Dog/ Cat Bacterial Infections

Question 1

Common themes of bacterial infections

Answer 1

• Often secondary, If diagnose often need to find out what the primary is
• Isolation does not necessarily equate to clinical relevance.
• Sometimes difficult to interpret a positive result.
• Carriers – clinically normal animals, shedding bacteria
• Antibacterial resistance must be considered.
– is treatment of bacteria always necessary?
• Often not species specific raising questions of zoonosis (and reverse zoonosis).

Question 2

BActerial infections of dogs

Answer 2

• Salmonella
• Campylobacter
• E.coli
• Leptospirosis
• Borrelia
• Staph
• Ehrlichia
• Tetanus – talk about last 3 another day as primarily in relation to other species
• Botulism
• Brucella

Question 3

Facts about salmonella

Answer 3

Opportunistic
1. BActeria
2. Gram negative
3. Family enterobacteriaceae
4. Infect wide range of animals, birds and reptiles
5. Gasteroenteritis in humans
6. Food borne most common transmission
• Carried by healthy animals – reservoir (carry without showing symptoms of infection
• Dogs, cats & reptiles – turtles, lizards, snakes, frogs etc – leave salmonella traces in through house if left to free-reign, faeces.
o 10-100% reptiles can shed it
• High incidence in young children  due to them testing things with mouths etc
• Outbreak linked to feeder mice

Question 4

what is illness from salmonella called?

Answer 4

Salmonellosis

Question 5

Talk about salmonellosis
infection vs disease?
Lots of serovars?

Answer 5

• Infection much more common than disease
– 1-5% normal cats shedding
– up to 25% dogs < 6 months old
• Possible cause of ‘garbage guts syndrome’ in puppies and kittens (e.g. from food or wild birds/rodents).
• Wide range of serovars involved (whatever is local) mostly belonging to Salmonella enterica subspecies enterica…

Question 6

How is salmonella transmitted?

Answer 6

• indirect: Ingestion of contaminated (raw) food, water or fomites (contaminated by infected faeces)
• Direct contact with an infected animal or human (less common)

Question 7

What are clinical signs of salmonellosis?

Answer 7

1. Pyrexia
2. Anorexia
3. Vomiting and diarrhoae
4. Abdominal pain
5. Bacteraemia
6. Abortion. stillbirth
7. Severe disease in some individuals

Question 8

How do you diagnose salmonellosis?

Answer 8

• Isolation of Salmonella from faeces

* Infected dogs shed for 4 to 6 weeks – some become carriers

Question 9

How do you treat salmonellosis?

Answer 9

1. Local GI disease (a bit unwell, little diarrhoea) DO NOT USE ANTIBACTERIALS
   a) risk of inc AMR
   b) evidence that antibacterial use can prolonge shedding
   c) let the animal clear the infection. Monitor this by repeat samples
2. BActeraemia requires antibacterial therapy - minority of cases
   a) Suggested antibiotics - trimethoprim and sulphonamide, amoxycillin), do sensitivity tests to make sure get correct antibac first time

Question 10

Name of disease caused by campylobacter bacteria

Answer 10

CAMPYLOBACTEROSIS

Question 11

CAMPYLOBACTEROSIS

What type in humans, and dogs?

Answer 11

• In humans mainly C. jejuni (poultry associated most typically) but also C. coli and others
• In dogs mainly C.upsaliensis
• Common with no clinical signs

Question 12

Campylobacterosis:
what is it usually a result of?
Diagnosis
Treatment
What to be aware of?

Answer 12

• Probably secondary or opportunistic pathogens
• Diagnosis: fresh fecal material, special transport and growth media
• Treatment: supportive, like salmonella.
• Potentially zoonotic (relatively rare but if immunocompromsied be more aware)

Question 13

E coli

Answer 13

• Normal gut flora, certain types can cause damage = toxin producing
• Enteropathogenic E.coli – toxin production
• Commonly use production of Haemolysins as measure of potential significance.
• Isolating E coli from fecal sample is normal but if cultures on blood agar, around colony lysis of blood cells = E coli producing harmolysin and so clinically more significant

Question 14

Leptospirosis about

Answer 14

• Mobile spirochaete

* Affects humans & a wide range of animals (not species specific) , including mammals, birds, amphibians, and reptiles

Question 15

Most common serovars of lepto in dogs:

Answer 15

– Leptospira icterohaemorrhagiae
– Leptospira canicola
– Leptospira grippotyphosa

Question 16

How is lepto transmitted? What about humans?

