I'm sorry you lost your mare. However I am very reluctant to blame the vet. Miscarrages are common in horses although they usually happen very early in the pregnancy. You didn't say at what point the miscarriage happened. Before the next breeding this mare should have been cultured and ultrasounded to make sure her uterus was not affected by the miscarriage. The resulting stillborn foal could have been from a residual infection.
The stallion too should be cultured regularly. I am assuming you are live covering these mares. He can easily pass infections from one mare to the next.
The stillborn twins were completely avoidable if you had had her ultrasounded. Twins are almost always stillborn or born VERY sick and small. Horses are not designed to carry twins. The mare causes twins not the stallion so he cannot be blamed. If the mare had been checked early the vet can usually eliminate one foal to allow the other to live. I don't mean to be insensitive but this pregnancy was botched by you not the mare, stallion or vet. I hope you have learned from this to, in the future, have your mares checked for signs of twins or infection.
When the vet examined your mare and said everything was OK he/she could very well been right. Your mare did not die from cancer. Cancer is a progressive disease.... cancer patients don't look healthy one day and fall over dead the next. My guess is that she died from a ruptured uterine artery and bled out. That is NO ONES fault. It can rupture from the physical strain of birthing. There is no way to predict it and almost never any way to save the mare. If the bleeding is slow sometimes with multiple blood transfusions the mare can be saved... but usually they bleed out before you can hook up your trailer. Even the fanciest of breeding facilities can lose a mare this way.
The fact that the necropsy found uterine cancer may be coincidental. It obviously didn't affect the foal since you had a live birth and it didn't kill your mare. When the vet examined her before you bred her it is very likely that the cancer was not detectable at that point. A uterine biopsy would have had to been performed and even then it can be missed if it is in stage 1. Cancers are often accelerated by the hormones during pregnancy and it would have been over a year since the mare was examine by the vet. It is reasonable that the cancer could have developed during that year AFTER the vet gave you the OK to breed. And did you have the mare checked during the pregnancy to make sure everything was progressing normally and there weren't twins? I'm guessing no.
In my opinion your lawsuit against this vet is a complete joke. There are reasonable explanations for everything you described and your lack of proper care for a pregnant mare raises even more doubt that the vet did anything wrong. Don't waste your money with a lawsuit.
Also, it is NOT normal for a foal to mope around... even if it just lost its mother. Foals have a very short memory... Lucky probably forgot about the mare by the next day. Moping foals are usually a sign of malnutrition, illness or infection.... all of which are VERY serious. Have a vet examine the foal and advise you on nutritional needs and care of the foal. I would hate for you to lose the foal also.
