Perianal Pruritus: What a Drag
Perianal pruritus (PP) is common in dogs with anal sac disease (ASD) and manifests as scooting, licking, or chewing at the anal area. In dogs with allergic skin disease, the perianal skin is commonly affected; however, the prevalence of PP as a manifestation of allergy without concurrent ASD is unknown. In this prospective study, dogs (n = 250) with skin disease were evaluated. Exclusion criteria included history of ASD, anal sacs that required regular emptying, perineal hernia, GI disorders within the week before consultation, and a variety of empiric therapies.
A total of 31 dermatologic diagnoses were identified, and those most commonly associated with PP included canine atopic dermatitis (CAD), adverse food reaction (AFR), and concurrent CAD and AFR. The presence of PP was significantly higher in dogs with CAD and AFR than for other diseases. The most common clinical signs were perianal alopecia, erythema, excoriations, lichenification, and hyperpigmentation. The most common behaviors were licking, chewing, or scooting. PP was not associated with anal sac impaction.
Global Commentary
This study confirmed what have been anecdotal reports that PP is mostly associated with allergy, especially CAD. CAD commonly affects the front feet and ear pinnae, while the ear margins and dorsolumbar skin are normally spared.1 The perianal site is not included as a predisposed area for CAD but, based on this study, perhaps it should be. It is not uncommon for my practice’s dermatology department to see PP patients that have their anal glands removed without any improvement in clinical signs. Most of these dogs have allergy. Anal gland involvement should be assessed in all cases of PP with palpation of the gland and cytology of the exudate, but glands should not be removed if these findings are normal without first investigating a possible allergic cause of the clinical signs.—Sue Paterson, MA, VetMB, DVD, DipECVD, MRCVS
Source
Perianal pruritus in dogs with skin disease. Maina E, Galzerano M, Noli C. VET DERMATOL 25:204-e52, 2014.
This capsule is part of the Global Edition of Clinician's Brief.