Excess Alkali in the Blood in Cats

If your cat appears weak, vomits excessively and is constipated, you should consult a veterinarian. Once the veterinarian determines the cause, the proper treatment can ensure a full recovery even in cats with severe cases.

When a cat’s blood bicarbonate (HCO3) rises to abnormal levels, the condition can develop into excess alkali, or metabolic alkalosis. The kidneys and lungs help maintain the right balance of acid and alkali in the blood, or pH. While kidney and gastrointestinal disorders commonly affect the alkalinity of the blood, an unrelated disease may also cause metabolic alkalosis. When sodium, chloride and water are passed in the urine, bicarbonate levels will increase, disturbing the acid/alkali balance. 

The symptoms of metabolic alkalosis may vary according to the cause of the condition. Some of the common symptoms are:

• Dehydration
• Irregular heartbeats
• Muscle twitching
• General weakness
• Stoppage of intestinal movements
• Excessive vomiting

The increased level of bicarbonate in cats may indicate metabolic alkalosis. Primary metabolic alkalosis develops when gastric secretions are lost in vomiting. It is often seen in cats that regularly vomit their gastric contents. It may also concur with a disease that causes vomiting. The most common reasons are:

• Gastrointestinal tract obstruction
• Respiratory disease
• Renal disease
• Furosemide administration, a medication to treat congestive heart failure, kidney disease and liver disease
• Intracellular shift of hydrogen ion
• Retention of HCO3-

When acids are lost, alkalosis may develop. Other causes include:

• Medication given to increase urine flow that results in loss of acid
• Decreased levels of albumin in the blood
• Diseases that cause the kidneys to retain bicarbonate
• Bicarbonate given as a medicine
• Laxative misuse and diuretic misuse
• Hormone imbalance

The common causes of excess alkali in the blood of cats may be diagnosed by the medical history of the cat and by a physical examination. If there is no medical history available and the kidneys are functioning properly, the veterinarian may measure the chloride (Cl-) and potassium (K+) concentrations in the urine. If there is significant renal chloride reabsorption, this may be the cause. If there is potassium in the urine, it may indicate laxative misuse or diuretic abuse. High levels of urinary potassium may indicate more tests are needed. The doctor may test for hormone disorders such as hyperaldosteronism and mineralocorticoid excess. 

The treatment prescribed will depend on the underlying cause of excess alkali in the blood in cats. In order to stop the effects of excess bicarbonate, treating the cause is of primary importance. Particular attention is given to hypokalemia that may appear as muscle weakness or cardiac conduction disturbances and means there may be lower K levels and hypovolemia, which is decreased blood plasma.

Cl Responsive Patients

If Cl-responsive metabolic alkalosis is the cause, an intravenous solution of saline may be given until the urinary Cl rises to acceptable levels and the urine pH normalizes after it initially rises when the kidneys do not properly acidify the urine (bicarbonaturia). These patients may not benefit from rehydration alone. 

Severe Metabolic Alkalosis

These patients need immediate correction of the blood pH. The doctor may use hemodialysis to purify the blood or replace the function of the kidneys (hemofiltration) especially if there is kidney failure. Acetazolamide to remove excess fluid in the body may be given intravenously once. Patients with diuretic-induced metabolic alkalosis and increased acidity (posthypercapnic) metabolic alkalosis may especially benefit from this treatment.

Severe Metabolic Alkalosis and Kidney Failure

If the cat has severe metabolic alkalosis as well as kidney failure, it may not be able to undergo dialysis. A normal IV solution of hydrochloric acid is safe and effective, but should be administered in a central catheter. Frequent monitoring of the patient is needed.

Surgery

If the cause is a foreign object in the system that is causing excessive vomiting, surgery may be needed to remove the foreign object. 

Once the cat recovers, it may require repeated testing to make sure there is a complete recovery or to make sure there is no unseen cause that again contributes to excess alkali in the blood. If you see any recurring symptoms in your cat, or other abnormal behavior, you should take your cat to the veterinarian as soon as possible. 

Making sure your cat gets the proper diet is one of the main ways you can prevent excess alkali in the blood. Since vomiting is a primary cause, a poor diet can cause your cat to vomit excessively, depleting the necessary stomach acid. You may think the diet is healthy, but in some cases, the same type of protein given on a regular basis can result in gastrointestinal inflammation and food allergies. This means the quality of protein may be good, but it needs to be changed frequently. For example, if your cat is partial to fish, you may need to gradually lure it to chicken or another protein.