Hello, We noticed my 14 year old Lhasa Apso / Poodle mix has developed this lump on his tail, we did not notice until his most recent grooming. He does not seem to be in pain from it but it looks very abnormal. He is in great health otherwise. Can you please tell me what this might be or if it requires immediate medical attention? Pet's info: Dog | Mixed Breed Medium (23 - 60lb) | Male | unneutered | 14 years and 2 months old | 15 lbs

Thank you for providing pictures of the lump on Skip's tail. It is possible, given his age, that he could have a malignant tumor causing the lump. It could also be a benign tumor. I would not rush him into an ER vet tonight, but I would have him seen by a vet tomorrow if possible for a fine needle aspirate. To do this, the vet sticks a small needle into the lump to get a sample of it's cells, and examines the cells on a slide under a microscope. It's usually painless to the animal, and relatively quick to perform. Once the cause of the lump is found, the vet can discuss treatment options if needed. I hope this helps :-)

Hi there. Lumps and bumps on dogs can have many underlying causes. It is often difficult to tell the difference between them just by looking at it. It could be cyst, a plugged hair follicle, a tumor...... My best guess by looking at the photo is that it may be a histiocytoma which is a benign tumor that usually goes away on it's own within a few weeks to months. https://www.veterinarypartner.com/Content.plx?P=A&S=0&C=0&A=1676 You must understand though, that it is impossible for me to diagnose over the internet so I strongly suggest you take Starky to your vet for an exam so they can give you a proper diagnosis. Hope this helps. Best wishes.

Unfortunately, the only way to understand the exact nature and origin of the bump/raised area would be through to your veterinarian clinical examination and laboratory tests. Clinical appearance can help differentiate among infectious and neoplastic disease but only by collecting a specimen of the lesion will give you a specific and definitive answer. A biopsy can be taken under general anesthetic/sedation, otherwise a smaller sample collected with a fine needle can be aspirated without anesthesia/sedation. Good luck Olivia. Please post again on the forum if you would like to discuss it further. I hope my answer was helpful.