Preliminary Notes on Babesia Found In Dead Bristol Foxes

 

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From the very outset of investigation and research I was told by my late colleague Franklyn A. Davin-Wilson to check, double-check and triple check any and all sources on a particular matter and where ever possible go to the source.  I found that this advice could be adapted to aspects of wildlife study and in particular foxes.

 

When the reports of sudden fox deaths began to reach me in June of 2021 what was being described seemed –seemed- to be poisoning cases. The difficulty breathing and sudden collapse and death all indicated that. In fact, there were opportunities to exploit this for press/media attention on the matter, especially when it was clear official bodies were being obstructive –particularly Bristol City Council. It was obvious some cases appeared to be poison and post mortem examination revealed that one of the foxes submitted was the victim of rodenticide and although I am not permitted to see the report sent to the Wildlife Incident Investigation Scheme (only the post mortem report) I am not giving up on getting a copy of that report.

 

However, in the back of my mind was the possibility of a virus or disease.

 

I have absolutely no interest in self promotion because my work is to help the animals (in this instance foxes) or find out what is going on. Ego has no place in that and the press has attempted that route –unsuccessfully. The headlines “Bristol Fox Poisoner Strikes Again!” was the intention as I saw it and if there was the possibility of a disease or virus no doubt “Fox Plague Sweeps Bristol!” would have been the headline.

 

Just announcing another fox death caused some very emotive responses despite attempts to make it clear that there was no cause of death known and for that we would need to wait for the post mortem results. Believe me when I write that reading through post mortem reports and checking the PM images are far from fun. We are still awaiting confirmation on one fox but I am able to give the conclusions of the pathologist regarding our two mystery jaundice cases.

 

The pathologist wrote that:

 

“Just a quick update on these two foxes.  They’ve been shown to be positive for babesia, which foxes can be infected with without being clinically affected.

Further work is on going to help confirm it’s possible significance.  There has been only one previous report of this and again it’s more a suggestion of it’s significant rather than confirmation.”

 

A link was attached to the email for an article titled Babesia (Theileria) annae in a Red Fox (Vulpes vulpes) from Prince Edward Island, Canada

April 2010 Journal of Wildlife Diseases 46(2):615-21.  The summary reads:

 

“A 4-6-mo-old female red fox (Vulpes vulpes) was presented to the Atlantic Veterinary College (AVC) Teaching Hospital, Prince Edward Island, Canada. On presentation, the fox was weak and had pale mucous membranes. A complete blood count and a serum biochemistry profile were performed. Blood smear examination revealed low numbers of erythrocytes containing centrally to paracentrally located, single, rarely multiple, approximately 1 x 2 microm, oval to round organisms with morphology similar to Babesia microti.

 

Polymerase chain reaction testing and DNA sequencing of the Babesia species 18S rRNA gene were performed on DNA extracted from whole blood. Results were positive for a Babesia microti-like parasite genetically identical to Babesia (Theileria) annae. The fox was euthanized due to poor prognosis for recovery.

 

Necropsy examination revealed multifocal to locally extensive subacute nonsuppurative meningoencephalitis, an eosinophilic broncho-pneumonia, a moderate diffuse vacuolar hepatopathy, and lesions associated with blunt trauma to the left abdominal region.

 

This is the first reported case of a red fox in Canada infected with a piroplasm. It remains uncertain whether the presence of this hemoparasite in this fox was pathogenic or an incidental finding.

 

 The potential for competent vectors of Babesia species on Prince Edward Island, the potential for this Babesia microti-like parasite to infect other wild and domestic canids, and the significance of this parasite to the health of infected individuals are yet to be determined.”

 

From the total official disinterest from the WIIS initially –the attitude was that the deaths were all down to rodenticides- interest is now more acute. There has even been international consultation in getting to the bottom of the jaundice cases. Just what the significance of this conclusion will be if confirmed we have no idea.

 

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One thing that must be changed are the attitudes of some fox rescues -I was told after initial enquiries that some had dealt with dead foxes showing signs of jaundice. When I asked what their vet had concluded I was told they had not asked for an opinion. Others stated that it was not incumbent on them to submit foxes for post mortem even if it did not cost them anything. Most took the stance “We patch them up and send them back out through re-release. Dead foxes are dead foxes.” 

