Yes, another Weird Al reference, which for regular readers should be no surprise. For the uninitiated...
Of course, a case brought this up and I thought it would be a good educational opportunity. Today I spayed a puppy with an inguinal hernia, one of the less common ones. Many clients will have been faced with hernias in their pets and most of the time it's not a serious issue. So Let's talk about exactly what a hernia is, a few common kinds, and why you need to treat them.
Essentially a hernia is a hole or defect in the muscle of a cavity, usually the abdominal cavity, with resulting escaping of some contents through the hernia. The hernia is usually named based on the location. In some cases the hernia is the result of a type of birth defect or developmental abnormality where the muscle never closes properly. Sometimes a hernia can be the result of trauma, such as being hit by a car, or a severe muscle tear from stretching or straining. In all cases the defect should be treated as potentially serious and be evaluated immediately.
Why are we so concerned about hernias? Because abdominal contents can migrate through the hole and under the skin or into the chest cavity. If that organ becomes entrapped and the blood supply is cut off, the tissue will start to die and you have a suddenly life-threatening emergency on your hands. Most hernias won't reach this point but that risk is enough to have a vet determine when and if surgery needs to be done.
So what are some common hernias?
Umbilical: This is the single most common hernia most vets see, and is something I diagnose just about every month. The place on the abdomen where the umbilical cord attaches has a small hole in the abdominal wall that allows blood vessels to pass between the placenta and the inside of the body. The hole should start to close immediately after the cord falls off, but this does not happen in some cases. Normally you will notice a swelling or bump at the "belly button" that may come and go. This is typically simply abdominal fat that is passing through the small opening. In some cases the opening will persist longer than normal and then close up, trapping abdominal fat outside of the body. The vet will be easily able to detect this hernia and tell you if it needs to be repaired. In most cases it's not large enough to be highly concerned about and we'll wait until time to spay or neuter and do it while the pet is under anesthesia. I've had two cases in my career that had frighteningly huge hernias and I got them into surgery by 10 weeks old because of the risk of intestinal loops passing through. But most cases are "NGS" ("No Great Shakes" as my old pathology professor used to say).
Inguinal: This is what I fixed today. The hernia is down in the groin where the abdomen meets the leg, at what is called the inguinal ring. This is a normal small opening in the abdomen through which blood vessels pass. In some cases the ring is too large and we have to go in and close the defect. This is a much trickier surgery because it's in a narrower and deeper area, as well as having large blood vessels that we need to avoid and not tie off. It's a delicate, slow surgery, but not highly complicated for a good surgeon. These are uncommon and I'll usually see one every couple of years.
Abdominal: This hernia is most commonly due to trauma and is a tear in the muscle of the abdominal wall, normally somewhere away from the inguinal or umbilical regions. It can be potentially more serious due to the fact that there is often trauma involved and the tear can be large.
Diaphragmatic: This kind of hernia is probably one of the scariest I've dealt with and the most life-threatening. The huge majority of the time this happens after receiving a sudden blow to the abdomen, usually when hit by a car. The sudden force causes a tear in the diphragm. Abdominal contents can start to move through the hernia and into the chest cavity. I've dealt with cases where intestines, liver, and spleen are all sitting in the chest. Not only is this a concern for strangulation of the organs passing through, but the abnormal contents puts pressure on the heart and lungs and can cause problems with proper air flow and blood pumping. Surgery for this kind of hernia carries considerable risk since you are opening the abdomen and chest and have to deal with the consequences of chest surgery as well as abdominal surgery. So far I've not lost any patients when I've done this surgery, but I know many vets who would refer the case to a specialist rather than tackling it themselves.
Of course there are many other kinds of hernias, but you start to get the idea. Muscle is torn, something moves through the hole, and problems happen. Always talk to your vet about any unusual swellings on your pets and pay attention if the start using "hernia" and "surgery".