A Wander in Vetland

by John Hicks

  The eggs of some Nematodirus species require freezing before they will hatch – after the frosts of winter; not unlike the strategy of vernalization employed by some plant seeds to ensure that they germinate in spring This is an ingenious adaptation because, in temperate regions, it ensures that the larvae are triggered to hatch from their old dung patches and crawl to the succulent tips of the fresh new grass. What better launching pad to infect young lambs tucking into rich spring pastures? Reflect on these blood sucking parasites sapping the strength from those darling lambs gambolling amongst the daffodils. Before long they will suffer a black scour: blackened by their own partially digested blood as it is voided by the blood-sucking worms within them. Without treatment some will die of anaemia and dehydration. Others will fail to fatten. But can we really blame Noah for ensuring that even these little blood suckers survived the great flood? Did he really have access to freezer facilities on board the Ark to maintain his lines of Nematodirus battus?

  It could be argued that we of Otautau Vets, facing our daily deluge of dung, were victims of our own success. Staff complained about the unsavoury stench wafting through the building. We installed an extractor fan. We insisted that the farmers wrapped their samples in clean bags before they dumped them on our front desk. But farmer laxity was not the only risk.

  Vets, by the very nature of their dirty job, can become blasé about its dangers. The thoughtful bacteriologist could, with some justification, become an obsessive-compulsive hand washer and the parasitologist a food faddist. The parasitologist at the barbecue, by one definition, is the one who cuts his pork sausages longitudinally prior to cooking. Trichinella spiralis, a nasty parasite found in pig meat that can wreck humans, certainly justifies this caution. Vets should be fully aware of the risks from bacteria and parasites; yet for a few of them, the idle conditioning of their days in student flats overrides the sheer inconvenience of applying the principles of their new-found knowledge and the very good reasons why they, as vets, should have especially high standards of personal hygiene. One of our veterinary employees, a brilliant academic who subsequently left to pursue a career in research, resented being ticked off about the suspicious smears on his arms at morning tea one day. To the horror of all present he reached for the tea towel hanging by his elbow, wiped off the offending matter, and replaced it back on its rail. The ensuing chorus of protest could be politely rendered: “Hey, Z~, do you realise what you’ve just done?”

  Z~ was surprisingly unabashed: “This isn’t an effing girls’ school, is it?”

  We were on the verge of mutiny from the rest of our staff. Perhaps we had uncovered the mystery of the vanishing teaspoons. A ruling was made: henceforth any teaspoon or tea strainer disappearing from the tearoom for faecal egg counting purposes could not be returned there, no matter how thoroughly it was washed. But the next phase in the development of our faecal egg counting service rendered these mundane kitchen implements obsolete.

  The process of preparing the samples was tedious. Even the glories of Nematodirus eggs pall on the hundredth viewing. We needed to mechanise, and Giles had some ideas. A milkshake mixer should do the job… A few days later Giles and I met at a kitchenware store in Invercargill. We found a couple of models, but they looked flimsy. “Haven’t you got anything a bit more robust?” we asked. “This is going to have heavy use on a daily basis.”

  “We don’t have any complaints from home-users about either of these models,” the salesman tried to convince us, “after all, you’re not going to be running them all day long, are you?”

  “But it’s possible we might be.” Giles replied, “We’d really prefer one designed for commercial use, rather than for a home kitchen.”

  We turned aside to discuss our options. It required a lot of grunt to break down the hard-pelleted droppings of sheep on dry summer pastures sufficiently to make a suitable solution. The salesman must have overheard some of our conversation. He looked at us dubiously, glancing around to make sure no other customers were within earshot: “Hey, what sort of guys are yous?”

  “Vets!” The light was dawning, but he seemed unimpressed when we disclosed the full story; alas, such a mixer was not to be had. Reluctantly, we bore our compromise purchase back to the clinic to see what we could do with it.

