Weight loss after Doxycycline in cats

The FDA has received 28 reports of weight loss in cats after Doxycycline. That is 11% of all reports for this medicine, compared with 4.6% across reports for all cat medicines, so it is reported unusually often with this medicine.

28Reports

75%Marked serious

11%Recovered

43%Died or euthanised

23 daysTypical onset

How soon it started

Same day

0 0.0%

1–2 days

4 17%

3–7 days

2 8.3%

1–4 weeks

11 46%

Over a month

7 29%

How the animals did

Recovered

2 7.1%

Recovered with lasting effects

1 3.6%

Still unwell when reported

10 36%

Died

3 11%

Euthanised

9 32%

Not known

3 11%

Problems reported at the same time

17 61%

12 43%

12 43%

12 43%

10 36%

8 29%

Didn't work as expected

8 29%

Dehydration

6 21%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Doxycycline treats bacterial and tick-borne infections.

Questions owners ask

Can Doxycycline cause weight loss in cats?: 28 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 23 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).

Weight loss with similar medicines

Weight loss after Cefovecin (Convenia) 768 reports · 8.8% of its reports
Weight loss after Amoxicillin + Clavulanate (Clavamox) 139 reports · 5.8% of its reports
Weight loss after Enrofloxacin (Baytril) 60 reports · 3.8% of its reports
Weight loss after Amoxicillin 39 reports · 7.6% of its reports
Weight loss after Metronidazole 62 reports · 16% of its reports

All reported side effects of Doxycycline in cats · Medicines most reported with weight loss