Table 3

Cause of death and histopathological lesions in the central nervous system of non-releasable California sea lions placed at US institutions between 2000 and 2016 that died during this time period (n=29)

Blinded study numberAge class at strandingReason for non-releasabilityNeurological signsCNS lesionsHippocampal lesionsCause of death
1NeonatePreweanedSeizuresNENEUnknown—acute death
2NeonatePreweanedNANENEUnknown—acute death*
3NeonatePreweanedAtaxiaNormalNormalUnknown—acute death
4NeonatePreweanedSeizuresNormalNormalUnknown—acute death
5NeonatePreweanedRepetitive regurgitationMild MF non-suppurative encephalitis focused on hippocampus
Perivascular cuffing
MF non-suppurative inflammationDomoic acid toxicosis
6NeonatePreweanedSeizuresAcute cerebral oedemaNormalSeizures
7NeonatePreweanedSeizuresNon-suppurative meningoencephalitis due to Toxoplasma infectionUnknownOther
8NeonatePreweanedNANENEOther
9Non-neonate (juvenile)RestrandNAMF haemorrhageUnknownSuspect drowning
10Non-neonate (adult)RestrandNAMeningeal oedemaUnknownSuspect drowning
11Non-neonate (yearling)TraumaSeizuresNormalNormalSeizures
12Non-neonate (yearling)Chronic IllnessSeizuresNormalNormalSeizures
13Non-neonate (yearling)RestrandSeizuresMF haemorrhageNormalSeizures
14Non-neonate (adult)RestrandSeizuresMF Purkinje cell necrosisNEOther
15Non-neonate (yearling)TraumaAtaxia, head twitchingMeningitis due to Coccioides infectionUnknownOther
16Non-neonate (juvenile)RestrandSeizuresMetastatic neoplasiaNormalOther
17Non-neonate (juvenile)Chronic IllnessNANormalUnknownOther
18Non-neonate (yearling)RestrandSeizuresNormalNormalOther
19Non-neonate (yearling)Chronic illnessObtundation, nystagmusNormalUnknownOther
20Non-neonate (juvenile)TraumaNANormalNEOther
21Non-neonate (pup)RestrandNAUnknownUnknownOther
22Non-neonate (pup)TraumaNAMild perivascular haemorrhageNormalOther
23Non-neonate (pup)RestrandNANENEOther
24Non-neonate (pup)HabituationNANormalNormalOther
25Non-neonate (yearling)Chronic illnessNANormalUnknownOther
26Non-neonate (adult)Chronic illnessNANENEOther
27Non-neonate (pup)TraumaNANENEOther
28Non-neonate (yearling)TraumaAtaxia, hypermetriaInfarctsUnknownOther
29Non-neonate (pup)RestrandNANormalNormalOther
  • *Sudden, unexplained death.

  • CNS, central nervous system; MF, multifocal; NA, not applicable; NE, not evaluated.