  Overnight Giles performed one of his mechanical miracles. Our bench top ectomorph had become unrecognisable. He was now a wall-mounted warrior, complete with a hands-free lever arm and new splashguard. His blade had been modified to cut the crap. When, after several years, and thousands of shit-shakes later, the gearing started to slip, Giles modified the motor. That unpretentious little machine was still battling on ten years later – one of the best $20 investments Otautau Vets ever made.

  ~

  A tribute to Noah: consummate stockman and supreme survivalist.

  One problem with creative writing is the risk of making fundamental errors, especially when it comes to the use of humour. If you feel that by using the words “fundamental” and “creative” in a sentence relating to religious faith I am inviting trouble, you are correct.

  And so, inevitably, I have been drawn – like a moth to a flame – to give a veterinary perspective on creationism. Moths are probably quite a good place to start, but since there are new species of moths being discovered practically every day, from Aotearoa to the Ruwenzori, perhaps we should gloss over Noah-the-entomologist. Besides, it’s just too difficult to imagine suitable habitats aboard the Ark for porina moth, argentine stem weevil or varroa mites. The parasites, as we have seen, are very problematical. In my opinion Noah must have had a large basket hidden somewhere aboard. This would have been labelled with the Hebrew equivalent of “too hard”. Let’s not think about it.

  I prefer to revisit my childhood picture books – the animals going in two by two. In hindsight I hadn’t then appreciated Noah’s consummate stockmanship. Without the use of tranquillizer darts he coaxed rhinoceri, elephants, giraffe and okapi (rediscovered by western science only last century) into the capacious hold of his magnificent Ark, plus all the parasites that in and on them dwell.

  He was also, no less, an amazing traveller – prepared to go beyond the boundaries of his known world. Imagine his mighty ship ploughing through the icebergs off Tairoa Heads on his hoiho gathering expedition, bouncing into Botany Bay for a pair of kangaroos or lazing up the Limpopo in search of hippos; and all without the help of Pontius Pilot for those tricky estuaries. Hoiho, the name given by Maori to the yellow-eyed penguin, are substantial birds that he couldn’t possibly have overlooked, but how Noah caught them is not recorded. What a shame that his exertions on behalf of the Dodo, the Tasmanian Thylacine and the Little Swan Island Hutia were to prove in vain.

  Recent speculation by protagonists of intelligent design ingenuously explains how all this teeming life could have been crammed aboard the ark, by proposing that Noah merely required pairs of genera, not individual species: a generic “rhinoceros” rather than an Indian, White, Black, Javan or Sumatran rhino, and so on. This is precisely in agreement with my childhood picture books. Of course, this theory blithely ignores a central tenet of fundamentalists own beliefs, for surely these generics must have evolved (dirty word) into species later? Why not make it simpler still and take Noah’s mission one further step backwards and lighten his burden to representatives of taxonomic families? This would have made for a lot more ship room. It would have been so much easier if he could have just taken his house cats and not bothered with those pesky lions and tigers. With further logic we could go to the very base of the taxonomic tree and deduce that all life as we know it descended from the basic microflora and fauna – the primordial soup – within Noah’s body.

  We shall never know, but perhaps we can piece it all together to our own satisfaction with a bit of education and an ounce of common sense. I have my own theories about the parasites...

  Chapter Fifteen

  Holes in the Head: Windows to the Soul

  Such is the human ra
ce. Often it does seem such a pity that Noah and his party did not miss the boat. – Mark Twain

  One of the life forms on board with Noah must have been Coenurus cerebralis, perhaps developing in the brain of one of his sheep. The name does not explain that Coenurus is the larval cyst, in sheep, of a tapeworm called Taenia multiceps – which infects dogs. The two names bear no resemblance because when they were named, the connection was not realised. The eggs of this tapeworm pass out in dogs’ faeces which, when disintegrated and dried, can be blown by the wind for miles. The eggs hatch into larvae in the intestines of sheep which have had the misfortune to ingest pasture contaminated with them. Eventually the larvae travel through the blood and take up residence in the spinal cord or, classically, the brain (hence cerebralis), where the cyst grows. The life cycle of the parasite is completed when another dog eats the cyst in the carcase of the sheep.

