Aside from spending money for the sake of it why would I want to start BAER testing my ferrets? I have never produced a deaf kit after all, what’s the point? Well, many years ago I was looking at a beautiful ferret whose lines I wanted to import. After digging though I noticed some relatives that looked… a little waardy. It could have just been bad pictures, but did I want to take that risk. So, with melancholy I put that line aside and on the DO NOT TOUCH list. Between then and now though at least one breeder has imported that line, and sure enough they’ve produced deaf kits. If we BAER tested as standard the breeder would have known about this without doing the border line Joe from You stalking of different ferretrys around the world that I did. Everything would be much more open. Secondly this person has since said to paraphrase “well of course they’re deaf, all marked kits carry deafness” which I know is false but without proof we’re just two mental patients shouting at each other. By bringing in BAER testing I’m not just helping keep the population health and making things more open, I’m also covering my own backside because I don’t need someone making up rumours about me, and if there’s one thing I know it’s that there is always someone making up nonsense to set breeders against each other. The other thing I’m not sure many people have considered yet is that Brexit is making importing harder. Not to mention we still don’t know what the long term impact of the pandemic will be on ferret movement between countries. I think everyone will still do it but we do need to start working together more, and that might mean we need to consider more line breeding. Line breeding can be great, but you really need to know what you’re doing. In other species health testing is very helpful in making wise choices within line breeding programs. I’m not saying lets scrap all this keep the inbreeding co-ef low concept. What I am saying is as things get harder we, as a community, might need to breed 3rd cousins, and that’s a lot safer if we know the good, the bad and the ugly.
Which ferrets are we worried about?
Ferrets that we are concerned about hearing loss in are in particular firstly are those that show signs of Waardenburg syndrome, secondly in any that have white markings over the head and neck particularly the skull between the ears, and finally in silver lines, whether or not they have the white markings, this is due to the previous breeding practices of silvers making them more likely to carry deleterious genes. I would also consider any line with angora within it as these lines I have also not always been bred with the best practices. Those breeding for higher angora percentages and higher inbreeding percentages, especially with recessive genes like full angoras as the goal will in particular be more likely to suffer the backlash of these deleterious genes. Though this can be said for any line breeding which in most cases includes micro ferrets. In short, I would recommend that everyone looks to adding BAER testing to their program eventually however not everyone will be put high risk of hereditary deafness due to the breeding practices behind the lines that they are working with. Although it will be useful and helpful to be able to track hearing issues due to lack of pigment in the inner ear we are more concerned with the hearing loss due to neural tube deformation as in Waardenburg, because of the other health risks associated. That said tracking and removing lines prone to producing deafness or selectively breeding out the hearing issues in such lines will be a very important going forward for domesticated ferrets as a whole. Eye colour, like in humans, of mammals in general tends to be unrelated to hereditary deafness. Huskies would be my go-to example of this. Leucism in mammals on the other hand can be connected. Eye colour change you may see in conjunction with leucism could be a sign of pigment loss in the inner ear examples of this are breeds like Dalmatians and Bull breeds with white or high white coats in dogs, and white cats especially with bi or heterochromatic eyes. Dogs with double merle can also experience hearing loss however this is associated more with malformation of eyes and ears leading to the hearing loss, and again in other species similar genes doubled up result in unviable offspring. There is not currently a merle gene known in ferrets, but that isn’t to say it does not exist. We just don’t know about it yet. To err on the side of caution, and with more bright-eyed ferrets being bred to bright eyed ferrets these days I would highly encourage that breeders BAER test these ferrets too. Until we do, we won’t really know for certain if there is a link or not, and it once again would protect them from someone making up nonsense to discredit them. Oddly the trend of leucism with deafness doesn't seem to be the case with guinea pigs which I can testify can hear a fridge be opened from 50ft no matter the colour. Perhaps this is due to head markings, as dalmatian dogs with patches in the litter are considered a good sign not only for themselves but their littermates as well. Guinea pig breeds which rely on albinism related genes are often either required to have patches of colour on the nose and ears or have entirely coloured heads. It could also be related to the size of the guinea pigs. The little pigmentation available we'll be less thinly spread within the ear canal perhaps protecting from hearing issues however this does not explain why we do see it in ferrets whose skulls are generally about the same size. Perhaps the problem is simply that although we do associate deafness with markings it is only certain lines, ones that throw white markings inside the inner ear, that are deaf, and these lines just happen to be more prominent in ferret farms resulting in a kind of by proxy belief. If the deaf lines have more babies than the hearing lines people will see more deaf ferrets and assume it’s the markings not the lines. It will be interesting to see how Sandy's fare in BAER tests in the future especially those with eye colours like red, green and blue. This may provide better insight into if Sandy is related to albinism. It should be noted that albinism is not a guarantee that a ferret will be blind or deaf either. Some albinos with deafness are bad luck but if you’re seeing it consistently, I would be worried there’s a predisposition in the line.
