Final answer:
The beagle's symptoms suggest glaucoma, characterized by high intraocular pressure leading to optic nerve damage, not commonly presented in acute purulent bacterial conjunctivitis or exophthalmia related to hyperthyroidism.
Step-by-step explanation:
The described symptoms in the obese spayed female beagle, which include a buphthalmic (enlarged) and cloudy eye, very red, injected sclera vessels, and pain, along with multiple striae in the cornea and a dilated pupil, suggest the presence of a serious eye condition.
These signs are indicative of glaucoma, an ocular condition characterized by increased intraocular pressure that can lead to damage of the optic nerve and vision loss. The cloudy cornea and pain are consistent with the eye being under high pressure, while the dilated pupil that does not react well to light suggests compromised function of the eye due to the increased pressure.
Conditions like acute purulent bacterial conjunctivitis and hyperthyroidism-related exophthalmia can also cause significant ocular symptoms, but they present differently from what is described in the case of the beagle. Conjunctivitis would typically include symptoms like inflammation of the conjunctiva with purulent discharge, and exophthalmia would be indicative of a systemic condition like Graves' disease, which is uncommon in dogs.
Immediate veterinary attention is required for glaucoma due to its rapid progression and potential to cause irreversible blindness. Identification and treatment of the underlying cause, whether it is primary or secondary glaucoma, are crucial to preserve vision in the affected eye.