Objective—To compare pathologic changes of the
horizontal ear canal associated with chronic severe
otitis externa between Cocker Spaniels and dogs of
Animals—80 dogs with severe otitis externa that
required total ear canal ablation with lateral bulla
Procedure—Medical records were reviewed for
breed, sex, and age at time of surgery. Histologic
specimens from the horizontal ear canal were evaluated
by a single examiner for overall tissue response
pattern and scored for sebaceous gland hyperplasia,
ceruminous gland hyperplasia, ceruminous gland
ectasia, fibrosis, pigment-laden macrophages, and
Results—48 of 80 (60%) dogs were Cocker Spaniels.
Thirty-five of 48 (72.9%) Cocker Spaniels had a predominately
ceruminous tissue response pattern; only
9 of 32 (28.1%) dogs of other breeds had the same
pattern. Other breeds most commonly had a pattern
dominated by fibrosis (n = 13 [40.6%]); fibrosis was
the predominant pattern in only 4 of 48 (8.3%) Cocker
Spaniels. Discriminant analysis and K-means clustering
of 4 histopathologic criteria correctly classified
75% of the dogs as Cocker Spaniels or all other
Conclusions and Clinical Relevance—Cocker
Spaniels are at increased risk for chronic severe otitis
externa requiring total ear canal ablation with lateral
bulla osteotomy, indicating that earlier and more
aggressive management of the primary otitis externa
and secondary inflammation is warranted in this
breed. Cocker Spaniels with chronic severe otitis
externa have distinct differences in pathologic characteristics
of the horizontal ear canal, compared with
other breeds. (J Am Vet Med Assoc 2002;221:
To compare the cumulative incidences of malignancies and benign skin masses and the mean age at death or euthanasia in dogs with allergic dermatitis treated long-term with versus without oclacitinib.
660 client-owned dogs.
Medical records were searched to identify dogs with allergic dermatitis treated for ≥ 6 months with oclacitinib (exposed dogs; n = 339) versus other available treatments before the introduction of oclacitinib (nonexposed dogs; 321) and with ≥ 24 months of follow-up information available. Nonexposed dogs were age and breed matched with 321 of the exposed dogs; data for the remained 18 exposed dogs were included in statistical analyses. Results for cumulative incidences of malignancies and other variables were compared between groups, and the effect of daily maintenance dosage of oclacitinib on cumulative incidences of malignancies and other skin masses was evaluated within the exposed group.
No meaningful differences were detected in the cumulative incidences of malignancies and overall skin masses or the mean age at death or euthanasia for dogs in the exposed group (16.5% [56/339], 56.6% [192/339], and 11.2 years [n = 80], respectively) versus the nonexposed group (12.8% [41/321], 58.3% [187/321], and 11.8 years , respectively). There was no association identified between daily maintenance dosage of oclacitinib and odds of malignancy or benign skin masses for dogs in the exposed group.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that long-term treatment with oclacitinib did not pose additional risk for malignancy in dogs; however, veterinarians should continue to observe FDA-approved label warning and precaution statements for oclacitinib and regularly screen for neoplasia in dogs with allergic skin disease treated with or without oclacitinib.