Two different problems, often confused
These two conditions sound similar and are often mixed up, but they happen in different ways. Water intoxication is about volume swallowed: a dog playing in water can take in far more than his body can handle, most commonly during repeated retrieving from a pool, lake, or sea, snapping at water from a hose or sprinkler, or diving again and again for a sinking toy. The excess water dilutes the salts in his bloodstream, and that imbalance is what makes him ill — it is a whole-body problem, not a lung problem. Small dogs reach a dangerous volume faster than large ones simply because the same swallowed amount is larger relative to their size.
Secondary drowning — the condition people usually mean by dry drowning — is about water where it should not be: in the airways and lungs. A dog who has been dunked, knocked under by a wave, or struggled in water may inhale or aspirate some of it. The lungs can react over the following hours, becoming irritated and less able to move oxygen, which is why a dog can seem to recover on the shore and become unwell later at home. The gap between the swim and the signs is what makes this one easy to miss.
Signs to watch for, in general terms
For water intoxication, the general picture is a dog who, during or after heavy water play, becomes unsteady or wobbly on his feet, seems bloated, drools heavily, vomits, looks glazed or vacant, or becomes lethargic and disoriented. Signs can progress: loss of coordination can deepen, and in serious cases a dog may collapse or have a seizure. This can develop quickly — a dog who was fetching happily can be clearly unwell within a short time afterwards.
For secondary drowning, watch in the hours after a swim — and be especially alert if your dog went under, coughed hard in the water, or came out spluttering. The signs centre on breathing and energy: a new or worsening cough, breathing that is faster, noisier, or visibly harder work than usual, gums that look pale or take on a bluish tinge instead of healthy pink, and a tiredness that is out of proportion to the exercise he did. A dog who is quieter than he should be after swimming deserves attention, not just a towel and a nap.
What to do if you see any of these signs
Treat either picture as an emergency. Stop the water play, keep the dog calm and still, and contact a veterinarian immediately — describe what he was doing in the water, for how long, whether he went under or swallowed a lot, and which signs you are seeing. Do not wait to see whether he improves on his own: both conditions can worsen after they first appear, and early treatment gives a vet far more to work with. If breathing is laboured or he collapses on the way, let the practice know you are coming so they are ready. This article is general information only; only a veterinarian who examines your dog can say what is happening in his case.
Prevention during ordinary water play
Most cases follow enthusiasm, not neglect, so shape the play: build rest breaks into retrieving sessions instead of throwing until the dog stops, swap endless water retrieves for a mix of land games, discourage prolonged snapping at hoses and sprinklers, and lift sinking toys out of the game so he is not diving and gulping. After any swim, do a deliberate ten-second check at home that evening — breathing comfortable, gums pink, energy as expected — and write down anything unusual with the time you noticed it. Keeping those notes in your dog's KinsLe Pet Passport, alongside his other records in one portable packet, means the details a vet asks for are ready if a late-evening sign sends you to an emergency clinic.