The Canine Ledger

Emergency Signs in Dogs: When to Go Now, Not Tomorrow

The signs that mean your dog needs a vet now, condition by condition, with the source for each one and what to do on the way.

Written by thecanineledger

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If your dog is in trouble right now, stop reading. Phone a vet or an emergency clinic, tell them what is happening, and go.

This page is for the moments either side of that: the list to read before anything happens, so that you recognise the signs when they come, and the reasons behind each one. Every sign below comes from a veterinary source, and the source is named next to it.

1. The short list

The Merck Veterinary Manual’s owner guidance gives these as “Examples of emergencies requiring immediate veterinary care” (Merck, What to Do in a Dog or Cat Emergency):

  • Poisoning
  • Severe pain
  • Severe or uncontrolled bleeding
  • Trouble breathing
  • Eye injuries
  • Suspected broken bones or a limb that can’t move

To those, the sections below add six conditions where a specific veterinary source says, in effect, go now: bloat, long or repeated seizures, sudden back-leg weakness, heatstroke, a painful red eye, and a puppy with vomiting and diarrhoea.

Phone first if you can. “Emergency care often starts with your phone call to the veterinarian,” Merck says. “Calling ahead also helps the clinic to prepare for your arrival.”

Our note: A male dog straining but unable to pass urine, and repeated vomiting that brings nothing up, are widely described as emergencies. We couldn’t trace either to a guideline.

2. Bloat (gastric dilatation-volvulus)

Bloat is when the stomach fills with gas and twists. It mostly affects large and deep-chested dogs, and it kills quickly. The Merck Veterinary Manual describes it as “an acute, life-threatening condition that primarily affects large- and giant-breed dogs, with a mortality rate of 20% in treated animals. Immediate medical and surgical intervention is required.” (Merck, Gastric Dilation and Volvulus in Small Animals).

That 20% is among dogs who are treated.

The signs. The American College of Veterinary Surgeons lists the early ones (ACVS, Gastric Dilatation-Volvulus):

  • an anxious look, or looking at the belly
  • standing and stretching
  • drooling
  • a swelling belly
  • retching without bringing anything up

As it gets worse, the ACVS adds, the dog “may begin to pant, have abdominal distension (bloated belly), or be weak and collapse and be recumbent.” Its instruction is plain: “If your pet has exhibited any of the above clinical signs, they should be evaluated by your primary care veterinarian immediately.”

The sign owners miss is the retching. A dog trying to vomit and producing nothing can look like a dog with something stuck, or a cough. Merck lists “nonproductive retching, hypersalivation, and restlessness” among the first signs. In a big dog with a swelling belly, treat it as bloat until a vet says otherwise.

→ Bloat (GDV): The Signs, the Odds, and What a Gastropexy Does

Our note: Merck gives a 20% death rate in treated dogs. Its own pages have given different figures in the past.

3. Seizures that don’t stop, or keep coming

Most seizures stop on their own. Merck notes that “Most seizures last from a few seconds to a few minutes, although some may persist for hours” (Merck, Epilepsy in Small Animals).

The 2024 consensus statement from the American College of Veterinary Internal Medicine (ACVIM) defines when a seizure becomes an emergency: “Seizures are considered an emergency when their duration is prolonged and they are not self-limiting, or when they occur as a closely grouped series” (Charalambous et al., J Vet Intern Med 2024).

It also gives the line in minutes. Following the international human definition, the panel describes status epilepticus, the dangerous continuous form, as “any prolonged seizure lasting >5 minutes.” It treats more than two seizures within 24 hours as a cluster.

In practice, go now if:

  • a seizure lasts more than five minutes;
  • a second seizure starts before your dog has fully come round from the first;
  • your dog has had several seizures in one day;
  • or it is the first seizure your dog has ever had, and you can’t reach your vet to ask.

Time the seizure if you can. It feels much longer than it is, and the number helps the vet.

→ First Seizure: What to Do, and What Counts as an Emergency

Our note: The last bullet is ours, not the consensus statement’s.

4. Sudden back-leg weakness or back pain

Disc disease (IVDD) is common in dachshunds, French bulldogs and other short-legged breeds. A disc in the spine bulges or bursts and presses on the spinal cord. The signs range from back pain and reluctance to jump, through wobbliness, to dogs who suddenly can’t use their back legs.

Any dog that suddenly can’t walk properly, or can’t feel or move its back legs, needs a vet now.

What the evidence does not support is the deadline you will often read online, that surgery must happen within 24 hours. The 2022 ACVIM consensus on disc extrusion looked at it directly and concluded that “taken as a whole, the current literature does not generally support the use of a specific timeline for urgent surgical decompression, even for DPN dogs that are paraplegic at the time of presentation” (Olby et al., J Vet Intern Med 2022). DPN here means dogs that have lost deep pain sensation in their legs, the most severe group.

