Older dogs often get mammary tumors and benign (not cancerous) masses. Though benign, these lumps can cause problems if they get very large or start to restrict movement. They can be surgically removed, but this is not an option for many older dogs due to the risk of anesthesia and recovery.

Calcium chloride dihydrate solution, which is used as a testicular injection to shrink the testes for nonsurgical neuter, may be an option for shrinking dog tumors (or tumor bulk reduction). The first known report of this use was in 1977 by Koger. Besides allowing veterinarians to offer their clients an anesthesia-free treatment for older dogs, calcium chloride solution has the advantage of being made from readily available ingredients and thus being an option for use in exceedingly low-resource or remote settings. It provides an option for treating animals that otherwise wouldn’t get treated.

A case study using 0.3-0.5 ml injections of alcohol and 20% calcium chloride in alcohol was successful in reducing the bulk of a mammary mass on the abdomen of an older female dog by 75%. The study was presented in 2011.

Veterinarians can order the solution from a sterile-filling-capable compounding pharmacy by requesting “20% (w/v) Calcium Chloride Dihydrate, USP in Ethyl Alcohol 190 proof, USP.” It is important not to inject too much calcium chloride solution. It works by to killing tissue it comes into contact with. Side effects including dry abscesses or skin necrosis can occur if it is injected into healthy tissue. Additionally, larger tumors will likely require repeated treatments.

Calcium chloride has been used to reduce the size of lipomas, which are fatty tumors. Albers and Theilen (1985) published a study using 10% calcium chloride injected into the subcutaneous lipomas of 10 dogs. The authors reported that six months later, four tumors had disappeared and 14 were less than 50% of their original size. However, skin necrosis over the tumor developed in three dogs.

A higher concentration of calcium chloride is likely counterproductive. Our experience using 20% calcium chloride in alcohol in a lipoma resulted in complications. By 24-48 hours after the injection, the mass may be shrunk by half, but the skin ruptured, creating a draining wound that had to be treated with antibiotics. Severe complications may require surgical excision. It may be that the body cannot absorb the lipoma adequately using the 20% calcium chloride, but more research is needed to clarify this issue.

Other nonsurgical injections to treat lipomas have been attempted. A study in 2005 by Rotunda and colleagues evaluated deoxycholate, a bile salt, to treat lipomas in human patients. They reported an average of 75% reduction in tumor size after 2 or more injections, and concluded that this injectable treatment might be useful for small lipomas, but that further research was needed. Steroid injection at a dose of 40 mg/mL was also used to treat lipomas in dogs (Lamagna et al., 2012). Nine of 15 tumors showed a complete regression, with shrinkage in the remaining dogs with only minor complications.

New noninvasive methods used for human fat removal may one day be applied to dog lipomas. Cryolipolysis (“CoolSculpting”) applies cool temperatures to fat cells, which break down when exposed to extreme cold. Radiofrequency (“Vanquish”) or light therapy (“Sculptsure”) both work by heating fat cells to kill them.

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Last updated on October 29, 2024