Exotics Flashcards
1
Q
Briefly describe avian renal anatomy
A
- large pair of lobulated kidneys surrounded by abdominal air sac
- Reptilian and mammalian nephrons
- No urinary bladder, empty into cloaca
- Reflux of urine into coprodeum and colon aids water reabsorption
- Ischiatic (and others) nerves run through and dorsal to kidneys
2
Q
List the common causes of primary renal disease in birds
A
- Hypervitaminosis A
- Hypervitaminosis D3
- Dehydration
- Heavy metal toxicity
- Infection (e.g. extension of air sacculitis, systemic spread, ascending infection)
- Neoplasia
- Amyloidosis and lipidosis
3
Q
What condition may lead to amyloidosis in birds?
A
Bumblefoot
4
Q
Compare the types of nephrons found in the avian kidney
A
- Reptilian: no LoH, cortex only
- Mammalian: LoH, extends from cortex to medulla
5
Q
Compare visceral and articular gout
A
- Visceral: uric acid tophi in soft tissues e.g. liver, pericardium, kidney
- Articular: uric acid tophi in and around joints, often feet and hocks
6
Q
Describe the development of gout in birds and reptiles
A
- Decreased uric acid secretion: dehydration, renal tubular disease, hypovit A, infection/inflammation, post-renal obstruction
- Increased uric acid production: excess dietary protein
7
Q
Outline the typical presentation of avian renal disease
A
- early signs often subtle
- Advanced signs: non-specific, fluffed up, lethargic, eyes closed
- More specific signs: PUPD, uni or bilateral HL paresis, haematuria, feather picking over kidneys, gout, leaning when standing
8
Q
What factors is the level of dehydration in a bird assessed on?
A
- PCV/TS
- Skin elasticity
- MM moisture
- Brightness of the eye
- Ulna refill time
- Most sick birds are 5-10% dehydrated at presentation
9
Q
List the diagnostic tests that may be used in the investigation of urinary tract disease in birds
A
- Uric acid
- Blood biochem and haematology
- Urinalysis
- Murexide test
- Radiogaphy
- Ultrasound
- Endoscopy
- (MRI/CT)
10
Q
Outline the interpretation of haem and biochem in a bird with urinary tract disease
A
- Uric acid: elevated once >70% renal function lost, post-prandial rise in carnivores
- Urea as indicator of dehydration only
- Creatinine not useful
- Phosphorous: may be elevated in renal failure (and haemolysis)
- Calcium: reduced in renal failure
- Potassium: elevated in acute renal failure
- Sodium: hyper in dehydration, hypo in renal failure
11
Q
Discuss the use of urinalysis in the investigation of urinary tract disease in birds
A
- Difficult to obtain pure sample
- Normal urine contains crystals and bacteria
- Look for renal casts, abnormal cells, glucose etc.
- USG species specific (aroun 1.005-1.020)
12
Q
Outline the murexide test in birds
A
- Confirmation of gout
- Sample of material e.g. joint aspirate mixed with nitric acid and dried over flame
- Add 1 drop concentrated ammonium
- Mauve = uric acid (positive)
13
Q
Outline the use of radiography in the investigation of urinary tract disease in birds
A
- VD and lateral, wings and legs extended
- Normal kidneys difficult to see, but have small rim of air dorsal to kidneys on lateral view (absent in renomegaly)
- May see eggs, cloacaliths, evidence of gout in rest of body
14
Q
Evaluate the use of ultrasonography in the investigation of urinary tract disease in birds
A
Useful to look at architecture of kidney but often severely hampered by air sacs
15
Q
Evaluate the use of endoscopy in the investigation of urinary tract disease in birds
A
- Most useful to visualise and biopsy kidneys
- Can assess most other organs at the same time
- Requires specific training and expertise
16
Q
Outline the supportive care for the average sick bird
A
- Keep warm (29-30˚C)
- Quiet, away from predators
- Dim lighting
- Oxygen
- Nebulise saline for 20-30mins
- Fluid therapy (SC, IV, IO but not humerus or femur)
- metoclopramide 0.5-1mg/kg IM q8-12hours if ileus
17
Q
Outline a basic fluid therapy plan for a bird
A
- Maintenance fluids ~50ml/kg/day
- Rehydrate over 48 hours
- Day 1 and 2: maintenance + half calculated rehydration fluids
- Day 3: maintenance fluids
18
Q
List the treatment factors that should be considered for a bird with urinary tract disease
A
- General supportive care
- Assessment of dehydration
- Fluid therapy
- Food
- Antibiotics
- Allopurinol
19
Q
Outline the nutrition for a bird with urinary tract disease
A
- High fat and carb, lower protein
- Ensure balanced diet for species
- Vitamin supplementation may be needed in some
20
Q
Discuss the use of antibiotics in a bird with urinary tract disease
A
- Aminoglycosides nephrotoxic
- TMPS and amoxyclav can be nephrotoxic if bird is dehydrated
21
Q
Discuss the use of allopurinol in a bird with urinary tract disease
A
- Xanthine oxidase inhibitor
- May help reduce hyperuricaemia, thereby reducing gout
- BUT may worsen gout in some species e.g. Red tail hawk
22
Q
Briefly outline the reptilian renal anatomy
A
- Renal portal system similar to birds
- No LoH
- Urinary bladder in chelonia and some lizards
- Urine can be modified in bladder/colon
- Salt glands present in some desert and aquatic species
23
Q
List the common causes of reptile renal disease
A
- Inadequate husbandry: humidity, temp, diet, supplements
- Chronic dehydration
- Infection e.g. bacterial, parasitic
- Neoplasia
24
Q
How might chronic dehydration occur in a reptile?
