My phone buzzed at 2 a.m. on a Saturday.A woman I'd never met was calling the emergency line because her cat had been vomiting for six hours straight. Read our guide to common dog health problems for detailed information. I talked her through what to look for, told her to come in. The cat had a urinary blockage — not a stomach problem at all. Caught early enough to save him without surgery.
Two days later, a different client brought in a dog who'd been limping for three weeks. Three weeks. The dog had a bone tumor. The owner had assumed it was a pulled muscle because the dog was "still eating fine."
These two cases sit on opposite ends of a spectrum I see every week: owners who rush in for things that could wait, and owners who wait on things that can't. Neither approach is wrong, exactly — the instinct to worry is healthy. But knowing which symptoms demand urgency and which allow you a day to observe can genuinely save your pet's life, save you money, and spare everyone unnecessary panic.
Pet health warning signs symptoms fall into a handful of categories, and once you learn the framework, the decisions get much easier.
The "Drop Everything" Signs
Some symptoms mean you stop what you're doing and get to a veterinarian. Not tomorrow morning. Not after you finish dinner. Now.
Difficulty breathing tops this list. A dog who's panting hard after a run is normal. A dog who's panting at rest, whose sides are heaving, who's sitting with elbows splayed and neck extended — that dog is in respiratory distress. Cats are even more telling: any cat breathing with an open mouth is having an emergency. Cats don't pant like dogs do. If a cat's mouth is open and they're breathing through it, something is seriously wrong with their lungs, airway, or heart.
Inability to urinate. A male cat straining in the litter box with nothing coming out is a classic presentation for urethral obstruction. Left untreated, this kills within 24-48 hours. Dogs can obstruct too, though it's less common. Any pet straining repeatedly without producing urine needs same-day evaluation.
Sudden collapse or loss of consciousness. A pet who collapses and then bounces back in 30 seconds might have a heart arrhythmia, a neurological event, or low blood sugar. A pet who collapses and doesn't get back up is in critical trouble. Either way, this isn't something to Google and ponder.
Uncontrolled bleeding. A small cut on a paw pad can look dramatic but stops with pressure. Blood coming from the nose, mouth, or rectum without an obvious injury source — or any wound that soaks through a towel within minutes — needs professional assessment.
Seizures lasting more than three minutes, or multiple seizures in a row (cluster seizures), are neurological emergencies. A single brief seizure in a dog who recovers quickly is scary but doesn't always require a 2 a.m. trip. I'll get into the nuances below.
Appetite, Weight, and Thirst Changes
These are subtler. They don't usually mean midnight emergency visits, but they're the symptoms I wish more owners took seriously earlier.
A dog who skips one meal isn't necessarily sick — dogs do that, especially in warm weather or after a stressful event. But a dog who won't eat for two days, or a cat who won't eat for even one day, needs investigation. Cats in particular are metabolically vulnerable to fasting. After roughly 48-72 hours without food, cats can develop hepatic lipidosis — fatty liver disease — which is a whole separate emergency. I've treated cats who stopped eating because of a dental abscess and ended up hospitalized for liver failure. The original problem was a bad tooth. The consequence of waiting was nearly fatal.
Unexplained weight loss is one of the most common early signs of serious disease that owners miss. You see your pet every day, so gradual weight loss is invisible until suddenly their spine feels sharp or their collar is loose. I had a Siamese who'd lost almost two pounds over three months — her owner only noticed when a friend who hadn't seen the cat in a while commented on it. Blood work revealed hyperthyroidism. Very treatable, but only if you catch it.
And then there's drinking. Increased water consumption — polydipsia — paired with increased urination is the textbook presentation for diabetes, kidney disease, Cushing's disease, and several other conditions. If you're refilling the water bowl more than usual, or your cat is suddenly drinking from the faucet when they never did before, that's worth noting.
Digestive Signals
Vomiting and diarrhea are the reason for maybe a third of all the urgent calls I get. And honestly, most of the time, it's dietary indiscretion — the dog ate something stupid, the cat hacked up a hairball, everyone's going to be fine.
