What dogs can tell us about early detection

Dr Andrew Robson shares insight on compensation in sick dogs, which highlights how important early detection is.

Animals are masters of adaptation

In veterinary medicine, the term compensation is often used. The quiet ways animals adjust long before disease becomes obvious. A dog developing arthritis doesn’t wake up one morning suddenly lame. Instead, the signs build gradually. They hesitate before jumping into the car. They sleep a little more. They avoid stairs. They become slower.

Yet when the diagnosis is made, owners often say, “But it happened so quickly.” 

In reality, it didn’t. The disease had been brewing for months, sometimes years. The dog was coping. Adjusting. Compensating, until it could no longer hide it.

Cancer in humans can follow a similar pattern. Early disease rarely arrives dramatically. It appears in small changes, persistent fatigue, unexplained weight loss, altered appetite, a new lump, a change in bowel habits, a cough that doesn’t resolve. These symptoms are often subtle at first. 

The body adapts. Life continues. We explain things away: stress, ageing, being busy.

Then, when a diagnosis is made, it can feel sudden. Rapid. Out of nowhere. But often, it has been developing quietly.

One of the most important lessons animals teach us is that small changes matter. In veterinary consultations, when an owner says, “He’s just not himself,” we pay attention. That sentence frequently precedes a meaningful diagnosis. Subtle behavioural or energy shifts are early indicators that something deeper may be happening.

Early detection

You are allowed to take your own subtle changes just as seriously.

Early detection is not about anxiety or hypervigilance; it’s about awareness and consistency, responding to persistent changes rather than dismissing them, and participating in recommended screening, even when you feel well.

National screening guidelines are designed to detect cancer before it becomes advanced. Mammograms for breast cancer, Pap smears for cervical screening, colorectal cancer screening from midlife onward, discussions around prostate screening, and low-dose CT scans for high-risk smokers all exist to identify disease in its earlier stages. 

Screening does not prevent every cancer, but it significantly improves the likelihood of finding it sooner, when treatment options are broader, and outcomes are often better.

In animals, routine health checks allow us to pick up small masses before they ulcerate or metastasise, weight loss before it becomes severe, and dental disease before full mouth extractions are necessary to curb decay and infection. Early detection is rarely dramatic. It is the result of paying attention over time.

Fear can delay that attention. Many people avoid screening or postpone medical appointments because they are afraid of what might be found. That reaction is deeply human. But in both veterinary and human medicine, we see repeatedly that earlier diagnosis usually offers more choice.

Choice matters

Dogs remind us that illness often begins in whispers, not loud Grey’s Anatomy type emergencies. The question is not whether every small change is serious because most are not. The question is whether you are willing to notice patterns, to act when something persists, and to value prevention as much as treatment.

What feels sudden is often simply the moment compensation ends.

Dr Andrew Robson is a veterinarian with a Master of Science Degree from Wits University. Based at Oaklands Veterinary Hospital in Johannesburg, Andrew forms part of a multi-disciplinary team of veterinary professionals dedicated to providing the highest standard of care to small animal patients and their families. With a strong interest in companion animal medicine, animal physiology, and client education, he is passionate about strengthening the human–animal bond and supporting pet parents through evidence-based, compassionate veterinary care.

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