Internal medicine of small animals Flashcards
Skin diseases - Pyoderma, pyotraumatic dermatitis, pododermatitis
Pyoderma - superficial/deep
S.intermedius (dog)
S.pseudointermedius (cat)
-Once primary (commenal) bacteria colonise –> 2ndary e.coli/pseudomonas
SURFACE PYODERMA
pyotraumatic dermatitis
-self-trauma (pruritis, pain, allergy)
Intertrigo (skin fold pyo)
- S.intermedius or Malassezia pachydermatis
- Folds = moist, warm, irritated
- exudative + malodorous
SUPERFICIAL
impetigo (puppy pyoderma)
-<1yr, Multifactor (nutrition, environment, parasites)
-pustules on ventrum
Pododermatitis (ALG)
-Stress/anxiety
Allergies
-parasites, contact, food, inhalant
Malassezia
-pruritus malodorous (can be sweet)
Localised demodicosis
Plasma cell pododermatitis
-AI (FIV?) T: cyclosporin
Cs: lesion, malodour, discharge
Dx: Scrapes, swabs, biopsy or vesicle fluid
-culture, KOH stain
T: peroxide shampoo, chlorhexidine, iodine, ATB, fluconazole
SKin disease - folliculitis + furunculosis
Superficial folliculitis
-Infection of hair follicle
-Primary: S.intermedius following trauma,
-Secondary: systemic illness (lowered IS), malassezia or pseudomonas folliculitis
Cs:Moth eaten ventrum
irritant folliculitis
chemical folliculitis
occlusive folliculitis (canine acne) -overuse of emollients
Keratosis pilaris
-Follicles clogged with keratin
Deep folliculitis (hair follicle) + furunculosis (follicle + hair)
- S.int, pseudo, proteus, e.coli
- Superficial –> deep –> destroys hair –> disseminates bacteria
- If left –> cutaneous LN’s –> Lymphadenopathy + generalisation
Sycosis vulgaris
-“Barbers itch” –> post clipping irritation and infection
Eosinophilic furunculosis of face
-Occurs in dogs usually idiopathic
-Callus pyoderma
Cs: much more common on pressure points, ulceration, pus weeping, fistulation
Dx: deep scrapes , cytology, culture
T: topical (Iodine, peroxide, chlorhex) + systemic (ATB)
Recurrence? (think…)
- Long term steroid use?
- Consider Atb’s
- FAD? (other ecto’s)
- Atopy?
Skin diseases - Alopecia
Alopecia
-Focal, multifocal, diffuse, symmetrical
Mechanisms
-Self-trauma, folliculitis, endocrine, anatomical (follicle)
Primary
- Genetic
- -Alopecia X (sex hormone imbalances)
- -Pituitary dwarfism (hyposomatotropism)
- -Canine pattern baldness
- -Bald thigh syndrome
- -Hairless breeds (Sphynx cat, chinese crested dog, xolo)
- Neoplastic
- Epitheliotrophic leukaemia
- Inflammatory
- -Post clipping alopecia
- -injection reaction
Auto-immune
- -Alopecia areata
- -pemphigus
-Demodecosis
Secondary Endocrine -Hyperadrenocorticism (Cushings) -Hypothyroidism -Hyperoestrogenism
Stress
–feline psychogenic alopecia
Nutritional
- Vit B1, 2, 3, 5, 7
- Vit A + C
Onset
- Gradual : endocrine/nutritional
- Rapid: inflammatory, parasitic
- Seasonal: FAD, ectoparasites, allergies (atopy)
Distribution
- Dorsal –> lumbosacral = FAD
- Diffuse = bacterial
- Symmetrical = endocrine
Pruritic skin diseases
Signs
-trauma, saliva staining, alopecia
Age
- young : FAD, ectoparasites, genetic
- Old: Endocrine, allergy
- Seasonal?
