Ever had a near-invisible but palpable lump on cat post-injection?

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Felis-Felidae
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Ever had a near-invisible but palpable lump on cat post-injection?

Post by Felis-Felidae »

Hello everyone, I'm a new member. I'm posting because I'd like to know if anyone else here has had a cat develop a nearly invisible but palpable lump on their flank following an injection.

I mean it when I say it's nearly invisible. I have to angle a light and use the shadow on her (already-shaved) fur in that area to see where it is.

I can feel it, though. It's rather shallow -- only 2mm-3mm in elevation and perhaps just 1cm wide. It's like a weird little bump that showed up shortly after the injection. What concerns me is that it's still here, 3 months later. Not good because it could indicate FISS, I know.

Yes, I've seen the vet. Prescribed a short course of prednisone first to see if the lump would diminish. Still, while that's happening, I'd like to know if any other cat owners have seen something like this. It's worrying me quite a bit, but I'd like to gather as much info as I can anyway. It's the only way I can help my cat right now.

Thank you to everyone who responds in advance!
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Re: Ever had a near-invisible but palpable lump on cat post-injection?

Post by Mollycat »

Confused - was the injection given in the flank? What injection was it, and what for?
Lumps are common at the vaccination injection site, personally I'm convinced it's because vets no longer seem to massage the area to disperse the fluid like they used to, but to be honest it's been a long time since I had a vaccinated cat.
As you say you've seen the vet I suppose there's no chance it can be something to do with why the area was shaved and what the injection was for?
If it's not at the injection site then cats can get fatty lumps like dogs and most of the time they are harmless. My ex's 23 year old cat has one on on her ankle joint about the size of half a quail's egg that hasn't bothered her for 10 years and counting.
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Re: Ever had a near-invisible but palpable lump on cat post-injection?

Post by ArgyllCat »

This probably isnt much help but my female cat always gets a lump after her yearly injections. My male cat has never had that and they both get done at the same time by the same vet. I think she just has a reaction to it - it doesnt seem to bother her and usually disappears after about a week or so.
Felis-Felidae
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Re: Ever had a near-invisible but palpable lump on cat post-injection?

Post by Felis-Felidae »

Pardon me, I should have stated it! It was her vaccination for rabies. Yes, the lump is on the injection site, roughly around the point where a cat's latissimus dorsi approaches what I believe is their lumbar fascia. [I may be mistaken: I'm no vet :oops: ]

And thank you for sharing that, ArgyllCat. Mine has never had a post-injection lump either, but now she's had it for 3 months now... so I'm not nearly as sanguine about it as I could have been.

And I see, Mollycat, thank you for that bit of veterinary trivia. The vet actually shaved her fur to measure the lump and see if the fortnight of prednisone therapy diminishes it at all. Still crossing my fingers for that, but if it doesn't work, it's obviously time for an FNA.

What you said about your ex's cat is actually part of what is throwing me so much about this. You Google cats' post-injection lumps and nearly all the results you see talk about more or less visibly spheroid masses -- people talk about grapes or quail's eggs, or post photos of clear lumps on their cats.

Whereas even though I can feel my cat's lump if I run my fingers carefully over her flank, I myself can barely see it unless I use a light source for shading, as I said. I'd love to know if anyone's ever seen anything of this type before.
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Re: Ever had a near-invisible but palpable lump on cat post-injection?

Post by Mollycat »

Thanks for the extra details. The flank threw me as I'm used to subcutaneous in the back of the neck or intravenous in the paw.
I don't know a lot about the rabies vaccine as I live in the UK and never had any need for it, but I found this
There are a number of different brands of rabies vaccines for cats available on the market, and each brand comes with manufacturer guidelines that must be adhered to by the administering veterinarian.
The major differences between feline rabies vaccines are whether they contain an adjuvant or not.
Older vaccines contained materials called adjuvants, which act to boost the immune response to the vaccine. These vaccines worked very well to prevent disease, but in a very small numbers of cats, they were linked to the development of both local reactions (such as swellings) and much more serious problems, like growths at the site of the vaccine.
Most veterinarians have now changed to the non-adjuvanted form of the rabies vaccine for cats. Originally, this vaccine was only released as a one-year vaccine. That meant that starting at the age of 12 weeks, a cat would need to receive the vaccine annually to ensure protection from the disease.
Recently, however, a non-adjuvanted three-year vaccine has been made available to veterinarians. This vaccine is only given once every three years after the initial one-year booster.
It is relatively expensive, so many veterinarians still prefer to use the annual form of the non-adjuvanted vaccine.

What Are the Side Effects of Rabies Vaccines in Cats?
Fortunately, reactions to vaccines are very uncommon in cats. In fact, side effects of rabies vaccines in cats are very rare. When they do happen, they include slight fever, lethargy, decreased appetite and a localized swelling at the vaccine site.
These rabies vaccine side effects usually disappear within a few days.
In extremely rare cases, cats may develop an allergic reaction to the vaccine, which includes hives, swelling of the face and itchiness.
Severe reaction can include weakness and collapse. Keep in mind that these reactions are extremely rare; allergic reactions occur in fewer than 10 cats out of each 10,000 cats vaccinated.
from: https://m.petmd.com/cat/care/what-you-n ... cines-cats

You probably found the same site if you've been googling! It certainly doesn't seem to describe your situation at all but interesting anyway.

