Dangerous symptoms in dogs and cats: when should you not wait?

Sometimes it is difficult to decide whether you should take your pet to a clinic immediately or whether it is reasonable to monitor the situation for a while. The same symptom may be fairly harmless in one situation but the first sign of a condition where every hour matters in another.

The most important starting point is that you know your pet’s normal behaviour best. If something suddenly feels different, your dog or cat is not acting like themselves, or you have a persistent feeling that something is wrong, take that feeling seriously.

This article is not a list of reasons to rush to emergency care for every small change. It is a guide to symptoms where it is not wise to automatically assume that “it will pass”.

My own experience with Oscar

I still remember the Sunday when Oscar was about six months old. That morning he was a little lethargic and, unusually for a puppy, did not want to play. I let him out onto the terrace and he simply lay there. When I checked again a little later, he still had no interest in getting up or moving.

I got him to stand and noticed that he was not bearing weight properly on one hind leg and was dragging it slightly. I even discussed it with his breeder, who could only suggest monitoring him. I googled, searched and tried to understand what was happening, but I could not find anything specific.

When we moved around for a moment, he even seemed a little better. At one point I started wondering whether we really needed emergency care after all. But once we were home, he lay down on the terrace again. Nothing dramatically obvious was happening, yet I could not shake the feeling that something was wrong.

At around 3–4 p.m. I decided to go to the emergency clinic anyway. By then Oscar was already quite apathetic and would not get out of the car by himself. At the clinic we found out that his temperature was over 40 °C and his inflammatory marker CRP was above 180.

That experience taught me something very simple: you do not always need a neat, clear diagnosis before going to the clinic. Sometimes the most important change is simply that your pet is no longer themselves.

When is immediate veterinary care needed?

In veterinary emergency medicine, some symptoms are fairly clear red flags. Difficulty breathing, loss of consciousness, severe bleeding, urinary obstruction, severe pain, seizures, a distended painful abdomen with unproductive retching, and sudden collapse are among the signs that are assessed urgently.

This does not mean that every symptom described below automatically indicates a life-threatening disease. It means that with some symptoms, the cost of waiting is simply too high.

Difficulty breathing or shortness of breath

If a dog or cat is visibly struggling to breathe, breathing with effort, stretching the neck, holding the elbows away from the body, breathing with an open mouth, or developing greyish or bluish mucous membranes, this is an emergency.

There are many possible causes of breathing difficulty: airway obstruction, lung disease, fluid in the chest or lungs, heart disease, a severe allergic reaction, trauma and other conditions. At home, it is not possible to reliably assess how much oxygen is actually reaching the tissues.

If breathing difficulty is new or has suddenly worsened, do not wait to see whether it “passes”.

Fainting, collapse or inability to stand

Collapse means a sudden loss of strength or balance that causes the animal to fall and possibly be unable to stand up. If loss of consciousness is also present, the animal has fainted.

Even if your pet recovers within seconds or minutes and appears normal again, the episode needs to be assessed. Possible causes include heart and circulatory problems, arrhythmias, breathing disorders, neurological conditions, blood loss, metabolic disorders or another serious problem.

Difficulty urinating or no urine output

If your pet repeatedly tries to urinate, strains but produces only drops or no urine at all, licks the genital area, vocalises or is visibly restless, they need prompt assessment.

Especially in cats, and often male cats in particular, a complete urinary blockage can quickly become life-threatening. The same principle applies to dogs: if urine is not passing, this is not a symptom to monitor at home for several days.

Restlessness, pacing and unproductive retching

Restlessness can be a sign of pain, nausea, anxiety or another form of discomfort. One condition that requires rapid action is gastric dilatation and volvulus, or GDV.

If a dog suddenly becomes very restless, the abdomen becomes distended or painful, and the dog repeatedly tries to vomit but nothing comes up, go to a clinic immediately. The risk is higher in large, deep-chested dogs, but the condition cannot be ruled out based on breed alone.

Blood in vomit, stool or urine

Not all blood means the same thing.

