Why is my dog reverse sneezing, snorting or sneezing a lot?
Reviewed against VCA Animal Hospitals, AKC and AVMA material. Last updated 5 October 2026. This page covers ordinary sneezing and the reverse sneeze together, because the red flags are the same.
A reverse sneeze that passes in seconds and leaves your dog normal afterwards is a watch-and-log sign, not an emergency. Two red flags make it an emergency: trouble breathing between episodes, and sudden swelling of the face or muzzle. Four more mean a vet visit within 24 to 48 hours.
Below is the same urgency table the free 1-minute check uses, with the source behind each line. Nothing here is a diagnosis: the point is to tell you how fast to call, and what to say when you do.
Urgency table: sneezing and reverse sneezing
| What you see | How fast | Source |
|---|---|---|
| Short episodes only: your dog is completely normal before and after, nose is clean | Watch and log | VCA, AKC |
| Struggles to breathe between episodes, or an episode won't stop | Vet now | VCA, reverse sneeze |
| Sudden swelling of the face or muzzle | Vet now | VCA, hives |
| Struggling to breathe, or gums look pale, white, blue or gray | Vet now | AVMA |
| Collapsed, can't stand up, or is unusually unresponsive | Vet now | AVMA |
| Having or just had a seizure (stiff body, paddling legs, not responding) | Vet now | VCA, seizures |
| In severe pain: crying out, or can't get comfortable | Vet now | AVMA |
| Nosebleed or bloody discharge from the nose | Vet in 24 to 48 hours | VCA, nasal discharge |
| Thick yellow or green discharge, or discharge from one nostril only | Vet in 24 to 48 hours | VCA, nasal discharge |
| Violent sneezing or pawing at the nose that started on a walk | Vet in 24 to 48 hours | VCA, nasal discharge |
| Episodes are getting more frequent or longer | Vet in 24 to 48 hours | AKC |
What each level means
- Vet now. Call your vet or the nearest emergency vet clinic now. Don't wait to see if it passes.
- Vet in 24 to 48 hours. Book a visit within 24 to 48 hours. If your dog gets worse or a red flag appears, go now.
- Watch and log. This is not an all-clear. Watch closely and log what you see. If it lasts, gets worse or any red flag appears, call your vet.
Why the honking sound is usually the least worrying part
The noise is what makes owners panic, and it is not what decides the level. These are the facts behind the table.
- How long an episode runs. VCA Animal Hospitals puts a reverse sneezing episode at several seconds to a minute, describes it as not a harmful condition with no ill effects, and notes the dog is completely normal before and after. AKC says the same about before and after. That is the whole basis for the watch-and-log row.
- Which dogs do it more. AKC says it affects all types of dogs but is more common in smaller dogs such as miniatures and terriers, and in brachycephalic (flat-faced) breeds.
- What sets it off. VCA lists irritation to the nose, sinuses or back of the throat as the trigger, naming nasal mites, secretions, foreign bodies such as seeds, pollens, grasses, allergies, smoke, odours, masses or an elongated soft palate. That is a long list, which is exactly why this page does not try to tell you which one it is.
- What a vet rules out. VCA names upper respiratory infection, a collapsing trachea, nasal tumours or polyps and foreign bodies in the nose or mouth among the other causes of abnormal breathing and snorting a vet will exclude. Those are the questions a visit answers, not things you can tell apart from the sound.
- The swelling row. VCA's page on hives says that if swelling progresses to the throat, breathing can be compromised, which it names as a medical emergency. That is why sudden facial swelling is on the vet-now row rather than the 24-hour row.
What to write down for your vet
These four things turn "he keeps making that noise" into something a vet can work with. Write them on your phone before the visit.
- A video of an episode
- How long it lasts and how often
- Any nose discharge (colour, one or both sides)
- Triggers: walks, excitement, dust
The video matters more here than on almost any other sign. A reverse sneeze, a cough, a gag and a collapsing trachea are hard to tell apart in words and easy to tell apart on a ten-second clip.
Check your dog in one minute
The free check asks what you see, applies the table above plus the four signs that are an emergency on their own, and gives you an urgency level and a list to bring to the vet. No email needed.
Questions
Is reverse sneezing dangerous?
VCA Animal Hospitals describes an episode as lasting several seconds to a minute, says it is not a harmful condition with no ill effects, and notes the dog is completely normal before and after. It becomes an emergency if your dog struggles to breathe between episodes or an episode won't stop, or if the face or muzzle suddenly swells.
What's the difference between a sneeze and a reverse sneeze?
A sneeze pushes air out through the nose. In a reverse sneeze the dog pulls air in fast, which is why it sounds like a honk or a snort rather than a sneeze. This page covers both, because the red flags that matter are the same: how your dog breathes between episodes, whether the face swells, and what is coming out of the nose.
Which dogs reverse sneeze most?
AKC says reverse sneezing affects all types of dogs but is more common in smaller dogs such as miniatures and terriers, and in brachycephalic (flat-faced) breeds. Being in a higher-risk group doesn't change the urgency level: the flags in the table do.
Why does discharge from one nostril only matter?
It is on the 24-to-48-hour row because one-sided signs point a vet's investigation in a different direction from two-sided ones. VCA Animal Hospitals gives the example of a dog that suddenly sneezes violently after coming in from outdoors and has grass or a small seed stuck in the nasal passage. This page doesn't diagnose; it tells you how fast to call and what to record.
What this page doesn't do
- It doesn't diagnose. The causes named above are what a vet rules in or out, not a verdict on your dog.
- It doesn't give treatment, doses, antihistamines or anything to put in your dog's nose.
- No vet wrote or reviewed it. It is a published rule set with a named source per line, assembled by Guides Daily.
- It can't hear your dog. If the noise frightens you and the table says watch and log, record a video and call anyway.
Sources
- VCA Animal Hospitals — Reverse sneeze in dogs. Accessed 5 October 2026.
- AKC — What happens when a dog reverse sneezes? Accessed 5 October 2026.
- VCA Animal Hospitals — Testing for sneezing and nasal discharge. Accessed 5 October 2026.
- VCA Animal Hospitals — Hives (urticaria) in dogs. Accessed 5 October 2026.
- AVMA — First aid tips for pet owners. Accessed 5 October 2026.
- VCA Animal Hospitals — Seizures in dogs. Accessed 5 October 2026.
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Not veterinary advice, and not a diagnosis. In an emergency, contact your vet or an emergency animal hospital. Written and published by Guides Daily; see our editorial policy.