Contact Dermatitis in Dogs

Contact Dermatitis in Dogs

By: Dr. Rosanna Marsalla

Section: Overview

Contact dermatitis is an uncommon skin disease of dogs and cats caused by contact with plants (especially plants of the wandering Jew family), medications, and various chemicals. Contact dermatitis is not as common in animals as in people because the skin of dogs normally is protected by their hair coat. Contact dermatitis can develop, however, in areas of the body where the hair is sparse.

Contact dermatitis can be of two different types: allergic or irritant.

  • Allergic reactions require a period of sensitization during which the immunologic reaction develops. On the average, sensitization takes six months to two years to develop. Thus, medications and chemicals that have been used in the past without problems still may be responsible for an allergic reaction at some later time.

    Contact allergy is a delayed reaction with signs occurring 24 to 48 hours after contact with the offending substance.
    The reaction is the same type that occurs in people who develop poison ivy.

    Typical signs of contact allergy include pruritus (itchiness) and a papular eruption (red bumps). Pruritus can be severe. The paws and muzzle commonly are affected in animals, and sometimes, the insides of the ears are affected, especially in dogs with pendulous ears that come into contact with plants and grasses. In households with several animals, it is uncommon for more than one animal to develop an allergic reaction.

  • Irritant reactions, on the other hand, do not require a period of sensitization because they are not immunologically mediated. Thus, reactions occur the first time a substance makes contact with the skin. If several animals are present in the household, all animals coming into contact with the substance will develop skin reactions.

    Irritant reactions are more painful than pruritic. Small vesicles (blisters) and ulcerations develop. The distribution of the lesions depends on the nature of the offending substance and the pattern of contact.

    Secondary bacterial skin infections may develop due to trauma and inflammation.

    What to Watch For

  • Pruritis (itchiness)
  • Papules
  • Secondary superficial bacterial infection
  • Increased pigmentation
  • Crusting
  • Thickening of the skin
  • Blisters (vesicles) and ulcerations that are more painful than pruritic

     
    Printable Version
     
    Have a Pet Question?
    Send Your Pet Question to Dr. Jon
    and His Staff of Veterinarians Ask Dr. Jon
    Dr. Jon's Newsletter
    Yes! Send Me the Latest Health Information, Pet Tips, Pet Stories and more...
     
     

    Related Articles

    • 1 Atopy in Dogs

      Atopic disease (atopy) is a pruritic (itchy) skin disease of animals that is caused by an allergy.

      Read MoreRead More
    • 2 Skin Discharge or Odor in Dogs

      Skin odor is a common manifestation of a skin infection; the most common skin infections are bacterial (superficial pyoderma) and yeast (Malassezia dermatitis) infections.

      Read MoreRead More
    • 3 Pruritus (Itchiness) in Dogs

      How pruritus affects your dog’s health depends on the degree of the pruritus. Severe pruritus leads to intense scratching, which may result in painful skin lesions that may become infected.

      Read MoreRead More
    • 4 Skin Lesion or Sore in Dogs

      There are many different types of skin lesions that can occur in the skin of dogs, and each lesion or combination of lesions can be caused by multiple diseases and conditions.

      Read MoreRead More
    • Related Articles
    • 1Skin Lesion or Sore in Dogs

      There are many different types of skin lesions that can occur in the skin of dogs, and each lesion or combination of lesions can be caused by multiple diseases and conditions.

      Read MoreRead More
    • 2Atopy in Dogs

      Atopic disease (atopy) is a pruritic (itchy) skin disease of animals that is caused by an allergy.

      Read MoreRead More
    • 3Skin Discharge or Odor in Dogs

      Skin odor is a common manifestation of a skin infection; the most common skin infections are bacterial (superficial pyoderma) and yeast (Malassezia dermatitis) infections.

      Read MoreRead More
    • 4Pruritus (Itchiness) in Dogs

      How pruritus affects your dog’s health depends on the degree of the pruritus. Severe pruritus leads to intense scratching, which may result in painful skin lesions that may become infected.

      Read MoreRead More
     

    Over 10,000 Veterinarian Approved Articles

    Dogs & Puppies
    Cats
    Related Articles
    • 1Skin Lesion or Sore in Dogs

      There are many different types of skin lesions that can occur in the skin of dogs, and each lesion or combination of lesions can be caused by multiple diseases and conditions.

      Read MoreRead More
    • 2Atopy in Dogs

      Atopic disease (atopy) is a pruritic (itchy) skin disease of animals that is caused by an allergy.

      Read MoreRead More
    • 3Skin Discharge or Odor in Dogs

      Skin odor is a common manifestation of a skin infection; the most common skin infections are bacterial (superficial pyoderma) and yeast (Malassezia dermatitis) infections.

      Read MoreRead More
    • 4Pruritus (Itchiness) in Dogs

      How pruritus affects your dog’s health depends on the degree of the pruritus. Severe pruritus leads to intense scratching, which may result in painful skin lesions that may become infected.

      Read MoreRead More