Conditions
Parasitic - Demodex, sarcoptes, fleas, flies, mites, lice
Fungal - dermatophytosis (m. canis), malessezia
Bacterial pyoderma - primary and secondary
Viral - Mad itch (Pseudorabies)
AI - pemphigus
Endocrine - cushings, Hyper and hypo T4
Chemical - contact dermatitis, photosensitivity
Dx
- Parasites/infectious –> Allergies –> AI
- Scrapes/culture –> elimination diet ID skin test –>
Milliary dermatitis + eosinophilic complexes
Miliary dermatitis
Generalised or localised
Often develops in cats as a reaction to allergy
Due to FAD, Food allergy, Environmental allergy (Atopy)
Cs: sand like skin, grooming, 2nd trauma
Eosinophilic complexes
common inflammatory lesion of cats
usually atopy, food allergy or ectoparasites (FAD)
Ag-Ab –> recruits eosinophils
Eosinophilic (Feline indolent) ulcer -upper lip Feline eosinophilic plaque -Ventral abdomen Feline eosinophilic granuloma -foot pads (occasionally mouth) Eosinophilic furunculosis of face -Occurs in dogs usually idiopathic
Dx: cytology/histopath (eosinophils)
T: Steroids can be used if underlying isn’t infectious
Cyclosporin, anti-histamines
Atopy, FAD, food sensitivity
Atopy
- Genetic response to environment Ag’s
- 3 mnth –> 6 yr onset
- Facial alopecia
- Cyclosporin, preds, anti-serum immunotherapy
Food sensitivity
- presents <1 year
- Elimination diet
FAD Cnemidocoptes canis, felis Purlex irritans 3-5 years onset Cause Fe2+ def anaemia + transmit D.caninum FAD --> Hypersensitivity I + IV
Flea control
- Adovate (Imidocloprid + moxidectin)
- Frontline PLUS (fipronil + Methroprene)
- Frontline (Fipronil)
Cs:
Dogs - facial, digital alopecia and otitis ext
Cats - miliary dermatitis, eosinophilic ulcers
Dx
- Parasites/infectious –> Allergies –> AI
- Scrapes/culture –> elimination diet ID skin test –>
DDx: Atopy = seasonal, Food allergy = Non-seasonal
Ear diseases (otitis ext, med, int) + skin adnexa
Skin Adnexes
Sebaceous adenitis
inflammation of sebaceous gland –> destruction of gland
Cs: silver dandruff
T: Anti-seborrheic shampoo + cover with baby oil
Seborrhea
Over production of keratinocytes
primary - hyperkeratosis (distemper)
secondary (FAD, Ectos, atopy, self trauma)
Cs: scaling of pressure points and nose
Dx: Histopath (para/hyperkeratosis)
T: Keratinolytic (removes excess keratinocytes)
Keratinoplastic (normalises keratinisation)
Vit A, Vit D3, cyclosporin, preds
Ear diseases
Long/floppy ears
Primary - FB, neoplasia, AI, parasites
secondary
Otitis externa (often results in haematoma)
5-8 years
-Otodectes cynotis (mostly cats) - dark + dry
-Allergies (FAD, food, Atopy)
-FB
-Infectious (s.int, pseudo) - moist, yellow, smelly
-Fungal - waxy + brown
-endocrinopathies (Hypothyroidism, hyperoestrogenism)
-AI (Pemphigus)
T: Do not use in rupture ear drum (ototoxicity) Chlorhexidine, ATB's Auriflush Ceruminolytic agent cleaning and drying Steroids
Otitis media (tympanic mem, ossicles, tympanic nerve)
-Horners syndrome (ptosis, miosis, enopthalmus, 3rd eyelid prolapse)
T:
Bulla osteotomy, ear ablation
Otitis interna (cochlear, vestibular + semi-circ canals) Ventroflexion, torticolis, rolling, circling, nystagmus - vestibular syndrome
Dx:
Otoscopy + swab
contrast canalography
myringotomy (sample of ear fluid)
Tumours of skin and subcutis
Basal cell tumour - more common in cats
-Maybe pigmented, head + trunk
Mast cell tumour - most common skin tumour of dogs
Grades
-1: Cell differentiated well
-2: Cell semi-differentiated
-3: Cells not differentiated, high Mx chance
Darier’s sign: skin becomes red and irritated on palpation due to hyperreactive mast cells
Adenomas/adenocarcinomas
