Canine Infectious Diseases Flashcards
What are the main Canine infectious diseases to consider?
» Leptospirosis
» Aspergillosis
» Canine parvovirus
» Canine adenovirus
» Canine distemper virus
» Angiostrongylosis
» Brucellosis
» Toxoplasmosis
»** Giardia, Toxocara**
» Campylobacter, Salmonella
Is infectious disease test results diagnostic?
NO
What infectious dx testing can we do?
- Bact cultures
- Serology
- Cytology / histology
- PCR
Describe a ‘false positive’
- ‘False positive’: previous infection/exposure without clinical relevance (e.g., Toxoplasma antibodies)
- ‘False positive’: previous vaccination
‘False negative’
recent infection (i.e before seroconversion)
or
Inappropriate sample/ sampling site
What rapid in house screening tests can we do?
- SNAP 4Dx Plus (blood)
- SNAP Lepto (blood)
- SNAP Parvo (faeces)
- SNAP Giardia (faeces)
- Angio Detect (blood)
ELISA technology -> detect antibody or antigen
Describe Canine Leptospirosis
- Gr - bact, multiple pathogenic & non pathogenic serovars
- Worldwide
- Resistant bacteria: survivak for many months in water and soil
Who are the reservoir hosts for LEpto?
Mostly rodents & other wildlife
Dogs = accidental hosts
ex: rodent dies in stream and dog drinsk from it
What are the principle serovars dogs wll get with Lepto?
- L. canicola, icterohaemorrhagiae
- L. bratislava, grippotyphosa, australis
What mode of transmission/ entry point?
Usually indirect contact through CONTAMINATED WATER (infected urine)
Entry points: MM or broken skin
What is the pathogenesis of Canine Lepto?
Host entry -> leptospiraemia -> kidneys, livern other organs -> ongoing urinary shedding (renal carrier)
What main CLS of Lepto?
- Lethargy, anorexia, pyrexia
- V+ / D+ PUPD - oliguria/ anuria due to AKI
- Bleeding tendicies (pulm haemorrhages)
- Icterus (cholestatic hepatopathy)
What will we see on blood & urine results with canine lepto?
naine
- Thrombocytopaenia
- Azotaemia
- Inc liver enymes
- Hyperbilirubinaemia
Urine:
- Isothernuria, proteinuria, sometimes glucosuria
How do we diagnose Canine Lepto?
» History: - contact with rats / rural environment / swimming in slow-moving streams – ponds
- unvaccinated dog
» AKI +/- acute hepatopathy (+/- haemorrhagic diathesis)
→ any AKI and/or acute hepatopathy without identified cause: Lepto-suspect until proven otherwise
What diagnostic tests to do for Lepto?
- MAT Serology (Microscopic Agglutination test)
-PCR (on blood + urine before starting ABs) -> quick and quite reliable
Describe MAT serology?
- vaccination → + MAT titers for months (usually low level titers)
- repeat MAT after 2 weeks (to document seroconversion / 4-fold increase)
- cross-reaction between serovars/groups
What Tx for Canine Lepto ?
- ABs (treat before lab confirms)
- Supportive / symptomatic for AKI /hepatopathy
remember to follow up renal function: full recovery vs CKD
WHICH ABs to give for Lepto?
- 1) acute disease / during leptospiraemia: IV penicillin (amoxicillin)
- 2) PO doxycycline (5 mg/kg q12h, 2 weeks)
Switch from 1 to 2 when GI signs controlled
What prevention for Lepto?
- Vaccination
- Core vaccination > new 4 serovars: Leptospira canicola, icterohaemorrhagiae, grippotyphosa, australis
Most routine disinfectants kill lepto
Describe Aspergillosis broadly
- sinonasal aspergillosis: fungal infection from Aspergillus fumigatus
- One of the msot common causes of chronic nasal discharge (+/_ epistaxis) in dogs
- Dolichocephalic breed over represented
How do you diagnose Aspergillosis?
- Cultue of nasal disC
- Serology (variable Se/Sp) (AGID: low sensitivity but false positives = rare)
- CT (destructive rhinits, rhinoscopy (plaques)
- Confirmation: fungal culture, histology
Tx/ management of aspergillosis?
- challenging, relapses possible
- oral antifungals (itraconazole)
- +/- topical treatment (endoscopic debridement + antifungals / sinus trepanation) to increase
chances of successful therapy (but multiple treatments often needed)
Describe broadly canine parvo?
