New Year, New Diseases? What to look out for…

diseases in 2017It’s always traditional at this time of year to look back at the previous year, and make some predictions about the one to come. 2016 was an… interesting… year in infectious diseases, and I think 2017 might be even more interesting.

I always think it’s strange how, as soon as the Christmas decorations come down, people start planning to go away on holiday. Perhaps, on second thoughts, it isn’t that odd – as I write this it’s snowing outside without being quite cold enough to settle, which makes this one of the most miserable months of the year! I mention it because there are a number of exotic nasties that we are increasingly seeing in the UK as a result of jet-setting dogs and cats. Sadly, some of these are now starting to be established here, and Brexit or no Brexit, we’re going to see more of them over the next few years.

At the same time, we’re developing some new diseases of our own here in the UK, and some older diseases out there haven’t gone away, but are still lurking in the shadows. So, I’m going to take a punt and make a guess at the the Big Five “exotic” diseases that I think we’re going to have to worry about in 2017. (This time in 2018, perhaps I’ll revisit the list and see how right, or wrong, I was!)

Babesia

This is a parasite that is carried by ticks, which infests the red blood cells of dogs, causing severe (often fatal) anaemia. Until 2016, there were no known native cases (all the dogs who were diagnosed with the disease had contracted it in Europe). However, as it is no longer a legal requirement for dogs to be treated for ticks before returning to the UK from Europe, it was only a matter of time before the parasite set up home here. In 2016, it was confirmed that a number of cases in Essex had been contracted in the UK. This condition is carried by the European Meadow Tick, Dermacentor reticulatus, which lives in the south east, south west England and parts of Wales. Now Babesia is here, it is unlikely to vanish again, and I think it will spread – the ticks will be carried by foxes and dogs to new areas, and we’ll start seeing cases further afield.

Bird Flu

Avian Influenza is always around, and normally we ignore it – because most strains aren’t terribly contagious, or dangerous. However, at the end of 2016, an aggressive and virulent strain of the H5N8 started spreading through wild and domestic birds in mainland Europe. A closely related strain has been associated with infection of humans in southeast Asia, although fortunately that particular variant hasn’t made it this far west. However, as a result, all poultry (commercial or pet) have been ordered into protective isolation by the Chief Vet, a situation that is likely to remain in force well into February, if not longer. Already, the virus is killing wild waterfowl and domestic poultry – we really can’t afford to have it established here. The hope is that, by the spring, the epidemic will die down as migratory birds move away, hopefully carrying the virus away with them – but if there’s one thing we can be certain of, it’s that Bird Flu will be back sooner or later.

Leishmania

This is a parasite transmitted primarily by sandflies in southern Europe and around the Mediterranean. The nasty thing about it is that it can lie dormant for months or even years before becoming active; once activated, it causes nodules to form in the skin, enlarged lymph nodes, and often weight loss, emaciation, and a wide range of multisystemic disease syndromes. It is often fatal if untreated; however, treatment is difficult and usually life-long.

Once an infected dog is in the UK, the current evidence (see references below) is that it CAN spread the disease to others even in the absence of sandflies (although this is very rare, and poorly understood) – through mating, blood (e.g. transfusions, and probably open bites or wounds), or possibly through local ticks or fleas. Although we don’t know exactly how many cases there were in 2016, it is highly likely that there will be more in 2017, as reports have been steadily increasing for several years now.

CRGV (“Alabama Rot”)

This is a really odd disease, and we still don’t know the cause. However, it seems to be here to stay, and is now being recognised across the country, far from its original “heartland” of the New Forest. The technical name is Cutaneous and Renal Glomerular Vasculopathy, but most people (sensibly enough) still refer to it as Alabama Rot – even though it probably is nothing to do with Alabama. It causes damage to the blood vessels in the legs and the kidneys, leading to ulcers on the skin of the dog’s legs and then kidney failure. Although a wide range of possible causes have been suggested, none of them have yet been confirmed, but it does seem to be concentrated in certain geographical areas. For more information, check out Anderson Moores Referrals, who are the vets with the most experience in this condition.