Cerumin glands (ear) - ear ablation
Sebaceous glands (skin) - rare in cats (self limiting)
Apocrine gland (Anal sac) - near anal sac
Peri-anal gland - Castration (androgen stimulated)
Melanoma
Solitary brown/black mass (ulcerated = malignant)
Occular in cats
Histiocytoma - button tumour
benign tumour of histiocyte (skin macrophage)
Papiloma/lipoma
-benign lumps
Squamous cell carcinoma
Related to sun damage –> non-healing ulcer
Cutaneous lymphosarcoma
-older animals (8-10years) linked to FeLV
TVT
Only dogs
Keratoacanthoma
Benign tumour of cells between hair follicles
young dogs only
Epidermal cysts
- inclusion: acne
- Dermoid: developmental abnormality (filled with hair, skin, pus, keratin)
Dx: Biopsy, tumour factors, clinical appearnace
T: Excision (capsular, marginal, wide), chemo (vincristine), radiotherapy
Immune-mediated diseases (pemphigus, lupus, AIHA)
Lupus
Systemic lupus erythematosus
Ab development to DNA, RBC, WBC, Platelets
Inflammation damages skin, joints, kidneys, anaemia
Skin lesions have boarder (lupus band)
Discoid lupus erythematous
similar to SLE –> mainly on face only
pemphigus complex
Ag-Ab to epithelial cells –> desmosome lysis –> acantholysis –> sloughing + clefts
P. Vegetans - benign
P. foliaceus - most common (head, ears, pads)
P. erythematous - as PF + photosensitivity + nose depigmentation
P. vulgaris - bullous lesions of palate or rectum
Dx:
IFA - samples from lesion boarders
Histopathology (acantholytic cells, inflammatory cells)
AIHA
Type II. Primary or secondary (inf, drugs, maternal)
Dx: Coombes test (binds Ag’s attached to RBC’s)
T:
immunosuppressives (cyclosporin, clenbuterol, azathioprine)
Steroids (act to suppress immune system)
Hypothyroid, hyperthyroid, hyperparathyroidism
Hypothyroidism
Dogs > Cats
Types: juvenile or acquired (primary/secondary)
Cs: bilateral alopecia, lethargy, obesity, cold, bradycardia
Dx: serum or free T4
Hyperthyroidism
Cats > Dogs
95% adenomas
Cs: Polyphagia, PU/PD, weight loss, excessive licking alopecia, goitre (USG)
Dx: T3 suppression - response to TSH -Apply T3 for 2 days (3x/day) -normal: T4 and TSH suppressed -Hyperthyroid: T4 high and TSH low (unchanged)
TSH stim test
Measure T4 pre and post appliation of TSH
-Normal: T4 increases
-hyperthyroid: T4 unchanged
T: oral antithyroid (thiamazole), surgical removal
Hyperparathyroidism
PTH –> stims Ca abs in GIT and release from bones
-Primary: adenoma
-secondary: hypocalcemia, hyperphosphatemia
Cs: hypercalcemia –> muscle weakness
T: calcitonin, surgical
Diabete mellitus, acromegaly, insulinoma
DM
B-cells of islets of langerhan
Type I - insulin dependant (Dogs) - inherited
Type II - non-insulin dependant (Cats) - obesity, acromegally, cushings, pregnancy (tissue has reduced response to insulin)
Transient diabetes
-stress –> hyperglycaemia –> prolonged insulin secretion (lowers tissue response)
Islet amyloid polypeptide (IAPP)
- lowers glucose sensitivity in pancreas (less insulin)
- lowers tissue insulin sensitivity (glucose stays in blood)
- Increases hepatic GNG
- Hyperglycaemia
Cs: PU/PD, Polyphagia, weight loss
–Glucose cannot enter cells –> fat/protein metabolism
UTI’s - glucose in urine
Retinopathy - increase BP
Ketoacidosis - lipid metabolism
Dx: Bloods (hyperglycaemia), Liver enzymes, Hepatic lipidosis (increase fat metabolism), Urinalysis (Glucose 8-10mmol/L, SG >1.015, ketones)
Insulin supplementation
-human or porcine insulin
Fructosamine
-long term blood sugar, allows us to determine owner compliance
OVH
-80% DM in complete females related to hyperP4
