Zinc Poisoning in Dogs

In this guide

Zinc is an everyday metal that turns up in far more household items than most people realise, and while it is genuinely essential to a dog's diet in tiny amounts, a swallowed object made largely of zinc can cause severe, sometimes fatal poisoning.

Common sources of zinc

• Galvanised hardware such as nuts, bolts, nails, screws, wire and cage fittings
• Zinc oxide-based ointments and creams, including some diaper rash creams and sunscreens
• Zippers, buckles and some toys or game pieces
• Certain coins, depending on their metal composition
• Zinc supplements meant for humans

How zinc poisoning develops

When a zinc-containing object sits in the acidic environment of a dog's stomach, the acid gradually breaks it down and releases zinc into the bloodstream. Once absorbed, zinc damages red blood cells, causing them to rupture in a process called haemolysis, which leads to anaemia and, if severe, can affect the liver and kidneys as well.

Symptoms of zinc poisoning

Initial signs relate to stomach irritation, followed by the effects of anaemia as red blood cells break down.

• Vomiting and loss of appetite
• Lethargy and weakness
• Pale or yellowish gums
• Dark or discoloured urine, from the breakdown products of damaged red blood cells
• Rapid breathing and an elevated heart rate
• Abdominal pain
• In severe, prolonged cases, collapse and organ failure

What to do

If you know or suspect your dog has swallowed a zinc-containing object, contact your vet, who will likely want to X-ray the abdomen to look for a metal object, since even a single small item can cause significant zinc toxicity, particularly in smaller dogs. Removing the object, whether surgically, endoscopically, or by inducing vomiting if the timing and object allow it, is the priority, since zinc continues to leach into the body for as long as the object remains in the stomach. Supportive care such as fluids and, in some cases, a blood transfusion may be needed if significant anaemia has developed.

Prevention

Keep loose hardware, zippers, and small metal fittings away from areas your dog can access, particularly during home repairs or renovation. Store zinc oxide creams and sunscreens out of reach, the same way you would any medicine or ointment, and be mindful of galvanised fittings on kennels, crates and outdoor structures that a chewing dog might work loose over time.

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