Drug profile

The FDA adverse-event record for Clos P*2/Cl Oth*4/H.Somnus Kb

119 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Clos P*2/Cl Oth*4/H.Somnus Kb. See the species affected, top reactions, and outcomes below.

119
adverse-event reports
82.4%
death-coded share
Cattle
most-reported species
83
Death - top reaction
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Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
119
Total Reports
98
Deaths Reported
82.4%
Death Rate

Active Ingredients

Clos P*2/Cl Oth*4/H.Somnus Kb

Administration Routes

SubcutaneousUnknownSubconjunctival

Species Affected

Cattle 119

Most Affected Breeds

Cattle (other) 55
Aberdeen Angus 29
Crossbred Bovine/Cattle 18
Holstein-Friesian also known as Holstein 6
Red Angus 3
Charolais 3
Mixed (Cattle) 2
Unknown 1
Cattle (unspecified) 1
Simmental 1

Most Reported Reactions

Death 83
Lack of efficacy - NOS 48
Lack of efficacy (bacteria) - NOS 18
Found dead 10
Lack of efficacy (endoparasite NOS) 9
Respiratory signs 7
Anaphylaxis 7
NT - Abnormal necropsy finding NOS 7
Lack of efficacy (virus) - coronavirus - NOS 5
Not eating 4
Pneumonia 4
Foam in the nose 4

Outcome Breakdown

Died
97 (44.7%)
Ongoing
64 (29.5%)
Recovered/Normal
38 (17.5%)
Outcome Unknown
13 (6.0%)
Euthanized
4 (1.8%)
Recovered with Sequela
1 (0.5%)

Clos P*2/Cl Oth*4/H.Somnus Kb Adverse Event Insights

119 reports name Clos P*2/Cl Oth*4/H.Somnus Kb; 98 recorded a death outcome (82.4% of reported events, not a population-level mortality rate). Active ingredient: Clos P*2/Cl Oth*4/H.Somnus Kb. Administration routes: Subcutaneous, Unknown, Subconjunctival.

By species: Cattle (119 reports). By breed: Cattle (other) (55), Aberdeen Angus (29), Crossbred Bovine/Cattle (18).

Leading clinical signs: Death (83), Lack of efficacy - NOS (48), Lack of efficacy (bacteria) - NOS (18), Found dead (10). Outcome, 217 coded reports: Died leads at 44.7%.

Read these counts as reporting volume, not risk: per our methodology, a widely-prescribed drug will rack up more raw FDA reports in a given year than a rarely-used one at an identical true rate, so we recommend comparing within similar-exposure products rather than across the full 2025 catalog.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.