My dog has a brain tumor. Will his bulging eye pop out as it grows?

I can appreciate an increase in size/swelling above the right eye in your photos here. A brain tumor itself normally wouldn't cause a visible swelling, as the brain is encased in the bony skull and a tumor would just cause increased pressure on the brain but not cause changes in the shape of the skull. That being said, we can have bony tumors of the skull that can change the skull shape. We can also have tumors of the soft tissue (skin, muscle, connective tissue) that could be seen on the head, and also tumors of the eye/muscles behind the eye. Your dog should definitely have an examination done by the vet. They may recommend an aspirate of the swelling to help tell what is causing it, an x-ray of the skull, and possibly more advanced imaging like a CT scan. This problem may be something easily fixed or may be more involved, but we won't know without further testing.

The shrunken eye is much less painful than the distended eyeball but would be prone to developing dry eye and infections. Removal of the eye is recommended if any complications develop but otherwise can be monitored for any pain or discomfoort, including difficulty chewing or eating

I am afraid that this red mass looks like a tumor or multicystic mass. This is definitely something that needs to be seen by a vet as it a) keeps your dog from closing his eye lid which can damage the eye to the point of losing vision (will dry out the cornea), and b), tumors can grow invasively, ie destroy the eye. Your vet will examine the mass, possibly take a little bit of tissue to examine under the microscope or send in to a pathology lab and then, depending on the findings, discuss treatment options, which could include removal of the mass alone (if possible), medication to remove it or make it shrink, or even removal of the eye. Please make an appointment with your veterinarian soon.

I'm glad to hear that Fli does not seem bothered by the lesion on her eye. Your thinking is likely correct in that when Fli's blood pressure increases with excitement, blood rushes to the lump, causing it to become red. Possible causes of the lesion on the sclera (white of the eye) include a conjunctival cyst, benign or malignant mass, among others. Cancer, or malignant masses, seem less likely due to a slow rate of growth, but are certainly not impossible. I do recommend taking Fli to her vet in the next week for an exam to determine if further diagnostics or intervention are needed, or if continuing to monitor the lesion for changes is the best course of action.

I strongly recommend you seek referral to a specialist ophthalmologist, it looks like there may be increased pressure or glaucoma which is very painful. It may be rarely associated with tumors but there are many other possible causes

Thank you for your question regarding Peppy. I'm sorry to hear about his eye problem. I'm glad that he does not appear painful. He could have a tooth root abscess depending on the location of the affected tooth. On the upper jaw, however, I tend to see them in front of and just below the eye most frequently. He could have an eye infection behind the eye that is pushing it forward. This tends to happen in dogs that chew sticks. They get a wound in the very back of their mouth and it travels up behind the eye. The other consideration is if he has a mass growing behind his eye. He will likely need to see his veterinarian again if it is not resolving. I hope this information helps you and Peppy!

This looks like a swelling of Poppy's conjunctiva as opposed to the eye itself. It could be due to an allergic reaction or infection such as conjunctivitis. She will need eye drops and antinflammatories to settle this down so go to your vet as soon as you can. In the mean time pressing a cooled tea bag on the outside of the eye can provide some relief.