 

I understand fully the work carried out by fox and wildlife rescues and how expensive vet treatments are. However, they are supposed to be there for fox welfare and repeatedly refusing to make any sort of move when they have an unusual death is in my opinion totally unacceptable. If there are no apparent external breakages or signs of a car strike (RTA) or other wounds then that is a fox that needs to be checked out. If you examine a sickly fox that then dies or that is already dead and you see signs of jaundice then that fox must be submitted for examination. The Submission form takes less than a minute and you may need to keep the carcass chilled until asked to take it to the post mortem facility. That should not be beyond a rescue.

 

Finding out what killed a fox may very well save other foxes in future as vets will know what to look out for and how to treat. The fact that, at the time, two out of three dead foxes had this jaundice is significant since they came from different parts of the City and the odds against both of them having jaundice were high.

 

We have just submitted fox number 10 which had breathing difficulties as did an earlier one (tests are still ongoing).

 

What have the post mortems revealed? Firstly, due to initial disinterest we lost four recently deceased foxes that would have been “fresh” for PM. Others were lost due to continually hitting official barriers.

 

We lost another fox that was removed from a vet practice chiller despite being marked “possible wildlife crime evidence do not remove” –we have to accept that, as the vet explained, there were a series of breaches of official practice protocols. 

 

We then lost another carcass stored at a council waste facility that was clearly marked as “Potential evidence DO NOT remove”. In this case we are told that “any number of people” can access the site without notification and this is how the carcass was probably removed. Of this I am highly suspicious.

 

Two foxes, which looked as though they were in good condition (Dog fox and vixen) were picked up by the City Council. The City Council then stated that the foxes had not been retrieved by its team. I then had confirmation from the man in charge of collections that “Oh, yes. We have them I’ll go and check and get back to you” –followed by silence. I have since that time had three independent confirmations that the council did pickup the foxes; one individual who spoke to the men was told that they pick up a lot of dead foxes in the area and we know that is a fact as we have reports of two other foxes found dead just around the corner from the “vanished” foxes but these were too far gone for submission for PM.

 

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That two areas of Bristol are focal points for fox deaths indicates something is going on: disease or poisoning? In certain case the obstruction and lying from Bristol City Council leads us to believe rodenticides may be involved and that I was not permitted to see a copy of the report to the WIIS seems to confirm this.

 

We have Babesia and two more may be added to that list though there is no certainty of that yet. We have definite rodenticide as a cause. The main killer, however, fits in well with what we already know: cars. Zoe Webber collaborates on the Fox Death Project and she examines any that seem to fit our criteria in situ.  Initially, bearing in mind the two “vanished” foxes, we prefer to have a photograph of the fox as found as this can tell us a great deal including whether a fox died there or was placed there. It also means that if the fox in question “vanishes” we at least have photographic evidence that it was there. Zoe examines the carcass as best she can looking for broken limbs or injuries consistent with RTA. If none can be found then we say that fits our criteria for collection and submission. There may be a small amount of blood around the mouth but this is not a 100% indicator of internal damage from an RTA as we now know.

 

We can now also say that foxes can be hit by cars and receive internal damage that goes unnoticed by people who see them regularly and to whom the sudden collapse and death are a shock.  It is doubtful whether the injuries would have been treatable and their lives saved had they been picked up after initial car strike. The details and images are not pretty.

 

We were very lucky that despite some delays by PM Services in Bristol acceptance of foxes for PM are now sent by the next morning –showing that interest is now more significant than before. We are also very lucky that we got a senior and experienced pathologist (I’m not really sure that I can name him and the amount of press attention may become an annoyance) who has stuck with each case until he can find and prove a cause of death or consult with international colleagues to do so. This has been beyond what we initially expected and made all of the bureaucratic arguing worth it.

 

In total some 50 foxes are known to have died suddenly in Bristol since June 2021 and those are only the ones I receive reports on and have sufficient details (“dead fox in a garden in Bedminster” and no further details or contact just do not make it into my notes). There are still open cases were local and regularly seen fox groups have simply vanished. All poisoned in one go seems to be unlikely so we have no idea what happened. Added to all of these are the actual fox RTA deaths and, again, only those reported to me amount to a dozen.

 

RTA deaths we can do nothing about but we can certainly do something about the fox deaths with no outward visible cause. I would urge any and every rescue that finds a dead fox with signs of jaundice to submit them for post mortem examination so that we can assess whether babesia is a national or regional issue.