changes the picture in Delta
For most of the summer the ditches around Ladner run low or dry out altogether. Then the rain returns, usually in the second half of September, and everything refills at once. Standing water reappears along the dyke trails, in the field margins, in the roadside ditches and in the low corners of back gardens.
That matters because leptospira bacteria do not survive well in hot, dry conditions. They survive very well in exactly what Delta gets from mid-September onward: mild temperatures, persistent damp, and shallow water that sits still for days.
The other half of the picture is the wildlife. Delta is farmland, foreshore and waterway, and it supports a large population of rats, mice, raccoons, skunks and other animals that carry leptospira without appearing unwell. They pass the bacteria in their urine. Rain moves it into puddles and ditches. A dog takes a drink, wades through, or walks through and licks its paws afterward, and that is the whole transmission route.
Autumn also concentrates rodents. As fields are harvested and the weather turns, rats and mice move toward barns, outbuildings, compost heaps and houses. More rodents in the places dogs go means more opportunity.
How dogs actually pick it up around here
It is rarely dramatic. The common routes are ordinary:
- Drinking from a puddle, ditch, slough or a flooded field edge on a walk
- Wading or swimming in slow-moving or standing water
- Walking through wet ground, then grooming the paws and legs at home
- Nosing around compost, woodpiles, sheds or feed stores where rodents are active
- Contact with rodents directly, including dogs who hunt them
- Standing water in your own garden, including under a tap, in a wheelbarrow or in a saucer beneath a plant pot
Bacteria enter through the mouth, the nose, the eyes, or through a scratch or graze in the skin. A dog does not need to swim to be exposed. A muddy walk and a thorough paw-lick afterward is enough.
Cats can be exposed too but very rarely become unwell, so this is mostly a dog conversation.
The early signs are frustratingly vague
This is the part worth reading twice, because leptospirosis does not announce itself. The first days often look like a dog who is simply off colour. Watch for:
- Low energy, or reluctance to go on the usual walk
- Reduced appetite or refusing food entirely
- Vomiting, sometimes with diarrhea
- Fever, shivering, or a dog who feels warm and looks miserable
- Stiffness, a hunched posture, or apparent muscle soreness
- Drinking noticeably more, or passing much more or much less urine than usual
- Yellowing of the gums, the whites of the eyes or the skin inside the ears
- Reluctance to be touched around the back or belly
The change in drinking and urinating is the one owners most often dismiss, and it is one of the more meaningful. Any dog that suddenly empties the water bowl and asks to go out repeatedly deserves a call, whatever the season.
Yellowing of the gums or eyes, or a dog that becomes withdrawn and will not stand, should be seen at once through our urgent care rather than waited on overnight.
Why we take it seriously
Leptospirosis is not just an upset stomach that passes. The bacteria target the kidneys and the liver, and the damage can be significant and can develop quickly. Some dogs recover fully with prompt care. Some are left with lasting kidney changes. A proportion do not survive it.
Two things improve the odds more than anything else: getting the dog seen early rather than waiting out day three, and telling us about the water. A history of ditch swimming, puddle drinking or a farm walk changes what we look for and how fast we look for it. Please volunteer that detail even if it feels irrelevant.
The part that concerns your family too
Leptospirosis is zoonotic, meaning it can pass from animals to people. This is not a reason for alarm, but it is a reason for sensible hygiene while a dog is unwell and being investigated.
- Wash your hands after handling your dog, its bedding, its bowls or its waste
- Wear gloves when cleaning up urine, and avoid hosing it around as a spray
- Keep children away from puddles of your dog’s urine
- Tell us if anyone at home is pregnant, elderly or has a weakened immune system, so we can give you specific advice
The same goes for the source. Nobody in the household should be drinking from or swimming in a Delta ditch either.
Lowering the risk before the wet months set in
You cannot drain Delta, and you should not stop walking your dog. What you can do is reduce the easy exposures.
- Bring water with you. A dog with a full bowl before it leaves and a bottle on the walk is far less interested in a ditch. This is the single most effective habit.
- Discourage puddle drinking. Teach a reliable leave and use it. It is worth the training time.
- Choose the route. Gravel paths and mown grass over flooded field margins and slow ditch water, particularly after heavy rain. Our guide to trail and park safety around Ladner and Delta covers route choice in more depth.
- Rinse and dry after muddy walks. A quick rinse of the legs and belly removes what your dog would otherwise lick off.
- Deal with standing water at home. Tip out buckets, wheelbarrows, plant saucers and paddling pools. Refresh outdoor water bowls daily rather than topping them up.
- Make the garden less attractive to rodents. Secure bins, lift fallen fruit, store feed in sealed containers, and keep woodpiles away from where the dog sleeps or plays.
- Talk to us about vaccination. A leptospirosis vaccine exists and is widely used for dogs with this kind of lifestyle. Whether it suits your dog depends on where you walk, what you do together and your dog’s own history, so it is a conversation rather than a default. Our wellness programs are where that gets worked out.
A note for farm dogs and working dogs
Delta has plenty of dogs who live on or visit properties with livestock, outbuildings and grain stores. Their exposure profile is different from a dog who walks the village streets. Rodent contact is routine, water sources are less controlled, and the dogs are often out of sight for long stretches, so an early off day is easier to miss.
If that describes your dog, tell us. It changes what we recommend and how closely we want to hear about vague off-colour days.
Frequently asked questions
My dog drinks from puddles constantly. Should I panic?
No, but it is worth changing. Most puddle drinks cause nothing at all. The point is that it is a repeated, avoidable exposure across a long wet season, and the habit is easy to reduce by carrying water and teaching a leave command. Raise it at your next visit rather than worrying about a single drink.
How soon after exposure would my dog seem unwell?
Usually within about a week, though it can be longer. That gap is exactly why the water history matters. By the time a dog looks off, the muddy walk has often been forgotten, so mention any ditch, slough or flooded field from the previous couple of weeks even if it seems unconnected.
Is the vaccine a guarantee?
No vaccine is. It targets the strains most commonly seen and it substantially reduces risk, but it does not replace sensible avoidance of standing water. Think of it as one layer alongside the habits above rather than as permission to let your dog drink from ditches.
Can my indoor cat catch it from my dog?
Cats are exposed far less often and rarely become unwell, so this is not a common concern. Standard hygiene while a dog is being investigated is sensible regardless. If your cat goes outside and hunts rodents, mention that at your next appointment.
The ditches near me look clean. Does that mean the water is safe?
Clear water tells you nothing useful here. Leptospira are microscopic, and the water that carries them often looks perfectly ordinary. Judge by whether the water is still or slow moving and whether wildlife has access, not by how it looks.
My dog is off his food and a bit quiet. Is that enough to bring him in?
Yes, particularly in the autumn and particularly if he has been anywhere wet. A quiet dog who is off his food for a day is worth a phone call. Most turn out to be something minor, and the ones that are not benefit enormously from being seen early.
Speak to the team at 48th Avenue Animal Hospital
If your dog swims, wades or drinks from ditches around Delta, talk to us about the right prevention plan before the wet months set in.
Published by the team at 48th Avenue Animal Hospital.
This article is for general educational purposes only and is not a substitute for an in-person veterinary examination or advice about your individual pet. If you have an urgent concern about your pet, contact 48th Avenue Animal Hospital or your nearest emergency veterinary hospital right away.
48th Avenue Animal Hospital
5020 48 Ave, Delta, BC V4K 3V3
Phone: (604) 946-7779
Hours: Monday to Friday 8:00 AM to 8:00 PM; Saturday and Sunday 9:00 AM to 5:00 PM