Allergy medicine wouldn’t help here, it may be a case that the beef tendon is causing pain or an obstruction for Kingston which may explain his posture of sitting and his increased respiratory rate. I would keep an eye on him, but if there is no improvement within a few hours I would recommend taking him into your Veterinarian for an examination; I wouldn’t induce vomiting since if there is an obstruction this may cause more pain and distress for him. Regards Dr Callum Turner DVM
Rapid breathing (tachypnea) is a respiratory disorder characterised by abnormal breathing that is rapid and shallow. It is caused by a reduced level of oxygen, mechanical disorders (where the lungs aren’t able to expand as they should, usually due to a build-up of fluid in or around the lungs), and physiological disorders in which the cat’s respiratory centre in the brain is over stimulated.