What does BAER testing involve and what to look for in a technician
Through my research I have found that ferrets when put under anaesthetic can have hearing loss or a few days afterwards. For this reason, I would say it is incredibly important that those of us who truly wish to get an accurate reading of their ferret’s ability to hear will need to get there BEAR test done whilst it is fully conscious. This does require a technician who is experienced and competent as well as a good ferret handler in the owner, and ideally very friendly ferrets. If they do not hold still whilst the test is taking place you will not receive accurate results. The test itself is not harmful to the ferret, though rather annoying to them. It involves three probes being put into the skin around the skull one under each ear and one in the middle via needle and this being attached to the computer so the readings can be taken. The technician then plays a sound for the ferret via a headphone to first one ear then the next so that a separate reading can be taken for each ear. Upon hearing the sound in the headphone the ear automatically sends a signal to the brain, this is what hearing is. The signals through the nerves are transmitted via an electric current which the probes can pick up on and create a graph showing whether or not the ferret is hearing sounds and sending signals back to the brain. The standard test can only find if an animal is able to hear or not however there is slightly more advanced equipment that can be used to determine whether the hearing loss is complete or partial hearing as well as specific pitches that the animal can hear or not hear.
As for when to do the test I think it is important to consider what we are looking for. We want to know that the ferret can hear as an adult, and it is known for some breeds of dogs for example, to lose the hearing slowly over a period of time from approximately 6 weeks old to late puppyhood. we also know that they are born with their ears shut and the ferret has to be mature enough to hold still whilst the probes are in place for the test. We also need to hold into account that most people will be breeding their ferrets as yearlings, therefore must be known to be suitable for a breeding program before plans are made up generally between October and February for me personally I think that the best time to do this is around the time that we are looking to make or announce plans for the next year, because then if they're hearing as kits was to deteriorate it should already been noticeable and the ferrets should be mature enough to relax and allow the process to take place without trying to pull the probes out or at the very least relax and stay still enough that the owner/handler can control the impulse to remove them. Personally, I am more than happy to check the ferret hearing after this age, one of our boys Gilbert who is our first to get tested was done at approximately 2 years old the problem with waiting this long is that the ferret is more likely to have suffered some sort of hearing loss from an accident or an illness so you would not be getting a true idea of the genetic hearing ability of that ferret and of the line. You may think that the result is the same as the ferret will not be bred, but when it comes to trying to clean up lines you will want to know if hereditary deafness is seen in a litter at all, and “false” statistics can really muddy the water.
Additionally, although it would be ideal to test all the kits in a litter it is not financially viable for breeds like standards which are often sold for less than the costs of a BAER test. Nor is it likely that the ferrets will be mature enough to stop them from pulling out the probes at the time of rehoming. We could delay rehoming, but I would guesstimate that the ferret would need to be at least 4/5 months old before you would be able to guarantee that they would hold still for the test, and even then I think most of my ferrets would be in their pushing the boundaries stage and not cooperating. This means that they will have had to remain with the breeder until this age, meaning there will have been less one-on-one time with the kit and that the kit will not have had the opportunity to bond with their owner at a younger age. It also gives less time for the ferret to have naturally lost its hearing prematurely due to genetics, meaning that the test will not be as useful as it could otherwise be when we are looking at a breeding programme and eliminating any kind of hereditary deafness from our adults. In short it although it gives us less data, as we start to bring in health testing it is more important to focus on those in a breeding program. If there is concerns or a particularly high risk kit in a litter it is completely worth asking the new home if they would like to participate in the data set though. Lets say I’ve convinced you what should you be looking for? Well firstly you’ll be wanting someone with experience, not necessarily ferret since they’re not normally done yet, but someone who is used to doing puppies and kittens and qualified for the job. You’ll also want to check their machines are calibrated regularly so they are accurate and that they have the tiny puppy and kitten needles, which are a more appropriate size, especially for the girls. As with any service you should expect them to be insured as well. With the issues regarding anaesthetic and temporary deafness of ferrets you should specifically look for someone who does the BAER tests whilst fully conscious. Again, those who do tiny puppies and kittens are the ones most likely to do this regularly as in many dog breeds it is normal for pups to be BAER tested before rehoming at 8 weeks, and these tests are generally done at home whilst awake. You will need to have your ferrets microchipped, this will be used to identify the ferret on the health test certificate, and you should have the ferret under control. This includes handling and if necessary, distraction so some quite toy and/or some oil or other treats on hand would be wise.
For buyers and new homes
As a home should you expect your breeder to BAER test? Well, to be frank, not yet. At present I think only 4 or 5 breeders have seriously considered/ investigated it. To be brutally honest I know at least one of these breeders went in with the mentality of they did not want to and has been dissuading people from looking into it. The facts are though that this test costs about the same as a part angora or higher priced standard kit from a good breeder. How many kits are in the litter? How many litters does each ferret have? How much are these kits going for? I for one think that a one-off test for each breeding ferret is not excessive, even for someone like me who only breeds each ferret once or twice.
I have hopefully convinced you in this post that BAER testing is very worth it however and despite the answer being no I beseech you to ask every breeder if they are testing and if they say yes to show you the certificates. It is only by putting pressure on the breeders that this will become as normal in ferrets as it is in dogs and cats etc.
15 years ago we never wormed kits. 10 years ago we bred close without knowing. 5 years ago people laughed at you if you asked about a ferrets pedigree. Today we start health testing!