NTCA Pathology Flashcards
Anaesthetic risks and related morbidity mortality (rabbit)
- 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)
Anaesthetic risks (reptile)
- 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)
Most common endocrine disease in guinea pigs + need for spay
- Cystic ovaries - single/multiple affecting both ovaries, abdo distension
- Non-specific signs
- Functional cysts cause non-pruritic flank alopecia
Spay (gerbil)
- Ovarian cysts
- Neoplasia
Cystotomy (guinea pig)
- Urolithiasis
- Calcium oxalate or calcium carbonate (radioopaque)
Neoplasia (gerbil)
- Neoplasia common in entire males
- SSC, papilloma, benign hyperplasia, epithelioma + poorly differentiated carcinoma
- Start off as benign adenomas -> inc in size, become malignant
Neoplasia (rat)
- 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
Pharyngostomy tube placement (reptile)
- 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
Ovarian pathology -> ovariectomy (reptiles)
- Pre-ovulatory/follicular stasis (Green iguanas. Testudo tortoises, chameleons) - failure of follicle to ovulate -> accumulation
- Bacterial oophoritis (inflam of ovaries/solidified follicles)
- Neoplasia (iguana)
Salpingectomy (reptile)
- 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
Egg binding (reptile)
- Oviduct inertia (chelonia + lizards)
- Radio to differentiate if obstructive
Caesarian (reptile)
- Alternative to salpinectomy
- Where breeding must be preserved
Cloacal Sx - prolapses (reptile)
- 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
Hemipene/penile prolapse (reptile)
- Snakes + lizards - hemipene lesions (located in tail, caudal to vent), coelomic pathology
- Leopard gecko - localised infections
- Chelonia - coelomic/localised pathology (penis located within cloaca)
Hemipene abscessation (reptile)
- Can cause hemipene prolapse
Due to - Mating trauma
- Vit A deficiency
- Poor hygiene
Oviductal prolapse (reptile)
- Significant damage of supporting ligaments
- 2y to unilateral oophoritis + salpingitis
- Blind replacement -> intussusception + recurrence
Urinary bladder prolapse (reptile)
- Rare, chelonia
- Due to urinary calculi - chelonia bi-lobed - pressure from R lobe of liver -> most stones on left bladder lobe
Aural abscessation (aquatic chelonia, reptile)
Husbandry
- Poor water quality/hygiene
- Insufficient water heating
- Failure to provide basking spot
- Dietary deficiencies - vit A
Masses (goldfish)
- Epidermal neoplasia
- Granuloma
Dental Tx (fish)
- Puffer fish
- Constantly growing dental plates
- Lack of attrition in diet -> overgrowth
Air sac tube placement (bird)
- 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
Ingluviotomy (bird)
- ‘Ingluvi’ = crop, incision
- Remove FB/compacted material
Pododermatitis (bumblefoot) (bird)
- 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
Type 1 pododermatitis (bumblefoot) (bird)
- Loss of epidermal structures
- Scab formation
- No deeper changes
Pododermatitis (bumblefoot) (grade II-II) (bird)
- Fibrosis + necrosis present
- Medical therapy alone doesn’t penetrate lesion
Salpinectomy (bird)
- Where repro tract is end stage -> oviduct removal
- Chronic egg yolk peritonitis
- Inspissated (thickened) material in salpinx
- Neoplasia
- Salpingeal stricture
- Reduce ovarian activity
Wing Fx (bird)
- In-flight injury, caged birds damge wings in cage bars
Endoscopy (bird)
- Assessing viscera directly
- Air sac system allows direct visualisation of majority of organs
Leg Fx (bird)
- 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
Syringeal aspergilloma (bird)
- 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
Adrenalectomy (ferret)
- Manage adrenal ectopic sex hormone secretion -> dec hormones
- Dec symptoms of renal disease
Skin biopsy (reptile)
- 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
Thoracic radiographs (rabbit)
- Pulmonary uterine adenocarcinoma metastases (older animals) in lungs
Abdominal radiographs (rabbit)
- Urinary calculi/sludge
Ovariohysterectomy (rabbit)
- 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
Ovariectomy (rabbit)
- If before 1 y/o + no evidence of uterine disease
OVH complications (rabbit)
- 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
Orchiectomy (castration) (rabbit)
- 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
Castration anatomical considerations (rabbit)
- 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
Ochiectomy complications (rabbit)
- H+
- Evisceration/herniatioin
- Wound interference
- Gut stasis
- Haematoma
- Abscess
Facial (subcutaneous) abscesses (rabbit)
- 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
Facial (subcutaneous) abscesses - complications (rabbit)
- Jaw Fx
- Acquired malocclusion
- Recurrence or failure to resolve, poor Px
Cystotomy - uroliths + sludge (rabbit)
- 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