Canine maternal hydrops… I first heard about this term a few years ago, when my former boss called me because he was questioned on this disorder. Interestingly, the question came from Canada (at this time I never thought that I would one day live here!)…
Recently a colleague of mine sent me a long article on something called “canine maternal hydrops”. It mentioned that “there is a serious lack of available information for Maternal Hydrops in dogs”. Well, to tell the truth, there is no information at all!
When speaking about hydrops, veterinarians generally refer to “dropsy of the fetal membranes and fetus”. Basically, this means that there is an abnormal accumulation of fluid in one of these fetal sacs (there are two fetal sacs in mammals, the allantois and the amnios) or in the fetus itself. The dropsy of the fetus’s conditions are well known among repro vets (hydrocephalus, fetal ascites, fetal anasarca). However, the situation is completely different when it comes to the dropsy of the fetal sacs (disorders referred to as hydrallantois and hydramnios). Hydrallantois is only mentioned once in the scientific literature in the bitch (Smith& Oaksford, 1972, so as you can see not a really recent reference) and there is no mention at all of hydramnios in the canine species.
These diseases are essentially described in the cow, and, to a lesser extent, in the mare. In these species, hydrallantois is far more common than hydramnios and can indeed lead to life threatening conditions in certain cases. This large amount of fluid indeed compresses all the major blood vessels, leading to edemas, cardiac malfunction, and eventually death. To date, nobody really knows what the initial cause is… A malfunctioning placenta has always been reported, with no associated infectious signs. Interestingly, the incidence of the disease seems to be higher with pregnancies of bovine clones. The treatment is rather simple: stop the pregnancy (if it occurs early during pregnancy) or go for a c-section in later cases.
As you understood, there is no data in the canine species. I sometimes even wonder if it is not a north American specificity since in Europe, I never heard of it/dealt with it. But I assume it might exist. What do we need at this point? These data should be published, this is the only way to motivate the scientific community. The website I visited mentioned at least 50 cases reported. I am sure there are plenty of my colleagues would love to analyze these data and convert into a scientific publication. I think I said it before but all these strange cases you guys are dealing with are really important for the future of veterinary medicine, so don’t hesitate and share them with us! If we want to move forward, breeders and vets have to work together. That could definitely be a perfect example!
DR. EMMANUEL FONTAINE 
I just had a hydrops litter born yesterday. 9 puppies delivered by C-section. Heart rates extremely low on ultrasound. Akita bitch had excessively enlarged vulva and had been leaking for 1 week. She hadn’t eaten in 5 days but was drinking. Vomiting bile the last 24 hours. 61 days post first breeding. Temp drop from 101 to 99 followed by non-productive nesting behavior for 8 hours. Normally 78 lb bitch weighed in at 122 lbs. Uterus had huge volumes of fluid. When the first horn was pulled out, it was distended at least twice normal size and you could see movement of puppies sloshing around in it (which was also seen in ultrasound). When uterine wall was opened, it was like someone dumped a 1 gallon bucket for both horns. Puppies were extremely slow to thrive, but okay now. Bitch’s mammary development dried up post surgery and was given Domperidone and was back in 5 hours later but she spiked 103 and showed all the behavior changes of dropped calcium levels with the sudden milk production, but she is responding to high volumes of oral calcium.
This is the second I have had … first was a litter of one puppy about 8 years ago.
I am happy to put you in touch with my veterinarian.
LikeLike