Somogyi effect - high insulin dose –> hypoglycaemia –> overswing to compensate –> hyperglycaemia –> next insulin dose is ineffective
Acromegaly Pituitary neoplasia --> GH increase Increased progesterone --> GH increase Anabolic effects down regulates insulin receptors = DM enlarged Jaw and feet + organomeglly
Insulinoma Insulin secreting tumour Hypoglycaemia --> neurological symptoms Surgical removal --> risk pancreatitis Diazoxide --> insulin antagonist
Polyuria/Polydipsia DDx
PU
Physiological urine output: 20-45ml/kg/day
Hypothalamus regulates hydration with ADH
PD
Physiological water intake: 20-70ml/kg/day
Factors:
Diet - high in salt, low protein (albumin)
Medication - diuretics
Persistent urethral obstruction
Potential aetiologies
- Addison’s
- Cushing’s
- DM/DI
- Hyperthyroidism
- Hepatic disease
- Pyometra
- Renal failure
Dx
Urinalysis
-Glucosuria - DM or renal damage
-Pus/bacteria - glomerulonephritis
Bloods
- increased PCV + Pancytopenia = HyperT4
- Stress leucogram = pyelonephritis, pyometra
- Non-regenerative anaemia = renal/liver failure
- No stress leucogram in sick animal = addisons
Biochemistry
- Hyperglycaemia - DM
- Azotemia - Renal, pyelonephritis
- Hyperkalemia + hyponatremia - Addison’s
- Hepatic enzymes - Liver failure
Specific tests
- ACTH stim test - Addisons/cushings
- T4, fT4, T3 suppression test - HyperT4
- ADH test - DI
- water deprivation test - DI
- creatinine clearance test - renal function
- Urine culture - pyelonephritis
- Radiographs + USG - pyometra, bladder
Hyperadrenocorticism (Cushing’s) Hypoadrenocorticism (Addison’s), Diabetes inspididus
Hyperadrenocorticism (Cushing’s)
Primary (non-pituitary) - Adrenal neoplasia (20%)
Secondary (pituitary) - Pituitary neoplasia (80%)
Iatrogenic - prolonged steroid use
Cs: PU/PD, Pot belly, Polyphagia (4 P’s), bilateral alopecia
Dx:
Bloods - stress leucoram
Biochem - Low T4 (cortisol suppresses), low BUN (due to PU)
Liver enzymes (ALP,ALT, cholesterol, hyperglycaemia)
Urinalysis
Glucose (DM is usually concurrent in cats)
Proteinuria
Specific testing
Cortisol-creatinine ratio (<13IU/L - not cushings)
ACTH stim test
-give ACTH and measure cortisol in blood, if increases = cushings
Low dose dex supp test
- 0.01mg/kg of dex
- measure in 4 + 8 hours
- if no suppression = cushings
High dose dex supp test
- 0.1mg/kg of dex
- 8 hours later
- Pituitary cushings - suppression
- Adrenal cushings - no change
USG/MRI
Treatment Medical -mitotane (cytotoxic to addrenal) -Trilostane (enzyme competitor) Surgical -Hypophesectomy
Hypoadrenocorticism (Addisons)
Primary - adrenal cortex destruction
–Disrupts mineralocorticoids (aldosterone) –> hyperK and hypoNa
Secondary - pituitary destruction
-Lower ACTH so less cortisol but no disruption to MC’s (no K or Na disruption)
Cs:
PU/PD (loss of Na = water loss)
Bradycardia (increased K)
Acidosis (increased K)
Dx: Biochem: lowered aldosterone --> loss of water, Na + Cl and increase in K BUN increase (lower GFR - hypovolemia)
ACTH stim test
- Primary: cortisol increased, aldosterone decreased
- Secondary: only cortisol is decreased
Treatment
- Fluids (hypovol) + electrolytes
- Bicarb –> acidosis
- Dex (fast acting), hydrocortisone (slow)
- MC’s if primary
Diabetes insipidus
Central = ADH deficiency
Nephrogenic = no renal responce to ADH
Congenital / acquired (neoplasia)
Cs: PU/PD –> neuro signs if severe
Dx:
Water deprivation test –> if losses >5% (BW) or SG: >1.030 = DI
ADH + WDT
Concentration of urine = central
Non-conccentration = nephrogenic
Treatment:
Central - Desmopressin (synthetic ADH)
Nephrogenic - Thiazide (diuretic)
Upper respiratory tract disease
Nose + nasal cavity
