In a 2003 study, both humans and dog oxytocin levels in the blood rose after a five to 24 minute petting session. This possibly plays a role in the emotional bonding between humans and dogs. Maternal behavior: Female rats given oxytocin antagonists after giving birth do not exhibit typical maternal behavior. By contrast, virgin female sheep show maternal behavior toward foreign lambs upon cerebrospinal fluid infusion of oxytocin, which they would not do otherwise. Oxytocin is involved in the initiation of human maternal behavior, not its maintenance; for example, it is higher in mothers after they interact with unfamiliar children rather than their own. Human ingroup bonding: Oxytocin can increase positive attitudes, such as bonding, toward individuals with similar characteristics, who then become classified as "in-group" members, whereas individuals who are dissimilar become classified as "out-group" members. Race can be used as an example of in-group and out-group tendencies because society often categorizes individuals into groups based on race (Caucasian, African American, Latino, etc.). One study that examined race and empathy found that participants receiving nasally administered oxytocin had stronger reactions to pictures of in-group members making pained faces than to pictures of out-group members with the same expression. Moreover, individuals of one race may be more inclined to help individuals of the same race than individuals of another race when they are experiencing pain. Oxytocin has also been implicated in lying when lying would prove beneficial to other in-group members.
Phlyctenular keratoconjunctivitis is an inflammatory syndrome caused by a delayed (aka type-IV) hypersensitivity reaction to one or more antigens. The triggering antigen is usually a bacterial protein (particularly from Staphylococcus aureus), but may also be a virus, fungus (particularly Candida albicans), or nematode. Symptoms
Irritation 
Discomfort or pain 
Foreign-body sensation 
Tearing 
Blepharospasm
Photophobia
Mucopurulent discharge (rarely) In cases where the cornea is affected, pain and photophobia are more likely, and corneal scarring can occur (potentially impairing vision). Presentation
The syndrome is marked by the appearance of characteristic lesions, known as phlyctenules, on the cornea and/or conjunctiva. These usually manifest as small (1 - 3 or 1 - 4 mm) raised nodules, pinkish-white or yellow in color, which may ulcerate (or, more rarely, necrose) and are often surrounded by dilated blood vessels. Corneal lesions are usually triangular in shape, with the base at the limbus and the apex pointing towards the center of the cornea. Diagnosis
Clinical findings of Corneal lesion or  corneal ulceration. Treatment
The symptoms of phlyctenular keratoconjunctivitis are primarily treated with application of an appropriate corticosteroid eye drop, such as prednisolone acetate (Pred Forte) or loteprednol (Lotemax). Loteprednol is increasingly preferred due to its lower risk of elevating intraocular pressure. The corticosteroid suppresses the immune response, reducing inflammation and improving most symptoms.The causative agent (i.e. the source of the antigen that triggered the hypersensitive immune response) should also be identified. Staphylococcus aureus is usually the primary suspect, along with Mycobacterium tuberculosis in areas where TB is endemic, followed by Chlamydia trachomatis.