[Follow-up ultrasonographic examinations in pregnant bitches - evaluation of frequency and significance of embryo resorption].

Objective: Follow-up ultrasonographic examinations in pregnant bitches to evaluate frequency and significance of embryo resorption.
Material and Methods: In 39 Kangal bitches the number of gestational sacs was measured and vitality of embryos/fetuses was evaluated by real time ultrasonography daily from the 15th till the last day of gestation.
Results: Five bitches (12.8%) showed embryonic resorption and one of these bitches exhibited a complete resorption. Fetal death could be observed in four females and was related to a total loss of the litter. After the first evidence of embryonic death gestational sacs remained detectable for 8.6±0.5days. The number of embryos of bitches with (10.8±1.8) or without embryo resorption (8.2±2.1) was statistically significantly different (p<0.05). On the other hand there was no statistically significant difference within the number of embryos of bitches suffering fetal death and bitches without embryo resorption (8.2±2.1) (p>0.05). A relationship between litter size and gestational length could not be verified (r=0.15; p>0.05).
Conclusion and Clinical Relevance: Due to these results the hypothesis is postulated that embryonic resorption is a kind of protective mechanism of the maternal organism against too large litter sizes.