A runny nose and frequent sneezing are the main signs of a cold in dogs, according to Vetinfo. Other symptoms include decreased appetite, watery eyes and general lack of energy.
The signs and symptoms of colds can mimic other conditions, so it's important to bring a sick dog to the vet as soon as possible, suggests Vetinfo. A runny nose is often accompanied by continuous sniffing sounds and sneezing. Other symptoms such as coughing and increased body temperature can also accompany common colds in dogs. Dogs with colds are also usually less energetic because their immune system is compromised, and the amount of nutrients they absorb from food is decreased, if their appetite isn't as good as usual.