Breed · Cat
Norwegian Forest: adverse event reports
FDA breed label "Norwegian Forest" · single-breed animals only
187 adverse event reports received by FDA describe an animal recorded as Norwegian Forest (FDA breed label "Norwegian Forest"). That is 0.1% of all reports about cats. Crossbred animals are not counted here, only reports that give this single breed.
16 reports arrived in the 12 months to March 2026, up 23% from 13 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 frunevetmab, selamectin and spinosad. Frunevetmab is named in 11.2% of this breed's reports, a larger share than in reports about all cats (5.1%).
The terms listed most often are lethargy (17.6%), vomiting (17.1%) and anorexia (10.2%). Lethargy appears in 17.6% of reports, a larger share than in all cat reports (9.7%). 38.5% of reports stating seriousness were classed as serious, against 35.6% for cats overall.
Drugs named most often, by active ingredient
| Active ingredients recorded for the drug | Reports | Share of Norwegian Forest reports | Share of all cat reports |
|---|---|---|---|
| Frunevetmab | 21 | 11.2% | 5.1% |
| Selamectin | 18 | 9.6% | 14.8% |
| Spinosad | 16 | 8.6% | 7.8% |
| Cefovecin sodium | 15 | 8% | 5.8% |
| Fluralaner | 14 | 7.5% | 7% |
| Insulin | 14 | 7.5% | 2.4% |
| Nitenpyram | 14 | 7.5% | 5.8% |
| Imidacloprid + Moxidectin | 11 | 5.9% | 5.5% |
| Sarolaner + Selamectin | 10 | 5.3% | 5.3% |
| Buprenorphine | 7 | 3.7% | 3.7% |
| Cyclosporine | 5 | 2.7% | 2% |
| Maropitant | 5 | 2.7% | 2.5% |
| Butorphanol Tartrate | 4 | 2.1% | 1.5% |
| Isoflurane | 4 | 2.1% | 1.3% |
| Robenacoxib | 4 | 2.1% | 2.2% |
| Velagliflozin | 4 | 2.1% | 2.9% |
| Amoxicillin | 3 | 1.6% | 1.1% |
| Bexagliflozin | 3 | 1.6% | 2.5% |
| Ketamine Hydrochloride | 3 | 1.6% | 2.5% |
| Methylprednisolone Acetate | 3 | 1.6% | 1% |
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 Norwegian Forest reports listing the termall cat reports
- Lethargy[unusually tired or inactive]17.6%33
- Vomiting17.1%32
- Anorexia[not eating]10.2%19
- Diarrhoea[diarrhea]8.6%16
- Lack of efficacy (ectoparasite) - flea[the product did not have the expected effect: fleas]7%13
- Weight loss5.9%11
- Hyperactivity5.3%10
- Ataxia[unsteady, uncoordinated movement]4.3%8
- Behavioural disorder NOS[behaviour change, type not specified]4.3%8
- Dehydration4.3%8
- Depression[dull, quiet or withdrawn]4.3%8
- Skin scab4.3%8
- Death3.7%7
- Elevated alanine aminotransferase (ALT)[a liver enzyme above the normal range]3.7%7
- Emesis[vomiting]3.7%7
- Lack of efficacy - NOS[the product did not have the expected effect]3.7%7
- Panting3.7%7
- Application site hair loss[hair loss where the product was applied]3.2%6
- Death by euthanasia[the animal was euthanized]3.2%6
- Fever3.2%6
- Hiding3.2%6
- Ineffective, glycemic control[legacy FDA term: the product did not have the expected effect (glycemic control)]3.2%6
- Not eating3.2%6
- Pruritus[itching]3.2%6
Age and weight
Age of the animal
Weight of the animal
Coloured bar: Norwegian Forest reports. Grey bar: all cat 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
Beside all cats
| Measure | Norwegian Forest | All cats |
|---|---|---|
| Reports | 187 | 148,080 |
| Latest 12 months | 16 | 12,477 |
| Classed serious, of reports stating it | 38.5% | 35.6% |
| Death or euthanasia recorded, per 1,000 reports | 74.9 | 95 |
Questions about Norwegian Forest reports
How many FDA adverse event reports involve Norwegian Forests?
187 reports through March 2026, 0.1% of reports about cats; 16 in the latest 12 months.
Which drugs are named most often in Norwegian Forest reports?
By active ingredient: frunevetmab (21), selamectin (18), spinosad (16), cefovecin sodium (15) and fluralaner (14). Brands are masked in the public data.
What signs are reported most for this breed?
lethargy (17.6%), vomiting (17.1%), anorexia (10.2%), diarrhoea (8.6%) and decreased appetite (7%).
Is the Norwegian Forest 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 Norwegian Forest 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 ("Norwegian Forest" becomes "Norwegian Forest"). 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.