John R. Vitek Jr., 67, a retired lieutenant colonel who began his Army career as a private in a horse cavalry regiment, died Thrusday of amyotrophic lateral sclerosis, also known as Lou Gehrig's disease, at a nursing home in Pinellas Park, Fla.

Col. Vitek was born in Baltimore. He enlisted in the 3rd Cavalry Regiment at Fort Myer, Va., in 1936. He was in F Troop of the regiment, which conducted the "Society Circus," regular weekly demonstrations of horsemanship and trick riding. By World War II, he had risen to sergeant major of the regiment.

In the war, Col. Vitek was commissioned and served with the 124th Cavalary Regiment, a Texas National Guard unit that was one of the last in the Army to train with horses. He fought in Burma as an infantryman and later in China.

After the war, he served with occupation forces in Germany, at Fort Riley, Kan., and in Thailand, where he was an armored cavalry adviser to the Thai army. His last post was in Washington. He retired in 1958.

He held the Bronze Star and a decoration from China.

Col. Vitek spent the next 10 years as an instructor at the Military Assistance Institute, which taught military officers how to be advisers to foreign armed forces. The institute was under contract to the Pentagon.

Beginning about 1956, Col. Vitek lived in Falls Church. He later moved to Bowie. In 1969, after his second retirement, he moved to Pinellas Park, Fla.

Survivors includes his wife, Jessalyn, of the home; a son, John R. III, of Brooklyn, N.Y., and three grandchildren.