Zulu and Scooby are wiley old hounds. As joint heads of security here at Plot 79, they patrol the grounds with zeal, ensuring that any potential intruder thinking of breaching the perimeter fence is made perfectly aware of the type of welcome they’re likely to get if they foolishly decide to set foot on the property. Retrieved a few years ago from the Botswana SPCA, these two World Spine Care mutts are unlikely ever to win any prizes at Crufts, but they are affectionate, charming and loyal. As a duo they are the canine equivalent of smoke alarms, launching into a chorus of barking at the faintest hint of something unusual.

So it was when, two nights ago, Zulu decided to unleash an incessant stream of woofing at around 2:30 in the morning. Popping his head out of the window to see what was going on and seeing nothing, my colleague Geoff thought that poor old Zulu had lost the plot over some scampering lizard on the patio. A few choice words aimed in his direction and the African night was peaceful once more.

Last night, Zulu and Scooby were both at it, their bark alarms in full glorious stereo at 1:30. Eventually, they calmed down without Geoff’s intervention being required. Having (we foolishly assumed) cried wolf the night before, we felt sure that another hapless gecko had dared to come on to their radar and that they were somewhat over-reacting.The combination of a clear balmy night and a spectacular full moon ensured that nothing was going to get past our canine sentries.

This morning (Tuesday) was another routine day for Geoff and I at the World Spine Care clinic at Mahalapye Hospital. After an early start, we settled into our respective patient lists, aided by the World Spine Care assistants Marcia and Malebogo. Everything was calm, orderly and relaxed.

With the day almost over, we were completing paperwork when Geoff took a call from Kgomotso, the housekeeper at Plot 79. Clearly distressed, she asked us to return immediately. She had seen a snake on the property and was terrified.

On the 15-minute journey back to the house, we discussed what it could be. Only two nights earlier we had been invited to a farm where the owner, who had lived in Botswana for 20 years, had told us in rather too much detail of the number of black and green mambas that had been found hanging from the leafy branches directly above our heads. Over the years, he  had become somewhat of an expert in dispatching them and along with scorpions and spiders, the African wildlife held no fear for him.

As someone who gets a little twitchy in the reptile house at Bristol Zoo with inches of shatterproof glass acting as an impenetrable barrier between me and the serpents on show, I could not say that I shared this indomitable African spirit.

As we swept through the steel gated entrance of Plot 79, Kgomotso stood nervously clutching a teacloth, while her husband Aaron, who had received the same emergency call as us and had raced over from the other side of Mahalapye, pointed us in the direction of a magnificent old tree standing close to the house next to the boundary wall.

There, in the opening of a hollow about eight feet from the ground, sat an enormous snake. Only a small portion of its mid section was visible, but its girth clearly marked it out as a very sizeable reptile indeed. With the aid of quickly retrieved binoculars we could see its black beady eyes calmly surveying the scene.

It was time to get the Book of African Snakes. Flicking through the pages, we quickly matched the distinctive markings of the scales and concluded that what was facing us was a snouted cobra.

i was on to Google in a flash. As I scanned the various websites, words like deadly, venomous and neurotoxin started jumping off the page. We were dealing with one of the most dangerous snakes in Africa. Further reading showed that they could grow up to eight feet in length and could deliver 250ml of venom in a single bite. It was time to stop reading.

This was clearly not a snake to mess with and with no cobra catchers listed in the Yellow Pages, it was time to take drastic action. Quickly, a local marksman was sourced and the equivalent of Mahalapye’s Snake SWAT Team was on the scene. Sadly, a single shot missed its target but was close enough to disturb the dozing cobra, which slowly withdrew into the depths of the tree and out of sight.

What the hell were we to do now? A deadly venomous snake was in a tree just feet from the house and was now aware that someone was taking pot shots at it. Cue one highly hissed off (sorry!) snake.

Meanwhile, word had got around the neighbourhood that Plot 79 had a cobra in its back yard. Even by African standards this is a rare event and it wasn’t long before curious visitors had come to see the slithery monster.

Advice was coming thick and fast but the general message was that we had to kill the snake. A nervous tension hung in the air. Africans do not like snakes one little bit, and to them the best snake is a dead one. To be honest, the prospect of just leaving it to set up home, have babies and live happily ever after did not exactly fill us with joyful excitement either.

With the Snake Swat Team covering all of the exits, the main hollow was plugged with an empty tin. By now, the crowd had swelled to about 20, some of whom seemed to be virtually advocating the use of weapons of mass destruction to eliminate the threat of a snake bite.

Eventually, it was decided that concrete was the answer to seal up the remaining holes. Seemingly taking inspiration from the designers of Alcatraz, no escape route was left unplugged. Our unwelcome visitor was destined to be permanently incarcerated within a wood and concrete prison.

Throughout all of this Zulu and Scooby sat impassively, watching the proceedings from a safe vantage point. Did they know what all of the fuss was about? As I looked into their eyes I wondered whether I detected a knowing look. Had they encountered our new resident on the move the two nights before? Who knows. The one thing I’m sure of is that when a smoke alarm goes off again, I’m going to take it  more seriously.