Nationwide members spent more than $96 million in veterinary care last year to treat the top 10 most common medical conditions affecting their dogs and cats, according to the pet health insurer. Based on more than 1.4 million pet insurance claims submitted to the company last year for more than 650,000 insured pets, Nationwide has identified the top 10 medical conditions affecting dogs and cats (and their associated costs). Top 10 most common medical conditions for dogs Atopic or allergic dermatitis – average cost to treat: $255 Otitis externa – average cost to treat: $172 Benign skin neoplasia – average cost to treat: $377 Pyoderma – average cost to treat: $128 Enteropathy – average cost to treat: $175 Gastropathy Degenerative arthritis Periodontitis/Tooth infection – average cost to treat: $400 Cystitis or urinary tract infection Anal gland sacculitis/Expression Top 10 most common medical conditions for cats Cystitis or urinary tract disease – average cost to treat: $495 Periodontitis/Tooth infection – average cost to treat: $434 Gastropathy – average cost to treat: $334 Renal disease or failure – average cost to treat: $649 Enteropathy – average cost to treat: $221 Hyperthyroidism Feline upper respiratory infection Diabetes mellitus – average cost to treat: $889 Atopic or allergic dermatitis Valvular heart disease or murmur