  There are other tapeworm species which share similar dog-to-sheep lifecycles. Echinococcus granulosus is perhaps the most infamous of these. Its larval forms can develop into massive hydatid cysts in the abdominal cavity. Here there is space for them to grow into sacs containing many litres of fluid. Unfortunately, they can infect people as well as sheep and have caused many deaths and untold misery throughout history. Hydatid disease has been all but eradicated in New Zealand, but only after many years of concerted effort.

  It has not been recorded how Noah elected to perpetuate all these nasty tapeworms. He had several options with these multi-host parasites: via sheep infected with larval cysts, via tapeworm infested dogs or by separating the tapeworm eggs from the dog faeces and storing them. Tapeworm eggs are extremely durable and resistant to desiccation, so the latter would have been the most pragmatic solution, especially with space on board at such a premium. No matter which, humanity has no cause to celebrate the success of his efforts.

  The expanding Coenurus cyst causes a variety of signs in affected sheep because the brain tissue surrounding it is slowly compressed within the bony confines of the skull. These include head tilting, walking in circles, or head pressing – where the animal presses its head hard against a wall or a post. The common name for these afflictions is “gid”. If the cyst is close to the surface of the brain, the overlying bone is sometimes softened, especially in young animals.

  A very valuable and strapping young Suffolk ram was brought into the Liverpool University Veterinary hospital. He was circling. What a gift for tutors trying to expand our clinical thinking!

  “OK Miss Coster, if he’s circling anticlockwise, which hemisphere of the brain do you expect to be affected?”...

  “And if he was blind, in which eye would you expect impaired vision?”...

  “How would you check a ram’s eyesight? You can’t exactly cover one eye and ask him to read an eye chart!” Laughter…

  Later, “All right, so we think there is a space-occupying lesion somewhere in the left cranial hemisphere. What are the differentials?” At which stage gid would be mentioned along with a host of other possible causes, most of them carrying a grave prognosis.

  “Well then, Mr Hardcastle, let’s see if we can feel any softening of the bone.” And we could!

  In the end it was relatively simple surgery to make an incision in the form of an X in the skin over the softer bone, peel back the four skin flaps, break down the soft bone underneath, and remove the gelatinous cyst. The ram was much brighter the next day, perhaps relieved of a monumental headache, and over a few days he gradually gained direction and stopped circling. It was one of the more memorable moments of my clinical years at university. I particularly remembered how thrilled the farmer was when he came to collect his newly invigorated, and by now quite stroppy, ram.

  There is nothing new about brain surgery. Making holes in the skulls of others is an ancient occupation. However, when the procedure is not performed by a weapon, but carefully and deliberately, presumably for curative purposes, it is described as trephination. Hundreds of trephined skulls belonging to Neolithic people have been found, some of which have been trephined up to six times – veritable colanders. But why did they do it? Perhaps Neolithic man suspected that the soul resided within the skull. He may not have been too far from the truth. A new science, neurotheology has linked electromagnetic stimulation of the temporal lobes of the brain to intense religious experiences, where 80 per cent of people become aware of a “sensed presence”.

  Later poets described the eyes as windows of the soul (although the idea is at least as old as Cicero), and the great Sir Isaac Newton, displaying extreme dedication to science, investigated this by inserting steel bodkins through his eyelids and calmly recording the effects. But this was mere child’s play by comparison with our earlier ancestors who, by trephination, obtained far more direct access.

  Closer examination has shown that these windows in Neolithic skulls were made with flint tools in one of three ways: either by patiently scraping away the bone, by cutting ever deeper in a circle, or drilling a series of small holes in a circle and then cutting the bony bridges between them.

