(Resolved) What Is Microvascular Dysplasia In Dogs?

Patients with hepatic vascular anomalies are generally evaluated and followed by the internal medicine specialists at Veterinary Specialty Center 😁 Patients with mild forms of MVD that do not have a significant loss of liver function, receive recommendations about diet, medications, monitoring, and long term precautions, but may not necessarily need frequent rechecks at Veterinary Specialty Center 🙈 Patients that have a significant loss of liver function generally are closely monitored over time for lab tests and medication adjustments. Because decisions about changes in medication are based on observations made during the physical exam in addition to other testing, our recommendation is that follow-up for this disease be done at Veterinary Specialty Center. All routine preventive care should continue with your primary care veterinarian.
A definitive diagnosis of HMD is made by proving that the dogs do not have any shunts but that they do have abnormal vessels on their liver biopsies. Dogs with HMD have normal portal blood flow on nuclear scintigraphies (nuclear scans of liver blood flow), portograms (x-ray studies of liver blood flow), and CT angiograms (CAT scans of liver blood flow), but they have abnormal microscopic portal blood vessels on liver biopsy. The liver biopsy is usually taken surgically through a belly incision or with a laparoscope so that enough liver tissue can be obtained to evaluate the blood vessels. Needle biopsy using ultrasound may not provide enough tissue to make the diagnosis.
Image #2 also explains how hepatoportal microvascular dysplasia (MVD) is a blood vessel abnormality inside the liver that causes shunting (bypass) between the portal vein (the blood vessel that connects the gastrointestinal tract with the liver) and circulation into the system. It may be caused by microscopic lesions on the liver, abnormal development, abnormal positioning, or throttling due to a prominent smooth muscle that prevents blood flow. The lobes of the liver are involved, some severely, others very little. This is suspected when the bile is not doing its work. In short, because of malformations in the blood vessels, the blood is not flowing to the liver as it should. (we truly appreciate Akiva Hartley from Aurangabad, India for their feedback).
Hepatocytes make up about 80% of your dog’s liver. These cells are arranged into circular structures (lobules) with numerous blood channels (sinusoidal spaces) separating long lines (cords) of liver cells – much like supermarket isles separate the lines of products and produce. For hepatocytes to perform their diversified functions, those blood channels need to receive, at their outer lobule (island) borders, blood from the intestine that is rich in recently absorbed nutrients. Hepatocytes also need this tremendous blood flow to cleanse the body of toxins. (read here) This nutrient-rich blood is delivered to the liver through the portal vein that drains blood arriving from their intestines. Liver cells (hepatocytes) also need a lot of oxygen because of the high metabolic demands required to accomplish their many chores. That blood comes to them from the lungs through their hepatic artery. When the amount of fresh blood bathing them is insufficient, liver cells cannot maintain body health. (revised by Claudette Dietrich on January 15, 2020)
The liver performs an incredible number of functions to maintain health of animals, including filtering out toxins, storing sugar, and making proteins. Most of the blood that is carried to the liver for these processes arrives via the portal vein, which drains the intestines, stomach, pancreas, and spleen. Within the liver, the portal vein branches into smaller and smaller vessels so that the blood can percolate throughout the tissues to each liver cell. When these microscopic vessels are abnormal on liver biopsy, the condition is called “hepatic microvascular dysplasia (HMD or MVD)” or “portal atresia”. When the microscopic vessels within the liver are underdeveloped or absent, the liver becomes small (“atrophied”) and the animal can no longer process toxins or make proteins necessary for growth and normal function. (we thank Sherrina Driver for their recommendations).
Mae Chow

Written by Mae Chow

Passionate about writing and studying Chinese, I blog about anything from fashion to food. And of course, study chinese! I'm a passionate blogger and life enthusiast who loves to share my thoughts, views and opinions with the world. I share things that are close to my heart as well as topics from all over the world.

Why Is It Called A Trojan Virus? [SOLVED]

What Is A Br Bulb? [SOLVED!]