Mortellaro (Day -289)

Mortellaros disease in cows

There are many diseases and conditions in animals – and many great vets out there have discovered these and their related treatments. With cows one of the great names is from Italy – Professor Carlos Mortellaro, who started the development of knowledge of digital dermatitis in 1974. This week Prof. Mortellaro has been visiting and was asked to be allowed to lecture us on the treatment of Mortellaro disease.

Another name for this disease is strawberry disease, where lesions develop in the gap of the toes. Something that I found interesting was the amount of controversy over whether or not it is due to management or in fact is contagious.

Whilst a lot of literature says that digital dermatitis is contagious Prof Mortellaro made a strong case for this not being true. In different countries the same disease is caused by different bacteria. With Koch’s postulates of microbiology for a disease to be contagious the bacteria must cause the same disease in a healthy animal. Now with digital dermatitis when the bacteria from the affected animal are inoculated into a healthy animal it does not cause disease. There has been studies where the bacteria has caused disease after the leg is wrapped in wet bandages for several weeks – however whether it was the bacteria or the damage from the bandages that caused the disease is controversial.

This disease has an enormous economic impact on dairy farm production with lameness being the third most common disease in cows. Whilst the number of diary farms are decreasing the size of the remaining farms is increasing, and with this the incidence of digital dermatitis. The thoughts of Prof. Mortellaro are that the disease is environmentally linked – and with improved husbandry and housing it allows for better prevention of the disease.

When foot disease does occur there is often a rush of dairy farmers to try treating it themselves with antibiotics in order to save costs – unfortunately many of these antibiotics are not needed. There are several different diseases all of which affect the foot, and the treatment for each is very different. Prof. Mortellaro placed emphasis on the proper diagnosis as the inappropriate use of antibiotics increases the risk of antibiotic resistance.

The problem of lameness in cows is one driven by economics, which are driven by the supermarkets. Unfortunately even though you pay £1 in a supermarket for your milk the farmer only gets around 38p from this with the rest going to the dairy and supermarket. This money often is less than it costs to produce and in the UK dairy farmers often are subsidised by the EU. This money ensures a basic standard on farms, and the improvement of machines. However it does not allow the improvements needed to reduce the level of lameness – so whilst lameness cause a drop in milk production, and loss of money. It is a vicious cycle and one that needs to change for the welfare of the animals.

Take a read of this to find out how to help UK dairy farmers.

Animal Hygiene, or how to prevent environmental diseases in animals… (Day 158)

Draught wind speed and velocity measurement device

Today’s Diary Entry sponsored by Pet Hooligans

Nearly the end of the first week of my second semester here in vet school, today is the start of Animal Hygiene which is a module I have been looking forward to as it is actually taught by the vice-rector. We have just 4 weeks of classroom learning at the start of the semester and then each week will alternate between a farm visit and looking at the needs of specific animals. When posting on Twitter I’ve realised that many people do not understand just what animal hygiene is or covers (It’s not as simple as bathing animals!) so wanted to take a few minutes today to introduce the subject to you. Taking the definition of hygiene from the free dictionary it is simply

“The science that deals with the promotion and preservation of health.”

Ok, so its now become a science, and it promotes and preserves health. Relating this to animals basically animal hygiene becomes the science that promotes and preserves the animals health. This is where it gets interesting as instead of just purely treating diseases as vets we are responsible for preventing disease in the first place!

The first thing to consider when thinking about animal health is the conditions in which the animal lives – in fact with reptiles incorrect environmental conditions cause around 90% of medical problems! Sadly this module is primarily focused at production animals so things like sheep, goats, pigs, cattle, and chickens. When we talk about hygiene we are considering what the animal needs; the temperature, ventilation, light, space, materials, layout etc.

Today we covered the equipment used to measure these things – aka we spent an hour having thermometers explained to us – before moving onto cool things such as this…

Draught wind speed and velocity measurement deviceLooks pretty cool, basically its a fan that the wind or draught in the building blows around and it measures the velocity. Having proper ventilation is good as animals produce a lot of waste gases (not just methane but things like ammonia too) which are detrimental to their health. Ventilation also allows for the distribution of heated air and the limit for the speed of the movement of air is dependant on the animal species and season however above 3 meters a second is considered a draught.

Obviously temperature is also important as too cold the animals have depressed metabolism, however too hot and the animals have hyperthermia which is even worse. Then you have the lighting, animals are sensitive to light patterns (and even to the colour of the light) with it actually regulating the reproductive cycle in sheep.

I hope that I’ve explained just what animal hygiene is pretty well, as always feel free to leave comments and questions below!

A naked look inside the nucleus at the chromosomes… (Day 60)

Human Chromosome Genetics Microscope

Another Friday, Milk hygiene today was looking at the properties of tinned milk and condensed milk. I am now at the stage where I feel like I know more about milk than any single sane person would ever want to. Some of its useful, some not so useful, and then theres the plain interesting such as how many tests are carried out. Some of its scientific such as the massive list of potential bacterias, and then theres the not so scientific such as the “Cooked Taste” that steralised milk has.

Now genetics today we started looking at the Chromosomes that basically contain the code for all living things. Its amazing how something so small can determine whether you are male or female, in fact determine everything about you. Now lets make it a little more interesting, this is what you look like when everything else is stripped away…

Human Chromosome Genetics Microscope
The Chromosomes from the nucleus of a human cell… Yes, this is what we look like inside!

Now obviously this cell nucleus has been increased, this is done by using a hypotonic solution which causes the cells to swell whilst leaving the centromeres intact. This allows you to view the chromosomes under a normal light microscope as above (this image is at 1000x magnification if I remember correctly).

When examining the chromosomes we use something called the karyotype which is unique to each animal species (the number of chromosomes is different between species too). Basically the different chromosomes are arranged on different rows representing groups based on shape, size and where their center is. Using this it is then possible to identify the species, and even determine whether it is male or female from looking at the sex chromosomes. Here are the chromosomes from a Rat…

The chromosomes from a Rat in Genetics
Rat Chromosomes under the microscope

And here are the chromosomes from cattle (cows/bulls etc), if you click on the picture you can see a bigger version as well! 🙂

Cattle Chromosomes under the microscope in Genetics
Cattle Chromosomes under the microscope

A few weeks ago you may remember me talking about the bone marrow and how it was harvested from the femur of the mouse. We came back to it this week in addition to the bone marrow and blood collected from the cow. Today we prepared these for microscopic examination removing them from the solution and staining them (they are not naturally pink/purple) onto slides.

Histology Blood and Bone Marrow Stained Slides
Blood and Bone Marrow slides prepared for the microscope

These then were examined under the microscope, and I did actually find a cell in the metaphase stage of mitosis in the bone marrow I collected from the mouse! Looks pretty cool right (the small circle of purple chromosomes)? Amazing how something so small can control something so complicated…

My mouse chromosome in metaphase stage of mitosis
Mouse chromosome in Metaphase stage of mitosis

Hopefully you have enjoyed todays diary as much as me! Now I really must sleep, Friday always is so long, and by the end I am always so exhausted I think it is because the week catches up with me.