When Not to Swim Your Dog: Hydrotherapy for Dogs Contraindications Explained
October 7, 2026
Swimming has a reputation as the gentlest exercise a dog can get, and for a healthy dog in a clean, calm lake it usually is. The buoyancy and resistance that make it useful can work against a dog with an unhealed wound, a weak heart or an unstable back, though. Canine rehabilitation staff go through a list of hydrotherapy for dogs contraindications before a patient gets wet, and most of that list matters just as much to pet owners heading for the dock at the cottage. Some conditions rule swimming out until they are treated; others only mean the session has to change. Your veterinarian decides which applies to your dog.
Contraindications and precautions are not the same
A contraindication is a reason not to swim for now. A precaution means the dog can go in, with changes: shorter sessions, a treadmill instead of a pool, closer supervision, a life jacket. A skin infection keeps a dog out until it clears, and afterwards it is only a reason to rinse and dry with care. Arthritis is usually a reason to use aquatic exercise, yet VCA names it, together with heart disease and epilepsy, among conditions that can make swimming risky unless a vet has checked the dog first.
Hydrotherapy for dogs: contraindications at a glance
| Condition | Usual advice | When it may change |
|---|---|---|
| Open wound, unhealed incision, external fixator | Stay out | Once healed, or the frame is removed |
| Skin or ear infection | Stay out | After treatment, with drying afterwards |
| Chronic ear disease | Usually no swimming | Vet's call |
| Heart or lung disease | Vet clearance first | Lower-intensity work may be allowed |
| Uncontrolled seizures | Stay out | Vet's call once controlled |
| Unstable spine, fresh ligament injury | No free swimming | Controlled rehab work only |
| Vomiting, diarrhea, urinary infection | Postpone | When recovered |
| Flat-faced breed | Life jacket at all times, or avoid | Treadmill may suit better |
Open wounds, incisions and coat problems
Healing tissue and pool water are a poor match. Open wounds, unhealed surgical incisions and infected skin generally keep a dog out until the area has closed or cleared, to protect the wound and, in a shared hydrotherapy pool, other pets. After surgery that means waiting at least until the stitches come out. An external fixator, the frame of pins used for certain fractures, is on the standard list as well, since the pin sites give bacteria a way in.
A matted coat is easily overlooked. Mats hold moisture against the body, and sores can form underneath, so they should be clipped or brushed out first. Dogs with chronic skin conditions may still swim with veterinary approval; chlorine, salt and lake debris can irritate them, so a rinse with fresh water afterwards helps.
Ear infections
Ears are among the most common casualties of a swimming season. Water trapped in the ear canal gives yeast and bacteria the warm, damp setting they like, and a dog with recurring ear infections can be set back by one afternoon of retrieving. Dogs with chronic ear disease are usually told to stay out entirely. For healthy ears, a cleaner with a drying agent after each swim is the routine VCA recommends.
Heart, lung and breathing conditions
Paddling is sustained aerobic exercise, and a dog cannot pause mid-lake the way it can stop on a walk. With heart disease, that effort can do real harm, so cardiac patients need clearance and often a gentler option. Lung disease and an active respiratory infection are reasons to wait.
Flat-faced breeds raise extra safety questions. Bulldogs, pugs and similar dogs have trouble keeping the nose up and breathing efficiently, and many swim poorly; some veterinary sources say to avoid swimming with them, others that they should never go in without a life jacket. Laryngeal paralysis is another reason a dog is usually kept out of a swimming pool, though some rehabilitation teams use a treadmill with the head well clear of the surface. In any breed, coughing or laboured breathing means taking the dog out at once.
Seizures, spinal problems and fresh injuries
A seizure while swimming can lead to drowning within moments, so uncontrolled epilepsy is a firm no. Even well-controlled epilepsy calls for a talk with the vet, a life jacket and a handler within arm's reach.
Spinal and ligament injuries are less clear-cut, because aquatic work is often part of their treatment. What matters is whether the spine or joint is stable. Rehabilitation vets warn that free swimming can stress an unstable spine, and that hard kicking, or a scramble up a slippery pool edge, can tear an injured ligament completely. These dogs may do well with controlled sessions on a treadmill, but a game of fetch off the dock is a different matter.
Illness, incontinence and untreated disease
Vomiting, diarrhea and urinary tract infections are standard reasons to postpone, as is incontinence in a shared pool. Untreated liver or kidney disease belongs on the same list until a vet has assessed the dog. Most hydrotherapy for dogs contraindications in this group are temporary, and once the illness is under control the dog can usually go back to its sessions.
Fear, fatigue and low fitness
Many retrievers jump in without a second thought, but plenty of dogs have little experience of deep water, so never assume your dog swims well. A dog hanging back at the edge may be sore, worn out or afraid. Do not force your dog in: a frightened dog can scratch its handler and panic, and fear sends heart rate and blood pressure up. If your vet wants a nervous dog to swim, a rehabilitation centre can teach your dog in small steps.
Low fitness is a risk too. Paddling is harder exercise than walking, and an out-of-shape dog can tire before it gets back to shore. Call it in if it sits lower in the water, pants heavily or trembles. Long swims in cold water can also cause limber tail, a painful strain at the base of the tail seen mostly in larger breeds. Keep swims short, with rests on land, and lengthen them over weeks.
When the lake is the problem
Sometimes the dog is fine and the water is not. Several hazards turn up in Canadian lakes and rivers every summer:
- Blue-green algae. Blooms can look like pea soup, a paint spill or streaks on the surface, and their toxins have killed dogs. Parks Canada advises keeping pets leashed and away from affected areas; check local advisories before you go.
- Leptospirosis. The bacteria spread through ponds and puddles contaminated by wildlife urine, so ask your vet whether the leptospirosis vaccine makes sense for a dog that swims outdoors.
- Strong currents and cold water. Spring runoff, big waves and a lake that is still frigid in June can overwhelm a capable swimmer.
- Swallowing water. A dog gulping mouthfuls while it retrieves can develop water intoxication, and inhaling it can lead to pneumonia. A bottle and bowl brought from home cut down on drinking from the lake.
A backyard pool has its own danger: a dog that falls in unattended may paddle along the wall without finding the way out. Fence and cover the pool, and walk your dog to the steps a few times so it knows the exit.
Safer options and a pre-swim check
A dog ruled out of free swimming is not always ruled out of aquatic therapy. An underwater treadmill, filled with warm water, keeps the paws on the belt and the head above the surface while staff adjust depth and speed, and many dogs who should not swim can walk in it under supervision. Water walking and swimming work the body differently and do not replace each other, so your vet makes the call.
Before any swim, run through four questions:
- Has a vet cleared your dog for this level of effort, given the dog's health?
- Are wounds healed, ears and coat in good shape, and mats gone?
- Is the spot safe: calm, clean and free of advisories?
- Is a fitted life jacket on, and will someone monitor the dog the whole time?
If any answer is no, leave the swim for another day.