Hypercalcaemia in Cats: Causes, Signs and Treatments
Cats can suffer from hypercalcaemia, a condition characterised by elevated calcium levels in their bloodstream. The parathyroid glands, located just behind the thyroid gland, regulate calcium and phosphorus through hormone secretion. These hormones interact with vitamin D to manage calcium release from bones, kidneys, and the gut into the blood. Disruptions in this system, including cancerous cell growth, can cause hypercalcaemia.
1. Recognising the Signs of Hypercalcaemia in Cats
Early awareness of symptoms is vital. Cats affected by hypercalcaemia may display the following signs:
- Increased urination (polyuria)
- Excessive thirst (polydipsia)
- Loss of appetite
- Vomiting
- Constipation
- Lethargy
- Depression
- Confusion
- Swollen lymph nodes
- High blood pressure (hypertension)
- Gastrointestinal disturbances
- Bladder stones
- Collapse and coma in severe or untreated cases
2. Understanding the Causes
The condition can arise from various underlying issues:
- Parathyroid gland dysfunction
- Hyperparathyroidism (overactive parathyroid gland)
- Cancers and tumours, notably lymphoma or squamous cell carcinoma
- Bone diseases
- Kidney disease, chronic or acute
- Adrenal gland problems
- Toxin exposure including aluminium toxicity
- Idiopathic hypercalcaemia, where no apparent cause is found (the most common in cats)
3. Diagnosing Hypercalcaemia in Cats
Your veterinarian will take a full history and carry out a thorough physical examination. Essential tests often include:
- Complete blood count (CBC)
- Blood chemistry panel including ionised calcium measurement
- Urinalysis
- X-rays and ultrasound to evaluate organs and identify tumours or bone lesions
- Bone marrow biopsy in rare cases
Accurate measurement of ionised calcium is crucial, as this represents the biologically active calcium in blood. Values above 1.40 mmol/L generally confirm hypercalcaemia.
4. Treatment Options and Management
Treatment focuses on addressing the underlying cause alongside managing the calcium levels. Hospitalisation may be necessary for close monitoring and fluid therapy. Depending on the diagnosis, treatment can include:
- Intravenous fluids to support hydration and kidney function
- Medications to lower blood calcium if needed
- Surgery or other specific treatments if a tumour or glandular abnormality is detected
Regular follow-up is essential to monitor serum calcium and avoid recurrence. Mild cases without symptoms may only require careful observation.
5. Prognosis and Outlook
Prognosis improves substantially with early diagnosis and treating the underlying condition. Untreated hypercalcaemia can lead to serious complications including kidney damage and neurological symptoms. Thus, prompt veterinary care is vital to improving quality of life and survival.
6. Frequently Asked Questions: What Causes Hypercalcaemia in Cats?
Quick Answer: Hypercalcaemia in cats results from parathyroid gland disorders, kidney disease, certain cancers, and idiopathic causes where no clear reason is identified.
It is important to understand that hypercalcaemia is a symptom rather than a disease itself. The most common reason in cats is idiopathic hypercalcaemia, where despite thorough investigation, no definitive cause is found. Other causes include chronic kidney disease, which affects mineral balance, and malignancies like lymphoma producing substances that increase calcium levels. Primary hyperparathyroidism, although rarer in cats, involves gland overactivity causing excessive calcium release from bones. Proper diagnosis by a vet, including blood tests and imaging, helps to identify the specific cause and guides treatment decisions.
