Health experts are investigating whether a child from Gloucestershire caught TB from the family pet dog.
The child, who is aged under 10, caught a latent form of the disease last year and made a full recovery.
It followed an episode in which the family dog fell ill.
The family were all screened for tuberculosis and the dog was put down.
If confirmed it would be the first ever case of its kind in the UK, Public Health England said.
But a spokesman added that it was “scientifically impossible” to prove whether the dormant form of TB contracted by the child had come from the dog or another source.
The spokesman said: “A family in Gloucestershire were tested for tuberculosis (TB) last year after their pet dog was confirmed with the bovine form of the infection.
“Mycobacterium bovis (M. bovis) is a bacterium that causes bovine TB in cattle and although the organism can infect and cause TB in humans, the risk of infection for the general public is very low.
“Human TB caused by M. bovis accounts for less than one per cent of the total TB cases in the UK and it is usually those who work closely with livestock and/or regularly drink unpasteurised (raw) milk who have a higher risk of catching the infection.
“The family is known to have connections to a veterinary practice and this was investigated as a potential source of infection.
“Public Health England offered TB screening to the family as a precautionary measure.
“This case differs from that of human TB infection from cats because there two people involved developed active TB with cat-to-human transmission.”
The news followed a case in which a teenage girl contracted TB from her pet kitten