Also found this about dogs:
It is not uncommon for dogs to develop small lumps at the sites where they receive vaccines. In my experience, the rabies vaccine is particularly likely to cause this reaction.
Vaccines, by nature, are designed to stimulate the immune system. Lumps after dog vaccinations can occur for two reasons. First, the immune system can become active at the site of the injection, causing an infiltration of immune cells that leads to a small lump. Second, a lymph node near the injection site may become activated and enlarged for a period of time after the injection. These responses do not occur in every dog, but they generally are nothing to worry about.
I have seen post-vaccination lumps on dogs persist for several months. The lump on Pebbles should not grow, cause pain or produce a discharge or foul odor. These symptoms can be signs of a more serious reaction to vaccination, such as an infection at the injection site. As well, have Pebbles checked if she seems sick or lethargic in any way. The odds are good that the lump will resolve spontaneously over time.
Of course, if you are worried about Pebbles, it never hurts to have a vet check her out.
A note to people with cats: post-vaccination lumps also occur in our feline companions. However, these lumps (especially if they occur at the site of a rabies or leukemia vaccine) are potential harbingers of serious problems in the future. If your cat develops a lump after a vaccination, always have a veterinarian evaluate the area.
Well you are under veterinary supervision but whereas we are used to being concerned if a injection site lump lasts more than a week or two, it seems at least in dogs they can last longer without trouble.

Sorry I found all this very interesting but really doesn't help with your question at all :)
Felis-Felidae
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Re: Ever had a near-invisible but palpable lump on cat post-injection?

Post by Felis-Felidae »

Hah, you're right, it hardly touches on my situation :lol: Thank you nonetheless, Mollycat. It may still be useful in the future as I have 4 dogs too ;)
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Re: Ever had a near-invisible but palpable lump on cat post-injection?

Post by Itchymoimoi »

Good morning

Did this lump ever resolve itself.
My cat has similar but from a steroid 6 weeks ago came up instantly. Vets say it’s very unlikely that it’s anything but they can’t say it isn’t ISS but that for now I should watch’s it and wait (I’ve been back three times in those 6 weeks)

Hasn’t grown significantly feels shallow and almost a bit fatty but definitely at injection site.

Nobody ever seems to post good news from these things which is so worrying

Thanks so much!
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Re: Ever had a near-invisible but palpable lump on cat post-injection?

Post by Mollycat »

Itchymoimoi wrote: Mon May 03, 2021 7:28 am
Nobody ever seems to post good news from these things which is so worrying
The majority of injection site lumps are nothing and dissipate in a few weeks. I guess we just don't hear so much about those.

Can the vet give you a timescale to come back if it's still there, or is not getting any smaller/softer/whatever?
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Re: Ever had a near-invisible but palpable lump on cat post-injection?

Post by Itchymoimoi »

they said to come back beginning of June - I was hesitant to wait so long..but then they made it clear that there are dangers to aspirating it too early and it might not get a reliable result and if they remove it and treat it like a fibrosarcoma they will have to remove a huge amount of skin, and it might not be necessary.

it came up immediately and It definitely feels like it has changed shape slightly - as in feels slightly longer than it did but its still less than a cm long maybe 5mm wide but it isn't a hard lumpy mass.
I've had four "second" opinions now all say feels benign and fatty and moves around, but they cant rule anything out as its a tiny possibility.

Im not feeling it every day as it was becoming an obsession.

i dont know how people cope with sick pets!
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Re: Ever had a near-invisible but palpable lump on cat post-injection?

Post by Katja »

Hey @Felis-Felidae, I would love to know if the lump has ever resolved?
I’m in quite a similar situation, my boy has had the lump similar described as yours for exactly 3 months now. I felt it 2 days after he received his shot. I had him for almost a year after his previous owner abandoned him. He’s 16 years old apparently and has never seen a vet in years. He’s a happy and healthy one, indoor, and just a real gem. The vet persisted he needs to get shots when she came see him although I questioned the rabies shot quite a bit for him for his age and the fact he doesn’t go outside. She said she gave the rabies in his back leg and the fvrcp in his foreleg (where he has the lump). He has his lump on his left side and she said she gave the shots on his right side. It seems to much of a coincidence that the lump appeared right after the shots so I’m convinced she mixed up the sides...

Still very frustrated with what happened esp now that the lump is still there after 3 months. So I’m hoping your kitty is alright and would love to know what happened eventually!

Best,
K
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Re: Ever had a near-invisible but palpable lump on cat post-injection?

Post by Mollycat »

In some countries the rabies shot is compulsory regardless of whether your animal ever has contact with other animals. Some other shots are compulsory in different countries. Also if you ever have to go away and leave your cat in kennels, or with a professional petsitter, you may not be able to unless it is fully vaccinated.
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Re: Ever had a near-invisible but palpable lump on cat post-injection?

Post by Worried about my cat »

O my god, the same with my cat. I noticed my cat’s lump 3 weeks after the rabies( i need it for travelling), went to vet immediately and she said she was going to cut it if it does not disappear in 2 weeks. I question her expertise, she is a young vet. Also i think i will sue her if my cat develops health complications. Anywho seems extreme starting operating the animal without checking first what is it.
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