Table 3. Amino acid differences among the hemagglutinin proteins of canine and contemporary equine influenza viruses* http://www.cdc.gov/Eid/content/14/6/902-T3.htm.
| Virus | Amino acid positions in mature HA |
|||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 7† | 29 | 54 | 78 | 79 | 83 | 92 | 107 | 118 | 159 | 218 | 222 | 261 | 328 | 479 | 483 | 492 | 541 | |
| A/equine/Kentucky/5/2002 | G | I | N | V | F | N | S | S | L | N | G | W | K | I | G | N | R | K |
| A/equine/Massachusetts/213/2003 | . | . | . | A | . | . | . | . | . | S | . | . | . | . | . | . | . | . |
| A/equine/Ohio/1/2003 | . | . | . | A | . | . | . | . | . | S | . | . | . | . | . | . | . | . |
| A/equine/Bari/2005 | D | . | . | . | . | . | . | . | . | . | . | . | . | . | . | . | . | . |
| A/canine/Florida/242/2003 | D | . | K | A | . | S | . | . | . | S | . | L | . | T | . | T | . | . |
| A/canine/Florida/43/2004 | . | M | K | A | . | S | N | . | . | S | . | L | . | T | . | T | . | R |
| A/canine/Texas/1/2004 | . | M | K | A | . | S | . | . | V | S | . | L | N | T | E | T | . | . |
| A/canine/Iowa/2005 | . | M | K | A | L | S | . | . | V | S | E | L | N | T | E | T | . | . |
| A/canine/Miami/2005 | . | M | K | A | . | S | . | . | V | S | . | L | N | T | E | T | K | . |
| A/canine/Jacksonville/2005 | . | M | K | A | . | S | . | P | V | S | . | L | N | T | E | T | K | . |
*Dots represent the same amino acids as in A/equine/Kentucky/5/2002 hemagglutinin (HA). Conserved residues in the canine HA that differentiate them from the equine HA are in boldface within blue-shaded boxes. Residues that differentiate the A/canine/Texas/2004 clade from A/canine/Florida/242/2003 and A/canine/Florida/43/2004 are in boldface within gray-shaded boxes. †Only variable positions are shown; numbering is for mature HAO.