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Why is my senior dog suddenly ill with skin sores and vomiting?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed Large (61lb +) | Female | spayed | 18 years and 4 months old | 61 lbs

Older dog has skin lesions and they bleed and are sore. Recently.ill and through up several times and could hardly walk. Area in question was very painful. Was in good health till today.

1 Answer

Most Helpful Answer

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Answered By Ricardo Fernandez, DVM

Veterinarian, Veterinary Oncology Resident

Published on February 18th, 2018

Thanks for using Petco Pet Education Center, formerly Petcoach! This is possibly due to allergies though other things like mites are also possible. It really comes down to figuring out what is causing her allergies so that they can be treated or the specific allergen avoided. If she is still vomiting, that should be investigated further. There are many things that can cause allergies though in most cases they can be broken down into 3 big categories: flea, food and environmental allergies. Allergies are usually worked up in a stepwise fashion starting with flea allergies as this is the easiest and cheapest to take care of. If not on a flea preventative, then it would be a good idea to get started on one. If already on one then it would be a good idea to change to something else (there are many new products out in the market). If not improved in 1-3 months then it is time to move on and check for food allergies by switching to a novel diet (new protein and new carbohydrate). If that does not seem to be the issue then you are left out having to check for environmental allergies which require blood and/or skin tests. Allergies can be very frustrating to deal with at first but so rewarding at the end when we are able to treat them effectively!

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