Distemper

OK, this one I’m really sticking my neck out with – I’ve been in practice 12 years and I’ve never seen a clinical case. However, I am genuinely worried that it might make a return. Distemper is a really nasty (and often fatal) disease of dogs that affects the gut, respiratory system, and sometimes nervous system and eyes too. For many years, it has been well controlled by some very effective vaccines. So why am I worried? Well, Distemper is very closely related to Measles – another disease well controlled by vaccination. However, like my medical colleagues are seeing human vaccination percentages fall, we’re seeing more and more people choosing not to vaccinate their dogs because of perceived health risks. Sooner or later, the percentage of vaccinated dogs is going to fall below the “herd immunity” level, and we’re going to get an outbreak. When people have seen what this disease does, we might get an upsurge in vaccination – but I hope we don’t have to lose a lot of pets before that happens.

So, what can you do to protect your animals this year?

Simple –

  1. Monitor their health carefully and get them checked out by your vet if they seem ill.
  2. Make sure you stay up to date with preventative medicines such as wormers, flea and tick treatments, and vaccines.
  3. If you’re going abroad, talk to your vet for health advice first.

That said, I would be very pleased to be proven wrong – here’s hoping!

Happy New Year,

David Harris and all at VetHelpDirect

 

References:

There’s a really nice description on the American CDC website, explaining the role (and importance) of dog-to-dog Leishmania transmission in the USA: https://wwwnc.cdc.gov/eid/article/12/3/05-0811_article

Owens, SD et al (2001), “Transmission of visceral leishmaniasis through blood transfusions from infected English foxhounds to anemic dogs” J Am Vet Med Assoc. 2001, 219(8):1078-83; see https://www.ncbi.nlm.nih.gov/pubmed/11700704

Nauucke, TJ & Lorentz, S (2012), “First report of venereal and vertical transmission of canine leishmaniosis from naturally infected dogs in Germany”, Parasit Vectors 5:6 (available at https://parasitesandvectors.biomedcentral.com/articles/10.1186/1756-3305-5-67

Naucke, TH, Amelung, S, and Lorentz, S (2016), “First report of transmission of canine leishmaniosis through bite wounds from a naturally infected dog in Germany”, Parasit Vectors 9: 256 (see https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4862214/)

http://www.langfordvets.co.uk/diagnostic-laboratories/services/mdu-pcr-acarus/list-acarus-tests/diseases-transmitted-sand-flies

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11 thoughts on “New Year, New Diseases? What to look out for…

  1. Please can you link me to the studies showing leishmania can be transmitted dog to dog without the sandfly vector. Is this based on scientific or anecdotal evidence?

    1. There’s quite a lot of scientific published evidence for this now – the highlights are:

      There is both experimental and clinical evidence of transmission via blood transfusion (Owens, SD et al (2001), “Transmission of visceral leishmaniasis through blood transfusions from infected English foxhounds to anemic dogs” J Am Vet Med Assoc. 2001, 219(8):1078-83; see https://www.ncbi.nlm.nih.gov/pubmed/11700704)

      There are a number of case reports of venereal and vertical (from mother to puppy) transmission, this is probably the most detailed available without an academic login: Nauucke, TJ & Lorentz, S (2012), “First report of venereal and vertical transmission of canine leishmaniosis from naturally infected dogs in Germany”, Parasit Vectors 5:67 (see https://parasitesandvectors.biomedcentral.com/articles/10.1186/1756-3305-5-67)

      And there are now a number of well described cases where direct transmission has occurred from dog to dog that are believed to have resulted from bite wounds (typically the uninfected dog biting an infected one) –
      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4862214/
      https://www.ncbi.nlm.nih.gov/pubmed/25492266/
      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4766704/

      There’s a really nice description on the American CDC website too, explaining the role (and importance) of dog-to-dog transmission in the USA: https://wwwnc.cdc.gov/eid/article/12/3/05-0811_article

      I hope that helps!

      David

  2. The leish stuff is wrong. Although it is theoretically possible to pass leish from dog to dog without a sandfly, I’ve never heard of a single case of that happening, have you?

