Breed · Dog

Fox Terrier: adverse event reports

FDA breed label "Terrier - Fox (unspecified)" · single-breed animals only

Read this first · FDA's caveat, in its words

An API dataset query result cannot be used to estimate the risk associated with the product or compare one drug or device product with another. When looking at the results, be aware that there is no certainty that the reported drug or device caused the adverse event. This dataset should not be the sole source of information for clinical decision-making or other assumptions about the safety or effectiveness of a product. The adverse event may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources. FDA Center for Veterinary Medicine

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated. We may limit or otherwise restrict your access to the API in line with our Terms of Service.

Not veterinary advice. This site lists what was reported to FDA. For an animal that is unwell, contact a veterinarian.

1,220reports, 1987–20260.1% of dog reports

15reports, 12 months to March 202624 in the 12 months before

40%classed serious, as reportedall dogs: 38.3%

13%name ivermectin + pyrantel pamoateall dogs: 14.9%

FDA's database holds 1,220 reports where the animal's breed is given as "Terrier - Fox (unspecified)", shown here as Fox Terrier: 0.1% of reports about dogs. Reports on crossbred animals are left out of breed pages.

15 reports arrived in the 12 months to March 2026, down 37% from 24 in the 12 months before. A breed's count mostly mirrors how common the breed is; registration and ownership figures by breed are not public data, so no per-animal rate can be given.

By active ingredient, the drugs named most often are ivermectin + pyrantel pamoate, milbemycin oxime + spinosad and carprofen. Ivermectin + Pyrantel Pamoate is named in 13% of this breed's reports, about the same share as in reports about all dogs (14.9%).

The terms listed most often are vomiting (24.1%), diarrhoea (9.3%) and depression (8.9%). Vomiting appears in 24.1% of reports, about the same share as in all dog reports (19.7%). 40% of reports stating seriousness were classed as serious, against 38.3% for dogs overall.

Drugs named most often, by active ingredient

Active ingredients recorded for the drug	Reports	Share of Fox Terrier reports	Share of all dog reports
Ivermectin + Pyrantel Pamoate	158	13%	14.9%
Milbemycin Oxime + Spinosad	91	7.5%	13.1%
Carprofen	84	6.9%	4.8%
Afoxolaner	82	6.7%	5.7%
Spinosad	81	6.6%	5.8%
Cyclosporine	72	5.9%	1.5%
Selamectin	72	5.9%	3%
Moxidectin	49	4%	5%
Oclacitinib	48	3.9%	2.9%
Fluralaner	47	3.9%	6.7%
Lufenuron + Milbemycin Oxime	33	2.7%	2.7%
Milbemycin Oxime	33	2.7%	3%
Selegiline Hydrochloride	29	2.4%	0.4%
Ivermectin	23	1.9%	1.3%
Imidacloprid + Moxidectin	22	1.8%	1.3%
Insulin	19	1.6%	0.7%
Melarsomine Dihydrochloride	19	1.6%	2.3%
Pyrantel Pamoate + Sarolaner	17	1.4%	5.1%
Betamethasone Valerate + Clotrimazole + Gentamicin Sulfate	16	1.3%	0.2%
Sarolaner	16	1.3%	1.7%

Ordered by report count. Differences from the species column often come from body size (which drugs a breed is prescribed) and from how common the breed was in the years a drug sold most. FDA states that these data cannot be used to estimate risk or to compare one product with another. Brand and manufacturer names are masked by FDA in these records.

