Tag Archives: health

Affordable Genome Sequencing

Nanopore technology

Okay, so not the most exciting of blog post titles but hear me out because this is some pretty amazing technology that I am about to talk about here…

Imagine a day when it will be possible to pick up a small, handheld device and with it rapidly and reliably sequence your entire genetic code, or even that of your favourite pet. “To what end?” I hear you say. Well, the promise of personalised medicine is one that has been on the horizon for many years and the technology that one Oxford company and team of researchers is engaging in is casting some light on the very exciting future that we may be facing. The principle of personalised medicine, as I understand it, is to use the information that is unique to you, ie your DNA, or genetic code, in order to identify the risks of you developing certain conditions or diseases and either specifically intervening to halt or manage such eventualities or, in the case of a disease state developing, such as cancer, using both your own genetic blueprint and that of the disease causing entity in order to select, or even design, tailored, targeted and ultimately more effective and reliable treatments. The prospect of being able to take a cancer cell, sequencing it’s DNA and identifying which drugs are most likely to be highly effective at eradicating the tumour, whilst drastically reducing, or possibly even eliminating, side-effects is one that is simply too important to ignore. But how could this be possible?

One company based in Oxford, and borne out of the research efforts of Professor Hagan Bailey of Oxford University, is leading the field in the development and application of nanopore technology to sequence individual molecules, such as DNA, and determine their exact composition. This is achieved through the use of a specially engineered protein nanopore set into a layer, either of lipid (like our own cells), or a synthetic material, such as graphene, and through which a molecule such as DNA is passed. This is a little like a train passing through a mountain by way of a tunnel. The really clever part is the way this apparently simple process of passing the DNA through the pore can sequence the strand and tell us the exact order of bases.

Nanopore DNA sequencing
Nanopore in membrane

A current flows through the layer containing the nanopore and the passing of the DNA molecule causes disruptions in the current flow, with specific, characteristic disruptions attributable to each of the four bases making up the DNA sequence. By recording these unique current disruptions the technology is able to identify the bases and the exact order in which

Nanopore DNA sequencing
DNA strand passing through nanopore

they pass through the pore, and thus sit within the DNA strand. In other words, it is possible to sequence DNA in real-time. Very exciting!

What about veterinary applications? Of course the main uses of this promising new technology would be expected to be applied in human medicine initially but it is highly likely that veterinarians will be able to make use of it as well. Potential applications obviously include veterinary research, disease monitoring, therapeutic uses, such as treatment selections in cases of disease states such as cancer, and much more besides. Rapid and reliable ‘kennel-side’ analysis using a simple handheld device like the one alluded to in the opening paragraph may very well be a reality in the not too distant future. Exciting times indeed!

For more information on Oxford Nanopore Technology and their exciting work visit their website at www.nanoporetech.com.

This is a good blog by someone who really knows what they’re talking about – a real life geneticist. Click here to read.

Pet Blood Bank – Great to get involved

Chris the Nerdy Vet with Joseph, a proud pet blood donor
Me with a happy blood donor, Joseph the dog

I had the pleasure on Sunday of being involved in an official capacity with the Pet Blood Bank, a fantastic UK charity that collects blood from volunteer dogs, with the blood then being processed into packed red cells and plasma, which is then made available to vets around the country for use in emergency situations and for major surgeries.

The organisation was fantastic with the session overseen and administered by a fantastic team from the Pet Blood Bank HQ based in Loughborough. The whole day was relaxed – for donor dogs, owners, and even vets! My role, as an official vet, was to health check the donors, including taking pre-screening blood samples, and to decide whether, in my professional opinion, the dogs could indeed go through to donate. Every dog I saw was an absolute picture of health, and so well behaved, that the entire day just seemed to whiz by in a happy, healthy blur of activity. The criteria for dogs to donate is quite strict, and rightly so, with dogs having to meet the following criteria:

  • be aged between one and eight years old
  • weigh more than 25kg
  • have a good temperament
  • never have travelled abroad
  • be up to date on all vaccinations, and not have been vaccinated within the last two weeks
  • be fit and healthy
  • not be on any medication, other than routine flea and worm control

Before the dogs can donate they have a blood sample taken, and their packed cell volume (PCV), which is the percentage of the blood that is made up of red blood cells, and total protein (TP) are measured. If they are both within certain healthy limits then they can be cleared for donation. Every dog I saw passed with flying colours! Each dog then donates 1 unit of blood, which is equivalent to about 450ml of blood, and the actual donation stage only takes about 5-10 minutes. The great thing is that every dog then gets to tuck into some tasty food – the equivalent, I guess, of our ‘tea and biscuit’ – after their session and gets a goody bag, complete with toy, to say a huge thank you for their donation.

The great thing is that the blood that is donated goes to help vets save lives in real practice – something that as an emergency vet myself, I have been involved in first hand. Donor blood truly does save lives! The wonderful thing was that the day saw experienced, repeat donors turn up as well as dogs and owners for whom this was their very first experience, and everyone had a good time doing something worthwhile.

