Don't assume that the "preventative" drugs mean you can sit back and relax, either. One of the preventative drugs for tick bite in dogs recommended in the article, "Deadly alert: vets try to box the ticks, November 20, p5) has had some bad press: As of the end of June 2016, European Medicine Agency reports for Bravecto include approximately 2000 serious cases of adverse reactions such as seizures, renal failure and liver damage, resulting in 470 deaths.

Nexgard can lead to vomiting (with or without blood), dry/flaky skin, diarrhoea (with or without blood), lethargy, and anorexia.

Effectiveness seems to have only been evaluated by the drug suppliers.

Jennifer Heywood, Spence

For readers interested in a little diversionary therapy, here is a conundrum to muse over.

In 1976, when I came from Sydney to live in Canberra, there were two sets of traffic lights: one on the corner of Northbourne Avenue and Barry Drive and the other at Northbourne Avenue and London Circuit.

The ABS tells me that Canberra then had a total of 96,584 registered vehicles, of all types, including almost 80,000 cars. The population was some 200,000.

Fast-forward to 2016 and the total number of registered vehicles in the ACT has reached almost 300,000 and the population is nudging 400,000. The number of sets of traffic lights is now 315.

What could be the mysterious formula that connects a doubling of the population and a tripling of the number of registered vehicles to a skyrocketing number of traffic lights?

Or, is it all just down to chaos theory?

Penleigh Boyd, Reid

I was watching an old movie, Pollyanna, recently and was taken by a heartfelt comment from the young star that it is easy to find badness in humanity if you look for it.

It made me think about the state of the world and our political system in Australia at the present time. Isn't it about time we looked for and found our better angels.

Our Federal Parliament now resembles hand-to-hand trench warfare where if the government somehow manages to get a piece of legislation through the Parliament it is hailed as a "victory".

Whatever happened to the concept of governing for all Australians, where passing good legislation though both Houses was par for the course if the government was on its game and had taken the people with it?

Yes, I know the Senate composition is now tricky but this is the hand that our Prime Minister engineered and the Coalition has to deal with it.

Politics in Australia today is profoundly depressing and the electorate is starting to feel this and express it at the ballot box.

Let's look for our better angels and hope they will triumph over the political mediocrity suffocating Australia today. Our country deserves much better.

Barry Harris, Curtin

Last Sunday's Canberra Times reported: "SpringOUT parade and family fun day celebrates Canberra's queer community. Civic streets turned rainbow on Saturday morning as the SpringOUT Pride Festival concluded with a pride march through the city centre."

There's little doubt that if this was a "few hundred" of the 8641 motorsport participants and supporters who signed a petition about the Canberra International Dragway several years ago parading through the city centre on a busy Saturday morning they would still be trying to make bail.

I would also like to commend The Canberra Times on it's wonderful [lack of] coverage of the American Car Show at Queanbeyan ... not.

Michael Attwell, Canberra Motorsport Suppporters Group, Dunlop

I am usually enlightened after reading a Gittins piece, but his "No sugar coating issue" (Canberra Times, November 23, p18) left me disappointed when he authoritatively starts a paragraph with "Yet the incidence of obesity – a BMI

of more than 30 – is growing in rich countries." The appeal to

BMI by medical profession as a diagnostic tool for individuals is a story that should have been part of the Andrew Masterton story "Clairvoyance is real – the latest pseudo-science hiccup to be published" (Canberra Times, November 20).

Gittins' use of BMI to back his claim is at odds with the photo on the Canberra Times website adjacent the Peter Martin article on sugar tax, namely a fat-bellied man with a girth of 109 centimetres.

BMI is a statistical calculation from the the 1800s developed by Belgian polymath and social statistician Lambeth Quetelet seeking a formula that would correlate, numerically, to the average citizen.

It was never developed as a diagnostic tool for obesity. To use it thus, according to Stanford mathematician Keith Devlin (Devlin's Angle on the web) is kindergarten arithmetic. BMI ignores the greater density of muscle to fat – sportsmen often have obese BMI readings because of muscle bulk.

BMI also ignores the belly fat-to- bum fat ratio and the amount of belly fat laid down. According to the Heart Foundation a simple tape measure around the belly of more than 94 centimetres for a man and 80 centimetres for a woman increases the risk of heart disease and stroke as it indicates the level of fat which coats the heart, kidneys, liver, digestive organs and pancreas.

So let's have much more tape- measure reportage and much less of the poorly understood dependence on BMI.

Instead of BMI calculators, health websites should tell Googlers to get a tape measure, not click in height and weight.

Yet, I am still with Gittins and Martin and agree that we should tax sugary drinks, as suggested by the Grattan Institute.

Denis Waters, Nicholls

To recent letter writers to The Canberra Times: Please note there is a difference in meaning between "flaunt" and "flout".

Some diplomats are flouting the law – certainly not flaunting it.

Jean Smyth, Conder

Email: letters.editor@canberratimes.com.au. Send from the message field, not as an attached file. Fax: 6280 2282. Mail: Letters to the Editor, The Canberra Times, PO Box 7155, Canberra Mail Centre, ACT 2610.

Keep your letter to 250 words or less. References to Canberra Times reports should include date and page number. Letters may be edited. Provide phone number and full home address (suburb only published).