What Is Reverse Sneezing?
Reverse sneezing, known medically as pharyngeal gag reflex or paroxysmal respiration, is one of the most commonly misunderstood canine behaviours that veterinary practices are asked about. Despite the dramatic sound and appearance, it is in the vast majority of cases completely harmless and requires no treatment whatsoever.
In a normal sneeze, air is rapidly expelled outward through the nose. In a reverse sneeze, the opposite happens — the dog rapidly and forcefully pulls air inward through the nose. This creates a distinctive snorting, honking, or snuffling sound that many owners describe as alarming, monstrous, or like the dog is choking. The first time you witness a reverse sneeze, particularly in a small or flat-faced dog, it can be genuinely frightening.
What Does It Look Like?
During a reverse sneezing episode, the dog typically adopts a very characteristic posture. They will stand still and extend their neck forward and upward, often widening their stance slightly. Their mouth is closed or nearly closed. They then produce a rapid series of loud snorting inhalations — sometimes five to ten in quick succession — before the episode ends as suddenly as it began. The whole event usually lasts between 30 seconds and two minutes.
What makes reverse sneezing so startling is the contrast with the moments on either side of it. The dog is completely normal immediately before the episode begins and returns to completely normal behaviour the moment it ends. They do not appear distressed, do not lose consciousness, and show no lasting symptoms. This rapid return to normality is one of the hallmarks that distinguishes reverse sneezing from more serious conditions.
If you search for "dog reverse sneezing" on video platforms, you will find many uploaded examples. Watching a few videos before you next see your dog do it can be enormously reassuring — you will immediately recognise the familiar posture and sound and know that no emergency intervention is needed.
What Causes Reverse Sneezing?
A reverse sneeze is caused by a spasm of the soft palate and nasopharynx — the area at the back of the nasal passage where it connects to the throat. When this tissue is irritated, it goes into spasm, and the dog's attempt to clear the irritation produces the characteristic inward snorting action.
Common triggers include:
- Excitement — many dogs reverse sneeze reliably when greeted by their owner or before a walk
- Pulling against a collar — pressure on the trachea and soft palate from a tight collar can trigger a spasm
- Eating or drinking quickly — rapid consumption can stimulate the nasopharynx
- Dust and household particles — common in dogs that sniff along floors or skirting boards
- Pollen and environmental allergens — seasonal patterns in some dogs suggest an allergic component
- Strong perfumes, air fresheners, or cleaning product fumes
- Post-nasal drip from seasonal allergies or mild respiratory irritation
- Scents from the garden — grass, flowers, and soil can all trigger susceptible dogs
Which Breeds Are Most Affected?
While any dog can reverse sneeze, the condition is significantly more common in certain types.
Brachycephalic breeds are the most frequently affected group. Dogs with flattened faces — Pugs, French Bulldogs, English Bulldogs, Shih Tzus, Cavalier King Charles Spaniels, and Boxers — have anatomically elongated soft palates relative to the length of their skulls. This excess soft palate tissue is more prone to being sucked into the airway during rapid inhalation, making it easier to trigger the spasm. In these breeds, reverse sneezing can be quite frequent and may occur multiple times a day without indicating any specific problem.
Small breeds in general are more prone to reverse sneezing than larger dogs, though the reason for this is not fully understood. Toy Poodles, Miniature Schnauzers, and Yorkshire Terriers are among the smaller breeds commonly reported to experience it.
Is It Dangerous?
In the vast majority of cases, no. A standard reverse sneezing episode causes no distress or harm to the dog. The dog is not choking, is not struggling to breathe, and is not in danger. Oxygen exchange continues normally during the episode. Most dogs do not even seem particularly troubled by it once it passes.
The primary concern in these episodes is nearly always the owner's distress rather than the dog's. If you can remain calm during an episode, this also helps the dog, as excitement or anxiety from the owner can sometimes prolong the spasm.
What to Do During an Episode
There is no requirement to intervene during a reverse sneezing episode, as they resolve on their own. However, if you would like to try to shorten the episode, the following approaches are often recommended:
- Gently cover one or both nostrils with a finger for a brief moment — this encourages the dog to swallow, which can break the spasm
- Gently stroke the throat in a downward direction
- Speak calmly and soothingly to the dog
- If you can identify the trigger — for example, pulling on the lead — remove it immediately
- Try to avoid over-reacting, as excitement can extend the episode
Switching from a collar to a harness is worth considering for dogs that frequently reverse sneeze during walks, as it removes pressure from the throat and tracheal area entirely.
When Should You Be Concerned?
Although most reverse sneezing is benign, there are specific circumstances in which the symptom warrants a veterinary examination. The behaviour itself is not the concern — it is changes in the pattern or accompanying symptoms that should prompt investigation.
Speak to your vet if:
- Episodes are lasting longer than two minutes consistently
- Your dog is having multiple episodes every day and this is a new pattern
- The frequency is increasing over time
- Episodes are accompanied by nasal discharge — particularly if it is coloured, bloody, or coming from only one nostril
- You notice facial swelling, deformity, or pain around the muzzle
- Your dog has any breathing difficulty between episodes, not just during them
- Your dog is losing weight, has reduced appetite, or seems unwell generally
These signs can occasionally indicate an underlying condition that deserves proper investigation. Possibilities a vet would consider include nasal polyps, a foreign body lodged in the nasal passage, nasal mites (Pneumonyssoides caninum — more common in Scandinavia but present elsewhere in Europe), nasal tumours in older dogs, or severe allergic rhinitis.
Distinguishing Reverse Sneezing from Tracheal Collapse
Tracheal collapse is a condition seen predominantly in small and toy breeds in which the rings of cartilage supporting the trachea weaken, causing the airway to partially collapse during breathing. It produces a chronic cough that is often described as a goose honk — superficially similar to reverse sneezing.
The key differences are that tracheal collapse produces a coughing sound during exhalation and is more persistent and ongoing, whereas reverse sneezing is characterised by rapid inhalations, comes in discrete episodes, and resolves completely between occurrences. If you are unsure which is occurring, a vet can usually distinguish them on examination and may use an X-ray or endoscopy to confirm tracheal collapse where suspected. The two conditions are managed quite differently, so an accurate diagnosis matters.