If you would like to find out more about the work of the Pet Blood Bank, including how to get involve yourself, then click here to visit the Pet Blood Bank website.

Aortic thrombo-Embolism in cats – a tragic condition

I had the tragic task of dealing with a case of aortic thrombo-embolism in the emergency clinic at the weekend, in a beautiful cat who had been presented by her owner after suddenly going off her back-legs.

This condition, which results in a blood clot forming and blocking the major blood vessels to the legs – most usually at the point where the body’s main artery, the aorta, branches to supply the hindlimbs – results in cat suddenly losing the use of their back legs, with the legs often feeling cold to the touch and with the absence of any normal sensation. This was confirmed when I performed a test to see whether there was any blood flow to the back legs by making a small needle impression in the pads (which normally results in a small spot of blood, as you would get if you pricked your finger with a needle) and by cutting the nail back past the quick, which is the equivalent of the very tip of our fingers and usually results in bleeding. The absence of any blood after both these tests confirmed the diagnosis and as a result the decision was made to put the cat to sleep.

There can be many reasons for such a clot to form in cats, with the most common reason being an underlying heart condition which if left undiagnosed and untreated can result in abnormal blood flow and potentially a clot forming, with some devastating and sudden effects. It is therefore important to ensure that you take your cat to the vet for regular check-ups, which will include the vet listening to their heart. Sometimes, however, as in the case yesterday, there is no apparent reason and it it just makes the situation that much more tragic.

Click here to read some more information about emergency situations with cats.

Caesarian Companion

Over the Christmas period I found myself performing a caesarian section on a Pug, with the result being four healthy young pups. Thankfully the anaesthetic was stable and we had more than one nurse who was able to step in and help to receive and revive the puppies as I delivered them. It did, however, get me thinking about those situations where you might find yourself with just you, the surgeon, and one nurse – a common situation in out-of-hours (OOH) emergency work. What would happen if the anaesthetic was unstable or there were simply more puppies than the nurse could manage on their own?

Rough sketch for 'Caesarian Companion'

The idea for the Caesarian Companion thus came to mind. The principle is that the surgeon can drop the newly delivered puppy/ kitten into one of the flexible ‘slings’ (flexible and clear to allow easy breathing, be comfortable and enable close visual monitoring), which can be detached, replaced and even come in different sizes, depending on the expected size of the delivered babies. The slings could be suspended within a frame that is gently vibrating to encourage tactile stimulation of the new pup/ kittens, with their heads poking out of the end into a chamber delivering the optimal amount of oxygen. The chamber would be heated to keep the puppies warm and made out of a clear, easily cleaned material to maximise hygiene. The idea behind carefully suspending and ‘agitating’ the newborns is to help any fluid that may be present on their chests to drain and to gently stimulate the newborns to start breathing on their own. Once suitably awake and when the nurse, or other staff member, is free then the newborns could be removed and transferred to a standard heated incubator, with the Caesarian Companion potentially doubling as one, with the newborns being placed on a heated, padded mat inside.

NB: This is simply an idea & the design is certainly not complete. Please feel free to comment/ suggest changes/ improvements.

Kennel Cough – more like ‘Doggy Common Cold’

Its the time of year again when we see lots of coughing dogs and, as a result, lots of anxious owners. The signs of Kennel Cough, which is simply a blanket term used to describe an upper respiratory infection, are typically a dry, hacking cough, which can sound like they have something stuck in their throat and can cause such frenzied coughing as to make your dog actually vomit. Gently pinching the dog’s windpipe (trachea) can often elicit a cough and this is what vets call the ‘tracheal pinch test.’ If the infection, which is usually a mixed infection caused by a cocktail of viruses and bacteria, is mild then a low grade cough may be the only feature and they will usually recover within about 1-2 weeks. Some cases can be more severe, however, and may require antibiotics and/ or antiinflammatories. The key signs that antibiotics are required are if your dog is hacking up phlegm, or has a nasal discharge, or has a really rattling cough – the kind that you would have with a nasty chest infection.

The best way of thinking of Kennel Cough is more like the ‘Doggy Common Cold,’ and the name is really an historical reference to the fact that we tended to see more cases in kenneled dogs as a result of lots of different dogs coming together and sharing the same airspace. This is very much like the situation when students all return to university and we see outbreaks of ‘Freshers Flu.’

There are Kennel Cough vaccines, which are given up the nose by your vet, and your dog’s annual vaccination actually already provides immunity to one common respiratory virus. The nasal vaccine is not, however, 100% protective and your dog can still pick up an infection, again, due in large part to the fact that the signs are caused by lots of different infectious agents and not simply by the few that are included as part of the vaccine.

So, if your dog has recently developed a cough then maybe, just maybe, they have picked up a spot of ‘Doggy Common Cold.’