Table 6. --Seal pups that died of malnutrition with secondary 

 bacterial enteritis, all mortality study areas, 

 St. Paul Island, 1964 and 1966-68 



Total deaths 

 from 



Pups with 

 secondary bacterial 

 enteritis 



1/ Permanent canine teeth had not erupted in 70.7 percent of 

 pups that died of malnutrition, indicating that deaths from 

 this cause usually occur before the age of 3 to 4 weeks. Per- 

 manent canine teeth usually erupt in females by the third week 

 and in males by the fourth week. 



also, and peculiarly, within the eyes (20-44 

 percent). Affected livers are usually friable, 

 swollen, and easily ruptured, and often have 

 blood blisters and focal necrosis on their 

 surfaces. One affected pup (necropsy number 

 68-N-133) had subcapsular hemorrhages of the 

 liver and generalized jaundice, but the liver 

 had not ruptured. Table A- 15 shows the lesions 

 and circumstances associated with this disease. 

 We do not know the cause but suspect a virus 

 infection, or some toxic process. Although 

 attempts to culture a virus from the liver of 

 affected seals using tissue culture cell lines 

 from human embryonic kidney and fibroblasts, 

 and African Green Monkey kidney, ^ were 

 negative, the results were inconclusive because 

 we were unable to try tissue culture cell lines 

 from the fur seal. 



intestinal tract to cause hemorrhagic anennia, 

 focal intestinal ulceration, inflammation, and, 

 in some cases, perforation. 



Although the percentage of deaths fron-i 

 hookworm disease for all areas combined in 

 1968 (16.9 percent) was nearly the same as in 

 1967 (16.0 percent), the actual nun-iber in- 

 creased from 37 to 64. 



The first cases of hookworm disease were 

 found on Reef Rookery 10 July 1968, 1 week 

 earlier than usual. The incidence there (6.3 

 percent) was much lower than on Northeast 

 Point (33.3 percent). We can only speculate 

 that the reason for this and a similar dif- 

 ference noted in 1967 is because of different 

 topography, or a cyclic variation in the level 

 of passive resistance transmitted from 

 mothers to their pups. 



The permanent canine teeth had not erupted 

 in 71.9 percent of the pups that died of hook- 

 worm disease, indicating that the pups died 

 from this cause before they were 3 to 4 weeks 

 old. 



Trauma 



Eight pups with ruptured livers did not have 

 definite symptoms of the multiple hemorrhage- 

 perinatal complex other than liver hemorrhage 

 and may have been trampled by adult seals. 

 For example, we assume that trampling 

 ruptured a heart and four stomachs, fractured 

 two skulls, and gave one pup severe contusions. 

 In addition, 13 pups died of infection or 

 hemorrhage owing to bite wounds. 



Multiple Hemorrhage- Perinatal Complex 



Thirty to forty percent of the pups that have 

 died of this complex have been stillborn, and 

 67 to 80 percent have had fresh umbilical cords 

 or placentas; hence the designation "perinatal" 

 (around birth). Except for liver rupture, the 

 most constant lesion has been hemorrhage, 

 usually from the liver but from other organs 



Infection (Microbial) 



The most prevalent form of microbial in- 

 fection (table 5) was enteritis, the primary 

 cause of death in 10 pups and the secondary 

 cause in 77. Navel infection (omphalophlebitis) 

 in 1968 was lower than expected (1 percent), 

 but pups that die of this cause deteriorate 

 rapidly and some may have been overlooked 

 among those classified as unsuitable for exam- 

 ination. Bite wounds in nine pups caused fatal 

 secondary infections. 



Miscellaneous 



This category included five stillbirths, one 

 meconium impaction, and one congenital pneu- 

 monia. Among those that died of the multiple- 

 hemorrhage-perinatal complex, 7 were still- 

 births, bringing the total to 12 stillbirths (3,2 

 percent) among 324 pups. 



SEASONAL AND ANNUAL TRENDS IN 

 SEAL PUP MORTALITY 



Table A- 16 shows the causes of death by 

 7-day periods on St. Paul Island. The number 

 of deaths was highest from 26 July to 1 August 

 when most were caused by malnutrition and 

 hookworm disease. Most of the deaths from 

 all other causes occurred before 26 July. 



Figures 7 and 8 compare mortality for 4 

 years on area 1, Reef Rookery, andfor 2 years 

 on area 3, Northeast Point. The relative size 

 of the five major causes of mortality varied 

 significantly between years on Reef Rookery 

 (P<0,005) but not on Northeast Point (P=0.25). 

 The causes of death that deviated most from 



This work was done by Dorothy F. Scott, Department 

 of Microbiology, Presbyierian-St. Luke's Hospital, Chi- 

 cago, through the courtesy of Friedrich Deinhardt, Chair- 

 man. 



