Absolutely yes, it does a lot effect on your pet. This is because pets breathe the same air as humans do. Apparently, the metabolism of nicotine takes place in their body due to respiration in the same air where owners smoke 

They reside in your home, spends time on your lap, cuddle with you. And because of staying too close to your pet, cotinine can be diagnosed and detected in the urine of both dogs and cats who exposed to secondhand smoke. As a consequence, we can conclude that small dogs who spend much time with their smoking owners may have a major chance to have cotinine levels equivalent to that of the smokers themselves.

Dogs are more prone to suffer from smoking-related illnesses the same as humans, like cancer and lung disease. Plus, exposure to secondhand smoke also causes effects on their respiratory system.

Similarly, cats are likely to suffer from concerning disease which is Lymphoma - cancer of the lymphatic system. This is the most common tumor found in the cat. Risk of developing the disease is even more increased when pet cats are exposed to secondhand smoke. The list of problems and diseases that we discussed above sounds a bit concerning. Kindly consider your pet’s health and give them the priority that they are capable of. And try hard to reduce your pet’s exposure to smoke.