Understanding Your Pet’s Lumps and Bumps

By Dr. Laura Hady

As pets lose their winter coats or undergo spring grooming, their owners tend to find skin lumps and bumps that went unnoticed in the winter. It is a good idea to point these out to your veterinarian during your dog or cat’s yearly exam, so that the areas may be aspirated with a fine needle or even biopsied for further analysis. Many times, the lumps contain fatty material, fluid, sludge, pus, tissue, or blood. The following is about what these skin abnormalities could be and courses of treatment.

  • Fatty material (adipose) usually makes up benign lumps that are very common in middle-aged to older dogs. When a sample of this material is stained on a slide, foamy white cells are noted. Lipomas can develop almost anywhere in and on the body. If the lipoma is impeding movement of your pet, has doubled in size in a month, has changed in feel (firmer for example), or if a sore is noted on the top, I recommend removal. While most of these tumors are benign, some can be malignant and spread to other parts of the body. Please discuss the best treatment options with your family veterinarian.
  • Fluid-containing cysts can come from the hair follicles. Simply draining the cysts may not stop the fluid from returning, indicating the whole cyst may need to be removed under anesthesia. Some dog breeds, such as the American Pitt Bull Terrier, tend to develop cysts called interdigital cysts that appear between the toes. These can be due to an ingrown hair, foxtail from grass, or a piece of cactus. If your veterinarian aspirates a gray, sludge-like material, this indicates a benign sebaceous gland adenoma is likely. It is similar to a blocked follicle on human skin. Occasionally, sebaceous cysts rupture and become infected if the animal scratches or licks the area. In this case, an antibiotic in the form of solutions, creams, or oral medication may be warranted.
  • Pus is the common term for a thick yellowish or white fluid that is mostly made up of white blood cells with or without bacteria. A sac of pus is called an abscess, and dogs and cats can have them in spots where they were scratched or bitten by another animal. Abscesses may contain fluid or be of a thicker “cheesy” consistency. The veterinary staff will help clip, clean, open, and flush the area with anesthesia on board. Occasionally, a plastic drain will be used to keep the wound open for three to five days to make sure enough of the pus has drained. Antibiotics and anti-inflammatories are usually prescribed to help the healing process.
  • Welts on your pet’s skin may be the result of an allergic reaction. Allergic reactions can be due to spider bites, bee stings, ant bites, plants, food, drugs, or vaccines. Please contact your veterinary staff for guidance for getting an appointment immediately and to find out if an over-the-counter antihistamine is needed. To help determine more quickly the type of treatment needed, it is a good idea to provide your veterinarian with photos, a written history of any traveling the pet has done with you, and information about its yard and house environment, diet, and types of medicines recently administered.
  • Tissue can also be aspirated, or a small section of a lump can be removed (biopsy) in if a granuloma or soft tissue tumor is suspected. Granulomas, which can be located throughout the body, contain white blood cells and other tissue. They can result from the body’s reaction to an infection, inflammation, irritation (such as a lick granuloma), or foreign objects such as a stick. A skin tumor can feel like a granuloma, but it will contain abnormal cells of uncontrolled growth of a certain type of tissue. The most common skin tumor in dogs is the mast cell tumor. In cats, the squamous cell carcinoma is the most likely, especially in light-colored areas of cats that like to lie in the sun.
  • Blood can be found in benign hematomas (think blood blister) that are secondary to trauma in a pet. Within the skin, trauma to the small blood vessels can cause leakage into the surrounding tissues. Pets with skin allergies, ear infections, or foreign bodies in the ears can get an aural hematoma on the inner flap of the ear cartilage due to trauma of these blood vessels from shaking the head or scratching. Drainage, compresses, and special medications can help resolve the issue. Occasionally, some tumors may bleed when a needle is placed in the mass to aspirate cells or if the mass outgrows its blood supply and opens up to the surface. Your veterinarian can determine whether the tumor is benign or malignant, with a tendency to spread to other organs.

Next month, I will take a closer look at the more common forms of skin tumors in pets. I will explain the differences of the tumors based on the types of cells inside, the growth of the tumors, whether or not they are likely to spread to other areas, as well as causes and treatments. Please help your veterinary team help your pet by showing us lumps and bumps, as well as by taking pictures of these areas.



Featured Posts