Editing Caspian seal (section)

===Diseases===
Several recent cases of large numbers of Caspian seals dying due to [[canine distemper]] virus have been reported, in 1997, 2000 and 2001.<ref name=role /> In April 2000, a mass die-off of Caspian seals was first reported near the mouth of the [[Ural River]] in Kazakhstan. It spread south to the [[Mangistau]] region, and by the end of May, more than 10,000 seals had died along the Kazakhstan coast. High death rates were also recorded in May and June along the [[Apsheron peninsula]] of Azerbaijan and the Turkmenistan coast.<ref name=mass>{{cite journal |last1=Kennedy |first1=Seamus |last2=Kuiken |first2=Thijs |last3=Jepson |first3=Paul |last4=Deaville |first4=Robert|last5=Forsyth|first5=Morag|last6=Barrett|first6=Tom|last7=van de Bilt |first7=Marco |last8=Osterhaus |first8=Albert |last9=Eybatov |first9=Tariel |last10=Callan |first10=Duck |last11=Kydyrmanov |first11=Aidyn|last12=Mitrofanov|first12=Igor|last13=Wilson|first13=Susan|title=Mass die-off of Caspian Seals by Canine Distemper Virus |journal=Emerging Infectious Diseases|date=2000 |volume=6|issue=6|pages=637–639 |pmid=11076723 |doi=10.3201/eid0606.000613 |pmc=2640919}}</ref>

Clinical signs of infected seals included debilitation, muscle spasms, ocular and nasal exudation, and sneezing.  Necropsies performed in June 2000 on eight Azerbaijan seals revealed microscopic lesions, including bronchointerstitial [[pneumonia]], [[encephalitis]], [[pancreatitis]] and lymphocytic depletion in lymphoid tissues.  Similar lesions were also discovered on four seals from Kazakhstan. ''Morbillivirus'' antigen was also detected in multiple tissues, including lung, [[lymph nodes]], spleen, brain, pancreas, liver, and [[epithelial tissue]] of the reproductive, urinary, and gastrointestinal tracts. Such tissue lesions are characteristic of distemper in both terrestrial and aquatic mammals.<ref name=mass />

Tissues from 12 carcasses found in [[Kazakhstan]], [[Azerbaijan]], and [[Turkmenistan]] were examined for [[morbillivirus]] nucleic acid. Sequences from the examination showed that canine distemper virus, which is part of the genus ''Morbillivirus'', was the primary cause of death. The sequences also proved that seals from widely separated regions of the Caspian Sea were infected by the same virus. This finding established spatial and temporal links between the seal deaths in these regions. The sequences were also identical to that of canine distemper virus found in the brain tissue of a seal that died in 1997 and showed no morbillivirus lesions. This suggests persistence of canine distemper virus in the Caspian seal population over a span of several years or repeated spillover from the same terrestrial reservoir.<ref name=mass />

Another study in 2000 using 18 Caspian seal corpses found several concurrent bacterial infections that could have contributed to the illness of the affected seals. These include ''[[Bordetella bronchiseptica]]'', ''Streptococcus phocae'', ''Salmonella dublin'', and ''S. choleraesuis''. ''Corynebacterium caspium'', a new bacterium, was identified in one of the seals, and poxvirus, ''Atopobacter phocae'', ''[[Eimeria]]''- and ''[[Sarcocystis]]''-like organisms, and a ''[[Halarachne]]'' species were identified in Caspian seals for the first time. The study also asserts that the "unusually mild" winter that preceded the die-off in 2000 could have contributed to its cause "through increased ambient air pressure and accelerated disappearance of ice cover at the breeding areas in the northern Caspian Sea."<ref name=canine>{{cite journal |last1=Kuiken |first1=T. |last2=Kennedy |first2=S. |last3=Barrett |first3=T.|last4=Van de Bilt |first4=M.W.G. |last5=Borgsteede |first5=F.H. |last6=Brew |first6=S.D. |last7=Codd |first7=G.A.|last8=Duck|first8=C.|last9=Deaville|first9=R.|last10=Eybatov|first10=T. |last11=Forsyth |first11=M.A. |last12=Foster |first12=G. |last13=Jepson |first13=P.D. |last14=Kydyrmanov |first14=A. |last15=Mitrofanov |first15=I. |last16=Ward |first16=C.J. |last17=Wilson |first17=S. |last18=Osterhaus |first18=A.D.M.E. |title=The 2000 Canine Distemper epidemic in Caspian Seals (''Phoca caspica''): Pathology and analysis of contributory factors |journal=Veterinary Pathology |date=2006 |volume=43 |issue=3|pages=321–338 |pmid=16672579 |doi=10.1354/vp.43-3-321|doi-access=free}}</ref>