Anasarca in English Bulldog puppies: pathological findings and etiopathogenic considerations

Anasarca is a condition of fetal hydropsy able to cause obstetric injuries both in animals and humans. It consists of a diffuse oedematous status of the subcutaneous connective tissue, with or without production of transudate in serosal cavities. The pathogenesis of the condition is not entirely understood. A pregnant 3.5 years old female English bulldog was admitted to the Veterinary Teaching Hospital of the University of Messina, 62 days after mating. Clinical examination showed anorexia, moderate depression, dyspnoea, abdominal enlargement and vulvar swelling. Ultrasonographic examination revealed the death of two oversized foetuses. Six puppies were removed by caesarean section. Three of them were very weak and died within two hours, whereas the lastone is still live and alive. Complete necropsies of four puppies were performed. Samples of different tissues and organs were collected, fixed in 10% buffered formalin and paraffin wax embedded. Histological sections were stained with haematoxylin and eosin. The puppies showed variable degrees of size increasing and diffuse anasarca. The skin was thickened and a yellowish fluid spoured at skinning. The same fluid filled the serosal cavities. The majority of body organs were unremarkable, except the hearts, which were enlarged and pale. The most important histopathological lesions were located in the skin (diffuse dermic oedema), heart (myocarditis), spleen and thymus (hyperplasia) of all subjects. The observed findings were similar to those already reported in literature in dogs and other animal species. In dogs, English bulldogs present the higher incidence of this status in comparison with other canine breeds. In dogs, the anasarca is also known as “water pups” and a similar condition has been described in humans. In bovines and bovines, the pathogenesis seems to be related to an autosomal recessive gene, whereas in other animals it has not been verified, even if the high predisposition in some breed of dogs indicates a genetic defect. Among the different pathogenic hypotheses, minute virus of canines (MCV) has been shown to cause transplacental infections with ccasional findings of anasarca or myocarditis in some pups. This evenience could be considered also in our cases, where the occurrence of gross and istopathological inflammatory lesions particularly in the heart and lymphoid tissues of the puppies suggested a probable viral infection as the cause of the condition.