d) w/c 7-Oct-13 Flashcards
What colour drenches are benzimidazoles?
White drenches
Which drug is commonly used to treat Fasciolosis?
The benzimidazole, triclobendazone
Why property of white drenches e.g. fenbendazole means they are only used an oral drenches?
Low water solubility. Lead to death by inhibiting glucose uptake
What type of drug is Pyrantel and how does it kill the parasite?
Pyrantel is a yellow drench i.e. a Imidazothiazole. It kills the parasite as a cholinergic agonist; causing a rapid and reversible spastic paralysis. Also levamisole broad spectrum against nematodes
What is the difference in the way Imidazothiazoles and Macrocytic Lactones cause paralysis?
Imidazothiazoles: Spastic paralysis by acting as a cholingeric agonist
Macrocytic Lactones cause flaccid paralysis by opening glutimate-choloride channels in post-synaptic membrane
Ivermectin is an example of a
Avermectin (group of Macrocytic Lactone) ‘clear drench’
Difference between prophalaxis and metaphylaxis?
Prophyaxis: Preventing pasture contamination
Metaphylaxis: Protection of animals grazing contaminated pasture
White, yellow and clear drenches all act as nemotocides. What extra population can macrocytic lactones target that the other two cannot?
ML’s e.g. the avermectin- ivermectin can control arthropods.
Which narrow spectrum anthelmintic causes death the same was as the Imidazothiazoles?
Imidazothiazoles cause death by spastic paralysis (by opening the glutimate-chloride channels.
The narrow spectrum cestodicide, Praziquantel causes a spastic paralysis by destroying the tegument, therefore allowing the influx of calcium.
What are salicylanilides, how do they work? Why can’t they be used in beef or milk cattle?
Salicylanilides are fluckicides that cause starvation by uncoupling oxidative phosphorylation (therefore decreased phosphate compounds= starvation)
c.f. with benzimidazoles which cause starvation by decreasing glucose uptake.
Cannot be used in beef or milk cattle because they bind to plasma proteins and have a long plasma half life.
Which worm populations are most resistant in a) sheep b) cows and c ) horses
SHEEP: Haemonchus in south hemisphere. In UK widespread BZ resistance
COWS: Cooperia ML resistance
HORSES: BZ against cyathostomins
Clinical signs of Colic
Pawing, trying to go down, rolling (sawdust?), abrasions, recumbant, muscle fasciculations, looking at flanks, kicking abdomen, sweating
DDx of Colic
Laminitis- Recumbant
Botulism- Recumbant
Neurological disease - Recumbant
Musculoskeletal pain - ‘tieing up’
What procedure should you also do when you visit a horse with suspected colic?
Pass a nasogastric tube.
Horses cannot vomit therefore stomach doesn’t rupture.
IF YOU GET REFLUX DON’T GIVE ANYTHING VIA THE TUBE
Example of a very effective analgesic for colic pain in horses
Dotomidine.
If given and horse still painful =serious
Can be useful diagnostically.
Older horses are more likely to get one type of colic?
Colic caused by a strangulating lipoma
6 categories of non- strangulating lesion
Spasmodic colic, Impaction, displacement, enteritis/ileus (failure of peristalsis), typhlocolitis, peritonitis.
Enteritis: Small intestine
Typhlocolitis: Large intestine
(tie-flow-colitis)
Which type of strangulation lesion can stallions get but not mares?
Inguinal/ Scrotal hernia
How does volvulus occur in the small intestine?
Around the root of the mesentery
Three types of large intestine intussusception
Caeco-colic, ileo-caecal, caeco-caecal
There is more surgical treatment for (small/large intestine) therefore if suspect a problem here REFER!
Surgical list for small intestine much longer
Few on large intestine list: Colon torsion, non resolving displacement/impactions
Is ultrasound imaging more useful for viewing the small intestine or large intestine
Small intestine. Cannot pass through gas in large intestine.
Abdominocentesis with a nucelated cell count of 100x 109/l would be suggestive of medical/surgical colic?
Medical = peritonitis.
Surgical colic: Haemorrage, abdominocentesis nucleated cell 25g/l
What is pyelonephritis?
Inflammation of the kidney and its pelvis
DDx for abdominal pain
Spinal pain; do not palpate with thumbs of spine.
Also could have spinal pain and appear to have abdominal pain. Neurological signs??
Converserly if spinal unlikely to show CVS signs.
USE HISTORY, changes in gait, appetite.
What is the prayer position and what is it indicitive of?
Front legs down but back legs standing.
Abdominal pain.
Often how dogs present.
During a laporotomy use notice the stomach is visibily covered in omentum. What is the diagnosis?
Clockwise rotation of the stomach i.e. GDV
In which dogs is GDV most common?
Large, deep chested dogs e.g. standard poodle, great dane, GSD, Irish Setter
What is the radiographic sign that can help the clinician distinguish GD from GDV?
‘Poppi’s arm’ i.e. stomach appearing as two compartments, top one being smaller.
Which radiograph should be taken to diagnose GDV?
RIGHT LATERAL of CRANIAL ABDO
What should be done prior to rotating the stomach back to its original position?
Stabilise patient and decompress stomach (needle gastrocentesis or stomach tube care oesophageal sphincter). Treat hypovolemic shock with IV fluids
In which area of the stomach is necrosis most commonly seen in dogs with GDV?
Fundus due to displacement of the spleen and avulsion of the gastric branches of splenic artery which normally supply this part of the stomach
Explain the process that causes the systemic effects associated with GDV?
