Finding the Cause of Skin Disease

By: Carol S. Hillhouse, DVM, DABVP

TVMA Member
Panhandle, TX

Published April 2015

Many skin diseases that appear identical can actually be caused by very different problems, which is why testing is required to identify which condition is causing the problem. Veterinarians use the information obtained from taking a careful history, performing a physical examination and ordering certain diagnostic procedures to help formulate a list of possible diagnoses. Testing will either yield a definitive answer or allow some diseases to be ruled out. The following is a list of some of the more common procedures used for diagnosing skin disease:

  • Skin scraping: One of the most common tests to identify parasitic infections
  • Cytology: An impression taken of the lesionA region in an organ or tissue that has suffered damage through injury or disease, such as a wound, ulcer, abscess, tumor, etc. using an adhesive, which helps to identify bacterial or fungal infections and different types of cells
  • Fungal culture: Used to isolate and identify the agents that cause ringworm
  • Woods lamp: A special UV light that causes some strains of ringworm to shine a bright apple green color
  • Trichogram: A procedure that microscopically examines hairs for evidence of fungal infections, pigmentation defects and the growth phase of the hair
  • Bacterial culture: Helps with selection of antibiotics
  • Skin biopsy: Surgically taking a piece of skin in order to have a pathologist examine its deeper layers, possibly providing more information than superficial tests
  • Allergy testing: Recommended for long-term management of allergic skin disease to help desensitize the pet to its allergens

The results obtained from the history, examination and necessary tests will allow the veterinarian to place the skin disease process into one of six categories: allergy, infection, immune-mediated, hormonal, defects in skin metabolism or cancer. With that knowledge, a treatment plan can be developed, which may include more specific testing, topical or systemic medication and special diets. Because so many skin problems look alike, finding the answer may be complicated. However, it is a process that is eventually rewarding to the pet, the owner and the veterinarian!

Dr. Carol Hillhouse owns two mixed animal practices in the Texas Panhandle: Carson County Veterinary Clinic and High Plains Animal Hospital.