Under the skin when things go wrong in marine mammals

Vet summer school with dolphins

So this morning we did our anaesthesia and immobilisation workshop, unfortunately there were no procedures required in the marine mammals so we got a wild horse instead that needed x-rays and hoof trimming. Slightly disappointed but a great speaker and I’ve taken away pages full of tips and tricks that will help me with future anaesthesia in different species. So after lunch with these guys…

Vet summer school with dolphinsWe started with the pathology of marine mammals, this is a pretty special area and we had one of the top vets in the world taking the afternoon. We covered so many disorders including diseases and parasites not seen in normal animals that I finished with a headache, and a ton of notes to go over. Then we got to try our hands at histology of marine mammals as well, this was interesting especially as I have not finished veterinary pathological anatomy yet biut was well worth it to get a good explaination of just what was going on as well as a demonstration of just what can be achieved using simple histological stains.

The evening then went to scientific writting, with us being given blood data for the past few years for all the dolphins here to look at which was pretty interesting. Before we finished for the day we decided to check out the directors claim on Monday that night boxes were not used here and animals were left outside at night – he was telling the truth and it was interesting to be able to see how some animals sleep at night.

The start of Veterinary Embryology… (Day 218)

Histology of the eye section of the retina

Today’s Diary Entry is sponsored by Pets Bureau

For those that don’t know what embryology is; it is the growth of an animal after fertilisation of an egg (ovum) by sperm (or in the case of some species self-fertilisation). The sperm and egg fuse together with the haploid DNA contained in each combining to form diploid DNA within the nucleus. This single cell the goes on to rapidly divide multiple times with the number of cells doubling with each division (2-4-8-16 etc). Talking simply, this then folds in on itself (invaginates) to form a tube through the middle which will later become the digestive system. At this stage 3 different layers are formed; the ectoderm which is the outer later, the mesoderm which is the middle layer and the internal layer which is the endoderm. The cells in each of these layers are then differentiated to form different organs and structures related to that part of the body – for example the ectoderm forms the majority of the skin.

After embryology we then had the histology lecture that we had missed previously on the senses and today looked at the eye and ear. Personally I think the eye is amazing as the cells here are some of the fastest replicating cells within the body – most injuries to the surface layer heal within hours! The retina is the part of the back of the eye that is responsible for processing images into nerve pulses for the brain to understand and under the microscope looks like this…

Histology of the eye section of the retina

Looking at it quickly the layer at the top which is thick forms the fibres that holds the eye together known as the choroid and is attached to the sclera. Under this we then have a layer of pigment before the layer of rods and cones with the associated ganglionic nerve structures.

We finished this afternoon with our Physiology lecture which was looking at the brain, this is something so complex that by the end of the lecture most of use had our head aches. As vets we need to understand how different signals are processed, and the areas of the brain that deal with different functions of the body. In fact if we wanted we could actually progress to become Veterinary Neurosurgeons…. Is that cool or what?!?!

Talking testes, the histology of the male reproductive tract (Day 190)

Testis before and after puberty

Today’s Diary Entry is sponsored by Pet Hooligans Working With Animals Series

Ok so I’ve decided that instead of speaking about everything everyday I’ve decided that I am going try and focus on one topic each day to keep it easier to read about and so I can go into the detail it deserves rather than just skimming over stuff.

One of the most fascinating things about the reproductive system I find is that it continues developing months if not years after the animal is born. When you think that a mouse reaches puberty at an average of 35 days whilst a rhesus monkey reaches puberty at around 3 years, humpback whales at 4-7 years and elephants around 12-14 years. I’m on a mission to find out which animal has the oldest age of puberty though so stay tuned! Anyways talking puberty, most people are aware of the external changes, however looking inside the testes this is the chance that happens at puberty…

Testis before and after puberty
The change in testis at puberty

So we can see that instead of closed follicles we have larger follicles which have a lumen (space) in the center which is starting to be filled with spermatogonia cells which will eventually become sperm.

Development of sperm in the testisI will talk more about the penis on Wednesday with anatomy, however hopefully this has given you a little more understanding of the Testes and the changes with puberty.