TRANSFER OF COLOSTRAL ANTIBODIES FROM QUEENS TO THEIR KITTENS

Objective-To examine systemic immunity in kittens, including transfer of maternal immunoglobulins from the queen to kittens, and subsequent decay of passively obtained immunoglobulins. Animals-6 healthy queens and their 46 kittens. Procedure-Immunoglobulin concentrations were mea sured in serum, colostrum, and milk of queens and in their kittens' se ra. Decay rate constants and half-lives of maternally derived immunogl obulins were determined. To determine intestinal absorption, foreign I gG was given to kittens at 6- to 8-hour intervals after birth, and bov ine IgM was given to kittens at birth. Results-Immunoglobulin concentr ations of milk and colostrum did not differ significantly after remova l of milk fat. Mean IgG concentration was higher in colostrum/ milk, w hereas mean IgA and IgM concentrations were lower than those in the qu eens' serum. No IgG or IgA was detected in any of the precolostral ser um samples obtained from kittens. Small amounts of IgM were present in the sera from 5 kittens at birth. Transferred IgG and IgA decreased r apidly with half-lives of 4.4 +/- 3.57 and 1.93 +/- 1.94 days, respect ively. Serum IgM concentration increased irregularly during the first week of life, followed by a steady increase. Foreign IgG given up to 1 2 hours after birth was detected in kittens' serum, whereas IgG given at or after 16 hours was not found in any kitten's serum. Conclusions- Milk and colostral immunoglobulin concentrations did not differ signif icantly. The half-lives of maternally derived IgG and IgA in kittens w ere shorter than those reported in dogs. IgG given at or after 16 hour s of life was not absorbed by neonatal kittens. Clinical Relevance-Que en's milk obtained anytime during lactation may be used as a replaceme nt for colostrum as a source of antibodies for neonatal kittens. Kitte ns at risk for neonatal isoerythrolysis must only be removed from the queens during the first day of life.