First, do no harm. Second, try doing nothing?

"The art of medicine consists of amusing the patient while nature cures the disease."

I've come across this quote in a number of different places, though usually it's talking about human medicine, rather than veterinary. It's widely attributed to Voltaire, though WikiQuote suggests that this is misplaced, and it was actually written by Ben Johnson, playwright and contemporary/rival of Shakespeare.

Regardless, as a vet student, I certainly would have been affronted to read this. How dare it be suggested that medicine could not cure all ills? Is it not the noblest of sciences, the highest of pursuits, wherein man (or woman, in the case of most vets) strives against the harshness of nature to achieve a perfect, disease-free utopia?

A few years in the real world will do wonders. Since getting in to practice, I’ll happily concede that the author of that quote does has a (partial) point. Many of the ailments I see as a GP vet will heal by themselves, given time and a little TLC. Of course I also see pets who would die or suffer tremendously if not treated, and sadly a small minority who have already gone through this before they're brought to me. But there's still a significant number of cases I see where, if I suggest that the owner does nothing, the pet will still get better.

This can be a hard lesson to learn for newly graduated vets. We’ve spent the last five to six years learning how to treat animals, and we’re desperate to get out there and heal all the sick and needy creatures that come through our doors. Recognising those cases that can do without your magical healing elixirs is one of the first great lessons to learn in practice. The second, which follows on quite swiftly, is how to persuade an anxious owner that their sick pet doesn’t need any medication. In much the same way that human GPs may be pressured into prescribing antibiotics for sore throats when they're not needed, veterinary GPs can face significant pressure to "do something!" in the face of illness. When that illness is infection, people tend to want antibiotics.

Let Coughing Dogs Lie

Theory is all very well; let's try an example. Just like humans, coughs and colds are a common problem in cats and dogs. In dogs this is colloquially known as "kennel cough", and in cats, "cat flu". Dogs normally get a cough, which can be quite spectacular, and may come in bouts that can go on for several minutes at a time. Sneezing is also common, either dry or accompanied by varying quantities of snot. Cats don't tend to cough, instead preferring to go full-tilt for the sneezing, often with a bit of a mucus-y discharge from the nose and eyes. Both cats and dogs may also be a bit quiet and withdrawn, and a bit less keen on their food; I find this is more common with cats, probably because the stuffed-up nose means they can't smell their food, and it loses its appeal.

Saying a dog has kennel cough is a bit like saying a human has a cold - it's not one single virus or bacterium, but a collection of different ones that cause the symptoms. The story is much the same in cats. Viruses, as I hope you're aware, cannot be treated with antibiotics. Bacteria can, of course, but do they need to be? Current thinking is - often not.

The International Society for Companion Animal Infectious Diseases (ISCAID) has produced a set of guidelines, written by world leaders in the field, on treatment of respiratory infections in cats and dogs. In these guidelines, the authors recommend not to use antibiotics unless the patient has had symptoms for longer than ten days. There are a few exceptions, such as if the patient is getting worse after 5-7 days, or seem unusually unwell, but in general the advice is that it's best to just wait it out. Personally, I would say this agrees with my experience - the vast majority of my patients will pick up in that time without needing antibiotics. The ten-day wait is actually less than current recommendations in human medicine; acute sinus infections (which have similar symptoms to cat flu) should not be treated with antibiotics unless the symptoms have been going on for three weeks, and for similar reasons - most of the time, they just aren't needed.

In the consulting room, this is my go-to thing to discuss when my clients ask about antibiotics for a cough or cold. Usually, most of them are happy not to go for antibiotics, but occasionally I will still hear something along these lines:

"She's got an infection! You said it could be bacteria, you can treat that. What's the harm in giving her some anyway?"

Good question. Let's think about it a bit.

The benefits of Laissez-Faire

Why does your vet make you wait those ten days, forced to watch are pet cough and sneeze and splutter?

First and foremost it's because, as Voltaire (or whoever it was) observed, most patients will get better by themselves. There's no need for antibiotics in the vast majority of cases. But let's play devil's advocate for a minute - there are still a few dogs and cats who will go on to need antibiotics. It's not always possible to tell at the beginning of the illness which pets they are. So why not give out antibiotics to all pets just in case? Or at least, be a bit more liberal with them? Give them after five days, not ten? Or to all older pets, as a precaution? Or if my pet's needed them before, shouldn't I be able to get them earlier if they get sick again?

