ID - Bacterial Infections of Dogs and Cats Flashcards
Name 6 common themes to consider when dealing with bacterial infections
- Often secondary
- Isolation does not necessarily equate to clinical relevance
- Sometimes difficult to interpret a positive result
- Carriers
- Antibacterial resistance must be considered - is treatment of bacteria always necessary
- Often not species specific, raising questions of zoonosis (and reverse zoonosis)
What is the gram staining, family, susceptible host species, and affect on humans of Salmonella?
Gram negative
Family Enterobacteriaceae
Infects a wide range of mammals, birds, and reptiles
Gastroenteritis in humans
Why can it be said that Salmonella infection is much more common than disease?
1-5% normal cats are shedding the bacteria
up to 25% of dogs under 6 months old are shedding
(possible cause of ‘garbage guts syndrome’ in puppies and kittens(e.g from food or wild birds/rodents))
How is salmonella transmitted?
Ingestion of contaminated (raw) food, water, or fomites (contaminated by infected faeces).
Direct contact with an infected human or animal
What are the clinical signs of a salmonella infection?
Subclinical. Pyrexia. Anorexia. Vomiting, diarrhoea. Abdominal pain. Bacteraemia. Abortion, stillbirth.
How do you diagnoses and treat a salmonella infection?
Isolation of salmonella from faeces.
Infected dogs shed for 4 to 6 weeks - some become carriers.
For local GI disease, do not use antibacterials
- risk of AMR and prolonged shedding
Bacteraemia requires antibacterial therapy
- trimethoprim and sulphonamide, amoxycillin - do sensitivity tests
What are the main species involved in Campylobacteriosis?
In humans mainly C. jejuni, but also C. coli and others.
In dogs mainly C. upsaliensis
-common with no clinical signs
Probably secondary or opportunistic pathogens.
Potentially zoonotic.
How would you diagnose and treat a campylobacter infection?
Diagnosis: fresh material, special transport, and growth media
Treatment: supportive
E. coli
Normal gut flora.
Enteropathogenic E. coli - toxin production.
Commonly use production of Haemolysins as measure of potential significance
What is Leptospirosis/Leptospira?
Mobile spirochaete
Affects humans & a wide range of animals, including mammals, birds, amphibians, and reptiles.
Generally urine transmitted.
Relatively rare in humans
What are the 3 most common serovars of leptospira in dogs?
Leptospira icterohaemorrhagiae
Leptospira canicola
Leptospira grippotyphosa
Describe the pathogenesis of leptospirosis?
Direct or indirect contact with urine of infected animals
- contaminated water or soil
Penetration through mucous membrane.
Multiplication in blood.
Spread to tissues - kidney, liver, spleen, CNS, eyes, and genital tract.
Organisms cleared from most tissues but persist in kidneys with renal excretion for weeks/months after
How long does leptospira persist in the kidney?
Weeks or even months after initial infection
What are the clinical signs of leptospirosis?
Severity depends on serovar, age, and immunity of host.
Acute
- pyrexia, vomiting, shock, haemorrhage, jaundice, renal failure
Sub-acute
- pyrexia, PUPD (polyuria and polydipsia), petechia (red or purple spot caused by bleeding into the skin), jaundice
How can you diagnose leptospirosis?
Hard due to leptospira being a slow grower and potentially like liquid - difficult to culture.
Histology and clinical signs.
Serology (titre > 1 in 800; or a fourfold rise in titres).
Detection of spirochaetes in urine sample; fluorescent antibody.
PCR detection of leptospira.
How do you treat leptospirosis?
Supportive treatment e.g fluid replacement.
Penecillin - clears bacteraemia.
Tetracycline or doxycycline to eliminate organisms from carrier dogs.
Zoonotic implications.