    If caught early in our experience leish is easily controlled with Allopurinol – our leish dogs have died in old age of other causes.

    1. If you’d asked me 5 or 10 years ago, I would have agreed entirely with you. However, our understanding of the disease has moved on in recent years (although I agree it is frustrating how poor it still is).

      To answer your key points:
      There is both experimental and clinical evidence of transmission via blood transfusion (Owens, SD et al (2001), “Transmission of visceral leishmaniasis through blood transfusions from infected English foxhounds to anemic dogs” J Am Vet Med Assoc. 2001, 219(8):1078-83; see https://www.ncbi.nlm.nih.gov/pubmed/11700704)

      There are a number of case reports of venereal and vertical (from mother to puppy) transmission, this is probably the most detailed available without an academic login: Nauucke, TJ & Lorentz, S (2012), “First report of venereal and vertical transmission of canine leishmaniosis from naturally infected dogs in Germany”, Parasit Vectors 5:67 (see https://parasitesandvectors.biomedcentral.com/articles/10.1186/1756-3305-5-67)

      And there are now a number of well described cases where direct transmission has occurred from dog to dog that are believed to have resulted from bite wounds (typically the uninfected dog biting an infected one) –
      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4862214/
      https://www.ncbi.nlm.nih.gov/pubmed/25492266/
      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4766704/

      There’s a really nice description on the American CDC website too, explaining the role (and importance) of dog-to-dog transmission in the USA: https://wwwnc.cdc.gov/eid/article/12/3/05-0811_article

      Regarding treatment, allopurinol alone is relatively safe, but isn’t very effective in managing active infections (although I agree it’s good for keeping the infection suppressed long-term). Treatment is difficult for two reasons. Firstly, there are no drugs licensed in the UK for treating this condition, which is a significant legal barrier (yes, it is possible to get an SIC to import them from Spain and I have done this, but it isn’t always straightforward); and secondly, it is not a curable condition. It is manageable, but not curable, and there can be flare ups and sometimes complications from the meds (I would likewise describe diabetes mellitus as a “difficult” disease to treat, for the same reason). There’s a good breakdown of common drug combinations and known side effects here http://www.langfordvets.co.uk/diagnostic-laboratories/services/mdu-pcr-acarus/list-acarus-tests/diseases-transmitted-sand-flies

      For the record, I wasn’t trying to say it was incurable, but to give a very quick 150 word summary as to why I felt the condition deserved to be on my list of nasties! In view of the amount of interest, I have enlarged the section in the original blog to incorporate a little more detail, so thank you very much for your interest; I hope this helps.

  3. I really think you need to read up and learn more about leishmaniose. It does NOT spread without the sandfly! It does NOT spread if a infected dog bites!
    Doesnt help to have a veterinary title if you dont know the disease you are talking about. Please check your facts before writing in public.

    1. If you’d asked me 5 or 10 years ago, I would have agreed entirely with you. However, our understanding of the disease has moved on in recent years (although I agree it is frustrating how poor it still is).

      However, I believe there is now sufficient clinical and academic evidence that it CAN spread without the presence of Sandflies (I’m not saying it necessarily will, just that it can):

      1) There is both experimental and clinical evidence of transmission via blood transfusion (Owens, SD et al (2001), “Transmission of visceral leishmaniasis through blood transfusions from infected English foxhounds to anemic dogs” J Am Vet Med Assoc. 2001, 219(8):1078-83; see https://www.ncbi.nlm.nih.gov/pubmed/11700704)

      2) There are a number of case reports of venereal and vertical (from mother to puppy) transmission, this is probably the most detailed available without an academic login: Nauucke, TJ & Lorentz, S (2012), “First report of venereal and vertical transmission of canine leishmaniosis from naturally infected dogs in Germany”, Parasit Vectors 5:67 (see https://parasitesandvectors.biomedcentral.com/articles/10.1186/1756-3305-5-67)

      3) Most worrying of all, there are now a number of well described cases where direct transmission has occurred from dog to dog that are believed to have resulted from bite wounds (typically the uninfected dog biting an infected one) –
      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4862214/
      https://www.ncbi.nlm.nih.gov/pubmed/25492266/
      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4766704/

      Are there other possible explanations? Yes, but I think the evidence base is sound enough to say that, in rare cases, Leishmania can be transmitted from dog to dog without the need for sandflies.