The answer to this question comes in two parts - we don't like giving our patients unnecessary drugs in any circumstances, and we especially don't like using antibiotics when they're not needed.

The Wider Benefits

We'll look at the second half of that answer first. The most well-know harm that unnecessarily using antibiotics can do is to contribute to the development of antibiotic resistance. This is by far the most important reason why we shouldn't be over-using antibiotics, but as an argument I don't find it packs much of a punch in my consulting room. People often think of antibiotic resistance as a theoretical, far-off problem, something that researchers and statisticians and governments should be thinking about, not something that affects us in our everyday life. This might be a more comforting way to think about it, but we've all had a timely reminder in COVID-19 that wider public health issues can have very real and serious effects in our day-to-day lives. If the next pandemic is caused by antibiotic-resistant bacteria, life will get a whole lot more unpleasant for humans and pet.

This isn't something I want to dwell on a length here because it's not really the point of this post - it's a unique thing we only consider when contemplating antibiotic vs. no antibiotic, rather than treatment vs. no treatment - but it's such an important issue it should never go unsaid.

The Personal Benefits

The other big benefit of not treating - and something that is often forgotten - is that your pet will avoid any side-effects from the antibiotics. Often this isn't something that's talked about in the consulting room, mostly because antibiotics are viewed as being pretty safe drugs - and in fairness, they are. But they are drugs, and all drugs have side-effects. If someone - vet or otherwise - tells you a medication is free from side-effects, be very suspicious. It's more likely that either they're mistaken, or that the "drug" does nothing at all; biological bodies are messy things, and it's almost impossible to have an effect without a side-effect.

The ISCAID guidelines recommend doxycycline as the first-line treatment for both dogs and cats. It's a commonly-used antibiotic, and it's particularly good here because it kills all the common bacteria we see with kennel cough or cat flu, including a type called Mycoplasma that a lot of other common antibiotics don't treat.

So what harm can a common antibiotic do? Well, the BSAVA formulary (which is the standard reference book on drugs for UK vets) mentions the following side-effects for doxycycline:

• Nausea

• Vomiting

• Diarrhoea

• Oesophagitis (inflammation of the oesophagus, or food pipe)

• Discolouration of teeth in growing animals

The first three are side-effects seen with almost any antibiotic, though for varying reasons; in the case of doxycycline, it's slightly acidic when dissolved, which can irritate the stomach lining and cause the nausea and vomiting. The diarrhoea may be related to this, or it can be as a result of the antibiotic's effect on the bacteria in your pet's gut.

Data from dogs suggests that nearly one in five will vomit when on doxycycline; diarrhoea and anorexia (refusing to eat) seem to be less common, at 1 in 14 and 1 in 40, respectively. A smaller and somewhat more dubious study in cats found that around 1 in 8 developed vomiting, 1 in 9 developed diarrhoea, and 1 in 16 developed anorexia. Around 1 in 14 cats also developed a fever after starting treatment that; this has been reported elsewhere too, and for various reasons is thought to be due to the doxycycline itself, rather that just the infection that it's treating. To put these numbers in perspective, this means that vomiting in dogs, and vomiting and diarrhoea in cats, would be considered "very common"; the others would simply be considered "common".

Oesophagitis is also caused by the acidic nature of doxycycline. Sometimes, especially when tablets are swallowed on their own or with only a little food, they can briefly get stuck in the oesophagus before passing down into the stomach. If the drug is acidic, it may irritate and inflames the lining of the oesophagus. This can sometimes cause scarring, meaning the oesophagus becomes narrow and unable to stretch - an "oesophageal stricture". Depending on the size of the stricture, this can then make it very difficult or even impossible for the pet to swallow food properly. Treatment is available (something called "balloon dilation") but is quite intensive and not always successful.

Thankfully, this seems to be very rare - the two studies I mentioned above looked at 386 dogs and 168 cats, and none of them were reported to have had this issue. There are several published reports of this happening, and all of them involve cats, not dogs. We can't say from this that it never happens in dogs, but we can guess that it's more common in cats.