Foreign bodies
Tooth root abscess or oronasal fistula
Fungal rhinitis (cryptpococcus, aspergilus) Dx - Wrights stain --crypococcus = capsule, aspergillus = hyphae
Feline upper respiratory tract infection
-Herpes, calici, chlamydia
Neoplasia –> turbinate atrophy
Allergy
-eosinophils on blood
Naso-pharyngeal
especially eustacian tube
Nasal mites
capillaria
Cs: Uni/bilateral discharge, shaking head, sneezing
Dx: endoscope, X-Ray
OROPHARYNX
Laryngeal paralysis
-hyperthermia (panting), syncope (exercise)
Dantrolene (relaxes larynx)
Laryngitis
-KC, FB, Neoplasia
TRACHEA
Collapse
-small dogs especially, chondroitin deficiency
-cervical : inspiration
-thoracic: expiration
-Grades 1-4
-T: chondroitin supplement, horizontal mattress suture (1+2), prosthetics (2+3)
Tracheal hypoplasia
- brachycephalics
- Dx: X-Ray (trachea should be 3x width proximal ribs)
Primary ciliary dyskinesia
- congenital defect
- Dx: photoscopy, semen (tails are cilia)
Kennel cough
- Primary viral - CAV-2, para-influ, distemper, herpes
- Secondary bacterial - Bordetella, mycoplasma, pseudomonas
Brachycephalic syndrome
Anatomical abnormalities due to genetic selection
- stenotic nares + short nose
- elongated soft palate
- tracheal collapse/laryngeal collapse
- turbinate abnormalities
- hypoplastic trachea
Cs: dyspnea, snoring, swallowing issues, syncope, laying dorsal, hyperthermia
Dx: Breed, sinus arrthymia, X-Ray (soft palate enlongation and hypoplastic trachea), Laryngoscopy
During an episode: cool, intbuate, bronchodilators, steroids
T: Widen nares, shorten soft palate, widen larynx, tracheostomy
Keep weight down
LRT - Bronchi and lungs
BRONCHI
Kennel cough
Bronchiectasis
-irreversible dilation of airways (proteases neutrophils)
LUNGS
Bronchopneumonia
Factors - ciliary clearance, immune system, parasites, infection, aspiration, neoplasia
-B: mycoplasma, bordatella, pseudomonas
-V: CAV-2, Herpes, calici, Para-influ, distemper
-F: cryptococcus, aspergillus, histoplasma
-P: Angiostrongylus + aerostrongylus, pneumococcus
Non-cardiogenic pulmonary oedema
Increased thoracic pressure
Diuretics
Pulmonary eosinophilic infiltration
due to parasites or allergies
Pulmonary fibrosis
- Multi factors: genetics, irritants, infection
- Thickened alveoli –> destruction –> hypoxia
Pulmonary neoplasia
- 80% secondary Mx
- 20% Primary
Dx: BAL, X-Ray (alveolar/bronchial pattern), doppler USG
T: NSAID’s, bronchodilators, anti-tussives, mucolytics
Diseases of Pleura + Mediastinum
Pleura Pleural effusion fluid in the plural space -increased production / decrease clearance (absorption) Results from -Heart failure -renal failure -hypertension -hypoalbuminaemia -torsion or lungs -diaphragmatic hernia -pancreatitis -Thrombo-elbolism
Chylothorax - Lymph
Pyothorax - spetic inflammation
Haemothorax - coagulopathy, Vit K, Trauma
Dx: X-Ray - elevated heart from sternum, thoracocentesis, USG
T: O2, diuretics, bronchodilators, vasodilators, fluids, anti-arythmics, thoracocentesis (7-9 ICS)
Mediastinum
Mass
-Tumour (lymphoma, thyroma)
-abscess, cysts, haematoma, granuloma
Pneumothorax Open or Closed (fault in pleura make air leak from lungs) Types: -spontaneous -traumatic -iatrogenic -infectious -tension
As more air enters thorax (pressure goes up) and leaves less space for the lungs to inflate –> hypoxia
Flail chest/paradoxical breathing
Penumomediastinum
-Tracheostomy, bite wound, intubation, sudden thoracic pressure change
LRT - chronic bronchitis + feline asthma
Chronic bronchitis - obstructive
-Inf = neutrophils –> hypertrophy of goblet cells –> excess mucous production