      Many thanks for your comment, it’s always nice for us to be kept on our toes!

      David

  4. Sorry – but you’re wrong about Leishmania. It can’t be spread without the sandfly – there is no recorded evidence of this. I have two Cyprus rescues – one’s healthy and the second – which I adopted three years ago – has Leish. She was treated in Cyprus with Milteforan when she was very sick with it, and then was on Allopurinol for a couple of years. Since I adopted her, her titre levels (IFAT) have come down to 1/50 and after three successive blood results at that level we took her off the Allopurinol and she hasn’t taken any meds for 18 months. I test her 6 monthly for bloods+biochem, IFAT, Urinalysis and Serum Protein Electrophoresis (which is the most important test because it shows whether there is any active Leish). I have no worries that my other dog will catch it. I know there is a possibility that my Leish dog could have a relapse – but three years in so far, so good. And if she does will treat her with the Milteforan. Am very careful that I feed her the correct foods (no offal, red meats, oily fish and certain restricted veg). They can live a normal life and many go on for years quite happily on just their twice daily dose of Allopurinol. I live in London and have a very sympathetic, knowledgeable and open minded vet. Quite willing to answer any questions you may have.

    1. If you’d asked me 5 or 10 years ago, I would have agreed entirely with you. However, our understanding of the disease has moved on in recent years (although I agree it is frustrating how poor it still is).
      There is both experimental and clinical evidence of transmission via blood transfusion (Owens, SD et al (2001), “Transmission of visceral leishmaniasis through blood transfusions from infected English foxhounds to anemic dogs” J Am Vet Med Assoc. 2001, 219(8):1078-83; see https://www.ncbi.nlm.nih.gov/pubmed/11700704)
      There are a number of case reports of venereal and vertical (from mother to puppy) transmission, this is probably the most detailed available without an academic login: Nauucke, TJ & Lorentz, S (2012), “First report of venereal and vertical transmission of canine leishmaniosis from naturally infected dogs in Germany”, Parasit Vectors 5:67 (see https://parasitesandvectors.biomedcentral.com/articles/10.1186/1756-3305-5-67)

      And there are now a number of well described cases where direct transmission has occurred from dog to dog that are believed to have resulted from bite wounds (typically the uninfected dog biting an infected one) –
      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4862214/
      https://www.ncbi.nlm.nih.gov/pubmed/25492266/
      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4766704/

      Regarding treatment, it is difficult for two reasons. Firstly, there are no drugs licensed in the UK for treating this condition, which is a significant legal barrier (yes, it is possible to get an SIC to import them from Spain and I have done this, but it isn’t always straightforward); and secondly, it is not a curable condition. It is manageable, but not curable, and there can be flare ups and sometimes complications from the med (I would likewise describe diabetes mellitus as a “difficult” disease to treat, for the same reason).

      For the record, I wasn’t trying to say it was incurable, but to give a very quick 150 word summary as to why I felt the condition deserved to be on my list of nasties! In view of the amount of interest, I have enlarged the section in the original blog to incorporate a little more detail, so thank you very much for your interest; I hope this helps.

      David

      1. Thanks for this reply – haven’t had a chance to look at all the links yet but just have a couple of comments. Firstly, you state that it is possible for a dog that has never been out of the uk to contract this disease – do you have, or know of, one case of this happening? Also, I am aware that it’s not curable, but in many cases it is successfully manageable and dogs can live a long and happy life. When I first got my dog a uk vet that I approached said that he would have to be careful if he ever had to operate on my dog because of transmission via blood! The vet’s in Cyprus say not one of them has ever contracted Leish yet and they’re doing this all the time. Also, much as Langford Vet’s information is very helpful, they still say that the Serum Protein Electrophoresis test is optional, whereas vets in endemic areas say that it is very important, because it shows whether there is any active Leish. We are told that the titre test is secondary. I do rather think that many UK vets obviously have no practical knowledge of Leish because they rarely see it, and totally frighten prospective adopters without the proper knowledge to back up their opinion. How much time is spent on the subject during veterinary training? It is a serious illness and anybody adopting a dog with this disease needs to consider the matter carefully, not least because the cost of the six monthly blood tests etc. is much higher here than abroad and that is a consideration. I don’t question your knowledge or concern about the disease, but I do think that there is a tendency amongst some UK vets to be totally negative and to create a fear of it that perhaps isn’t justified. Will read the above with interest.