  Trephination has been performed by “primitive” tribes well into recent times, from the Pacific to the Balkans: for headaches, epilepsy, head injuries and the all-embracing category of “ritual”. In 1901 the Rev JA Crump described the technique, as practised in New Britain, where it was used to remove bone fragments and relieve the pressure of haemorrhage following trauma – reasons which would be entirely endorsed by today’s top surgeons. The patients were usually casualties from inter-tribal warfare. The task was entrusted to a tribal healer or priest, using a piece of shell, shark’s tooth or flake of obsidian for a trephine. The survival rate from the procedure in Melanesia was, reportedly, around seventy per cent. This compared more than favourably with the seventy-five per cent mortality achieved by St George’s and Guy’s hospitals in a survey of thirty-two cases between 1870 and 1877. However, without knowing the age ranges of the patients and the reasons for the operations, such comparisons can be misleading. One group comprised fit young warriors romping in a healthy, unpolluted environment; the others, most likely, were etiolated denizens of Dickensian London.

  By the middle of the twentieth century western surgeons, working in mental institutions, were opening skulls with reckless abandon – lobotomising patients with psychological disorders. Tens of thousands of these psychosurgery operations were performed in the United States alone. It was a crudely simple technique which involved thrusting an ice pick between the eyeball and the eyelid and up through the bone of the orbit and directly into the frontal lobe of the brain. The instrument was then swung from side to side, effectively destroying the brain tissue. By the admission of Walter Freeman, the neurologist who invented this technique, it was “disagreeable” to watch. Nevertheless, he advised that the patients could “get up and go home within an hour or two of surgery”. There might be the odd black eye as a consequence and “some minor behavior [sic] difficulties”. Had Sir Isaac Newton been a little more bold in his own experiments with the bodkin, he could have lobotomised himself and changed his personality into the semblance of a passive cabbage. Victims of psychosurgery filled the psychiatric wards until the technique fell into disfavour. Besides, after tranquillizers became available in the 1950s, the same effects could be produced chemically.

  ~

  Apart from my experience with the Suffolk ram, I am reminded of another instance when I needed to trephine a patient. This time it was a mare, and my trephine was rather make-shift – a hole-saw: the tool a plumber should use when making a hole to take a pipe through a board, but which the cruder of them don’t, hoping that the dreadful crimes they commit with their hammers will remain undiscovered in the hidden corners under your sink or bath.

  My patient had been dripping pus from a nostril for a long period of time. We concluded that it was most likely to be the overflow from a reservoir of pus in an infected sinus. Sinuses are bony cavities which line the skull in front of the brain and surround the nasal passages
down the long muzzle of the horse. Nowadays flexible fibre-optic scopes can be passed up the nostril which enables vets to explore the sinuses in detail and pin-point the source of such problems, but before they were available we had to rely on cruder methods, such as tapping over the suspect sinus. Was that a healthy hollow sound, or the dull thud of a pus-filled cavity? Was there pain, or was the horse snagging back because she resented being tapped in a strange place? Such tests were often inconclusive and, if the discharge did not resolve with prolonged medical therapy, exploratory surgery, in the hope of finding the seat of the problem, was the next step.

  Many horses take flight at the mere sight or smell of a vet – as readily, perhaps, as one of our Neolithic ancestors when approached by a shaman with a flint scraper. We certainly did not anticipate that our mare would stand still when we approached her with a noisy electric drill, still less when it was applied to the side of her face. So, unlike our poor ancestors, she benefited from a general anaesthetic administered by Giles. Once she was down and out, and the site of the operation shaved and prepared, I raised the skin flaps to expose the bone which I judged to be overlying her maxillary sinus and, carefully placing the hole-saw to avoid damaging important nerves and blood vessels, buzzed away till I had duly removed a neat circle of bone. The ancients would sometimes keep such roundels from their own skulls on a necklace, wearing them to the grave – perhaps as an amulet – little realising that this would be a matter of enormous speculation for anthropologists a few thousand years into the future.