SA Airway Disease Flashcards

Question

Describe the lung pattern here

Answer 1

Lung pattern – bronchial pattern, can see tramlines and doughnuts on both sides Also looks like a bit of an interstitial component also as not as black as it should be. Exudate within lumen, inflammatory process

Answer 2

•Interstitial pulmonary Fibrosis (IPF) – once you have heard one, you don’t forget it! –Typically in WHWT and other terriers (Staffordshire BT) –Middle aged to older dogs –History * Insidious onset – chronic onset, similar picture of humans with chronic emphysema * Chronic breathlessness which is slowly progressive * Coughing can be a feature * Exercise intolerance * Owner may notice cyanosis * Can cause syncope

Answer 3

–Clinical examination * Crackles throughout the lung fields – diffuse and dry * Prolonged expiratory phase with expiratory effort.

Answer 4

–Suggestive clinical signs •Diffuse crackles on auscultation, dyspnoea, coughing –Thoracic radiographs –Generalised interstitial lung pattern –+/- right sided cardiomegaly, +/- pulmonary hypertension –CT – method of choice in humans •Typical ground glass appearance – diffuse increase opacity without loss appearance of blood vessels. –Bronchoscopy –BAL samples are either normal or show low cellularity –Rules out other inflammatory conditions – primarily CB –Lung biopsy is the only method of definitive diagnosis –Relatively poorly understood compared with human fibrotic lung diseases –In absence of biopsies, efficacy of treatment difficult to determine * Lung pattern generally reflects severity * Bld gases – severely affected individuals can show hypoxia and show ventilation – perfusion mismatch

Answer 5

* Idiopathic pulmonary fibrosis. Pulmonary hypertension * Severe interstitial/alveolar pattern * Generalised cardiomegaly. Right sided emphasis. Abdominal distension * Airway with IPF, wide trachea – a lot of effort to breathe, may have degree of instability. Also got interstitial pattern and a heart that’s big

Answer 6

–Success of therapy depends largely on whether active inflammation present – depends on if its inflammatory or non-inflammatory –Symptomatic treatment •Avoid collars, harness only, avoid smoke inhalation –Inhaled therapy •Bronchodilator, corticosteroids –Oral therapy * Bronchodilators - especially if concurrent airway collapse * Corticosteroids –Additional immunosuppressive medication * Azathioprine and cyclosporin * No evidence of clinical efficacy –Antibiotics as necessary –Anti-fibrotics (e.g. colchicine) * Theoretically slows collagen deposition and reduces production of profibrotic cytokines * No evidence for efficacy of these in veterinary patients * No evidence of improved outcomes in humans either –Management of pulmonary hypertension – secondary complication of the fibrotic lung, if you can improve this right sided compliance and the hearts ability to get blood into to the lungs can improve •Phosphodiesterase inhibitors –Sidenafil, tadalafil –pimonbendan

Answer 7

–Guarded as this is a progressive disease –Long-term palliation of clinical signs may be possible with combination therapy –Reports in dogs suggest around 15 ½ months median survival times * Some dogs reported to survive up to 4 years * In humans the DIP form of the disease shows markedly improved prognosis over UIP * This would suggest in dogs that the prognosis is heavily dependent on biopsy findings

Answer 8

* Historically regionally endemic in UK * Now accepted to be widespread in South of UK and wales, with reports arising of infections in northern UK and Scotland * Rural environments were the mainstay of distribution initially * Becoming more widespread throughout the country due to increased fox urbanisation and more widespread travel with dogs * Also endemic in regions of Spain, France, Hungary, Germany, Italy, widespread in Ireland • •Big challenge is identifying it. Something you saw down south originally, but has spread more so now as people travel with their dog – UK wide problem. Less so in the states. Big issue is that it causes a lot more than just what you’d expect, but the most common problem this gets referred is because of coagulopathies. Any animal that has a clotting problem, that you check for lung worm.

Answer 9

–Clinically - anaemia, subcutaneous haematomas, internal haemorrhages, prolonged bleeding from wounds or after surgery –Thrombocytopenia, prolonged APTT and OSPT, elevated D-dimer (previously measurement of FDPs was used) –via consumptive coagulopathy – chronic DIC •Studies have shown deposition of immunoglobulins, complement and fibrinogen in pulmonary vessels –Also causes immune mediated thrombocytopaenia –Similar pathophysiology can lead to thrombopathia –Parasite releases – or stimulates host to release – factors that modulate blood clotting?

