Trans-generational and neonatal humoral immune responses in West Greenland sledge dogs ( Canis familiaris) exposed to organohalogenated environmental contaminants

Previous investigations in the Arctic have suggested OHC (organohalogen contaminant) induced immune toxic effects on e.g. polar bears ( Ursus maritimus). We therefore studied the dietary impact from minke whale blubber ( Balaenoptera acutorostrata), rich in polyunsaturated fatty acids and OHCs, on the humoral immunity of 7 captive West Greenland sledge dog ( Canis familiaris) bitches and their 4 pups constituting a sentinel model species for polar bears. A control group was composed of 8 bitches and their 5 pups all fed pork ( Suis scrofa) fat. The study included serum IgG measurements (bitches and pups) and specific immune responses towards tetanus toxoid (bitches) and diphtheria toxoid (pups) as well as influenza virus (pups). The analyses showed that IgG concentrations were non-significantly lowest in exposed bitches and pups (t-test: all p > 0.05). In addition, significant lower antibody response was detected in exposed pups immunized with influenza virus at age 3 months (t-test: both p < 0.05). No clear group differences were found for tetanus toxoid in bitches and diphtheria toxoid in pups. The results suggest that the humoral immune system of sledge dogs may be suppressed by the dietary blubber composition of OHCs and polyunsaturated fatty acids while a larger follow-up study is recommended in order to investigate this relationship further.