Fish general
Why do elasmobranchs need to continually move?
Elasmobranchs have a one-pump system and don't have an operculum. They are obligate ram ventilators
What virus in fish is OIE reportable but culling is not mandatory. Goldfish are resistant?
CyHV -3 (koi herpes)
A hatchery reports sudden mortality in juvenile trout. Affected fish show lethargy, rapid gill movement, and gather near the surface. You arrive at the hatchery and perform a water test. You notice that there is an increased amount of Nitrosomonas bacteria and decreased amounts of Nitrobacter bacteria. Oxygen water levels are within normal intervals.
What is the underlying condition seen in this hatchery?
How would you treat this scenario?
Increased levels of nitrite in the water cause fish hemoglobin to decrease and cause methemoglobin to increase. This indicates Nitrite toxicity “Brown Blood Disease”
Treatment:
Perform a large water change and stop feeding temporarily to dec nitrogenous waste production. Improve biofilm production
What hormone would be elevated on a hormone assay of a chelonian with metabolic bone disease?
PTH
What area of amphibian skin has a high density of capillaries to facilitate fluid exchange?
Drink patch
Teleosts don't have any bone marrow and most of their hematopoiesis occurs where?
Cranial kidney
Why is metastasis less common in fish?
Lack normal metastatic sites (LN) and lower ambient temperatures
An aquarium manager reports that some fish in a small saltwater aquarium have developed lesions on the head and side of body. You ask for the feeding log and notice the fish diet contains inadequate amounts of vitamin C. On inspection of the fish with the lesions, they seem to be swimming in an inorganized manner.
Based on these findings, what is a top differential? How to treat?
Head and lateral line erosion from hypovitaminosis C. Add feed with adequate vit C to diet and report if improvements occur. If they persist, can be due to varying other primary factors.
What groups of reptiles are efficient at converting carotenoids into retinol?
Herbivores (tortoises, iguanas) and omnivores (beardies)
A pacman frog “Pix”, comes into your clinic because the owner says she hasn't eaten in a week and a half. On physical exam, Pix has a BCS of ⅖ and swollen conjunctiva. You ask the owner what she puts on the crickets and she replies “only calcium dust”. What is this frog suffering from and what should you tell the owner?
Hypovitaminosis A- amphibians need a multivitamin supplement
What is the main immune response to injury or infection in fish?
Granulomatous formation
A tropical fish shop owner notices small cream colored external nodules covering a few of their molly fish that live in a community fresh water tank. The owner noticed a single fish had these lesions a few weeks ago, but now multiple fish have these lesions. No fish have died. Based on this information, what disease can this be and what can you tell the owner to do?
Iridovirus- Lymphocystis virus- Tell the owner to do a complete water change on this tank and to quarantine affected fish.
A rainbow trout farmer reports to you that many of his fish have been dyeing and have distended coelomic cavities. He reports that he changed his fish feed not too long ago. On necropsy of the dead fish, you find hepatobiliary adenomas and carcinomas.
What is your top differential?
How to treat?
Aflatoxin toxicosis from Aspergillus in fish feed (Hyphomycetes)
You warn the trout farmer that treatment is unrewarding and that depopulation with extensive cleaning is the best course of action
What are the different orders of reptilia?
Squamata, Testudinae (chelonians), crocodilia, and rhynchocephalia
A backyard water hobbyist created a fish/frog pond in their backyard last spring and has seen an explosion of life through spring and into summer. He decided to take some tadpoles from a lake a few miles away and introduce them into his pond. After a few weeks, he noticed the adult frogs have developed superficial lesions and some have died stuck in abnormal postures. Meanwhile, the tadpoles are fine. What is going on in this pond?
Chytridiomycosis
What type of fish have the swim bladder connected directly to the esophagus?
Physostomous
A Japanese style high class restaurant calls you over to check on their koi pond filled with decorative and expensive koi. The owners of the restaurant are displeased with their recent purchase of premium koi because when they were shipped, they came with blemishes on their scales towards the head and caudal fin area. You perform a skin scrape on these lesions and perform microscopy. You notice these lesions are fragile areas of epidermal hyperplasia. The owner wants to surgically remove these lesions.
What is happening in this koi pond and what should you tell the owner?
CyHV -1 virus (Carp pox) infection in these fish. Surgery isn’t rewarding. You raise the water temp and tell owner that if problems persist, culling is the next best option. You caution that when purchasing new fish, especially expensive ones, they should perform PCR and quarantine fish to observe any latent disease.
A freshwater hobbyist calls you over to take a look at his tank that isn’t doing well. Many of the fish show signs of lethargy, have a lack of appetite, and have abnormal swimming patterns. A few fish have died and have distended coelomic cavities. You take a sample of the water at the level of the substrate and the dead fish back for testing. On necropsy you notice massive cystic hyperplasia of the renal tubular epithelium. On closer examination of the water, you notice marine worms.
What is your main differential?
How to treat?
Hoferellus carassii (Myxozoan) infection causing kidney bloat
Treat: Get rid of intermediate host (marine worms) from tank and get rid of any infected fish. Most likely need to depopulate and clean whole set up.
What are the importance of UVA and UVB?
UVA- behavior
UVB- Vit D synthesis
What reportable disease in amphibians can lead to massive mortality events due to systemic organ failure?
Ranavirus
How do elasmobranchs maintain buoyancy?
No swim bladder. Rely on intrahepatic fat.
An outdoor beta fish farm in northern Thailand purchased 200 new fish during late winter. Everything was going swimmingly until the summer came around. On inspection of alive fish, you notice lethargy, anorexia, and abnormal swimming patterns. On deceased fish you observe multi-organ hemorrhage and necrosis of gills and coelomic cavity.
What is your top differential for this beta farm?
Megalocytivirus (Iridovirus)
A client with an outdoor koi pond went on vacation and asked the neighbors kid to clean, feed, and watch his koi while he was away. On return, the owner of the pond notices that the water looks very murky and some of his prized koi have died and others don’t look too well. He calls you over to take a look. You take a water sample and see very high amounts of bacteria. On inspection of the live fish, they are at the surface gasping for air, and some have gill lesions. You take gill clippings and skin scrapes of alive and dead fish and bring them back to your lab. You notice many colonies of organisms attached to the gills of the fish and see others that are freely moving. The ones that move are circular in shape.
What infection is occurring in this koi pond?
Sessile and motile peritricks
How many heart chambers are in squamates and chelonians?
3 chambers
What is the most common way of administering medication in an amphibian?
Topical