Diphenhydramine Hcl
2,109 adverse event reports submitted to the FDA
Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
2,109
Total Reports
300
Deaths Reported
1420.0%
Death Rate
Active Ingredients
Diphenhydramine Hcl
Administration Routes
UnknownOralIntramuscularIntravenousSubcutaneousOtherSubconjunctivalOphthalmicNasal
Species Affected
Dog 1,960
Cat 146
Horse 2
Ferret 1
Most Affected Breeds
Retriever - Labrador 181
Terrier - Bull - American Pit 158
Chihuahua 115
Domestic Shorthair 107
Boxer (German Boxer) 88
Terrier - Yorkshire 86
Maltese 64
Retriever - Golden 58
Shih Tzu 58
Bulldog - French 55
Most Reported Reactions
Vomiting 827
Lethargy (see also Central nervous system depression in 'Neurological') 594
Facial swelling (see also 'Skin') 323
Anaphylaxis 302
Diarrhoea 299
Hives (see also 'Skin') 270
Anorexia 198
Pale mucous membrane 185
Other abnormal test result NOS 178
Fever 161
Death 156
Death by euthanasia 139
Outcome Breakdown
Ongoing
1,179 (55.8%)
Recovered/Normal
508 (24.1%)
Died
162 (7.7%)
Euthanized
140 (6.6%)
Outcome Unknown
122 (5.8%)
Recovered with Sequela
1 (0.0%)
Source: FDA Center for Veterinary Medicine — Adverse Event Reports. Data reflects voluntary submissions and may not represent actual incidence rates.