Any time there is a problem with our beloved pets, it is important to know how quickly to get them to the vet. Urgent issues will need treatment the same day if possible, but may not necessitate an emergency (after hours) call. Emergency symptoms will need an immediate call to the vet, no matter what time it is.

Emergency
Loss of consciousness; seizures that won't stop; collapse
Poisoning: remember to bring any packaging of what your pet ingested
Allergic reactions if respiration is impaired
Heat or cold exposure
Trauma: animal attack, hit by car, severe lacerations
Snakebite
Respiratory distress

Urgent
Eye issues: 24 hours can make or break a treatment
Ear issues: again, it is important to get treatment as soon as possible
Constipation/Not urinating: to avoid this becoming an emergency, get your pet in as soon as possible
Allergic reactions: swelling on face or body. Can be emergency if respiration is impaired
Diarrhea: if ongoing for multiple days
Lacerations (cuts): normally, there is a 24 hour window to easily suture lacerations; after that the cut will usually have to heal as an open wound. Extensive lacerations, after the 24 hours period, may require surgery