Levothyroxine Sodium
1,384 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.
1,384
Total Reports
58
Deaths Reported
420.0%
Death Rate
Active Ingredients
Levothyroxine Sodium
Administration Routes
OralUnknownOphthalmic
Species Affected
Dog 1,284
Unknown 50
Human 41
Cat 7
Horse 2
Most Affected Breeds
Retriever - Labrador 183
Unknown 101
Retriever - Golden 100
Crossbred Canine/dog 51
Boxer (German Boxer) 47
Beagle 47
Shepherd Dog - German 42
Chihuahua 32
Pit Bull 31
Terrier - Yorkshire 29
Most Reported Reactions
Emesis 257
Lethargy (see also Central nervous system depression in 'Neurological') 171
Vomiting 170
Overdose 159
Lack of efficacy - NOS 116
Diarrhoea 107
Weight loss 92
Seizure NOS 87
Panting 85
Other abnormal test result NOS 72
Polydipsia 64
Elevated thyroxine (T4) 59
Outcome Breakdown
Recovered/Normal
577 (43.1%)
Outcome Unknown
391 (29.2%)
Ongoing
243 (18.2%)
Recovered with Sequela
69 (5.2%)
Euthanized
40 (3.0%)
Died
18 (1.3%)
Source: FDA Center for Veterinary Medicine — Adverse Event Reports. Data reflects voluntary submissions and may not represent actual incidence rates.