Black, tarry stool may indicate digested blood in the gastrointestinal tract. A large amount of fresh blood, repeated bloody diarrhoea, vomiting blood, or blood together with lethargy, weakness, pale mucous membranes, abdominal pain or dehydration needs prompt assessment.

A small streak of fresh blood in the stool can sometimes occur with irritation of the large intestine or colitis and does not automatically mean a catastrophe. But if the bleeding recurs, there is a lot of blood, or your pet is not otherwise acting normally, do not stay at home guessing at the cause.

Blood in the urine can occur with inflammation, stones, trauma, a tumour or urinary obstruction, among other causes. If the animal is also straining and practically no urine is coming out, the situation becomes urgent.

Severe lethargy: your pet is no longer “themselves”

Lethargy is a non-specific symptom. It can be caused by many different problems, from pain and fever to infection, anaemia, metabolic disorders or circulatory problems.

That is why I do not like a universal rule of “wait 24 hours”. With Oscar, 24 hours would clearly have been far too long for me.

If your pet is simply a little more tired but still eats, drinks, responds normally, moves normally and is improving, monitoring may be reasonable. But if they are very lethargic, difficult to rouse, unwilling to stand, or the lethargy is accompanied by fever, vomiting, breathing difficulty, pain, pale mucous membranes or another obvious change, do not wait for a preset number of hours on the clock.

A red, painful, cloudy or suddenly changed eye

Redness can be associated with relatively mild irritation, but also with corneal damage, uveitis, glaucoma or another eye disease.

An eye needs especially prompt assessment if it suddenly becomes very red and painful, the animal squints or keeps it closed, it becomes cloudy or enlarged, the pupil looks different from the other eye, or vision seems reduced. Acute glaucoma is an ocular emergency because elevated intraocular pressure can damage vision quickly.

Fever or unusually high body temperature

A dog’s normal rectal temperature is approximately 37.5–39.2 °C, and a cat’s approximately 38.1–39.2 °C. Stress, physical activity and the circumstances of measurement can influence temperature slightly.

Fever does not mean infection alone. An elevated body temperature can also be associated with inflammatory, immune-mediated, neoplastic or environmental causes.

If the temperature is above 40 °C, especially if your pet is lethargic, panting, vomiting, not drinking or behaving unusually, they need prompt veterinary assessment. If you suspect heatstroke, this is an emergency.

Persistent cough

A single cough does not necessarily mean disease. Repeated or persistent coughing deserves attention, however, because possible causes include kennel cough, bronchitis, pneumonia, tracheal problems, heart disease, parasites and, more rarely, tumours.

If coughing is accompanied by difficulty breathing or shortness of breath, the situation becomes an emergency.

If this is a familiar, typical case of kennel cough and your dog is breathing normally, eating and drinking, and is otherwise bright, you can start with previously agreed home support and monitoring. If the cough does not improve within a few days, becomes stronger, or fever, lethargy, loss of appetite or breathing difficulty appears, the dog needs veterinary assessment.

Loss of appetite and weight loss

Loss of appetite is often one of the first signs that an animal does not feel well. What matters is not only how many hours they have gone without food, but which animal is standing on the other side of the food bowl.

An adult dog who skips one meal but drinks, is bright and behaves normally is not in the same situation as a puppy, a cat, an animal with a chronic disease, or a dog who is lethargic and vomiting along with the loss of appetite.

In cats, not eating needs to be taken particularly seriously. Prolonged anorexia can promote hepatic lipidosis, or fatty liver, especially in overweight cats.

Unintentional weight loss also needs an explanation, especially when weight is dropping noticeably despite normal food intake or when other symptoms are present.

Pain, even if your pet does not whine

One thing I have learned very clearly from my own dogs is that pain does not always look the way people expect it to.

During a staphylococcal infection, Oscar refused to bear weight on one paw. He did not whine or protest. I could touch and flex the leg and his reaction was practically zero. At the clinic, however, the veterinarian said that he had been in very severe pain.

Animals can show pain much more quietly: a changed posture, restlessness, hiding, avoiding movement, sleeping more than usual, irritability, changes in appetite or simply being “different”.

If the pain seems severe, starts suddenly or interferes with normal movement and behaviour, the animal needs assessment.

