It may sound like an animated character straight out of a Disney movie, but anasarca is, sadly, a life-threatening condition common in Bulldogs, but recognized in other breeds as well. It can theoretically affect any breed of dog, although it is most common in brachycephalic breeds, such as English and French Bulldogs, Bullmastiffs, Pugs, and Boston Terriers. The condition is known to occur in Yorkshire Terriers, Cocker Spaniels, and—albeit rarely—in German Shepherds, Tervurens, and Australian Shepherds.
Anasarca puppies, also referred to as walrus puppies, or occasionally water puppies, rubber puppies, or swimmer puppies, are born with an abnormal and lethal amount of fluid under their skin. Anasarca has been recognized for many years, yet as with many canine neonatal illnesses, there is a discouraging lack of knowledge of the true causes of anasarca, and much of what experts believe about it is speculative.
When and Why It Occurs
The condition appears to develop in the later part of gestation; puppies can be born up to four or five times their normal weight, as a result of the excess fluid. One or all of the puppies may be affected. Survival rates are low, and because of the abnormally large size of the puppies, a cesarean delivery is necessary.
Experts consider anasarca to be a congenital problem—meaning it exists at or before birth—but it is unclear whether or not it is always inherited. Bulldogs and French Bulldogs are the only two breeds where anasarca is known to be a hereditary condition, although the mode of inheritance is unknown. In some breeds where the condition is rare, it is thought to be less likely to be inherited. The assumption is that if the genetic potential were there, breeders would be seeing a lot more of it.
Environmental factors influencing the condition have been discussed and debated on the internet, but again this is speculative. For example, some breeders, whose dogs have produced anasarca puppies, suggest the culprit may be a high sodium diet, which they believe causes the female to retain water. Experts caution that there is no scientific data to substantiate environmental claims, including those of a high-sodium diet.
A Lack of Symptoms
To further complicate the matter, symptoms are limited or seemingly non-existent in most cases. This, understandably, catches many breeders and veterinarians off guard. Some experts say that one indicator may be additional weight gain by the female, as a result of the extra fluid. Other breeders notice a water ring around the female’s teats in the later stages of pregnancy or large, swollen, mammary glands. Others observe a listing or shifting of the puppies from one side to the other. Again, experts caution against reading too much into these observations, as there is no viable scientific data to substantiate these symptoms.
As a precautionary measure, an ultrasound should be given at approximately 49 days (two weeks prior to the expected due date) that should, if there is a problem, indicate “big, oversized fetus that appear to contain excessive water in comparison to neighboring feti in the uterus.”
Multiple anecdotal remedies exist, yet none are proven or reported in scientific literature. Although survival rates are low, some water puppies do survive provided they receive immediate veterinary treatment. That's why it's a good idea to get pet insurance that covers hereditary conditions if you end up with a water puppy.
Theoretically, surviving puppies should live an otherwise healthy, normal life. The problem is that many puppies do not survive, with many being euthanized shortly after birth. Therefore, as with most everything pertaining to neonatal illnesses, little or no scientific documentation exists regarding the long-term effects of congenital edema in puppies.