        1. Although I haven’t found any published evidence of dogs in the UK developing the condition without going into an endemic area, there are well documented cases from Germany (in a non-endemic area), Finland and New Caledonia (with very similar risk factors to UK dogs) developing confirmed cases despite never having left their home areas. In all the cases I’m aware of, they had had direct contact with a known carrier dog (there’s even a report of a cat that seroconverted after a Leish+ dog was introduced into the house!).
          I do agree though that this is a poorly understood disease. When I was in Vet School, we were taught this was an exotic disease that we were unlikely ever to see – although we did spend an inordinate amount of time studying it’s pathology for some reason! However, even in the rural South West I’ve come across cases, so I don’t think we can call it a rare exotic any more.
          I wrote this post for that very reason – people need to be more familiar with it, but not to let familiarity breed contempt. It is potentially a very nasty condition (especially the visceral form), and most people only ever see the more common, relatively mild, cutaneous version of the disease. To be honest, the blog isn’t really aimed at people who are familiar with the condition (like yourself), but those who might ignore the clinical signs and come to grief.

  5. OK, a few comments about Leishmania. It is true that 99.9+% of cases involve sandflies, and I’m well aware of that. When I started writing this article, I was also of the opinion that no sandfly = no Leishmania. However, when I started researching the subject, I found that there had been enough reliably reported incidents of transmission in the absence of these insect vectors that other possibilities needed investigating.

    1) Blood-blood transmission has been demonstrated and is generally now accepted (the original paper is Owens, SD et al (2001), “Transmission of visceral leishmaniasis through blood transfusions from infected English foxhounds to anemic dogs” J Am Vet Med Assoc. 2001, 219(8):1078-83; see https://www.ncbi.nlm.nih.gov/pubmed/11700704). If a disease can be transmitted via blood to blood contact, then it can be transmitted through bite wounds – although I agree it is highly unlikely, I consider that this is a possibility that’s worth considering.

    2) Horizontal transmission via mating is also documented, as is vertical transmission from a bitch to her puppies: Nauucke, TJ & Lorentz, S (2012), “First report of venereal and vertical transmission of canine leishmaniosis from naturally infected dogs in Germany”, Parasit Vectors 5:6 (available at https://parasitesandvectors.biomedcentral.com/articles/10.1186/1756-3305-5-67; this article discusses the evidence in some detail and refers to a number of similar case reports in the published literature).

    3) Regarding the possibility of other vectors transmitting the disease, it is not a certainty, but has been suggested as a possible route of infection for dogs where no other cause is known, so I included it as a possibility.

    When I described treatment as being difficult, I was not trying to frighten people, but to describe the fact that there is no legally licensed treatment in the UK for this condition; nor is there any curative treatment. I would likewise describe the treatment for diabetes mellitus to be “difficult” in dogs, and yet this is also a manageable condition.

    There is a good summary of the current knowledge of the disease’s transmission and treatment here: http://www.langfordvets.co.uk/diagnostic-laboratories/services/mdu-pcr-acarus/list-acarus-tests/diseases-transmitted-sand-flies

    This is still a poorly understood disease, and I could have written a great deal more about it; however, contrary to popular opinion, it IS possible for a dog who has never been outside of the UK to contract this condition, and that is something I wanted to raise awareness of. After all, it’s happened in the sandfly-free regions of the USA and in Germany, so there is absolutely no reason it cannot happen here.

    So, should you panic? No, of course not. Should you exercise caution, however, especially when taking your dogs abroad? Yes, I would strongly advise that you do.

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