Abstract
Over 100 free-ranging adult California sea lions (Zalophus californianus) and one Northern fur seal (Callorhinus ursinus), predominantly adult females, were intoxicated by domoic acid (DA) during three harmful algal blooms between 1998 and 2000 in central and northern California coastal waters. The vector prey item was Northern anchovy (Engraulis mordax) and the primary DA-producing algal diatom was Psuedonitzschia australis. Postmortem examination revealed gross and histologic findings that were distinctive and aided in diagnosis. A total of 109 sea lions were examined, dying between 1 day and 10 months after admission to a marine mammal rehabilitation center. Persistent seizures with obtundation were the main clinical findings. Frequent gross findings in animals dying acutely consisted of piriform lobe malacia, myocardial pallor, bronchopneumonia, and complications related to pregnancy. Gross findings in animals dying months after intoxication included bilateral hippocampal atrophy. Histologic observations implicated limbic system seizure injury consistent with excitotoxin exposure. Peracutely, there was microvesicular hydropic degeneration within the neuropil of the hippocampus, amygdala, pyriform lobe, and other limbic structures. Acutely, there was ischemic neuronal necrosis, particularly apparent in the granular cells of the dentate gyrus and the pyramidal cells within the hippocampus cornu ammonis (CA) sectors CA4, CA3, and CA1. Dentate granular cell necrosis has not been reported in human or experimental animal DA toxicity and may be unique to sea lions. Chronically, there was gliosis, mild nonsuppurative inflammation, and loss of laminar organization in affected areas.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 184-191 |
| Number of pages | 8 |
| Journal | Veterinary Pathology |
| Volume | 42 |
| Issue number | 2 |
| DOIs | |
| State | Published - Mar 2005 |
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Keywords
- Amnesic shellfish poisoning
- California sea lions
- Domoic acid
- Excitotoxin
- Marine toxin
- Neurotoxin
- Red tide
- Seizure
- Zalophus californianus
ASJC Scopus subject areas
- veterinary(all)
Cite this
Pathology of domoic acid toxicity in California sea lions (Zalophus californianus). / Silvagni, P. A.; Lowenstine, Linda J; Spraker, T.; Lipscomb, T. P.; Gulland, F. M D.
In: Veterinary Pathology, Vol. 42, No. 2, 03.2005, p. 184-191.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Pathology of domoic acid toxicity in California sea lions (Zalophus californianus)
AU - Silvagni, P. A.
AU - Lowenstine, Linda J
AU - Spraker, T.
AU - Lipscomb, T. P.
AU - Gulland, F. M D
PY - 2005/3
Y1 - 2005/3
N2 - Over 100 free-ranging adult California sea lions (Zalophus californianus) and one Northern fur seal (Callorhinus ursinus), predominantly adult females, were intoxicated by domoic acid (DA) during three harmful algal blooms between 1998 and 2000 in central and northern California coastal waters. The vector prey item was Northern anchovy (Engraulis mordax) and the primary DA-producing algal diatom was Psuedonitzschia australis. Postmortem examination revealed gross and histologic findings that were distinctive and aided in diagnosis. A total of 109 sea lions were examined, dying between 1 day and 10 months after admission to a marine mammal rehabilitation center. Persistent seizures with obtundation were the main clinical findings. Frequent gross findings in animals dying acutely consisted of piriform lobe malacia, myocardial pallor, bronchopneumonia, and complications related to pregnancy. Gross findings in animals dying months after intoxication included bilateral hippocampal atrophy. Histologic observations implicated limbic system seizure injury consistent with excitotoxin exposure. Peracutely, there was microvesicular hydropic degeneration within the neuropil of the hippocampus, amygdala, pyriform lobe, and other limbic structures. Acutely, there was ischemic neuronal necrosis, particularly apparent in the granular cells of the dentate gyrus and the pyramidal cells within the hippocampus cornu ammonis (CA) sectors CA4, CA3, and CA1. Dentate granular cell necrosis has not been reported in human or experimental animal DA toxicity and may be unique to sea lions. Chronically, there was gliosis, mild nonsuppurative inflammation, and loss of laminar organization in affected areas.
AB - Over 100 free-ranging adult California sea lions (Zalophus californianus) and one Northern fur seal (Callorhinus ursinus), predominantly adult females, were intoxicated by domoic acid (DA) during three harmful algal blooms between 1998 and 2000 in central and northern California coastal waters. The vector prey item was Northern anchovy (Engraulis mordax) and the primary DA-producing algal diatom was Psuedonitzschia australis. Postmortem examination revealed gross and histologic findings that were distinctive and aided in diagnosis. A total of 109 sea lions were examined, dying between 1 day and 10 months after admission to a marine mammal rehabilitation center. Persistent seizures with obtundation were the main clinical findings. Frequent gross findings in animals dying acutely consisted of piriform lobe malacia, myocardial pallor, bronchopneumonia, and complications related to pregnancy. Gross findings in animals dying months after intoxication included bilateral hippocampal atrophy. Histologic observations implicated limbic system seizure injury consistent with excitotoxin exposure. Peracutely, there was microvesicular hydropic degeneration within the neuropil of the hippocampus, amygdala, pyriform lobe, and other limbic structures. Acutely, there was ischemic neuronal necrosis, particularly apparent in the granular cells of the dentate gyrus and the pyramidal cells within the hippocampus cornu ammonis (CA) sectors CA4, CA3, and CA1. Dentate granular cell necrosis has not been reported in human or experimental animal DA toxicity and may be unique to sea lions. Chronically, there was gliosis, mild nonsuppurative inflammation, and loss of laminar organization in affected areas.
KW - Amnesic shellfish poisoning
KW - California sea lions
KW - Domoic acid
KW - Excitotoxin
KW - Marine toxin
KW - Neurotoxin
KW - Red tide
KW - Seizure
KW - Zalophus californianus
UR - http://www.scopus.com/inward/record.url?scp=20144384720&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=20144384720&partnerID=8YFLogxK
U2 - 10.1354/vp.42-2-184
DO - 10.1354/vp.42-2-184
M3 - Article
VL - 42
SP - 184
EP - 191
JO - Veterinary Pathology
JF - Veterinary Pathology
SN - 0300-9858
IS - 2
ER -