Contact with other mammals (W55)

The ICD-10 code section W55 covers injuries related to contact with various mammals, such as cats, horses, cows, pigs, raccoons, and other hoof stock. These codes specify the type of contact, including bites, scratches, being struck, or other forms of accidental physical contact, and are used to document the cause of injury.

This set of codes allows healthcare providers and medical coders to identify specific incidents like a cat bite (e.g., W55.01XA for initial encounter of cat bite) or a horse strike (W55.12XA). It also distinguishes between the initial treatment, subsequent visits, and long-term complications (sequela) of such injuries. For example, a cat scratch, also known as cat scratch injury or scratch by animal claw, is coded with W55.03 and its extensions. Other codes capture less common mammal contacts, such as bites from large carnivores or punctures by quills (W55.81XA and W55.89XA). These detailed classifications help ensure precise recording of injury mechanisms, supporting accurate documentation of animal-related trauma and related medical care.

Instructional Notations

Includes

This note appears immediately under a three character code title to further define, or give examples of, the content of the category.

  • contact with saliva, feces or urine of mammal

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

  • animal being ridden- see transport accidents
  • bitten or struck by dog W54
  • bitten or struck by rodent W53
  • contact with marine mammals W56

7th Character Note

Certain ICD-10-CM categories have applicable 7th characters. The applicable 7th character is required for all codes within the category, or as the notes in the Tabular List instruct. The 7th character must always be the 7th character in the data field. If a code that requires a 7th character is not 6 characters, a placeholder X must be used to fill in the empty characters.

  • The appropriate 7th character is to be added to each code from category W55

7th Character

Indicates that a seventh character is to be assigned to codes in a subcategory.

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela