Common Causes of Liver Disease in Dogs: Symptoms and Insights

The dog liver is a crucial organ responsible for numerous vital functions including food metabolism, digestion support through enzyme and bile production, glycogen storage, detoxification, and hormone regulation. While up to 500 functions are attributed to the liver, many remain under study, underscoring how essential liver health is for your dog’s overall wellbeing.

Liver disease in dogs is a serious health concern, especially common in older pets. It often develops progressively, with symptoms that can be subtle initially, making early detection challenging but critical for effective management. Recognising early signs can lead to timely veterinary care that can greatly improve outcomes.

1. Infectious Diseases and Secondary Complications

Viral and bacterial infections are among the leading causes of liver disease in dogs. Canine infectious hepatitis, caused by adenovirus type 1, results in liver inflammation and can cause chronic liver scarring. Leptospirosis, spread by contaminated water, damages liver and kidneys and is zoonotic, meaning it can affect humans. Fungal infections like coccidioidomycosis, though less common in the UK, may also harm liver tissue. Untreated or resistant infections compound liver damage over time.

2. Accidents, Injuries, and Heatstroke

Trauma such as being hit by a car or a fall can cause direct liver injury, which might manifest immediately or months later. Prompt veterinary assessment after trauma is essential even if your dog seems unharmed. Additionally, heatstroke during hot weather poses a serious risk; it can cause acute liver failure or lasting hepatic damage, so never leave dogs unattended in hot cars or exposed to extreme heat without ways to cool down.

3. Inappropriate Diet and Metabolic Disorders

An unbalanced or inappropriate diet can contribute to long-term liver stress and malfunction. Feeding age-appropriate, nutrient-complete diets helps maintain liver health. Conditions like diabetes mellitus and Cushing’s disease (hyperadrenocorticism) can also lead to fatty liver changes and impair liver function. Regular vet check-ups aid in early identification and management of these metabolic disorders.

4. Long-Term Medication Effects

Some medications, especially long-term use of certain veterinary painkillers or steroids, may cause liver toxicity due to the liver processing and filtering these substances. While these drugs might be essential for managing other chronic conditions, vets will carefully balance risks and benefits and monitor liver function regularly.

5. Congenital Defects and Hepatic Vascular Abnormalities

Certain dogs are born with congenital liver issues such as portosystemic shunts—abnormal blood vessels that bypass normal liver circulation—leading to toxin buildup and liver underdevelopment. Early detection through screening, particularly in puppies of susceptible breeds, can facilitate surgical or medical intervention. Responsible breeding practices and pre-breeding health checks are fundamental to reducing inherited liver problems.

6. Toxins and Poisons

Exposure to toxins is a critical risk factor for acute liver damage. Dogs can ingest harmful substances including xylitol (common in sugar-free products), pesticides, certain plants, or household chemicals. Because the liver filters these toxins from the blood, it can suffer significant injury after ingestion. Immediate veterinary attention is crucial if poisoning is suspected to provide supportive care and improve recovery chances.

7. Cancer and Other Causes

Older dogs may develop liver cancers such as hepatocellular carcinoma or hemangiosarcoma, which disrupt liver function and overall health. Sometimes cancers from other organs metastasise to the liver. Additionally, inflammatory and immune-mediated diseases can cause hepatitis, further stressing the liver. Treatment and prognosis vary widely depending on the cause and progression of the disease, highlighting the importance of veterinary diagnosis and ongoing care.

How to Spot Early Symptoms of Liver Disease in Dogs

Quick Answer: Early signs include lethargy, decreased appetite, vomiting, jaundice (yellowing of gums or eyes), increased thirst, and behavioural changes. These subtle signals warrant prompt veterinary evaluation.

Detailed Explanation: Liver disease often manifests with vague symptoms that can be mistaken for other ailments. Keep an eye out for symptoms like your dog becoming unusually tired, losing interest in food, vomiting, diarrhoea, or showing signs of abdominal pain. Jaundice – yellowing of the eyes, skin or gums – is a distinct sign of liver issues. Any sudden or unexplained changes in your dog's behaviour or bodily functions should prompt a visit to the vet for assessment.

Treatment and Management Options

Management of liver disease depends on the underlying cause. Supportive therapies such as specialised diets, medications to support liver function, and fluid therapy may be prescribed. In cases of infection, antibiotics or antifungal treatments are essential. Surgery may be required for congenital shunts or tumours. Regular monitoring and early intervention can improve quality of life and extend survival. Collaborating closely with your vet is key to tailored care and responsible management.

Remember, early detection of liver disease can make a significant difference. If you ever suspect your dog is unwell, consulting your vet ensures your beloved companion receives the best possible care.