NTCA Pathology

Question 1

Anaesthetic risks and related morbidity mortality (rabbit)

Answer 1

• Small size/anatomy - airway obstruction (long narrow mouth, large tongue base), compression of thorax/abdomen, difficult vascular access, need for ET intubation
• High metabolic rate - hypoglycaemia, rapid drug metabolism, high fluid requirement - no fasting, cannot V+
• High SA:V - hypothermia - minimal fur removal, limit alcohol based products + wetting patient
• Stress, pain, starvation, change in diet -> ileus
• Underlying disease - malnutrition (dental disease, stabilise before anaesthesia); resp disease (pasteurellosis; hypoxaemia; precipitation of clinical disease)

Question 2

Anaesthetic risks (reptile)

Answer 2

• Heart w/ 2 atria + 1 ventricle - challenge to induce via inhalant, shunts blood to periphery instead of lungs
• Episodic respiratory pattern
• No diaphragm - same muscles for inspiration/expiration
• Inspiration/expiration active process
• Ectothermic - cannot internally regulate temp
• Glottis at base of tongue - don’t cuff complete tracheal rings (chelonia)
• Respiratory controlled by ppCO2 + ppO2 - preO2 w/ both CO2 + O2 (mammals = 100% O2)
• Renal portal system - use forelimbs for injection (hind leg veins drain to kindeys before liver)

Question 3

Most common endocrine disease in guinea pigs + need for spay

Answer 3

• Cystic ovaries - single/multiple affecting both ovaries, abdo distension
• Non-specific signs
• Functional cysts cause non-pruritic flank alopecia

Question 4

Spay (gerbil)

Answer 4

• Ovarian cysts
• Neoplasia

Question 5

Cystotomy (guinea pig)

Answer 5

• Urolithiasis
• Calcium oxalate or calcium carbonate (radioopaque)

Question 6

Neoplasia (gerbil)

Answer 6

• Neoplasia common in entire males
• SSC, papilloma, benign hyperplasia, epithelioma + poorly differentiated carcinoma
• Start off as benign adenomas -> inc in size, become malignant

Question 7

Neoplasia (rat)

Answer 7

• 1). Mammary gland neoplasia - mammary tissue present on most of body (85% benign, 10% adenocarcinomata), males less affected, prolactin dependent - associated w/ functional pituitary adenomas
• 2). Zymbal’s gland adenocarcinoma - mass at base of ear canal, pos 2y otitis, aggressive local spread

Question 8

Pharyngostomy tube placement (reptile)

Answer 8

• Nutritional support during pathological
  anorexia
• Enabling regular administration of medication - owners can then medicate animals at home,
  minimising hospitalisation costs and stress factors
• Nutritional support following orofacial trauma or surgery
• Countering inappropriate physiological anorexia - e.g. dry-docked aquatic chelonia

Question 9

Ovarian pathology -> ovariectomy (reptiles)

Answer 9

• Pre-ovulatory/follicular stasis (Green iguanas. Testudo tortoises, chameleons) - failure of follicle to ovulate -> accumulation
• Bacterial oophoritis (inflam of ovaries/solidified follicles)
• Neoplasia (iguana)

Question 10

Salpingectomy (reptile)

Answer 10

• Response to dystocia
• Post-ovulatory stasis (water dragons, snakes + geckos)
• Factors - ovidcut inertia w/ Ca deficiency; lack of appropriate nesting site; abnormally sized/shaped eggs; unfertilised eggs; obesity; chronic debilitation

Question 11

Egg binding (reptile)

Answer 11

• Oviduct inertia (chelonia + lizards)
• Radio to differentiate if obstructive

Question 12

Caesarian (reptile)

Answer 12

• Alternative to salpinectomy
• Where breeding must be preserved

Question 13

Cloacal Sx - prolapses (reptile)

Answer 13

• Colon; oviduct; cloacal wall; bladder (present in chelonia, some lizards); one or both hemipenes (lizards + snakes); penis (chelonia)
• Organ prolapsed may not be site of 1y lesion, due to straining, reoccurrence if not resolved
  Bacterial or parasitic enteritis
• Constipation/impaction
• Dystocia
• Infections/Inflammation of the reproductive tract
• Mating trauma
• Obesity
• Urolithiasis
• Coelomic masses
• Hypocalcaemia

Question 14

Hemipene/penile prolapse (reptile)

Answer 14

• Snakes + lizards - hemipene lesions (located in tail, caudal to vent), coelomic pathology
• Leopard gecko - localised infections
• Chelonia - coelomic/localised pathology (penis located within cloaca)

Question 15

Hemipene abscessation (reptile)

Answer 15

• Can cause hemipene prolapse
  Due to
• Mating trauma
• Vit A deficiency
• Poor hygiene

Question 16

Oviductal prolapse (reptile)

Answer 16

• Significant damage of supporting ligaments
• 2y to unilateral oophoritis + salpingitis
• Blind replacement -> intussusception + recurrence

Question 17

Urinary bladder prolapse (reptile)

Answer 17

• Rare, chelonia
• Due to urinary calculi - chelonia bi-lobed - pressure from R lobe of liver -> most stones on left bladder lobe

Question 18

Aural abscessation (aquatic chelonia, reptile)

Answer 18

Husbandry
- Poor water quality/hygiene
- Insufficient water heating
- Failure to provide basking spot
- Dietary deficiencies - vit A

Question 19

Masses (goldfish)

