Heartgard side effects in dogs

377 reports sent to the FDA between 2015 and 2026 involve Heartgard in dogs. The most reported problems were vomiting, loss of appetite, lethargy. 79% were marked serious.

377Reports
79%Marked serious
0.0%Only medicine involved
14%Recovered
5.0%Died or euthanised
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About this medicine

Type: medicine.

Most reported side effects

57 15%
26 6.9%
23 6.1%
22 5.8%
Breathing problems
18 4.8%
Tremors
17 4.5%
Weakness
14 3.7%
Weight loss
14 3.7%
Kidney problems
14 3.7%
Excessive thirst
13 3.4%
Wobbliness (ataxia)
12 3.2%
Itching
11 2.9%
Behaviour change
11 2.9%

Share = percentage of this medicine's reports that mention the problem. One report can list several problems.

Reports that it didn't work

Some reports are about the medicine not working (for example a dog still getting fleas or heartworm), not about a side effect.

Didn't work as expected
9 2.4%
Didn't stop worms
2 0.5%
Didn't stop ticks
1 0.3%

How soon problems started

Same day
37 18%
1–2 days
13 6.3%
3–7 days
9 4.4%
1–4 weeks
28 14%
Over a month
119 58%

Time from the first dose to the first sign, where both dates were reported (206 reports).

How the animals did

Recovered
50 13%
Recovered with lasting effects
1 0.3%
Still unwell when reported
271 72%
Died
6 1.6%
Euthanised
13 3.4%
Not known
36 9.5%

Breeds named most often

Popular breeds appear more often because there are more of them.

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