Didn't prevent heartworm after Firocoxib (Previcox) in dogs

The FDA has received 35 reports of didn't prevent heartworm in dogs after Firocoxib. That is 0.4% of all reports for this medicine, compared with 13% across reports for all dog medicines, so it is reported less often than average with this medicine.

35Reports
29%Marked serious
17%Recovered
0.0%Died or euthanised
155 daysTypical onset
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How soon it started

Same day
1 7.1%
1–2 days
1 7.1%
3–7 days
0 0.0%
1–4 weeks
1 7.1%
Over a month
11 79%

How the animals did

Recovered
1 2.9%
Recovered with lasting effects
5 14%
Still unwell when reported
6 17%
Not known
23 66%

Problems reported at the same time

Didn't work as expected
6 17%
Weight gain
4 11%
Arthritis
4 11%
Weight loss
3 8.6%
Skin disorders
2 5.7%
Injection site reaction
2 5.7%
Liver problems
2 5.7%
Lameness
2 5.7%

Age of the animals

Under 1 year
0
1–3 years
9
4–7 years
10
8–11 years
11
12+ years
4

About this medicine

Firocoxib relieves pain and inflammation from arthritis.

Products with this ingredient include Previcox. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

NSAIDs can affect the stomach, liver and kidneys. Vets usually recommend blood tests before and during long-term use.

Questions owners ask

Can Firocoxib cause didn't prevent heartworm in dogs?
35 reports link the two, but a report alone does not prove the medicine was the cause: other illnesses, other medicines or coincidence can be involved. Your vet can judge it for your animal.
How soon after a dose was it reported?
In half of the reports with dates, it started within 155 days of the first dose.
What should I do?
Don't give another dose until you've spoken to your vet, and keep the packaging so you can tell them the product and dose. Your vet can also report it to the FDA (or you can, through the manufacturer or FDA form 1932a).

Didn't prevent heartworm with similar medicines

All reported side effects of Firocoxib in dogs · Medicines most reported with didn't prevent heartworm