But here's what separates "wait and see" from "come in now": Learn more about common cat health problems here.
Vomiting that's productive (bringing up food or bile) and happens once or twice, with the pet acting normal otherwise, is usually fine to monitor for 12-24 hours. Vomiting that's unproductive — the pet is retching and heaving but nothing comes up — is much more concerning. In large, deep-chested dogs, unproductive retching is a hallmark of gastric dilatation-volvulus (bloat), which is fatal without surgery.
Diarrhea with bright red blood in it (hematochezia) looks alarming but is often caused by colitis — inflammation of the large intestine — and isn't usually an emergency in an otherwise healthy pet. Dark, tarry, almost black stool (melena) indicates bleeding higher up in the GI tract and is more concerning.
Any vomiting or diarrhea combined with lethargy, refusal to eat, or abdominal pain (hunched posture, crying when picked up, guarding the belly) needs same-day evaluation regardless of what came out.
Respiratory and Circulatory Clues
I mentioned open-mouth breathing in cats already. Beyond that, a persistent cough in a dog — especially a dry, honking cough that's worse at night or with excitement — could be anything from kennel cough to congestive heart failure. A cough that's been there for more than a few days, or a cough with exercise intolerance (the dog gets tired faster than they used to), deserves chest X-rays.
Gum color is something every pet owner should learn to check. Lift your pet's lip and look at the gums above the teeth. Healthy gums are pink — salmon pink in most pets, though some breeds have pigmented gums that make assessment harder. White or very pale gums suggest anemia or shock. Blue or purple gums (cyanosis) mean inadequate oxygen. Yellow gums indicate jaundice, which points to liver disease or red blood cell destruction. Bright brick-red gums can signal toxicity or heat stroke.
Press a finger against the gum for one second, then release. The spot should turn white and return to pink within two seconds. That's capillary refill time. Anything longer than two seconds suggests poor circulation.
I teach this to every new pet owner in my practice. It takes ten seconds and gives you more diagnostic information than almost anything else you can do at home.
Skin, Eyes, and Ears
Itching that won't stop, hair loss in patches, lumps that appear overnight — these don't typically require emergency visits, but they're the kinds of symptoms that owners either fixate on or completely ignore, with little middle ground.
New lumps should be checked at a regular appointment. Not all lumps are cancer — lipomas (fatty tumors) are extremely common in middle-aged dogs and are almost always benign. But some lumps are mast cell tumors, which can look identical to lipomas on the surface. The only way to tell the difference is with a fine-needle aspirate, which takes about 30 seconds and is mildly uncomfortable for the pet at most.
Eyes that are suddenly squinting, tearing excessively, or have a visible cloudiness need prompt attention — not emergency-level, but within a day or two. Corneal ulcers can worsen quickly, and glaucoma causes pain and permanent damage if untreated.
Ears that smell bad, have dark discharge, or cause the pet to shake their head repeatedly point to infection. Not an emergency, but uncomfortable enough that waiting weeks isn't kind.
Behavioral and Neurological Changes
This is the category that trips up the most owners, because behavioral changes are easy to attribute to mood, aging, or environmental factors.
A pet who suddenly becomes aggressive without provocation is possibly in pain. Pain makes animals defensive. I've seen countless dogs get snappy when their owners try to touch them, and the assumption is behavioral — "he's being difficult" — when the reality is a tooth root abscess or a slipped disc.
Hiding. Cats hide when they're sick. It's an evolutionary survival strategy — a sick cat in the wild is a vulnerable cat, so they seek concealment. If your normally social cat vanishes under the bed for a day, something may be wrong.
Head pressing — standing with the head pressed against a wall or corner — is a neurological sign that suggests brain or liver dysfunction. It's not the same as resting the head against a surface. It's a compulsive, sustained behavior, and it's always abnormal.
