Metabolic

Metabolic – this word often comes up for dog owners at the vet, sounds initially awkward, but simply means: everything to do with metabolism. And metabolism is literally what keeps the body running. It encompasses all chemical reactions that take place every second in every cell – to gain energy, process nutrients and get rid of waste products. In dogs, an intact metabolism supports growth, energy supply, all organ functions and ultimately overall health. If it gets out of balance, the consequences can be serious.

What does “metabolic” actually mean?

In short, “metabolic” is the adjective for metabolism. Metabolism is a dense network of chemical reactions in the cells that fulfils four core tasks:

1. Provide energy from food.
2. Nutrients – proteins, fats, carbohydrates – break them down and make them usable.
3. Ensure cell functions: renew tissue, grow, repair damage.
4. Remove waste and toxins from the body.

Metabolism operates simultaneously in two opposite directions:

1. Catabolism: This is where breakdown occurs. Large molecules – carbohydrates, fats, proteins – are broken down into smaller building blocks, and energy is released in the process.
2. Anabolism: This is where build-up occurs. The body uses the energy obtained to produce new cell structures and tissues. No build-up without prior breakdown – the two processes depend on each other.

Metabolic Processes in Dogs

In dogs, the following core processes take place – day after day, non-stop:

• Energy production: Carbohydrates and fats are broken down into glucose and fatty acids. From these, cells generate ATP (adenosine triphosphate) – the universal fuel of the body.
• Protein build-up and breakdown: Dietary proteins break down into amino acids, which are then reused for muscle tissue and other cell structures.
• Fat metabolism: Fats are stored in adipose tissue and mobilised when energy is needed – or serve as insulation and mechanical protection.
• Detoxification and excretion: The liver filters harmful substances and breaks down metabolic end products; the kidneys eliminate waste from the body via urine.

Metabolic Diseases in Dogs

When metabolism slows down or goes awry, metabolic diseases arise – triggered by genetic defects, nutritional problems or hormonal imbalances. An overview of the most well-known ones:

1. Diabetes mellitus: Blood sugar is permanently elevated because either too little insulin is produced or body cells no longer respond to it (insulin resistance). Insulin is the hormone that enables glucose to enter cells in the first place. Affected dogs drink noticeably more, urinate frequently and lose weight despite normal or increased appetite.
2. Hypothyroidism: The thyroid gland secretes too few thyroid hormones – the entire metabolism slows down. Typical symptoms are weight gain, lethargy, hair loss and skin problems. Medium to large dog breeds are particularly frequently affected.
3. Hyperthyroidism: The opposite: An overproduction of thyroid hormones drives metabolism into overdrive. Possible consequences include weight loss, restlessness, rapid heartbeat and increased appetite. In dogs, hyperthyroidism occurs significantly less frequently than in cats; thyroid tumours are primarily considered as the cause.
4. Cushing’s syndrome (hyperadrenocorticism): The adrenal glands produce too much cortisol. This manifests as weight gain, increased panting, excessive thirst and noticeably thin, fragile skin. The trigger is usually a tumour in the pituitary gland or in the adrenal glands themselves.
5. Addison’s disease (hypoadrenocorticism): Here, the adrenal glands fail: they produce too little cortisol and aldosterone. The disease is rare but dangerous – vomiting, diarrhoea, weakness and low blood pressure can occur. Without treatment, Addison’s disease is life-threatening.
6. Hepatic encephalopathy: In the case of liver dysfunction, toxins build up in the blood, affecting the brain. Affected dogs show behavioural changes, seizures and disorientation.
7. Ketoacidosis: A serious complication of diabetes mellitus. Due to insulin deficiency, the body cannot utilise glucose and switches to fat breakdown – harmful ketones are produced in the blood in the process. Possible consequences: vomiting, weakness, shortness of breath, and in the worst case, coma.

Symptoms of Metabolic Disorders

The complaints vary depending on which system is affected. Some warning signs that dog owners should know:

• Weight changes: Unwanted gain or loss without an apparent cause can indicate a metabolic disorder.
• Changed appetite: Suddenly significantly more or less hunger can be a sign of an imbalance in metabolism.
• Lethargy and tiredness: Persistent lack of drive is one of the most common signs – this is particularly noticeable with hypothyroidism.
• Increased drinking and urination: A classic combination with diabetes mellitus and Cushing’s syndrome.
• Skin and coat problems: Dull coat, hair loss or dry skin can indicate a hormonal disorder such as hypothyroidism.
• Gastrointestinal complaints: Diarrhoea, vomiting or constipation occur with various metabolic diseases.

Diagnosis of Metabolic Diseases

No single test is sufficient for a reliable diagnosis. In practice, the vet relies on a combination of clinical examination, lab values and – if necessary – specific function tests:

1. Blood tests: They provide values for glucose, thyroid hormones and cortisol and show where the values fall outside the normal range.
2. Urine analysis: The urine provides clues about diabetes or kidney problems – often noticeable at first glance by colour and smell.
3. Specific functional tests: If Cushing’s or Addison’s disease is suspected, hormone stimulation tests are used to check the responsiveness of the adrenal glands.
4. Imaging techniques: Ultrasound or X-rays help detect enlarged organs or tumours that could be behind the disorder.

Treatment of metabolic disorders

There is no one-size-fits-all solution – therapy always depends on the specific disease and the general condition of the dog. The most common approaches:

1. Medication: Diabetes requires insulin; hypothyroidism is balanced with thyroid hormone preparations. Cushing’s syndrome can often be controlled medicinally by reducing cortisol production.
2. Dietary adjustment: In diabetes or liver disease, adapted nutrition plays a central role – it is not an addition to therapy, but often a core component of it.
3. Regular veterinary check-ups: Dogs with metabolic disorders require close follow-up care so that treatment success can be monitored and complications detected early.