New/Improved Terminology for aquatic veterinary pathology.

Posted on by TheFishVet - Richmond's School of Fish

New/Improved Terminology

We’ve been learning about toxicopathology in fishes, taught by Dr Jeff Wolf, the last couple of days at Aquavet II and came across some great stuff I’d like to share.

I’ve been working as a fish veterinarian and a veterinary pathologist for the last 10+ years and have come across some new and improved terminology that I believe we should all adopt. It makes better sense than the older terms.

 

So, here they are:

“PMC” (pigmented macrophage centre) rather than “MMC” (melanomacrophage centre) because contain more than just melanin. Three pigments that have been demonstrated to be present in these PMCs include melanin, haemosiderin and the lipopigments, lipofuscin/ceroid (formed byoxidation of lipid and retaining a yellowish-brown appearance).

We can see pancreatic cells within most fish livers, but we should not call it “hepatopancreas” – this term reserved for invertebrates. Call intrahepatic or mesenteric pancreas. Liver is liver. Pancreas is pancreas.

When describing vacuolation in liver, use terms such as “glycogen-type vacuolation” or “lipid-type vacuolation” because cannot be sure what was inside them.

With “lipid-like vaculation” you can further classify them as “microvesicular lipid-type vacuolation” and “macrovesicular lipid-type vacuolation”.

“Hepatic lipidosis” should be reserved for pathological finding (deleterious/injurious to the animal’s health) – e.g. if there is breakdown of hepatocellular wall.

“Lepido-“ = “scale”.

Dr Loh’s trip to attend AquaVet has been made possible through the – “People development program: 2011 Aquatic Animal Health Training Scheme which is supported by funding from the FRDC on behalf of the Australian Government”.
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Yours sincerely,Dr Richmond Loh

BSc, BVMS, MPhil (Vet Path), MANZCVS (Aquatics), MANZCVS (Pathobiology), DipPM.
Veterinarian | Adjunct Senior Lecturer Murdoch University | WAVMA Communications Committee Member |
Secretary Aquatic Animal Health Chapter – Australian and New Zealand College of Veterinary Scientists (ANZCVS)
The Fish Vet, Perth, Western Australia. Mobile Veterinary Service for fish and other aquatic creatures.
http://www.thefishvet.com.au
Ph: +61 (0)421 822 383

How can you tell how old a fish is?

Posted on by TheFishVet - Richmond's School of Fish

Ever wondered how you can age fish? Ask them?

There’s a technique whereby the bone from middle ear is sectioned and the growth rings (much like the tree’s) can give you an indication as to the fish’s age.

“The otolith layers are generally oriented parallel to the outer surface of the otolith and are most densely aligned during periods of slower growth (usually associated with cooler months), thus forming characteristic, concentric opaque rings in otolith cross sections (Blacker 1974). Layers that are less densely spaced during periods of faster growth during warmer months make up the translucent ring. When the formation of successive opaque and translucent rings occur on an annual basis, they are collectively referred to as an annual growth zones….”

Unfortunately, this can only be done in a dead fish.

This technique is also used to age manatees (because asking them doesn’t work, especially if they’ve already passed on).

This information can be downloaded from this link (38Mb).

"A Practical Handbook for Determining the Ages of Gulf of Mexico Fishes".

This link was shared by a fellow classmate (Johnny Shelley) at Aquavet II.

What’s WAVMA stand for?

Posted on by TheFishVet - Richmond's School of Fish

Did you know there are fish veterinarians all over the world?

And there is a world body to represent and provide support to fish veterinarians.

Formed in 2007 as a global not-for-profit Professional Association, the mission of the World Aquatic Veterinary Medical Association (WAVMA) is to serve the discipline of aquatic veterinary medicine in enhancing aquatic animal health and welfare, public health and seafood safety, in support of the veterinary profession, aquatic animal owners and industries, and other stakeholders.

The purpose of the World Aquatic Veterinary Medical Association is:

1.      To serve aquatic veterinary medicine practitioners of many disciplines and backgrounds by developing programs to support and sustain members, and the aquatic species industries that they serve.

2.      To identify, foster and strengthen professional interactions among aquatic medical practitioners and other organizations around the world.

3.      To be an advocate for, develop guidance on, and promote the advancement of the science, ethics and professional aspects of aquatic animal medicine within the veterinary profession and a wider audience.

4.      To optimally position and advance the discipline of aquatic veterinary medicine, and support the practice of aquatic veterinary medicine in all countries.

If you are a veterinarian or a veterinary student with an interest in aquatic animal health, download some informational brochures from the links below, or go to the website.

World Aquatic Veterinary Medical Association – Brochure

World Aquatic Veterinary Medical Association – Student Brochure

AquaVet II – Corals, Disease and Histology.

Posted on by TheFishVet - Richmond's School of Fish

Day 2, Dr Ilze Berzins presented on Corals, Disease and Histology.

Did you know that coral reefs are home to over 25% of all marine life including 1/3 of all marine species, yet comprise less than 1% of the Earth’s surface? They support more species per unit area than any other marine habitat! Integral to our ecosystem. We need to protect them and keep a good eye on them.

Check out the really cool microscopic view of their nematocysts and zooxanthellae in the picture below!

20120528-145921.jpg

Dr Loh’s trip to attend AquaVet has been made possible through the – “People development program: 2011 Aquatic Animal Health Training Scheme which is supported by funding from the FRDC on behalf of the Australian Government”.

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Yours sincerely,

Dr Richmond Loh
BSc BVMS MPhil MANZCVS (Aq & Pathol)
The Fish Vet, Perth, Western Australia.
Veterinary Medicine for fish.
http://www.thefishvet.com.au
Ph: +61 (0)421 822 383

AquaVet II – Fish Haematology

Posted on by TheFishVet - Richmond's School of Fish

Day 1

We had a brief orientation and got to meet many of our teachers and classmates. We were then split into 2 classes, those attending Aquavet I (more general with emphasis on practical experience) and AquaVet II (with greater emphasis on microscopic work).

In AqV2, Dr Dianne Brown gave us an overview on fish blood. We covered the practical aspects of teleost vs elasmobranch vs mollusc blood types and how to sample, prepare and interpret blood films to give us some clues as to the health of the animals. You can tell if there is inflammation (e.g. bacterial infection), viral infection, what their immune status is, toxicity issues and more!

I can see great value in using this tool in a weekly routine in aquacultured fishes to give us an idea of their health and to be able to quickly detect signs of diseased states early on in the piece so we can do something about it. This is of particular importance because when things in aquaculture go wrong, they go very wrong, very quickly! To be able to predict disease states would save pens of fish from mass mortalities.

Is your farm routinely sampling and examining blood?

Dr Loh’s trip to attend AquaVet has been made possible through the – “People development program: 2011 Aquatic Animal Health Training Scheme which is supported by funding from the FRDC on behalf of the Australian Government”.

—
Yours sincerely,

Dr Richmond Loh
BSc BVMS MPhil MANZCVS (Aq & Pathol)
The Fish Vet, Perth, Western Australia.
Veterinary Medicine for fish.
http://www.thefishvet.com.au
Ph: +61 (0)421 822 383