Thank you for the additional information.
This isn't an ideal situation for you. And for this wee one, we would really want to know if she has been spayed (since this can have bearing on what you are seeing). And I am glad that she isn't as white as a sheet (which she might be had she been bleeding out from trauma or a splenic tumor) but I am concerned that she is paler then the other.

Now progressive (possibly intermittent) weakness in a young female ferret is concerning and can be precipitated by a number of causes. Therefore, we have to consider each in turn and rule them out to determine the definitive nature of her underlying condition and we might manage it properly and get her back to normal.

The first thing we always have to consider are possible toxic causes. The risk of this will vary depending on what you keep in your home and what she may have exposure to. If there is any chance that she may have been exposed to any chemicals, toxic plants, insecticides, rodenticides or heavy metals, then you do want to have her seen immediately. Typically, we will see drooling, vomiting, diarrhea, and anorexia, but if there is anything she could have gotten into, then you don’t want to delay intervention.

In regards XXXXX XXXXX infectious disease agents, the two we would associated with a weakness and possible neurological wobbliness would be parovirus (causing Aleutian disease) and distemper. Each can manifest with a generalized weakness, lethargy and anorexia, with distemper also causing fever, neurological and respiratory signs. If your ferret is up to date on her vaccinations, these will be less of a worry, but both diseases can be tested for by your veterinarian.

If we are able to rule out the acquired disease, then we’d have to consider those which arise from internal problems. This can include heart disease, diseases of the endocrine system (the hormone producing organs), organ disease, blood based disease, and tumors of a variety of organs.

Now even if she isn’t showing fits or faints, we do have to consider heart disease here. These diseases can affect both the heart and blood vessels. Heart disease in the ferret is very common and if the heart is struggling to work we will see a drop of oxygen in her blood thus leading to intermittent weakness, wobbliness, which can progress to fainting, continual weakness, and collapse on exercise. Affected ferrets will often be ok at rest, then show signs when moving about. You may also notice a paling or blue tint to her gums when she is exercising.

Another concern is the possible growth of a particular pancreatic tumor called an insulinoma. This tumor can arise in younger ferrets and causes trouble by causing intermittent low blood glucose due to the release of abnormally large amounts of insulin. This leads to the brain being starved of glucose and can manifest as muscle weakness, wobbliness, and sluggish activity. If left untreated, they can develop seizures. If she has an insulinoma, you might notice that when she eats, she then perks up (it can be subtle but sometimes you may be able to pick this up with them).

Finally, with this paler appearance we do have to consider anemia (low blood volume). While we can see a drop in red blood cells in a ferret that has had a trauma or an internal bleed, we can also see this for other serious and more subtle reasons. This can includes kidney disease, liver disease, heart disease, trauma (loss of blood through an injury), cancer of the blood cells, toxins that destroy RBCs, infections, nutrition, parasites and bleeding gastric ulcers.

That all said, the reason I am so keen for you to find out if this ferret has been spayed is because we can see anemia with hyperestrogenism. This is all too common and is where the female ferret is in heat too long and the excess estrogen in her system causes the body's normal production of red blood cell to be suppressed. This then leads to an unrelenting anemia, that will be fatal if not addressed. Just as with the other conditions, this can cause weakness (possibly more obvious with exercise).

So, these are our concerns for her and they are all fairly serious.

Because she has been dumped on you without a good history of her life so far, I would strongly advise that you do want to have her seen sooner rather then later. We do need to rule out all these differentials, and the first step is to have a vet perform a physical examination. We need them to listen to her heart, but also help you determine if this ferret has been spayed (this may require a blood sample to check her hormone levels). Overall, the sooner you get her checked out and able to address the causative agent, the more chance you will have to treat her effectively and restore her to normal.

I hope this information is helpful.
Please do let me know if you have any further questions.
If you have no further questions, feedback is always appreciated.

All the best,

Dr. B.

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