What about a mild digestive upset?

Here it is important to distinguish a mild, short-lived digestive upset from a situation where red flags are already present.

Some integrative veterinarians recommend a 12–24-hour fast for an otherwise healthy adult dog with mild vomiting or diarrhoea, to give the digestive tract a rest. We have written in more detail about when fasting may be appropriate and when it is not in the article “Vomiting and home remedies”.

Fasting is not a universal solution, however. Puppies, very small dogs, animals with diabetes or another chronic disease need more caution. Deliberate fasting is generally not recommended as a home measure for cats, because prolonged lack of food can increase the risk of hepatic lipidosis, among other problems.

And there is little point talking about fasting when an animal is apathetic, dehydrated, vomiting repeatedly, has a lot of blood in the stool or vomit, has a painful or distended abdomen, or shows another warning sign described above. At that point the question is why the animal is ill, not how many hours to keep them without food.

Dogs and cats are not the same patient in every situation

Many emergency signs are similar in dogs and cats, but the risks are not always identical.

For example, difficulty urinating in a male cat can mean a life-threatening urinary blockage. Prolonged lack of food is also a separate concern in cats. Cats may also hide breathing difficulty for a long time, and open-mouth breathing in a cat is always a reason to seek help quickly.

That is why you should consider not only the symptom, but also the species, age and size of the animal, previous diseases, and how sudden the change was.

Trust your observations, but do not try to invent a diagnosis or diagnose with AI

An owner’s observations are enormously valuable to a veterinarian. You know whether your dog normally jumps up the moment the refrigerator door opens. You know whether your cat always comes to eat in the evening. You are the first to notice when a tiny routine changes.

But an observation and a diagnosis are not the same thing.

If you do not know what is causing a symptom, you cannot always assess at home how dangerous it is. Sometimes the smartest step is to call the clinic, describe the symptoms as precisely as possible and let the veterinarian help decide how quickly the animal needs to be seen.

My own rule of thumb is still simple: if I have the feeling that something is genuinely wrong, I prefer to get it checked. Sometimes it turns out that everything is fine. That is much easier to live with than wondering afterwards why I waited.

In summary

Not every symptom means an emergency, but some warrant a very low threshold for seeking help.

Difficulty breathing, fainting or collapse, lack of urine, a distended painful abdomen with unproductive attempts to vomit, severe pain, a very poor general condition and acute eye problems are symptoms where it is not wise to wait.

With other symptoms, context matters: how long it has lasted, whether the condition is worsening, whether the animal eats and drinks, whether they are responsive, whether pain, blood, fever or breathing difficulty is present, and how different their behaviour is from normal.

The most important thing is not to memorise ten symptoms. It is to notice when your animal is saying through their behaviour: something is wrong.

Sources used

Veterinary medicine sources

• Merck Veterinary Manual – Evaluation and Initial Treatment of Dog and Cat Emergencies. Open source
• Merck Veterinary Manual – Initial Triage and Resuscitation of Small Animal Emergency Patients. Open source
• Merck Veterinary Manual – Obstructive Uropathy in Dogs and Cats. Open source
• Merck Veterinary Manual – Acute Glaucoma in Small Animals. Open source
• Merck Veterinary Manual – Normal Rectal Temperature Ranges. Open source
• Merck Veterinary Manual – Feline Hepatic Lipidosis. Open source
• VCA Animal Hospitals – Taking Your Pet’s Temperature. Open source
• VCA Animal Hospitals – Runny Nose, Coughing, Sneezing. Open source

Integrative perspective on gastrointestinal rest

• Peter Dobias – Why is my dog vomiting? How to tell if it’s an emergency. Open source
• Peter Dobias – Holistic and Natural Approach to Treating Diarrhea in Dogs. Open source
• Judy Morgan – Gastroenteritis and Colitis in Dogs and Cats. Open source

Note: This article is educational and does not replace veterinary consultation, diagnosis or treatment. If your pet has difficulty breathing, loss of consciousness, severe pain, urinary retention, severe bleeding or another rapidly worsening condition, contact a veterinary clinic immediately.

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