Diphenhydramine side effects in Chihuahuas

174 FDA reports involve Diphenhydramine in a Chihuahua. These are the problems they describe.

Vomiting
71 41%
Swelling
49 28%
Allergic reaction
44 25%
Lethargy
40 23%
Loss of appetite
37 21%
Itching
27 16%
Diarrhea
23 13%
Death
22 13%
Didn't work as expected
21 12%
Didn't stop fleas
19 11%
Tremors
18 10%
Skin redness
14 8.0%

All reports for Diphenhydramine in dogs