A
Some need to drink from droplets coming down, water bowl useless, will get dehydrated
25
Outline the clinical signs of renal disease in reptiles
- Early signs often subtle
- Advanced signs: non-specific, lethargy, anorexia, weight loss, dysecdysis, abnormal thermoregulation
- Other signs: HL weakness, constipation, gout, oedema
26
List the diagnostic tests that can be used in the investigation of renal disease in reptiles
- Blood biochem and haematology
- Urinalysis
- Murexide test
- Iohexol excretion test
- Radiography
- Ultrasound
- Endoscopy
- (MRI/CT_
27
Outline the interpretation of blood biochem and haematology in reptiles with renal disease
- Uric acid elevated once >70% function lost, post-prandial rise with carnivores, little to no effect of dehydration
- Urea: elevated in dehydration or anorexia, renal disease if uric acid also elevated, more useful in desert tortoises
- Creatinine not very useful
- Phos: may be elevated, renal disease more likely if phos > total calcium , may be elevated as a result of haemolysis
- Calcium: reduced in CRF, normal or increased in ARF
- Potassium elevated in ARF and haemolysis
28
Outline urinalysis in the investigation of renal disease in reptiles
- Try to avoid faecal contamination
- Normal urine contains crystals and bacteria
- Look for renal casts, cells, parasites e.g. Hexamita
- pH may change from normal alkaline to acidic in anorexic herbivores and post hibernation
- Normal USG: 1.003-1.014
29
Describe the iohexol test used in the investigation of renal disease in reptiles
- Excreted solely by glomerular filtration, good indicator of renal function
- Inject iohexol IV, take blood 4, 8 and 24 hours later
- Not routinely used
30
Outline the use of radiogaphy in the investigation of renal disease in reptiles
- 2-3 views, VD, horizontal beam lateral +/- horizontal beam craniocaudal (chelonia)
- Kidneys often difficult to see unless enlarged or increased density
- look for changes in size, density, contour
- Eggs, uroliths, bone density also assessed
31
Outline the basic treatment of all sick reptiles
- Heat: keep at preferred body temp
- Fluid: ensure correct humidity and appropriate access to water e.g. bath, spray
- Light: appropriate supplementation for the species
32
How can dehydration be assessed in reptiles
- PCV/TS
- Skin elasticity
- MM moisture
- Brightness of eye
- Appearance of urine and urates
- Assume most are 5-10% dehydrated or more at dehydration
33
What fluids are used in reptiles?
- Hartmann's
- 0.9% saline/electrolyte + amino acid at ratio 4:1
- 2.5% dextrose in 0.45% saline OR 4% dextrose in 0.18% saline
- 9:1 ratio of 5% glucose with 0.9% saline (9 parts) to sterile water (1 part)
34
Outline the adminstration of fluids to reptiles
- Warm fluids to upper level of POTZ
- Rehydration may take up to 10-14 days
- 10-30ml/kg/day for maintenance + 25% of fluid deficit
- Lizards: cephalic, jugular, ventral tail vein
- Chelonians: jugular
- Snakes: jugular, intra-cardiac
- All species: intracoelomic, subcut, oral routes
- Intraosseous other than snakes
- Daily bathing
35
Discuss the nutritional managment of reptiles with renal disease
- Oesophagostomy tube routine procedure, can be with local, sedation or GA but all need analgesia, can be left in place for years
- Amount via O tube: Lizards: 10-20ml/kg, snakes 15-30ml/kg, tortoises 5-15ml/kg
- Balanced diet for that species, generally high fat and carb, lower protein
36
Discuss the use of antibiotics in the treatment of renal disease in reptiles
- Most infections due to G-ve bacteria
- Aminoglycosides are nephrotoxic
- Fluoroquinolones and ceftazadime commonly used
37
List adjunctive treatments that may be used for reptiles with renal disease
- Allopurinol (may help reduce hyperuricaemia)
- Anabolic steroids
- B vitamins
- Phosphate binders