Answer 16

• Generally urine transmitted

* Relatively rare in humans

Question 17

Pathogenesis of lepto

Answer 17

• Direct or indirect contact with urine of infected animals
– Including contaminated water or soil
• Penetration through mucous membranes
• Multiplication in blood
• Spread to whole range of tissues – kidney (into urine then passed to next animal), liver (common CS jaundice), spleen, CNS, eyes and genital tract
• Organisms cleared from most tissues but persist in kidneys with renal excretion for weeks/months (carriers).

Question 18

Clinical signs of lepto in dogs

Answer 18

• Severity depends on serovar, age and immunity of host
• Acute (severe)
– pyrexia, vomiting, shock, haemorrhage, jaundice, renal failure
• Sub-acute
– pyrexia, PUPD, petechia (pin point round spot as result of bleeding, severe = haemorrhage), jaundice

Question 19

Diagnosis of lepto in dogs

Answer 19

• History and clinical signs
• Serology (titre > 1in 800; or a fourfold rise in titres)
• Detection of spirochaetes in urine sample; fluorescent antibody
• PCR detection of leptospira

Question 20

Treatment of lepto in dogs

Answer 20

• Supportive treatment e.g fluid replacement – animals often very ill when arrive
• Penicillin – clears bacteraemia
• Tetracycline or doxycycline to eliminate organisms from carrier dogs
• Zoonotic implications – make owner aware, need to keep infected animal in an environment for fairly long period of time while it is SHEDDING spirochetes
• Why most dogs are vaccinated

Question 21

Prevention of lepto

Answer 21

• Vaccination – does not necessarily protect against all serovars
– Considerable debate about what are the right serovars to include in vaccines.
• L2 vaccines historically
• L4 vaccines some now have
• Eliminate organism from carrier animals
• Prevent contact with reservoir hosts (rodents in this context)

Question 22

Borrelia burgdorferi:

Answer 22

– Lyme disease
– Likely very rare in UK pets
– Massive public awareness in humans
– Tick transmitted
– Zoonosis (but unlikely owner to get from infected pet)
– Clinical signs in animals: ?lameness, lymphadenopathy
– Anti-parasite companies use it as part of the drive tick prevention

Question 23

Staphylococcus

Answer 23

• Gram-positive bacteria

* Commensals of skin of man and animals

Question 24

Staphylococcus pseudintermedius

Answer 24

• Mucosal commensal and opportunistic pathogen
• Most common organism associated with canine pyoderma.
• ( multidrug-resistant bacterial pathogens) MRSP isolates now considered worldwide. ☹
• MRSP usually show MDR
• MRSP carriage in healthy dogs (0-4.5%) and cats (1.2-4%).
• Rare zoonosis in the immunocompromised people
Opportunistic: infection only occurs due to a primary underlying cause that disrupts the balance between host-defences and microbiota.
Typically skin and ear infections (surface, superficial and deep pyoderma), traumatic and post-surgical wound infections, possibly complicated by implants, suture material and biofilm

Question 25

Diagnosis of Staphylococcus

Answer 25

• Staph pyoderma: cytology. – degenerative neutrophils with intracellular coccoid bacteria in pairs or groups. • MRSP: culture and susceptibility testing. • The carriage or infection risk increases with administration of antimicrobials, surgery, hospitalisation or frequent veterinary premises contact.

Question 26

Control of staph

Answer 26

HAND HYGEINE is the single most effective

Question 27

Treatment Staphylococcus

Answer 27

• Often secondary infection • Investigation and treatment of the underlying disease is paramount for a successful outcome. • Superficial pyoderma cases, topical therapy alone is recommended. – 2-4% chlorhexidine (shampoo, sprays, wet wipes and mousse) • Severe/ widespread superficial pyoderma or deep pyoderma. – Systemic antibiotics based on culture – seek specialist advice

Question 28

Opportunistic infections with Staphylococcus .aureus

Answer 28

* S. aureus carried in nares of up to 30% of healthy people * In humans – food poisoning, pneumonia, skin infections and post-operative wound infections * In cattle – mastitis * In dogs and cats – can be associated with skin infections * Horses – pneumonia