Listing all the side-effects of a drug is a great way to put someone off taking it. If you think these are bad, why not go read the label for the paracetamol or ibuprofen you've probably got in your cupboard? Liver failure, heart attacks, kidney failure, strokes, blood clotting problems... there's been far more research done on these drugs in humans than any medication in pets, so we know more about what can happen, but it makes for alarming reading.

Doxycycline isn't especially dangerous - all of these side-effects are also seen with other common antibiotics. Other side-effects from less commonly-used antibiotics include cause kidney failure, fatal bone marrow suppression or blindness. But these are still risks, and shouldn't be discounted or ignored. Antibiotics are powerful, useful drugs in the right circumstances, but there are potential consequences to using them.

The bottom line is this: If your vet has examined your pet and recommended to be treat with antibiotics, then you're unlikely to do your pet any favours by trying to pressure your vet to prescribe them. On the flip side, if your vet has prescribed your pet doxycycline (or any other antibiotics), it's because they've weighed up the risks that I've just talked about above against the benefits of the treatment, and think that it's the right call. If you're worried, talk it through with them. They should be able to tell you why they've decided it's necessary to prescribe them; just ask!

How about some Lemsip instead?

Of course, just because your vet isn't going to prescribe antibiotics, doesn't mean there isn't anything else that they can do. There are several other types of medication out there that may be helpful in these kind of situations.

You vet can prescribe you various things that may help with the symptoms; the most common would probably be anti-inflammatories like meloxicam, cough suppressors like codeine, or decongestants of various sorts. This is what vets call "supportive care" - we're not trying to treat the illness itself, just to ease the symptoms whilst the body does the rest.

These types of treatment are all common, but the direct evidence for using them in kennel cough is actually pretty thin. For example, I often give my patients anti-inflammatories when they have a cough. It's basically the equivalent of taking ibuprofen when you have a cold (but please don't give your pet ibuprofen), and the idea is that it relieves some of the pain, swelling and irritation around the nose and throat.

We know that these drugs work in pets, and are useful to treat other conditions that cause pain and swelling, but we don't actually know how effective they are at relieving the symptoms of a cough or cold. They probably are - there's good reasons to think so, and anecdotally it seems to help - but we don't have the direct evidence to know for sure.

So should we be using them at all? That's a judgement that you and your vet have to make, and for me, it's on a case-by-case basis. For example, if my patient is otherwise healthy and looks miserable then I'll usually recommend them; if the symptoms are very mild, or the patient is known to have a very sensitive stomach (anti-inflammatories can cause vomiting or diarrhoea), then I probably wouldn't.

And lastly - of course - please don't actually give your pets Lemsip! Many human cough and cold medicines (of all kinds) are poisonous to cats and dogs, which is the last thing they need when they're already feeling sick.

The Broader Point

Coughs and colds aren't the only illnesses that will get better without my knight-in-shining-armor act. There are a good few other examples; often, it's illness that have come on quickly, but aren't that severe.

For example, acute (sudden-onset) diarrhoea will often settle by itself, and there's good evidence in dogs that antibiotics are almost always never needed, even if there's some blood in the stool.

Another common type of treatment will speed up how quickly your dog improves, and may make it less likely they need further treatment, but the majority of dogs will still heal by themselves.

Mild limps are often similar to our equivalent of a sprained ankle; painkillers are available and may make your pet more comfortable, but this must always be balanced against the side-effects (Common: vomiting, diarrhoea. Rare: stomach ulcers, kidney failure).

These are the simplest examples, but there are many others; even illnesses that have gone on for a while may suddenly resolve in spite of, rather than because of, a vet's treatment.

Does this mean you should just skip the trip to the vets? Often not. The part of this we haven't talked about is that, whilst coughing dogs commonly have kennel cough, it could be something else. This could be as benign as a hoarse voice from barking too much, or something more sinister like lungworm, an inhaled grass seed or even, yes, some kinds of cancer.

Of course, diseases like cancer are much less likely, but they are possible. For almost all of these diseases, the sooner we find them, the better chance we have of being able to treat them.If you have a gut feeling something is wrong, always err on the side of caution and get your vet take a look.

And remember - you're the expert on how your pet is at home. You spend far more time with them than we as vets do, and you're much more likely to pick up when something's wrong. Your vet's job is to listen, to examine your pet, and then to pull that all together and come up with a plan. And, just sometimes, your vet's plan might be to do nothing.