Hiccups

After reading ‘Your Inner Fish’ by Neil Shubin, I wanted to find out more about hiccups. A lot is still unknown about them, however, Shubin suggested a phylogenetic hypothesis.
Hiccups are caused by a disruption to the ventilatory central pattern generator resulting in a spasm in the diaphragm causing a sharp inspiration of air pulling the epiglottis shut, creating the ‘hic’ sound which characterises hiccups.

Although hiccups are only found in mammals, a link has been found to amphibians. Tadpoles are bimodal breathers because they have both lungs and gills. Therefore, they exhibit a motor pattern during gill ventilation, similar to that causing hiccups. Tadpoles gulp water allowing it to wash over their gills, however to do so without the water filling their lungs as well, their glottis has to snap shut immediately after inspiration. Further evidence shows that both hiccups and amphibian gulping can be stopped when the concentration of inhaled air is increased.

Although this seems like good evidence, it is very hard to prove phylogenetic connections. Other reasons for hiccups which have been suggested include to clear air from the stomach of a suckling infant to allow room for more milk. The air bubble could stimulate the contraction of the stomach and oesophagus, triggering the hiccup which creates suction in the chest, pulling the air from the stomach up and out. This is supported by the observation that hiccups are more common in infants.

Sometimes, hiccups can also be caused by infections such as pneumonia or nerve damage.

References:
http://onlinelibrary.wiley.com/doi/10.1002/bies.10224/abstract
http://en.wikipedia.org/wiki/Hiccup#Phylogenetic_hypothesis

Kingsnorth Vets – 5th February 2014

Today I arrived at the vets to see a police car parked in the car park. I soon found out that this was because of the horses in the fields which surround the surgery, although are not associated with them. Because of the awful weather we have been having, the fields have become sodden with water and as a result the animals are suffering. Two horses were found dead yesterday and today one was on its side in the mud, exhausted and unable to get up. The RSPCA had to intervene confiscating the horse of the owner but to do so the police had to be involved. The owner of the horses was going to be prosecuted on terms of animal welfare.

Apart from this, it was quite a quiet evening. In the kennels was a whippet with a poor liver. To assess their function, blood had been taken and then steroids had been administered, then blood tests were done at regular intervals to observe the liver’s response. Also there was a Cavalier King Charles spaniel with haemorrhagic, bloody diarrhoea. It could not control its bowel movements and regularly had to be cleaned. It was eating very little and more investigations needed to be done to find out the cause. Finally there was also a dog which had been vomiting, therefore x-rays were being taken at regular intervals to search for foreign bodies and monitor the movement of gas through the digestive system.

During the consults today a German Shepherd was brought in with diarrhoea. It was prone to diarrhoea and normally had bouts of it once a year. The vet prescribed medication to help the faeces to bind together and settle the stomach. The dog had previously responded quickly to medication, indicating that it was likely this dog just had a sensitive stomach. If it did not clear up rapidly, there could underlying causes and further investigation would be needed.

A dog was brought in with a skin tag on the inside of its outer ear. It was just a small cyst, probably the result of sweat glands secreting discharge. There were similar lumps on other places on the dog but this was the only one which where the skin had ruptured and not healed, exposing it to infection meaning that it was pussy and bleeding. The vet suggested several options including cauterising it under sedation and local anaesthetic or just cleaning it regularly to prevent the build up of infection and monitoring any development, taking action only if it got any worse. However, the vet chose to try using catgut suturing material to tie a knot at the base of the lump. This was likely to be unsuccessful but worth trying as it would at least provide a short term solution. After pulling it tight, the cyst came away, leaving only a small amount behind which was more likely to heal. This dog also had an underactive thyroid, meaning that the thyroid gland was not producing enough hormones to sufficiently stimulate the body’s metabolism. Therefore, the dog was putting on weight and the owners needed to consider changes to diet.

A flat-coated retriever was brought in with a lump under its leg. It was likely to be a mass cell tumour especially as smooth-haired breeds are more prone to them than other dogs. A nurse came in and together the nurse, owner and I held the dog on its side as the vet used a syringe to take a sample of cells and put them on a couple of slides. The vet warned the owner that there may not be sufficient cells to diagnose from, in which case a biopsy could be taken. The nurse then showed how to dip the slides in a fix then into two different dyes. Each slide had to be dipped 5 times in each chemical and the cells would be stained according their affinity for the different chemicals, meaning that different organelles could be identified under the microscope. Finally, they were rinsed with distilled water to wash off excess dye.

As it was quiet today, I spent some of time de-fluffing and folding scrub tops and trousers as well as cleaning some of the kennels out. I also took the whippet who was in the kennels for a walk and wee.