If you witness your dog collapse or find them collapsed, the first thing to do is to assess if they are conscious and breathing; fortunately, in the vast majority of cases, they will be. True cardiac arrest is extremely rare in dogs, so CPR is rarely indicated.
The most important thing to do is safely transport your pet to the nearest veterinary hospital. Emergency hospitals are ideal, but wherever you go, it’s a good idea to call ahead so they can be ready for you and your dog.
While frightening, rest assured that there are many treatable causes of collapse in dogs, including Addison’s Disease, Epilepsy, and toxin ingestion. Your veterinary team will work to assess and stabilize your pet if needed, then get to work on finding a diagnosis.
If your dog collapses but then quickly resumes their normal activity, it is still worth making a same-day appointment with your veterinarian. This kind of fainting activity is often associated with underlying heart disease. These episodes will likely happen again and the next time your dog may not be so lucky.
While not all causes of collapse are fatal if not immediately treated, there is no way to figure out the cause without examination, so you should always contact a vet right away.