Isolated cough for >2 weeks + BAR
Feline asthma - restrictive
-Inf to environmental Ag’s –> fibrosis of bronchi –> emphysema (destruction of bronchi walls)
Cats only cough with asthma
Dx: Bloods = Neutrophilia (CB), Eosinophilia (FA) X-Ray = Bronchial pattern Bronchoendoscopy (thickened/emphysema) BAL - cytology and culture
T:
O2, steroids/ATB (depending on if infectious), bronchodilators, anti-tussives, mucolytics, NSAID’s
Congenital heart diseases
Dogs must be >12 months of age to recieve congenital status
PDA - patent ductus arteriosus
Shunts the arcus aortae + pulmonary artery
Pressure increases in PA and decreases in aorta
Pulmonary oedema and left sided hypertrophy
T: guide wire with fluroscope from femoral artery to heart and occlude PDA (amplatz canine ductal occluder)
Open heart surgery
Atrial septal defect - PFO (patent foramen ovale)
Usually closes at birth
Ventricular septal defect
L –> R more common due to pressure
Pulmonic stenosis
R hypertrophy (more work)
congenital, infectious
Aortic stenosis
- Sub, aortic, supra
- Concentric hyperplasia
- myocardial ischemia
- arrythmia (V-Fib)
R- Ascites, thrills and distended jugular
L- Pulmonary oedema
T: shunt, balloon catheter, defib for (vfib)
Valvular defects
Mitral
Tricuspid
regurgitation –> lower stroke vol –> hyperplasia
ToF (tetrology of fallot)
- Right Vent hyperplasia
- Ventricular septal defect
- pulmonic stenosis
- dextroposition of blood
- -02 <80% saturated = syncope
Diseases of myocardium (cardiomyopathy)
Diseases of myocardium (without inflammation)
Primary / Secondary
Types of CM
Hypertrophic - more wall less chamber (male cats)
Diastolic failure (less filling)
Tachycardia
Dilated (>60% cases) Often large barrel chested dogs dilated chambers = loss of contractility systolic failure (less ejection)
Restrictive
Less relaxation + normal to decreased contractility
Fibrotic effusion in pericard –> fibrous myocard (rigid not thickened)
-Amyloidosis, calcinosis
Cs: Resp, Ascites, thromboembolism (Hind Limb paralysis)
Dx: Doppler, USG, ECG
Arrhythmogenic right ventricular cardiomyopathy
- inherited in boxers
- syncope
Myocarditis
- B: Borrelia, bacillus anthacis
- V: Parvovirus
- P: Dirofilaria, angiostrongylus
T:
Diuretics (furesomide)
beta blockers (anti arythmics - propranolol)
Diltiazem (Ca2+ blocker) relaxes myocard
Lowered Na diet
Vasodilators (Fortekor - benzapril ACE inhibitor)
Diseases of the valves and pericardium
VALVES
Mitral valve insufficiency
Regurgitation causes hypertrophy + dilation
Primary - ruptured cordae tendinae
Secondary - mitral dysplasia
Secondary - following dilated or hypertrophic CM
Cs: Pulmonary oedema
Dx: ECG - wide P (atrial enlargement). Tall QRS (ventricular enlargement)
Tricupid valve insufficiency Hypertrophy + dilation Ascites, hepatosplenomegaly Cs: Jugular distention, swollen abdomen Dx: ECG - Tall P waves
T:
ACE inhibitors (vasodilator)
Diuretics
Ionotropes (anti-arrythmics - Beta blockers or Ca2+ channel inhibitors)
Aortic valve insufficiency
Blood regurgitates into the LV causing hypertrophy
ECG - Tall R waves
Valvular + sub-valvular aortic stenosis
LV hypertrophy
Lower perfusion of coronary arteries = myocardial infarct
T: Stent
Pulmonic stenosis
RV hypertrophy
PERICARDIUM
Pericardioperitoneal diaphragmatic hernia
-Rare defect in diaphragm + pericardium allowing abdominal contents to enter pericardial space
Pericarditis infection --> exudate --> fibrous adhesions B - Mycobacteria V - FIP, Parvo F - Coccidiomycosis Dx: Pericardiocentesis
Pericardial effusion
Fluid increase –> tamponade
Hemangiosarcoma (dogs), lymphoma (cats)
