In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Throughout treatment , 56 . 9 % of dogs experienced neutropenia , 34 . 2 % experienced anaemia and 14 . 2 % experienced thrombocytopenia .
### Output Text:
Throughout treatment , 56 . 9 % of dogs experienced neutropenia , 34 . 2 % experienced anaemia and 14 . 2 % experienced thrombocytopenia . 