Mechanic obstruction to blood flow, decrease venous return, therefore decrease CARDIAC OUTPUT, Hypotension and compensatory tachycardia and increase CRT
Before preforming the gastropexy what should be routintely done to prevent a life threatning secondary problem?
Palpate the splenic vein and artery. If thrombi palpable remove to prevent the thrombi entering portal circulation and leading to an embolism
GASTROPEXY - Secure pylorus to RIGHT ABDO wall
Describe the normal structure of the liver, including the three zones.
Classic lobule 2mm in diameter, polyhedron bounded by several areas- each containing hepatic artery, portal vein and bile duct.
Periportal (centroacinar)- around portal triad, midzonal and centrilobular (periacinar)- boarding hepatic venules
Which of the three areas of the liver would you expect to be congested in heart disease?
The area boarding the hepatic venules
i.e. the centrilobar (periacinar)
Would also expect to see fatty change in the periportal (centriacinar) area
What is a portosystemic shunt?
Portal blood bypasses the liver i.e. is not detoxified. Shunting into vena cava/azgous vein/ renal vein
What is the azygous vein?
Single vein that provides an alternative route to the right atrium. Runs up right side of thoracic vertebral colounn. Paired in ruminants.
Two degenerative vascular hepatopathies
Hydropic change (common in hypoxia, mild toxin damage and metabolic stress.) Glycogen accumulation occurs in hyperadrenocorticalism. Enlarged paler liver. Reversible
What is hepatic lipidosis?
Fatty liver/ greasy appearance, type of degenerate disease. Can be caused by obesity, starvation (cats), and as a result of increased energy demand e.g. pregnancy, lactation.
Also caused by disease such as D.Mellotis, ketopsis, preg toxemia.
Example of an abnormal deposits and accumulations disease?
Amyloidosis is when a substance if desposited under the endothelium of a variety of tissues including renal glomeruli, pancreas and liver. can be primary (meyloma) or secondary amyloidosis (inflammation)
______deficinency causes necrosis of the liver in pigs
Selenium
What is liver cirrhosis?
End stage fibrosis of the liver. Extensive fibrotic lesions. May be concurrent with nodular regeneration
Inflammation of the liver is known as
Hepatitis. Cholangitis is inflammation of the bile ducts.
Cholangiohepatitis (inflamm of parenchyma and bile ducts)
Example of causative agents of viral hepatitis in DOGS, HORSES, CATS
Adenovirus: Canine infection hepatitis
Herpesvirus: Equine Herpes virus 1 also bovine rhinotrachitis
Coronavirus: Feline infectious peritonitis
How is infectious canine hepatitis spread?
How could the causative agent be identified microscopically?
In infected dogs urine. Recovering animals may show am imune-mediated uvelitis with corneal opacity. Hepatitis is an ADENOVIRUS HERPES VIRUS = MASSIVE NUCLEAR VIRAL. Also spotted areas of the small intestine INCLUSION BODIES (also with adenovirus)
Carcinomas and Sarcomas are both ___ tumours
types of MALIGNANT tumour
Inflammation of the gall bladder is known as _____
Gallstones are known as ____
Cholecystitis = inflamm
Gall stones are known as Choleliths
A calve presents with loss of condition despite polyphagia, is pot bellied and has diarrhoea. PM shows intestines are distended by bulky fatty ingesta, What could be the cause?
Pancreatic hypoplasia. Also common in German Shepherd dogs
What are the three different types of feeding tube?
- Oesophagostomy tube (if trauma to nasal passages i.e. RTA)
- Gastrostomy tube (if oesophagitis)
- Naso-oesophageal tube (if animal can’t undergo GA but need to give nutrition)
Would would be the main contraindication for an oesophagostomy tube and gastrostomy tube?
- Coagulation disorders
- Patient not stable enough for GA
USE NASOOESOESOPHAGAL TUBE
Causes of megacolon
Megacolon is the flaccid enlargement of the colon.
Primary/Idiopathic: Cats
Secondary: Pelvic fractures, intrapelvic space occupying lesion. Colorectal neoplasia, colorectal abcess, perineal hernia, inappropriate diet.
Treatment of Megacolon
Treat underlying disease. Medical management. Laxatives (lactulose), prokinetics e.g. ranitidine, frequent walks, high fibre.
Surgery: Subtotal colectomy.
How many cm of Rectum can you remove before increased risk of rectal incontinence?
6cm
Problems associated with colontomy. Which part needs to be preserved?
Decreased absorptive capacity - increased watery faeces. Must preserve ileocaecalcolic junction; prevents retrograde flow of colonic bacteria in SI, decreased risk of bacterial overgrowth
Types of colorectal neoplasm
Benign: 50% Adenomatous polyps, leiomyomas
Malignant: 50% Adenocarcinoma (median survival 22mnts), leiomyosarcoma, lymphoma, haemangiosarcoma
Most common cause of rectal prolapse in puppys?
Gastrointestinal prolapse
Where are the anal sacs located? What is the treatment for impacted anal glands?
4 and 8 o clock. Manuel expression or can be catherterised using lacrimal cannula. Lavaged with 0.9% sodium
Why can PU/PD be a presenting complaint for a dog with an anal sac apocrine gland adenocarcinoma?
Highly malignant tumour. Due to paraneoplastic syndrome= hypercalcemia = PU/PD. Good prognosis if treated, mainly financial
Two most common types of pancreatic neoplasm
Pancreatic adenoma: Extremely rare
Carcinoma: Dogs and Cats: Highly invasive and infiltrive with metastases to liver