Circling, stumbling, or a head tilt suggests vestibular disease (inner ear or brain issue). In older dogs, this can look like a stroke and is terrifying, but idiopathic vestibular disease — the most common cause — often resolves on its own within days to weeks. Still needs evaluation to rule out worse causes, though.
The Tricky In-Between Signs
Some symptoms don't fit neatly into "emergency" or "wait." A few worth knowing:
Reverse sneezing (a sudden, loud, honking inhale through the nose) is almost always benign. Dogs do it. It sounds horrifying. It's fine.
Occasional soft stool that resolves within a day? Probably fine. Soft stool every day for a week? Worth a fecal test.
A single episode of limping that resolves within an hour might be a minor strain. Limping that persists for more than two days, or any non-weight-bearing lameness (the pet won't put the leg down at all), warrants X-rays.
Bad breath that smells sour or foul might be dental disease — the most under-diagnosed condition in veterinary medicine, in my opinion. Bad breath that smells like nail polish remover (sweet, chemical) can indicate diabetic ketoacidosis. Bad breath that smells like ammonia suggests kidney failure.
When You're Not Sure
I tell every client the same thing: if you're worried enough to search for symptoms online, you're worried enough to call your vet. Most clinics have a nurse line or triage system. Describe what you're seeing, how long it's been going on, and whether the pet is eating and drinking normally. That information alone lets most veterinary professionals sort "come in today" from "let's watch this for 24 hours" from "schedule a routine appointment."
And here's the thing nobody wants to hear — you know your pet better than anyone. Including me. If your pet seems "off" in a way you can't articulate, that instinct is worth listening to. I've had owners bring in pets because "something just isn't right," and the blood work catches early kidney disease or a developing infection. The vague unease was accurate. Trust it.
Frequently Asked Questions
How can I tell if my pet is in pain?
Dogs and cats both hide pain, but they do it differently. Dogs may pant, pace, become restless, lick a specific area repeatedly, or lose interest in food. Cats are quieter about it — they may just stop jumping onto the counter, start sleeping more, or stop grooming themselves. A grimace scale exists for cats (narrowed eyes, flattened ears, muzzle tension, whiskers pulled forward) and it's surprisingly accurate once you learn it. I had an owner once who said her cat "just looked sad." Blood work showed pancreatitis. She wasn't wrong about the sadness — cats in pain genuinely look miserable if you know what to look for.
Should I take my pet's temperature at home?
You can, and a rectal thermometer gives accurate results. Normal for dogs is 101-102.5 degrees Fahrenheit; for cats, 100.5-102.5. Anything above 103.5 is a fever worth reporting. That said, most owners struggle with the mechanics of rectal temperature-taking in a stressed pet, and I don't blame them. If your pet is symptomatic enough that you're considering taking a temperature, calling the vet is probably the right move anyway.
My pet ate something they shouldn't have — do I make them vomit?
Do not induce vomiting without calling your veterinarian or a poison control hotline first. Some substances cause more damage on the way back up (caustic liquids, sharp objects). Hydrogen peroxide to induce vomiting in dogs works but isn't recommended for cats. The first call should always be to your vet or an animal poison control line — they'll tell you whether vomiting is appropriate, what to give, and what dose based on your pet's weight.
How many vet visits per year does a healthy adult pet need?
One annual exam is the minimum. Twice a year is better for pets over seven or eight, because six months in pet years covers a lot of physiological ground. Blood work at least annually for senior pets catches things early — kidney values trending upward, thyroid levels drifting, glucose creeping — and early detection almost always means cheaper, easier, more effective treatment.
My pet's nose is dry — does that mean they're sick?
No. This is one of the most persistent myths in pet ownership. A healthy pet can have a warm, dry nose or a cool, wet nose depending on the time of day, ambient humidity, how recently they licked it, and a dozen other factors. Nose moisture tells you almost nothing about health status. Look at the whole picture: energy, appetite, behavior, gum color. Those matter. Nose moisture doesn't.