Calcinosis Cutis in Dogs

There is usually an underlying cause of calcinosis cutis that needs to be addressed when deciding on the appropriate treatments for your dog. The most common underlying cause of calcinosis is either endogenous Cushing’s disease or iatrogenic Cushing’s disease. It can also be a sign of chronic renal failure. 

If caught early enough, your dog has a good chance of recovering from calcinosis cutis without having to undergo a surgical procedure to remove the deposits. Medications can be used to break up the deposit and have the calcium reabsorb back into your dog’s body.

Calcinosis cutis in dogs is when deposits of insoluble mineral salts occur in the different layers of the skin. These mineral deposits will cause dystrophic or metastatic calcification. In dogs, it is more common to have dystrophic calcification than metastatic. When calcinosis cutis becomes widespread, it is then referred to as calcinosis universalis.

Calcinosis cutis is a serious condition that should be addressed as soon as you notice something is amiss with your dog. The most common symptom is hard lumps that form under the skin, in the mouth or on the footpads. These lumps many times ulcerate and then discharge pus or a chalky substance. If you notice any of these symptoms, contact your veterinarian for an appointment. 

• Hard lumps under the skin, mouth or footpads
• Lesions on the skin
• Swelling of the abdomen
• Loss of body muscle
• Hair loss or patchy alopecia
• Black heads 
• Weight loss

The exact cause of calcinosis cutis in dogs is unknown. Many times a genetic link can be found but the most probable cause is an increase in the blood enzyme lipase. This will lead to the degeneration of the subcutaneous adipose tissue, or fat tissue, followed by the calcification of the degenerated tissue.

Dogs diagnosed with dystrophic calcinosis cutis can include idiosyncratic reactions to an injection or other foreign materials. Dogs diagnosed with metastatic calcinosis cutis often have the condition from the overproduction of adrenal hormones. The overproduction may be from cancer of the adrenal glands or the pituitary gland.

Your veterinarian will begin by asking you questions about what symptoms you have seen and about your dog’s habits. They will then conduct a thorough physical examination, paying close attention to any skin lesions that may have appeared.

A sample of the hard lump in your dog’s skin will be taken, usually by performing a skin scraping. Some cases may require the entire lump to be removed and biopsied. Histopathology is used to view the sample and search for any markers that show calcification. Histopathology is when specially prepared and stained cell samples are examined under a microscope. 

Your veterinarian will want to conduct blood tests to search for any underlying causes. A urinalysis and fecal examination may also be performed.

Your veterinarian will recommend surgical removal. This will require your dog to be put under general anesthetic while the mass or masses are removed. Your veterinarian will discuss the surgical procedure and what to expect during and after the procedure.

Some cases of calcinosis cutis will require additional treatments depending on any underlying cause. Your veterinarian will discuss all treatment options and the best plan for your dog. 

Smaller calcium deposits may be resorbed by your dog, some larger calcium deposits may be pushed out through the skin. Pushing them out through the skin can be messy because there is generally a white, chalky discharge. 

Your veterinarian may prescribe a dimethylsulfoxide or DMSO topical gel to apply to the affected areas once a day. This may help with mineral dissolution. Corticosteroids may also be used to treat the affected areas. As with all medications prescribed for your dog, follow dosing instructions carefully and finish the medications unless otherwise directed by your veterinarian. 

During treatments your dog’s serum calcium levels will need to be monitored as the calcium is being resorbed. This may cause a rise in the levels of calcium in their tissues.

During treatments, it will be important that you do not allow your dog to scratch, rub, bite or lick the problem areas on their skin. This will help reduce itching, ulceration, inflammation and bleeding. All affected areas will need to be kept clean and dry. 

Be sure to follow all post surgical instructions carefully. If you have any questions regarding your dog’s care, you should direct those to your veterinarian. Report any issues or complications that may arise during your dog’s recovery to your veterinarian.