Lexi's Bump

by  Krista Magnifico, DVM

Lexi is a  sweet, docile, lovable 5 year old spayed female dachshund. She is is an integral part of her family and is usually found snuggled up under their wings.

Can't you see the happiness in her eyes?

Her parents, being the devoted doting people that they are, noticed a few days ago that a round bump had appeared on her side They called me and rushed her right in for an examination.

When it comes to bumps there are a few guidelines that we use to help us identify which are worrisome and which are most likely to be simply benign and/or just cosmetically unpleasing. 

Learning which is which takes both practice and an in person hands on examination.

I am asked frequently to diagnose and provide guidance based on a picture alone and I always hedge my skepticism on being concerned versus trying to reassure a client that they are "probably OK."

Lexi's bump was firm, round, about 6 cm in diameter and directly behind her right armpit. 

It also seemed to appear quickly over the last week. There are a few things in this list that caused me concern; I am worried about the size, the area, and the quick appearance. Because of these we decided we needed to do something more than just watch it.

There are a few options when we talk about lumps and bumps on pets.

Watch and wait and see approach

This should only be done after your vet has examined it and agreed that it is most likely a cosmetic benign mass. This takes years of practice and is still at best an educated guess. There should be some take-home instructions if this approach is chosen. Here are mine; The mass is measured (a ruler r calipers on a scheduled basis. Record measurements in a journal. Have a "size to return to the vet" rule. I.e. if it grows by 20%, or gets this big.. we return. Don't wait until it is so big we can't safely remove it.) Here is a good example, Charlie's story.

Fine Needle Aspirate option

This is performed with a large bore needle (I prefer a 16 or 18 gauge needle) being placed into the mass to collect cells. This is a cheap, quick diagnostic tool. It doesn't require anesthesia, (I have never sedated a pet for it either), and within a few minutes a sample of the mass can be collected and submitted on slides for cytology. The cost at my clinic for this is about $40 for the aspirate, and $140 for the slides to be submitted to the lab for analysis. The disadvantage is that you have to be very careful that the needle is in the mass, not in the surrounding fat, or tissue, and that you can get a good sample. Occasionally, I have had difficulty in getting a good sample due to excessive bleeding.. and sometimes you aspirate a terrible tumor that bleeds and gets soo angry that you make the tumor bigger and scarier. Also, the more tissue you collect the better the pathologists ability to diagnose correctly.. FNA is about 70-95% accurately diagnostic. In the world of human medicine biopsies are the tissue sample size of choice and treatment plans are rarely decided on aspirates.


This is the best way to make a decision about a mass.. More tissue allows for more information to be collected for the pathologist. It also allows the surgeon to see what they are collecting. More tissue allows for more accurate diagnosing, which allows for a more successful treatment plan. This requires general anesthesia and hence is more costly. I would like to add that this also allows for a chance at excision being curative. In other words I approach every biopsy as an opportunity to remove something that I hope will not ever have to deal with again. A biopsy is accurate about 90-99 % of the time.

I should add that in some cases my clients elect to take the quicker, cheaper, and less invasive approach by having a fine needle aspirate done, but later need a biopsy and or mass removal after the FNA is done. This can be more expensive in the long run, (about $150 at my clinic).

In Lexi's case they elected for a fine needle aspirate.

I prefer to used an 18 gauge needle on a syringe. I isolate the mass in one hand and pierce the mass with the needle while pulling back on the plunger of the syringe. We call it the "woodpecker" technique because we stab the mass multiple times to pull as many cells into the syringe as possible.

After the sample is collected we examine them on a slide and submit the slides to the lab for a pathologist to analyze. I usually get an answer on a FNA in a day or two, versus a biopsy which usually takes about 4-6 days.

Luckily for Lexi, her FNA sample was all fat cells. 

We decided that as long as it didn't change too significantly that we would just keep an eye on it. Why did it appear to have grown so quickly? Well, Lexi's diet had actually begun to work, and now her new waistline was revealing a lipoma. The fat cells will grow bigger or smaller with weight changes to some extent, but fat cells only disappear with liposuction, or surgical excision.

Here is how I recommend that you monitor a mass:

  1. Measure the mass using either a ruler or calipers.
  2. Record the size in either your pets file, on your yearly refrigerator calender or ask your vet to help you by adding it to the pet record.
  3. Have a plan for action. Know what size is the time to go back and go to plan B.
  4. If the mass becomes too big for your pet to haul around go to plan B.
  5. If the skin covering the mass starts to tear, thin, or weaken, or if the mass ruptures go to plan B.

Identify plan B.. 

In almost all cases plan B indicates that it is time to stop watching the mass from the couch.. it is time to slay it with a scalpel and bid farewell to it forever.

Pawbly.com is a resource for pet people to ask questions, share information and help pets find the help and resources their parents need. It is free to join, use, and open to everyone who loves pets. Please visit us and share your pet stories, experiences, and lend a hand to a pet in need.

If you need help from me you can find me at the clinic, Jarrettsville Vet, or on Twitter @FreePetAdvice.


Krista Magnifico, DVM owns a small animal hospital in northern Maryland, where she practices everyday. She wants to make quality veterinary care available to everyone, everywhere at any time; trying to save the world 1 wet nose @ a time.  Her blog is a diary of he day-to-day life & the animals and people she meets. 

Dr. Krista is also the founder of pawbly.com, free pet advice and assistance.

To contact her, you may leave a comment on her blog, email her or catch her on Twitter or Facebook.

Articles by Dr. Magnifico:
Don't Make This Mistake: Ruby's Death To Heat Stroke 
Parvo: Cora's Story 
Jake's Laryngeal Paralysis
The Tip Of The Iceberg: The Unexpected Dental Dilemma
The Ear Ache That Wasn't Going Away: Tottsie's Story
Cody's Eyelid Tumor
Ruger's Mysterious Illness
The Day The Heart Stood Still: Timber's Story 
Different Definition Of Comfort Food: Levi's Story 
Savannah's Pancreatitis  
Histiocytoma: Rio's Mysterious Bump
Von Willebrand's Disease: Greta's Story 
Alice's Heart Murmur  
Jekyll Loses His Tail Mo-Jo 
Pale Gums Are An Emergency: Bailey's Story 
To Amputate Or Not To Amputate: Heidi's Story
Lessons From A Real-Life Veterinarian 
Charlie's Life Saving Lipoma Surgery  
Understanding and Diagnosing The Limping Dog, Why To Probe The Paw 
Angus' Dog Fight And The Consequences
When To Induce Vomiting And When It's Not A Good Idea  
Abby's Survived Being Run Over By Car But Sucumbed To A Mammary Tumor 
Palmer's Hemoabdomen: Nearly An Unnecessary Death Sentence
A Puppy That Doesn't Want To Eat Or Play Is An Emergency: Aurora's Story
Does Your Dog Like Chewing Sticks? Hank's Story 

Do you have a story to share?

Your story can help others, maybe even save a life!

What were the first signs you noticed? How did you dog get diagnosed? What treatment did/didn't work for you? What was your experience with your vet(s)? How did you cope with the challenges?

Email me, I'll be happy to hear from you!


  1. 6 cm, really? Not 6 mm? That is one HUGE bump if not a typo.


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