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Quick Overview: Low Calcium in Cats
Calcium is a highly important mineral for many systems in a cat’s body. It plays a vital role in bone and teeth development, muscle contraction, milk production, metabolism, nerve conduction, and blood clotting. A low level of calcium in the blood (hypocalcemia) can cause a lot of problems for cats. Calcium levels are usually kept under very tight control, but some medical conditions can cause disruption.
Low blood calcium is a serious condition in cats that needs urgent diagnosis and treatment with calcium supplements. Read on to find out why your cat might develop hypocalcemia, what symptoms you might see, how it’s diagnosed, and what treatment options are available.
Why Cats Develop Hypocalcemia
Low protein levels and poor calcium absorption can both contribute to hypocalcemia. Sasha Chornyi / Shutterstock
Low calcium levels in cats can happen for a few reasons. The most common cause is kidney failure, but there are multiple other health disorders that can lead to low blood calcium.
1. Chronic Renal Failure
When a cat’s kidneys begin to fail, they stop filtering the blood properly, and compounds such as phosphate begin to rise (hyperphosphatemia). Calcium and phosphate levels are strongly linked, and when phosphate rises, calcium levels decrease. Chronic kidney disease is common in older cats, and hypocalcemia is a key side effect to monitor for.
2. Hypoparathyroidism
The parathyroid glands are tiny and found in a cat’s neck, tucked up closely next to their thyroid glands. They secrete parathyroid hormones, which are important in regulating blood calcium levels. If the parathyroid glands are damaged (such as accidentally during thyroid surgery) or stop functioning, they produce less parathyroid hormone (hypoparathyroidism), which can impact blood calcium.
3. Low Protein Levels
Albumin is a type of protein that carries a large proportion of the body’s calcium through the blood. If the levels of albumin drop, so do calcium levels. Protein levels can be low due to inadequate intake—such as a lack of protein or poor absorption of protein. They can also be low due to the loss of protein through the gut. This loss could occur due to high parasite loads, cancers such as lymphoma, or inflammatory diseases such as IBD. Protein can also be lost through the kidneys.
4. Poor Calcium Absorption
Cats take in calcium from their diet through absorption in the digestive system. If calcium is not taken in well, then levels in the blood will be low. This can be caused by a range of conditions affecting the gastrointestinal tract, such as infection, inflammation, or cancer. It can also be caused by a lack of calcium in the diet.
5. Acute Pancreatitis
Inflammation of the pancreas (pancreatitis) is a painful condition causing poor appetite and sickness in cats. It can also lead to low calcium levels.
6. Pregnancy and Nursing Kittens
The production of milk in late pregnancy and then into the lactation phase of having newborn kittens can put great strain on the queen’s body. Low calcium levels at this time (also known as eclampsia, puerperal tetany, or milk fever) are not uncommon. Monitoring cat mummies for signs of low calcium is recommended.
7. Drugs and Toxins
Certain chemicals can cause a cat’s calcium levels to drop. These include poisoning with oxalate compounds, such as through eating lily plants, but also certain drugs, such as phosphate enemas given to constipated cats, and citrate poisoning through the use of multiple blood transfusions.
8. Rickets
Seen in younger cats, rickets occurs when a lack of Vitamin D affects the production of calcium. The low calcium levels then affect the kittens’ development, especially bone growth. This condition is thankfully now rare, as we have a much greater understanding of the nutritional requirements of young kittens.
Symptoms of Hypocalcemia in Cats
Excessive facial rubbing can be a symptom of low blood calcium in cats. Irina Safonova / Shutterstock
With mild decreases in blood calcium levels, there may not be any obvious clinical signs of hypocalcemia, but symptoms will become more apparent as the levels drop further.
