Common Causes of Hepatitis in Dogs
Dogs share many similarities with us humans. Though there are noticeable and significant differences between how our bodies and a dog’s system work, most bodily processes are pretty much the same across both species. The same goes with liver function and its role in processing toxins in both a dog and a human’s body. Granted, not all pathogens (viral or bacterial) that infect our liver can infect dogs, but the common causes of liver injury, medically known as hepatitis, can be the same for both humans and canines. In the following segments, we’ll deep dive into the specific functions of the liver, how liver injury happens, and the most common causes of hepatitis in dogs.
What does the liver do?
The liver’s main function in the body is detoxification. It’s responsible for filtering and processing food, drugs, vitamins, and other medications that dogs ingest. It processes protein metabolism by-products such as ammonia and converts it to urea to be eliminated by the body. This helps prevent the accumulation of ammonia in the dog’s bloodstream which is a common cause of neurological symptoms like ataxia (abnormal movement) and seizures.
Aside from helping the dog’s body eliminate toxins, the liver has other important functions in maintaining the animal’s health. It’s the organ responsible for fat digestion and metabolism and plays an integral role in the regulation of blood sugar in the dog’s system. It’s also the main organ that produces albumin, an important protein in the blood that helps transport nutrients, hormones, and certain medications. Lastly, it synthesizes clotting factors essential in controlling bleeding when there’s an injury in any of the body’s blood vessels.
Injury to the liver can lead to compromised liver function and affect the dog’s capacity to digest fat from the diet, can result in bleeding problems, and lead to neurological signs associated with encephalopathies. Any form of injury to the liver organ or its tissues is termed hepatitis.
Symptoms of Hepatitis in Dogs
Hepatitis is a general term describing inflammation or injury of the liver. Hepatitis can be caused by infectious pathogens or drug use, but the most common form of hepatitis reported in dogs is chronic hepatitis.
Symptoms associated include general signs of sickness such as weakness, lethargy, and a decrease in appetite. Gastrointestinal signs like vomiting can also be observed in dogs with hepatitis. Severe cases of hepatitis would often result in icterus, a yellow discoloration of the dog’s skin, mucus membranes, and eye sclera. Bruising and bleeding in mucus membranes can also be seen in dogs suffering from either acute or chronic hepatitis.
How do dogs get hepatitis?
Hepatitis is the most common form of liver disease in dogs and is generally classified into two main types: acute and chronic. Acute hepatitis is a type of liver damage that develops very rapidly over just a few days, while chronic hepatitis is described as a progressive liver disease that’s been causing damage for at least a few weeks.
Acute hepatitis in dogs is often caused by a viral infection called canine adenovirus 1. This viral organism infects other different organs like the spleen, kidneys, blood vessel walls, but causes the most damage to the liver. This is a contagious disease in dogs that are usually spread through bodily discharges like saliva, feces, or urine.
Infection occurs when a dog ingests bodily fluids from an infected animal, which sheds the virus for at least 6 months even after recovery. Clinical signs associated with infectious canine hepatitis vary greatly from a mild fever to death if not managed or controlled properly. This type of hepatitis can easily be prevented through regular vaccination. Dog owners should keep their canine buddies up to date with their vaccinations to prevent contracting this potentially fatal liver disease.
Chronic hepatitis, regarded as the most common form of hepatitis in dogs, has several different causes. The initial injury that the liver sustains is pretty similar to acute hepatitis, but it persists for longer than 2 weeks, unlike with the acute type that often spontaneously recovers.
One commonly reported cause of chronic hepatitis in dogs is persistent acute hepatitis. Though most cases of acute hepatitis recover and resolve on their own, around 30% progress into chronic hepatitis. Unlike in acute hepatitis, symptoms associated with chronic liver damage do not surface during the initial stages, giving the impression of recovery from the acute damage. It’s only later on that clinical signs start to develop, at which point the damage to the liver has already become extensive.
Another common cause of chronic hepatitis in dogs is prolonged drug use. Certain medications, like corticosteroids, NSAIDs (non-steroidal anti-inflammatory drugs), antibacterials, and antifungals can cause liver damage if given for a long period.
Chronic hepatitis can also be an inherited or genetic disorder, with breeds like Chihuahuas, Maltese, Beagles, and Cocker Spaniels being predisposed to developing the disease at a later stage of their lives. Toxicities from plants and food ingredients, as well as copper toxicity, are also some of the commonly reported causes of chronic hepatitis in dogs.
Treatment Options for Dogs with Hepatitis
In acute hepatitis caused by a viral infection, supportive treatment is the only possible approach to address the condition. As mentioned, acute hepatitis often resolves on its own but treatment is needed to support the dog’s immune system so they can fight the infection themselves.
Chronic hepatitis, unlike the acute type, will require long-term anti-inflammatory medication to control the inflammation in the liver tissue and minimize damage. Shifting the dog’s diet to a formula suited to support liver health can help speed up recovery and prevent the progression of the disease.
Regardless of the cause or the type, if your dog is showing signs of illness and you think it may be related to the liver, it’s best to visit your vet immediately for a thorough check-up.
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