Determine When the Symptoms Started
If your dog starts to show symptoms of sickness it is important to pay close attention to when you first noticed them. If your dog is not eating, determine for how long your dog has not been eating. The same holds true for other symptoms such as vomiting and lethargy. If your dog displays symptoms of illness it is important to know when they started. This information can help you and your vet rule out certain possible diagnoses such as poisoning, virus and infection.
Examine Your Dog's Body
If you dog displays symptoms that are associated with both cancer and other viruses or infections, then you should take the time to carefully examine your dog's body. Visually inspect your dog for any cuts or wounds that could be a source of infection. Feel around your dog's legs, joints and abdomen for a growth or tumor on your dog's body. Not all growths mean cancer and only your vet can make an accurate determination because in a dog cysts can develop that are non-cancerous, so keep that in mind if you discover an abnormal growth on your dog. If your dog displays symptoms of illness and you discover a growth, you need to take your dog to your veterinarian for a thorough examination, which should include blood tests and possibly biopsies of the growth. You also need to watch for any indication of pain, which could mean an infection under the skin or elsewhere in the body that you cannot see.
Additional Factors to Consider
If your dog contracts a virus, then it will pass and the symptoms will subside in approximately 24 to 48 hours. If your dog's symptoms last longer than two days your dog may have an infection that requires antibiotics.
Carefully watching your dog and tracking the changes in your dog's behavior will provide valuable information to your veterinarian if you decide to take your dog into the veterinarian's office. Symptoms of illness in your dog can have many different causes, so understanding what normal behavior is for your dog is key to making the distinction between cancer symptoms and symptoms brought on by virus or infection. Most illnesses that your dog will contract over the course of its life are very treatable and may not even require medication or a visit to your veterinarian. However, you know your dog best, so only you can make the determination of when to seek additional help from your veterinarian.