- Highly environmentally resistant & highly contagious virus, caused by strains of PCV-2
- Worldwide occurence, with high morbidity and mortality
- clinical dx MOSTLY in puppies
Pathogenesis of parvoV?
Tropism for rapidly dividing cells (GI tract & bone marrow) -> enteritis & BM suppression (neutropenia) -> secondary bacterial infections/ sepsis
Signs of PArvo?
V+ d+ watery -> haemorrhagi
Anorexia, lethargy, pyrexia, abdo pain
Diagnosis of Canine parvo?
- acute vomiting & diarrhoea (+/- haemorrhagic))
- age
- vaccination status
- neutropenia
- parvovirus detection in faeces:-> in house ELISA or PCR
Tx for Canine Parvo?
- IVT + electrolytes (hypoK common), glucose monitoring
- Early enteral feeding
- ABs (if neutropenic)
- Symptomatic / supportive (anti-emetics, analgesia)
Prevention of parvo?
Vaccination (core), disinfection of contaminated areas (bleach-based)
Broadly describe canine adenovirus
- type 1 (CAV-1) causing** Canine infectious canine hepatitis (ICH)**
- Uncommon diagnosis
- Viraeia with tropism for endothelial cells, various epithelial cells and hepatocytes -> variable systemic dx with coagulopathy & hepatopathy
What clinical presentation of adnovirus?
- pyrexia, lethargy & other non-specific systemic signs
- bleeding disorder / DIC, signs of hepatopathy / liver failure (vomiting, diarrhoea, neurological signs (HE))
- increased ALT/ALP, abnormal coagulation parameters
Diagnosis of adenovirus?
PCR (on secretions or excretions)
Tx & Prevention adenovirus?
supportive tx
Vaccinate & isolate infected dogs
Give broad description of distemper virus?
- CDV belonging to Parayxoviridae family, high mortality rate
- UNcommon diagnosis in UK
- Air-borne aerosols & other modes of transmission by excretions/ secretions
Presentation of distmeper virus?
All infected dogs can present with neuro gisnfs while systemic signs depend on immune system response
usually systemic signs first if any then neuro
Describe neuro signs.
- usually progressive signs: seizures, ataxia, hypermetria, para/tetraparesis, neck pain
- almost pathognomonic: ‘myoclonia’ (focal head / limbs or generalised)
Describe systemic signs of distemper?
t (pyrexia, GI signs, pneumonia (nasal discharge & cough), hyperkeratosis
nasal planum / foot pads & pustular skin lesions)
Diagnosis of distemper?
- clinical signs
- travel history
- (usually incomplete) vaccination history
- PCR on almost any sample type
(recent vaccination with modified-live vaccine: some PCR tests positive)
Tx & prevention of distemper?
- supportive, abs if secondary bact infection
- Prevention: vaccination, isolation of infected dogs
Describe Angiostrongylosis?
» Angiostrongylus vasorum: metastrongylid nematode, infecting canidae (dogs & foxes)
» Patchy distribution in Europe, widespread in UK
» Emerging & increasing prevalence: before mostly south of England, now also more in northern areas
Describe infection with angiostrongylus?
» Adults live in pulmonary vasculature (and right side of heart)
» Dogs become infected by L3 larvae after eating infected intermediate hosts:
molluscs (slugs and snails)
Describe the clinical presentation of angiostrongylus
mainly respiratory signs
* coughing, tachypnea, dyspnea
* right-sided heart failure (pulmonary hypertension)
* bleeding tendency (central nervous signs,…)
* (hypercalcaemia – PU/PD)
Diagnosis fo angiostrongylus?
- Faeces: BAermann flotation (intermittent shedding tho) -> gold standard
- Direct faecal smear (Se 50-60%)
- Cytology or tracheal wash/BAL (larvae)
- AngioDetect (blood antigen) - high Se & Sp but false neg poss
Tx of Angiostrongylus ?
- imidacloprid/moxidectin; milbemycin (MLs) (also for prevention – monthly)
- fenbendazole (7-21 days) (‘slower’ kill method)
(glucocorticoids against post-treatment anaphylaxis)
Describe Brucellosis
» Brucella canis: Gr- bacteria causing chronic disease, mostly reproductive signs
» Clinical disease in dogs & humans (dog = natural reservoir)
» Uncommon, but several cases reported in UK recently
Brucellosis is a reportable dx - what does this mean?
