The makers of Prozac have launched their first ever antidepressant for dogs, a once-a-day chewable tablet flavoured with beef.

The product, known as Reconcile, received approval from the Federal Drugs Administration in the United States today for use on dogs suffering from separation anxiety from being left alone for long periods.

Like Prozac, Reconcile is a selective serotonin reuptake inhibitor. The drugs should be used in conjunction with therapy to modify the dog's behaviour, the FDA said. It can be taken by puppies as young as six months.

Eli Lilly, which makes the new drug, says that more than 10 million US dogs exhibit strange symptoms from being left alone too long.

"Lilly research shows that 10.7 million, or up to 17 per cent, of US dogs suffer from separation anxiety," said Steve Connell, Lilly's manager of consumer services for companion animal health.

"We're thrilled that our first product for dogs can help restore the human-pet bond."

He said that in field studies of around 600 dogs, 73 per cent of dogs taking Reconcile and undergoing therapy showed better behaviour within eight weeks, compared to dogs receiving therapy alone.

In Britain, research among pet-owners carried out for Sainsbury's Bank in 2003 indicated that 632,000 dogs and cats had suffered from depression in the previous year.

Nearly three times as many pets had suffered from behavioural problems that which could be linked to depression, often resulting in the animal damaging its home or becoming moody or aggressive, according to the research.

Symptoms included attacking furniture, reported by an estimated 1.86 million owners; moodiness, suffered by 1.8 million cats and dogs; loss of appetite linked to stress or emotional problems, 922,000; and incontinence, reported to affect an estimated 803,000 pets.

"People are leading more stressful lives and unfortunately this can have an adverse effect on the health of our pets," said Clare Moyles, Sainsbury's pet insurance manager.

"Cats and dogs can be very susceptible to their owner's feelings and if they sense that they are unhappy they can become agitated and depressed."

Market research company TNS interviewed 1,002 people in the UK in December 2003.

Eli Lilly warned however that Reconcile had shown side effects in a small minority of dogs, including anorexia, vomiting, diarrhoea, barking and fits.

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