This week sees the start of the next series of articles, this time on dermatology (skin conditions). We have already discussed flea allergies and other parasite problems in previous articles, along with ear infections and ringworm. That leaves us with bacterial, viral and autoimmune problems, alongside where we start today, a topic that often causes owners great concern: skin tumours.
Skin tumours in dog and cats are common and are usually visible on the skin or easily felt just beneath it. Even if they are benign, they can still be prone to becoming ulcerated, painful or itchy, partially due to the animal traumatising them; sometimes they will even end up with secondary bacterial infections.
When your vet examines the suspicious lump they will be taking into account your pet’s age, sex, coat colour and breed, in addition to studying the actual mass itself. All these factors influence the type of tumour you are likely to find. When considering the mass itself they will be looking at the exact site, size, texture, colour, depth, whether it’s adhered to the tissue underneath, if it’s infected or itchy and the number of masses present. They are likely to want to know from you when it was noticed and how quickly it has grown or changed and if it is bothering the animal. When discussing individual types of skin tumour during the next couple of weeks, you will see how these factors can give us clues as to which one is suspected.
In general, the way a mass behaves may point towards whether it is more likely to be benign or malignant, although it’s important to remember they don’t always follow the rules. Many skin tumours look and feel very similar, and yet one may be nothing to worry about and another be life-threatening.
A number of options are available to aid diagnosis: a fine needle aspirate (where a needle is inserted into the mass and tissue from it is pulled into the needle hub and sprayed onto a slide), or impression smears (pressing a glass slide against the mass) can normally be done quickly and conscious. It can be extremely useful if you get a decent plug of cells from the mass and it has the advantage of not being overly invasive.
If you get confirmation of a definite type of tumour, it’s great but the method is prone to false negative results which can leave doubts. Numerous types of more substantial and more accurate biopsy can also be done but these normally require at least sedation so many owners (and vets) prefer just getting the mass removed and then sent off for laboratory analysis.
That said, skin tumours are most successfully managed on the first occasion. What this means is that prompt and adequate treatment initially will give the animal the best long-term prognosis, which is why if your vet (especially if suspicious of a highly malignant and aggressive tumour) may suggest a biopsy prior to surgical removal.
This will enable them to know what they are up against prior to surgery and so can be accurately guided as to how much normal tissue (margin) needs to removed around the mass to ensure all the tumour is gone. Depending on the nature of the tumour further tests such as X-rays, ultrasound or blood tests may be recommended to check for evidence of spread.
Next week we discuss some very common types of skin tumours that, despite often being a source of worry, for owners are actually benign.