Harmattan gets all the attention because it is dramatic. Dust, cracked paw pads, dry noses, visible discomfort. The rainy season is sneakier. Nothing looks urgent, so people relax, and then somewhere between June and October the dog develops a stubborn ear infection, the cat starts scratching bald patches, and a bag of kibble that smelled fine two weeks ago is quietly growing something you cannot see.
Three things change when the rains arrive: standing water, mosquito populations, and ambient humidity. Almost every rainy-season pet problem traces back to one of those three. Here is what each one does and what you can actually do about it.
Standing water is not just mud
The puddle at your gate, the water sitting in a blocked drain, the flooded corner of the compound: to your dog these are drinking bowls and paddling pools. To a vet they are the main rainy-season transmission route for leptospirosis.
Leptospirosis is a bacterial infection shed in the urine of infected animals, rats above all, and heavy rain washes that contamination into puddles, drains and low-lying ground where it survives well in warm, wet conditions. Dogs pick it up by drinking, wading, or getting it into a cut or a mucous membrane. It can cause vomiting, lethargy, fever, muscle pain, increased thirst and, in serious cases, kidney and liver failure. Nigerian veterinary studies have found meaningful exposure in dog populations in Jos and Abuja, so this is not an imported worry. It is also zoonotic, meaning an infected dog can pass it to the people in the house.
- Ask your vet whether a leptospirosis vaccine is available and appropriate for your dog. Local coverage varies, so this is a conversation, not an assumption.
- Do not let your dog drink from puddles, gutters or standing compound water. Carry water on walks.
- Clear standing water around the house where you can, and take rat control seriously. Fewer rats means less contamination.
- Rinse and dry your dog’s legs and belly after a wet walk, and wash your hands after handling a soaked dog.
- If your dog goes off food, seems weak, drinks unusually, or looks yellow around the gums or eyes after wet-weather exposure, treat it as urgent.
Floodwater carries more than bacteria. It also carries sewage, engine oil, broken glass and displaced snakes. If your area floods, keep pets indoors and off the water entirely rather than trusting them to pick their way through it.
Mosquitoes and the parasite season
Mosquito numbers climb sharply once the rains create breeding sites, and mosquitoes are how canine heartworm spreads. The larvae enter through a bite, mature into worms that live in the heart and lungs, and by the time a dog is coughing or tiring easily the disease is already advanced. Treatment is expensive, hard on the animal, and not always available locally. Prevention is a monthly or seasonal medication your vet prescribes, and it is dramatically cheaper than the alternative.
Ticks and fleas also do well in wet warmth. Tick-borne diseases like ehrlichiosis and babesiosis are a familiar problem for Nigerian vets, and they present vaguely at first: a dog that is quiet, off its food, running a fever, maybe with pale gums. Do not wait for the classic picture. Our guide to common pet health risks in West Africa goes into what these infections look like in practice.
- Keep parasite prevention running through the rains rather than pausing it. This is the season it earns its keep.
- Empty anything holding water: buckets, old tires, plant saucers, the lid of the generator. Those are mosquito nurseries.
- Check your dog for ticks daily during the rains, especially ears, armpits, groin and between the toes.
- Cut the grass. Long wet grass is where ticks wait.
Humidity, skin and ears
Persistent damp is what turns minor skin issues into month-long ones. Yeast and fungal organisms that live harmlessly on healthy skin multiply when the coat stays wet, and ringworm, a fungus despite the name, spreads more easily in humid conditions. Cats are as affected as dogs, and ringworm passes to people.
Ears are the most common casualty. A warm, wet ear canal is exactly the environment bacteria and yeast want, and floppy-eared dogs are worst affected because the flap seals the moisture in. Head shaking, scratching at one ear, a bad smell or dark discharge means a vet visit, not a home remedy. Pouring anything into an ear you have not had examined can make a treatable infection much worse.
- Dry your pet properly after every soaking, right down to the skin, not just the top of the coat. A towel and a fan beat leaving them to air-dry in humid air.
- Dry inside the ear flaps and check them weekly.
- Wash and fully dry bedding often. Damp bedding that never dries is a fungal culture.
- Watch the paws. Persistent licking between the toes usually means an infection has taken hold there.
- Treat any hairless, crusty, circular patch as possible ringworm and get it diagnosed rather than guessing.
Mould in the food, not just the walls
This is the one people miss. Dry pet food is largely grain-based, and moulds in the Aspergillus family grow readily on grain once ambient humidity is high. Some of them produce aflatoxins, which damage the liver. Dogs are notably sensitive to aflatoxin, and the toxins can be present with no visible mould and no obvious smell.
An opened bag left in a humid kitchen for weeks is the classic setup. So is buying loose kibble scooped from an open sack of unknown age at the market, which is common and which removes any batch information you would need if there were ever a recall.
- Buy smaller bags more often during the rains rather than bulk-buying to save money.
- Keep the food in its original bag, and put that bag inside a sealed airtight container. The bag carries the batch number.
- Store it off the floor and away from damp walls, not in the store or the boys’ quarters where humidity sits.
- Wash and dry food bowls daily. A film of old wet food in a humid room ferments fast.
- Throw out anything that smells musty or stale. Guessing is not worth a liver.
The routine that holds it together
Rain also disrupts exercise, and a bored dog indoors for three wet days becomes a destructive dog. Use the dry windows when they come, even if that means walking at odd hours, and fill the gaps with scent games, chew items and short training sessions inside. The same logic applies to cats, who get restless when they cannot patrol the compound.
Keep a small dry-season habit going all year: weekly hands-on checks of ears, paws, skin and coat. Two minutes tells you what is changing before it becomes a problem, and it makes a vet visit far more useful because you can say when something started. If you are not sure where to start, our pet first aid guide covers what to keep on hand, and the companion piece on harmattan season completes the picture for the other half of the Nigerian year.