That is not a reason to wait. It means that a dog who reaches a specialist on day two has not missed their chance. It does not mean day two is as good as day one, and the same consensus notes that a serious complication, progressive myelomalacia, “usually develops within days (24 hours up to 14 days)” of the injury.

→ Sudden Back Pain or Wobbly Legs: IVDD, and When It Is an Emergency

Our note: Go now, and don’t panic about a 24-hour cut-off.

5. Heatstroke

Heatstroke can happen on a mild day. It is not only about hot cars.

The signs. Merck’s owner guidance lists “hot skin, vomiting, drooling, rapid panting, distress, uncoordinated movement, collapse, or unconsciousness”, and is unambiguous: “Heat stroke is an emergency.” It adds that “Some breeds, especially short-nosed breeds, can overheat from stress or excitement even on cool days” (Merck, What to Do in a Dog or Cat Emergency).

What to do on the way. Merck’s instructions: move the dog out of the heat and “cool the head and body with cool water, ice packs, or wet towels—especially on the belly.” A fan helps. Then “Take your pet to the vet right away.” And one warning: “Do not immerse the animal in cold water.”

→ Heatstroke: It Isn’t Just Hot Cars

6. The painful, red or cloudy eye

One eye condition behaves like an emergency because it is one: sudden, closed-angle glaucoma, where pressure inside the eye rises fast.

The Merck Veterinary Manual’s owner page describes it as “a sudden increase in eye pressure with severe pain, redness, and loss of vision,” and lists what a vet sees: “a dilated, unmoving or slow-moving pupil; redness in the white of the eyes; swelling and discoloration of the cornea; and a firm eye globe” (Merck, Glaucoma in Dogs). Its instruction: “If your dog displays any signs of glaucoma, it should be seen by a veterinarian immediately.”

Owners don’t always see pain the way they expect. Merck notes that pain “usually shows itself as behavioral changes and occasional pain around the eye rather than by spasmodic winking.”

Any eye injury, and any eye that is suddenly red, cloudy, bulging or held shut, needs a vet the same day. Merck’s general emergency list includes “Eye injuries” on its own.

→ Glaucoma: The Red, Painful Eye That Can’t Wait

Our note: The “same day” line widens Merck’s glaucoma advice to any suddenly red, cloudy or closed eye, because owners can’t tell glaucoma from an ulcer. The wording is ours.

7. A puppy with vomiting and diarrhoea

In an adult dog, a single bout of vomiting or diarrhoea is usually not an emergency. In a puppy, especially one who is not fully vaccinated, it can be parvovirus.

Merck describes how it starts: “Initial clinical signs may be nonspecific (eg, lethargy, anorexia, fever) with progression to vomiting and hemorrhagic small bowel diarrhea within 24–48 hours.” Blood is not a reliable sign, because “Approximately 25% of dogs may have nonhemorrhagic diarrhea.” And the sickest puppies may already be in shock when they arrive: “collapsed with prolonged capillary refill time, poor pulse quality, tachycardia, and hypothermia” (Merck, Canine Parvovirus Infection).

A puppy who is vomiting, has diarrhoea and is flat or not eating needs a vet the same day. Phone ahead: clinics handle suspected parvovirus differently from other cases to protect other dogs.

→ Vomiting and Diarrhoea: When It Can Wait and When It Can’t · → Parvovirus: Survival, Hospital Care, and the Outpatient Option

8. Poisoning

If your dog has eaten something that might be poisonous, phone a vet or an animal poison helpline now, with the packaging. Don’t make your dog vomit unless a vet tells you to.

The things dogs most often get into, in US poison-control data, are over-the-counter medicines and supplements, food, and prescription medicines (ASPCA, Top 10 Toxins of 2025).

→ My Dog Ate Something: Why You Shouldn’t Make Them Vomit Without a Vet · → Foods That Are Toxic to Dogs, With the Actual Evidence · → Ibuprofen, Paracetamol and Other Human Painkillers · → Animal Poison Helplines by Country: Numbers, Fees, and What Works From Where

9. What we could not verify

Commonly saidWhat we found
“A seizure is only an emergency after three minutes”Not what the consensus says. The 2024 ACVIM consensus uses five minutes. We found no source for three.
“IVDD surgery must happen within 24 hours”Not supported. The 2022 ACVIM consensus found the literature does not support a specific timeline, even for the most severely affected dogs. That doesn’t make waiting safe.
“A male dog straining to pee is always an emergency”Widely said, and plausible, but we could not trace it to a veterinary guideline.
“Bloat only happens after a big meal and exercise”Not in the sources we read. Neither Merck nor the ACVS page frames it that way. Risk factors are covered in the bloat article.
“Heatstroke is a hot-car problem”Too narrow. Merck notes short-nosed breeds can overheat from stress or excitement on cool days.

Sources

Always confirm with your vet before acting on anything on this page.