Difference between infectious and contagious

Question
Hi,
I'm studying Veterinary Nursing and I'm having trouble finding an answer to this question.
"Can you explain the difference between contagious and infectious?"
Can you help please

Thankyou
Tamara Spratt

Answer
contagious: A disease is any abnormal condition of the body or mind that causes discomfort, dysfunction, or distress to the person affected or those in contact with the person. Sometimes the term is used broadly to include injuries, disabilities, syndromes, symptoms, deviant behaviors, and atypical variations of structure and function, while in other contexts these may be considered distinguishable categories.

infectious:# caused by infection or capable of causing infection; "viruses and other infective agents"; "a carrier remains infective without himself showing signs of the disease"
# easily spread; "fear is exceedlingly infectious; children catch it from their elders"- Bertrand Russell
# of or relating to infection; "infectious hospital"; "infectious disease"