Answer 10

–Paresis, depression, seizures, spinal pain, behavioural changes, ataxia and loss of vision have been described –Associated with aberrant nematode migration or subdural haemorrhage secondary to coagulopathies –Either because they may have bled into spinal cord or parasite migration through their parenchyma.

Answer 11

–Adult antigens * Cause Type III hypersensitivity (immune complex deposition) * Complement activation * Immune infiltrate in lungs and other tissues –Egg deposition/L1 * Pulmonary inflammation/granuloma formation * Pulmonary arteriolar vasoconstriction * End arteritis and fibrosis of vessels –Eggs, larvae and adults can all cause problems

Answer 12

A. Vasorum L1 in BAL Lots of eosinophils and coiled up larvae on left Right – coiled up view

Answer 13

* SNAP test from IDEXX * PCR – on BAL or pharynx swabs

Answer 14

–Over recent years products have become licensed •Previously no licensed products available in UK –Licensed products: * Advocate (Bayer), Prinovox (Virbac) spot on - (Imidacloprid and Moxidectin) – licensed * Milquantel (MSD), Milbemax (Elanco), Milbactor (Ceva) – milbemycin oxime and praziquantel – licensed –0.5mg/kg milbemax orally –Given 4 times at weekly intervals –Studies have also used 2 doses a month apart in the pre-patent period –Unlicensed products: •Fenbendazole – effective but unlicensed used at 25-50mg/kg orally for 7-21 days, some people suggest treating at weekly intervals every 3 weeks for 3 treatments –Some clinicians start with a low dose to reduce the complications of acute treatment deterioration from massive worm death and liberation of worm Ag – 20mg/kg orally •Levamisole and ivermectin also effective but unlicensed –alternative products are equally effective and licensed with fewer potential side effects

Answer 15

* Treatment and prophylaxis are different… * Dogs with sever lungworm, when you start treating, if all worms die – can get anaphylactic shock from this and the dog can look much worse! So be careful that when you start the treatment, warn owners the dog might die with treatment!! Don’t underestimate the severity of the disease

Answer 16

–Need to counsel owners about the risks of beginning therapy for Angiostrongylus –Considerations for supportive treatment in addition to anthelminthics with infections that have been identified •Bronchodilators –Aid with airway hyperresponsiveness •Corticosteroids –May reduce tendency for acute deterioration after beginning anthelminthic therapy * Phosphodiesterase inhibitors – for ongoing PH * Cage rest and possible oxygen therapy – keep them rested when you start treatment as if you have made them worse by increasing inflammation with dead lung worms, decreased lung capacity even more! –if dyspnoea present •Considerations for haematological dyscrasias –May be ongoing despite therapy for angiostrongylus

Answer 17

–Limited licensed products for prevention •Advocate and Prinovox (moxidectin and imidacloprid) –Evidence suggests treatment in pre-patent period with Milbemycin oxime or moxidectin decreases or prevents establishment of adult parasites –Unclear to what extent dogs are protected from reinfection by persistence of macrocyclic lactones nor how severity of disease relates to level or stage of infection –Dogs in endemic areas treated every 3 months with milbemycin are half as likely to test positive for angiostronglyus as those treated with fenbendazole or untreated * Important to have an idea of local epidemiology * Difficult to control slugs and snails but can reduce time dogs are in contact by more active exercise regimes – its contact with contaminated trails also! Not just eating them themselves, but avoid any contacted material

Answer 18

Pulmonary embolism (PE) is a blockage of an artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream (embolism) ## Footnote –Occur and they are difficult to identify –Acute onset dyspnoea –Few radiographic signs – because clot may have resolved by the time they present

Answer 19

–Often associated with hypercoagulable states * Trauma/surgery * Sepsis/DIC * HAC/exogenous corticosteroids * HypoT4 * IMHA * Glomerulonephropathies –Pulmonary hypertension –Its supportive care whilst their clots are being dealt with by the body and reducing the chances of other clots forming

Answer 20

* Hyperthermia/heat stroke/fever * Obesity * Excitement/fear/stress/pain/shock * Parturition/false pregnancy/eclampsia * Anaemia/abnormal haemoglobin * Acidosis – does it have DKA? * CNS disease – any changes in central control of breathing? * Endocrine dz, e.g. HAC & steroid tx, hypert4 * Neuromuscular disease where there is diaphragmatic weakness?