Brucellosis is= legally required to report pos result, but not NOTIFIABLE (where you have to report suspected cases too)
How do dogs get infected?
- infected through urine, aborted materials, vaginal/seminal secretions -> regional lymph nodes -> bacteraemia (months)
What systems does brucellosis affect
- Genital tract
- other: IVDs, eye , kidney
Clinical presentations of brucellosis?
- infertility, abortion, weak puppies; orchitis/epididymitis, prostatitis
- lymphadenopathy, discospondylitis, osteomyelitis, polyarthritis, uveitis, glomerulonephritis
Diagnosis brucellosis?
SEROLOGY send to APHA -> combined SAT & iELISA
SAT: semi quantitiave, false pos & neg possible but good screening test
What other indicators to diagnose brucellosis?
- Hyperglobulinaemia
- Reactive lymphadenopathy
- PCR & culture high Sp but low Se
Tx of brucellosis ?
Prolonged, combination antibiotics needed – not 100% succesful, treatment failure or relapse is common →
often recommendation for euthanasia (zoonosis), especially if clinically unwell
Zoonotic risk of brucellosis ?
make sure lab people know
- exposure to infected fluids/tissue, often laboratory-acquired
- fever, lymphadenopathy; sterility, abortion
ask about travel info & suspected case: do serology first & barrier nurs
Describe Toxoplasma (Zoonoti) ?
» Toxoplasma gondii: intracellular coccidian parasite infecting nearly all warm-blooded vertebrates
» Infection/exposure is common in cats, clinical disease is uncommon in dogs & cats
Who are the natural or intermedioate hosts of toxoplasma?
Cat = natural host - dog/human intermediate host
Intestinal cycle only in felines (excreting oocysts in faeces) - extra-intestinal cycle in all hosts (tissue cysts)
Clinical presentation of toxoP?
Extra-intestinal cycle leadin to hepatic, pancreaticn pulm, eyes, and/or neuroM signs
Diagnosis of ToxoP?
- Ante-mortem diagnosis difficult (PCR, cytology, histo)
- Serology (IgM,IgG abs) (IgG previosu exposure, IgM active dx)
TX for ToxoP?
Clindamycine (12.5mg/kg bid 4 weeks)
Describe Giardia
- Giardia duodenalis, coccidian flagellate protozoan parasite
- common in young animals but GI signs can occur at any age
- Many asymptomati carrier & intermittent shedding
What CLS of giardia?
Small intestine diarrhoea, sometimes wieght loss and vomiting
Diagnosis of Giardia?
(on several pooled faecal samples)
- Fresh faecal microscopy exam (see trophozoites), faecal flotation, faecal ELISA, PR
Tx of Giardia?
FENBENDAZOLE
Prevention of reinfection - contaminated area disinfected
Toxocara info?
- ROundworm , adult nematodes living in SI
- Toxacara anie or leonina
- very common in puppies
CLs in puppies fo toxocara?
D+, weight loss, failure to thrive, (migrating juvenile namtodes: hepatic , pulm, ocular damage)
Diagnosis & Tx of Toxacara?
Dx: faecal flotation
Tx: anthrlmintics
Prevention toxaara?
deworming at 2, 4, 6, 8, 12, and 16 weeks of age, then at a minimum of 6-month intervals
Campylobacter describe
» Gr- curved rods
» C. jejuni = species most commonly associated with
diarrhoea in dogs, cats, humans – most other species are
non-pathogenic
Diagnosis of Campy?
Fresh faecal analysis: culture, PCR
Salmonella general info?
» Gr- bacillus of Enterobacteriaceae family
» Primarily intestinal bacteria, but can cause systemic
disease (sepsis)
REPORTABLE DX IN DOGS
Diagnosis Salmonella?
Enriched culture or PCr on frrsh faecal smaple
BOth Campy & Salmonella are ……
ZOONOTIC
Signs & Tx for both campy & Slamonella?
» Acute haemorrhagic enterocolitis = main clinical presentation
» Pyrexia, lethargy, anorexia, vomiting, diarrhoea (watery, mucoid, haemorrhagic)
» No antibiotics for uncomplicated disease, only when signs of sepsis
» Isolation / barrier nursing in wards
» Hygienic measures for all faeces