Early clinical signs include:
Restlessness
Stiff gait
Disorientation
Weakness
Muscle twitching
Hypersensitivity or irritability to touch and sound
Excessive facial rubbing against the floor or furniture
These symptoms can progress to more severe signs:
Severe muscle tremors
Seizures
Death
Diagnosis of Hypocalcemia in Cats
Low blood calcium is usually diagnosed using a blood test. If low hypocalcemia is suspected, your veterinarian may recommend other diagnostic tests to look for the underlying cause of the low calcium levels, such as routine bloodwork, urinalysis, x-rays or ultrasound scan. Your vet may also recommend testing for ionized calcium, which is the active form of the total calcium in the blood.
Treatments for Cats With Hypocalcemia
Cats with severe hypocalcemia will need calcium supplementation intravenously. Ekaterina Vidiasova / Shutterstock
The usual treatment for hypocalcemia in cats is through calcium supplementation. This must be done carefully and under close supervision from a veterinarian – it is dangerous if blood calcium levels rise too high, which affects the heart rhythm and rate.
In cats with severely low calcium levels, supplementation will first be provided intravenously in a veterinary hospital environment. Your cat’s total calcium levels will be carefully monitored to ensure they retain their normal level (around 6.7mg/dL), but do not rise too high. After stabilization, or for more mild cases, oral calcium supplements will be used.
Calcium salts will often be given alongside Vitamin D supplements, to improve the absorption of the calcium from the intestinal tract. These supplements may be in liquid, tablet or capsule form.
How to Care for Your Cat With Hypocalcemia
While some cases of hypocalcemia in cats may be transient and easily resolved, some cases may need ongoing care and support.
Nutrition: cats need a diet that is nutritionally balanced, which includes appropriate levels of calcium, Vitamin D, and other essential nutrients. Make sure your cat’s diet has everything they need (a ‘complete’ diet) and is suitable for their age and life stage.
Feeding support: cats who are hypocalcemic can be weak and have a poor appetite. Tempt them with small, regular meals. Food with a strong meaty or fishy odor is often most appealing to cats.
Regular checks: calcium levels need to be maintained within fairly strict levels in the body, as both too little and too much can cause problems. Take your cat for regular vet checks to monitor their blood calcium carefully.
Pregnant queens: female cats who are expecting kittens need special care. Provide high-quality nutrition and careful monitoring.
How To Prevent Hypocalcemia in Cats
There are many causes of hypocalcemia in cats, many of which are difficult to prevent. Never allow cats access to lily plants, as they are highly toxic. Provide high-quality nutrition that is balanced for your cat’s age, and monitor pregnant queens carefully.
Early detection of conditions such as kidney disease, hormonal imbalances, nutritional deficiencies, and protein-losing disorders can have a huge impact on treatment and prognosis, so regular veterinary checks are advisable for every cat.
Frequently Asked Questions
What causes hypocalcemia in cats?
Hypocalcemia in cats has a range of causes. One of the most common is kidney failure, a disorder seen in a high percentage of senior cats. Hypocalcemia can also be related to low protein levels, poor absorption, pancreatitis and lily toxicity. Low calcium can also be seen in pregnant and nursing queens.
What are signs of hypocalcemia in cats?
Cats with low blood calcium may seem weak and disoriented. Sporadic muscle contractions – seen as tremors and twitching – are common signs, which can progress to full seizures. They may also rub their faces constantly along the couch or floor.
Why do blocked cats have hypocalcemia?
When cats have a urinary blockage, their phosphate levels rise as it is not being processed through the kidneys. Calcium levels are closely tied with phosphate, and when phosphate rises, calcium levels drop. A blocked cat will also have disturbances of their acid-base balance, which can further affect calcium levels.
How to increase calcium levels in cats?
Cats with very low blood calcium levels will need urgent calcium supplementation via an intravenous drip. When more stable, oral calcium salts are given. Vitamin D is usually supplemented alongside calcium, to increase absorption.
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Disorders of calcium: Hypocalcemia and Hypercalcemia https://www.researchgate.net/profile/Thomas-Rosol-2/publication/285432462_Disorders_of_Calcium_Hypercalcemia_and_Hypocalcemia/links/59f36c36458515547c205681/Disorders-of-Calcium-Hypercalcemia-and-Hypocalcemia.pdf