Signs listed in reports

share of Fox Terrier reports listing the termall dog reports

Vomiting24.1%294
Diarrhoea[diarrhea]9.3%114
Depression[dull, quiet or withdrawn]8.9%109
Anorexia[not eating]8.1%99
Lethargy[unusually tired or inactive]6.2%76
Lack of efficacy (ectoparasite) - flea[the product did not have the expected effect: fleas]5.5%67
Ineffective, heartworm larvae[legacy FDA term: the product did not have the expected effect (heartworm larvae)]5.4%66
Emesis[vomiting]4.7%57
Lack of efficacy (endoparasite) - hookworm[the product did not have the expected effect: hookworms]4.5%55
Elevated alanine aminotransferase (ALT)[a liver enzyme above the normal range]4.3%53
Ataxia[unsteady, uncoordinated movement]3.9%48
Pruritus[itching]3.9%48
Elevated serum alkaline phosphatase (SAP)[a liver and bone enzyme above the normal range]3.9%47
Death3.4%41
Lack of efficacy - NOS[the product did not have the expected effect]3.3%40
Convulsion[seizure]3.2%39
Elevated blood urea nitrogen (BUN)[a kidney value above the normal range]3%37
Death by euthanasia[the animal was euthanized]2.7%33
Trembling2.7%33
Behavioural disorder NOS[behaviour change, type not specified]2.4%29
Deafness2.3%28
Fever2.3%28
Elevated creatinine[a kidney value above the normal range]2.2%27
Other abnormal test result NOS[abnormal laboratory result, type not specified]2.1%26
Anaemia NOS[low red blood cell count]2%25

Age and weight

Age of the animal

Under 1 year6.5%79

1 to 3 years20.4%249

4 to 7 years26.9%328

8 to 11 years24.7%301

12 years and over17.9%218

Age not given3.7%45

Weight of the animal

Under 5 kg (11 lb)20.6%251

5 to 9.9 kg (11–22 lb)50%610

10 to 24.9 kg (22–55 lb)24.8%302

25 to 44.9 kg (55–99 lb)0.6%7

45 kg and over (99 lb+)0.1%1

Weight not given4%49

Coloured bar: Fox Terrier reports. Grey bar: all dog reports.

Trend and outcomes

Reports by month FDA received them. The newest months are incomplete because FDA posts reports with a delay of three to six months.

Outcome recorded in the report

Recovered/Normal18.3%223

Recovered with Sequela2.9%35

Ongoing10.4%127

Died5%61

Euthanized1.6%19

Outcome Unknown15.5%189

Beside all dogs

Measure	Fox Terrier	All dogs
Reports	1,220	985,675
Latest 12 months	15	53,292
Classed serious, of reports stating it	40%	38.3%
Death or euthanasia recorded, per 1,000 reports	65.6	55

Questions about Fox Terrier reports

How many FDA adverse event reports involve Fox Terriers?

1,220 reports through March 2026, 0.1% of reports about dogs; 15 in the latest 12 months.

Which drugs are named most often in Fox Terrier reports?

By active ingredient: ivermectin + pyrantel pamoate (158), milbemycin oxime + spinosad (91), carprofen (84), afoxolaner (82) and spinosad (81). Brands are masked in the public data.

What signs are reported most for this breed?

vomiting (24.1%), diarrhoea (9.3%), depression (8.9%), anorexia (8.1%) and lethargy (6.2%).

Is the Fox Terrier more sensitive to certain drugs?

Report counts cannot answer that. They show what was reported, not what a drug did, and they are not adjusted for how many Fox Terrier animals exist or were treated. Breed-related drug sensitivities that are established are described on FDA-approved labels; a veterinarian is the person to ask about an individual animal.

Why are crossbreds not included?

FDA records crossbred animals with one or more component breeds. Counting them under each component would double count, so breed pages use single-breed reports only. Crossbreds remain in the species totals.

How do I report a problem?

Call the drug company using the number on the label, or send Form FDA 1932a to FDA. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Animal & Veterinary adverse event bulk files released 28 Sep 2026, which hold reports FDA's Center for Veterinary Medicine received through 31 Mar 2026. openFDA masks brand and manufacturer names in these files, so drugs are counted by the active ingredients each record discloses and no figure is attributed to a brand, application or company. Ingredient names, and the separate reference lists of approved products, follow the FDA Green Book as of 1 Oct 2026. Breed names are FDA's labels rearranged into everyday order ("Terrier - Fox (unspecified)" becomes "Fox Terrier"). No report text, lot numbers or reporter details are published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.