People ask: Why does my cat press his head against the wall? I think it is quite rare.
Head pressing in cats is due to a bad headache. A worm called trichinosis acquired by a cat ingesting uncooked pork which contains encysted lavae of Trichina spiralis can cause muscle pain, headaches and joint pain. The cat might press his head against a wall.
Although cats are usually asymptomatic carriers of the rickettsial organism Bartonella henselae (cat scratch disease), in less than 5% of infected cats they develop generalised symptoms such as fatigue, loss of appetite and a headache. Once again, the headache may lead to head pressing.
Feline sinusitis caused by secondary infection of the frontal sinuses after a feline cold may result in a headache. The cat may sit with his eyes partially closed and his head hanging. He may head press.
Cat suffering from liver disease and impaired liver function lose appetite and weight. There may be signs of central nervous system involvement resulting in a bad headache and head pressing. There may be intermittent apparent blindness, stupor, seizure and coma. These are symptoms of advanced liver failure.
Feline head pressing may occur in cat suffering from a portosystemic shunt (liver shunt). This is when nutrients and waste products are not processed by the liver because an abnormal portal vein bypasses the liver taking blood directly to the heart. Ammonia products build up in the cat’s system. This causes behavioural abnormalities such as circling, seizures and head pressing. There may be weight loss, vomiting, diarrhoea and excessive drooling.
Source: Myself and Cat Owner’s Home Veterinary Handbook (various pages).