Answer 19

• Epidermal neoplasia
• Granuloma

Question 20

Dental Tx (fish)

Answer 20

• Puffer fish
• Constantly growing dental plates
• Lack of attrition in diet -> overgrowth

Question 21

Air sac tube placement (bird)

Answer 21

• Bypasses trachea + delivers air directly into the air sac system to enter the lungs
• Emergencies - tracheal obstruction
• To enable anaesthesia for head/tracheal Sx
• ‘Normal’ respiration at rest

Question 22

Ingluviotomy (bird)

Answer 22

• ‘Ingluvi’ = crop, incision
• Remove FB/compacted material

Question 23

Pododermatitis (bumblefoot) (bird)

Answer 23

• Inflam of base of foot
  Due to
• Pressure sore development: lameness, poor perching, obesity, exacerbated by Staphylococcus aureus causing fibrotic response
• Any bird species
• Falcons, penguins prediposed as heavier
• Flamingos - cracks + 2y infection

Question 24

Type 1 pododermatitis (bumblefoot) (bird)

Answer 24

• Loss of epidermal structures
• Scab formation
• No deeper changes

Question 25

Pododermatitis (bumblefoot) (grade II-II) (bird)

Answer 25

- Fibrosis + necrosis present - Medical therapy alone doesn't penetrate lesion

Question 26

Salpinectomy (bird)

Answer 26

- Where repro tract is end stage -> oviduct removal - Chronic egg yolk peritonitis - Inspissated (thickened) material in salpinx - Neoplasia - Salpingeal stricture - Reduce ovarian activity

Question 27

Wing Fx (bird)

Answer 27

- In-flight injury, caged birds damge wings in cage bars

Question 28

Endoscopy (bird)

Answer 28

- Assessing viscera directly - Air sac system allows direct visualisation of majority of organs

Question 29

Leg Fx (bird)

Answer 29

- Raptors when tethered or taking quarry (being hunted) - Cages birds - rings/legs stuck in cage bars - doors shutting on perched free ranging birds - Tibiotarsus most frequent - Weak area present at level of fibular crest - tethering - Tarsometatarsus + femure affected less freq

Question 30

Syringeal aspergilloma (bird)

Answer 30

- Fungal granulomas form on the syringeal mucosal folds - Progressive air flow obstruction develops - Early signs include changes in vocalisation - Acute dyspnoea occurs as granulomas grow - Diagnosis: tracheoscopy

Question 31

Adrenalectomy (ferret)

Answer 31

- Manage adrenal ectopic sex hormone secretion -> dec hormones - Dec symptoms of renal disease

Question 32

Skin biopsy (reptile)

Answer 32

- Dx of dermatological conditions (more Dx compared to skin scrape) - CS - hyperkeratosis - determine if environmental or medical Tx required - Fungal infection - yellow fungus disease, Chrysosporium anamorph, Chameleomyces - Bacterial infections e.g. Devriesea agamarum

Question 33

Thoracic radiographs (rabbit)

Answer 33

- Pulmonary uterine adenocarcinoma metastases (older animals) in lungs

Question 34

Abdominal radiographs (rabbit)

Answer 34

- Urinary calculi/sludge

Question 35

Ovariohysterectomy (rabbit)

Answer 35

- Prevent unwanted pregs - Avoid hormonal territorial behaviour - Adenocarcinomas - 75% in 7 y entire females, recommended for all female rabbits not intended for breeding - 5 - 9 months, young = uterus difficult to find, old = more fatty

Question 36

Ovariectomy (rabbit)

Answer 36

- If before 1 y/o + no evidence of uterine disease

Question 37

OVH complications (rabbit)

Answer 37

- H+ - v friable blood vv - Leakage of urine into abdo (transection of vagina) - Granuloma/adhesions - Fat necrosis - Wound interference - Gut stasis - Pododermatitis (on hocks) - in overweight animals

Question 38

Orchiectomy (castration) (rabbit)

Answer 38

- Hormone related aggression - Unwanted litters - Reduce unwanted sexual behaviour or sexual frustration - Testicular neoplasia - Testicular torsion - Once testicles descend - from 10 w, but usually from 5 m

Question 39

Castration anatomical considerations (rabbit)

Answer 39

- Cremaster m - well developed + readily retracts testicles - difficult to find -> pressure on inguinal region will encourage testicle into scrotum - Inguinal ring is open + prone to herniation - perform closed castration or close tunic (after open) - Tunica vaginalis - firmly attached to scrotal skin - section attachment w/ scissors to minimise tissue trauma

Question 40

Ochiectomy complications (rabbit)

Answer 40

- H+ - Evisceration/herniatioin - Wound interference - Gut stasis - Haematoma - Abscess

Question 41

Facial (subcutaneous) abscesses (rabbit)

Answer 41

- Underlying dental disease - radiograph, extract teeth, curette infected bone - Abnormal suppurative reaction -> thick caseous pus - Fibrous capsule - culture capsule, not pus -> give oral/PO AB until abscess has healed - Location can affect Px - Care w/ AB-associated diarrhoea - Guarded Px

Question 42

Facial (subcutaneous) abscesses - complications (rabbit)

Answer 42

- Jaw Fx - Acquired malocclusion - Recurrence or failure to resolve, poor Px

Question 43

Cystotomy - uroliths + sludge (rabbit)

Answer 43

- Have unique Ca metabolism + high levels of calcium excretion compared to other species - Overweight animals, arthritic, gut stasis - reduced exercise levels, low water intake pre-disposed