Question 29

MRSA

Answer 29

* Meticillin Resistant Staph Aureus – one of the first organisms that got us talking about AMR * Commensal skin and nasal passages * Zoonotic potential

Question 30

MRSA in dogs and cats

Answer 30

``` • EMRSA (Epidemic strain) 15 and 16 – Dominant types in UK human hospitals – Also most common in cats and dogs – Reverse zoonosis – Believed that cats and dogs are being infected by people who are often in hospitals. ```

Question 31

Treatment MRSA in dogs adn cats

Answer 31

– culture and sensitivity – Prevent spread – Decolonisation

Question 32

BVSA guidlines on reducing MRSA

Answer 32

• Hand hygiene ``` • Simple uniforms education • Gloves / aprons • Cover wounds • Isolation • Rational use of antibiotics • Aseptic technique • Ward cleaning • Segregation of all waste • Sterilisation ```

Question 33

Ehrlichiosis

Answer 33

Intracellular bacteria – E. canis • Monocytic ehrlichiosis • Only in travelled dogs – as far as we know not endemic in UK • Tick transmitted – Rhipicephalus sanguineus "Brown dog tick" LAteral projections on mouthparts • Co-infection with Babesia and Leishmaniasis common • Doxycycline treatment • Adapted to living in dog accommodation – very different to I ricinus • The ears, interdigital spaces, axilla are preferred • Females drop off at night , thousands of eggs deposited in crevices, cracks in dog kennels Huge numbers of ticks can infest single dogs but most ticks are in environment

Question 34

Bacterial infections of cats - the 3 main they tedn to get adn dogs don't

Answer 34

* Mycobacteria * Mycoplasma * Bartonella

Question 35

Mycobacteria | clinical signs

Answer 35

Cats only, dogs tend not to get • Various species of mycobacteria including tuberculosis • Zoonotic • Cutaneous nodules, draining sinuses, panniculitis (painful bumps, or nodules, to form under your skin)

Question 36

Diagnosis and treatment of mycobacteria

Answer 36

* Diagnosis by culture * Treatment * rifampicin, clarithromycin, and enrofloxacin * Some question legitimacy of treatment considering zoonotic potential and threat of antibacterial resistance

Question 37

What is mycoplasma knows as

Answer 37

Feline infectious anaemia

Question 38

Talk about feline infections anaemia Disease How transmitted Show signs

Answer 38

* Mycoplasma haemofelis causes it (previously Haemobartonella felis) adheres to erythrocytes, causing damage to membranes and removal of RBC in spleen and liver. * Probably transmitted by fleas, possibly also direct from queens to kittens. * Often asymptomatic, but if cat stressed or immunosuppressed, causes anaemia.

Question 39

Clinical signs of FIA

Answer 39

• Anaemia mainly – pale MM, lethargy, tachypnoea, dyspnoea on exertion, tachypnoea • Splenomegaly (enlarged spleen) • Pyrexia (sometimes) • Jaundice if haemolysis severe • Cyclical variation in signs said to be due to 3-8 week replication cycle

Question 40

Diagnosis of FIA

Answer 40

• Haematology (can do in practice) but PCR more sensitive – regenerative anaemia: polychromasia, nucleated RBC • Stain smears with Giemsa or acridine orange to reveal small round dots/rings adherent to RBC. – need experience to identify – if any antibiotics have been used, smears will be negative • PCR more sensitive

Question 41

Treatment FIA

Answer 41

* Oxytetracycline or doxycycline for 3 weeks controls, but does not eliminate the infection * Prednisilone may help as in addition to direct damage to RBC some cats develop an immune-mediated haemolytic anaemia * ??Blood transfusions * Underlying stress? Check for FeLV and other immunosuppressants

Question 42

What is the scientific name for cat scratch disease

Answer 42

Bartonella henselae

Question 43

Talk about bartonella henselae

Answer 43

``` CAT SCRATCH DISEASE • Caused by a bacterium endemic in cats and transmitted by fleas (~10%) • Transmitted to humans by scratch – mainly children – initially skin lesion – then lymphadenopathy – Prophylaxis; flea control ```