When Mrs Smith got home from work, Toby the terrier cross didn’t look very happy.

Usually delighted to see her, and annoying in the way he bounced at her like an over excited kangaroo, he sulked away into the corner of the room.

Or was it guilt that made him gulp when his owner looked at him disapprovingly?

Suspicious now, Mrs Smith scanned the kitchen for signs of aberrant behaviour but all looked well.

Toby appeared from his dark corner and lurked at her heel, swallowing hard; the way a defendant in court might when a stern judge cast his eye upon him.

Normally, in dogs at least, it is a sure sign of apprehension. But it was in the sitting room that the problem became clear.

Scattered on the floor were the chewed up remains of the television remote control.

Bits of plastic crunched under her feet but it was the punctured battery that really caught her attention. Oh Toby!

(Image: Unsplash) Toby gulped again and a long drool of saliva dropped from his quivering lips.

Mrs Smith reached down to placate him and realised his muzzle was soaking. The plot thickened.

Mrs Smith lifted poor Toby’s lip and saw that his teeth were blackened and his gums red.

There are lots of different types of battery. Your classic AA and AAA are ubiquitous in our environment, powering almost every small electrical item, and they can contain acid, in the form of zinc chloride, or alkali, typically as potassium hydroxide in alkaline manganese batteries.

Both can cause painful chemical burns if tissue is exposed when the battery is damaged and leaks.

Button batteries, such as you might find in watches, hearing aids and calculators, can contain zinc and lithium.

On contact with tissue, the high electrolyte composition of tissue fluid may allow button batteries to generate a low voltage direct current.

This leads to cellular death and electrical burns; not pleasant and potentially life threatening if the battery becomes lodged in the oesophagus.

Some hand held devices use rechargeable lithium-ion polymer (Li-Po) batteries that are not consumer replaceable. The electrolyte in these batteries is an irritant.

Car batteries are, of course, a different matter; they contain lead plates and sulphuric acid.

They have been responsible for lead toxicity in cattle when carelessly discarded, which is manifest as dullness, blindness, head pressing and incoordination, but the main risk to dogs and cats is corrosive damage from spillage of the acid.

Toby was lucky. Mrs Smith, feeling very negative about the situation brought him straight in and his mouth was flushed with copious quantities of water and the tissue damage proved to be minor. A positive outcome.

Other patients have not been so fortunate.

Luckily, batteries show up well on X-ray, so diagnosis of ingestion is not difficult.

When lodged in the oesophagus, removal is indicated.

Intact batteries can be left in the stomach and they usually pass uneventfully through the bowel.

Leaking batteries, however, may cause intestinal damage.

And the dilemma is… What do you charge the owner? And how will Mr Smith change channel on the telly?