7. Infectious diseases of dogs & cats affecting urinary system. Leptospirosis

What are examples of infectious diseases affecting the urinary system?

1. Leptospirosis

2. Cystitis

3. Pyelonephritis

4. Prostatitis

5. Borreliosis

6. Parasites

What type of bacteria is Leptospira?

Gram-negative, motile, spiral bacteria with flagella

What diseases does Leptospira cause?

Kidney and liver failure

Is Leptospirosis zoonotic?

Yes

What are some Leptospira aetiological agents?

Leptospira interrogans canicola, pomona, bratislava, ausatralis, autumnalis, copenhageni, icterohaemorrhagiae

L. kirschneri grippotyphosa

How is Leptospirosis transmitted?

1. Urine from infected animals (rodents are infected for life)

2. Direct contact between animals (bites, vertical, semen, eating infected carcasses)

3. Contaminated environment (ingestion of contaminated water, damaged and intact skin, MM (eyes, nose)

Which serovar is spread in dog urine (reservoir)?

L. interrogans canicola

What are the main target organs of Leptospira?

Kidneys and liver

What is the pathogenesis of leptospirosis?

1. Penetrates skin or MM → enter blood & cause → bacteraemia → spread by blood → affinity for kidney, liver → replicates in nephrons → kidney failure, hepatitis, necrosis

2. Damage of endothelium & lysis of RBC (haemolysin) → haemorrhages. Anaemia

3. Affinity for pregnant uterus → cross placenta, causes abortions

How can antibody titre affect presentation of leptospirosis?

1. High Ab titre → no disease

2. Moderate Ab titre → mild kidney damage → persistent infection → increase Ab & no disease OR mild/no clinical disease

3. Low/no Ab → replication in liver/nephrons → either renal failure/toxic hepatitis → then severe disease & death OR direct severe disease & death (or increase Ab → persistent infection → mild/no clinical disease)

What are some clinical signs of Leptospirosis?

1. Peracute: Pyrexia, vomiting, shivering, tachypnoea, dehydration, death

2. Sub-acute & Acute: Fever, anorexia, vomiting, increased thirst, olig/anuria, rhinitis, cough, ulcers in oral cavity, icterus.

3. Chronic (Most common): Diarrhoea, vomitus, hepatitis, nephritis, uveitis

How is Leptospirosis diagnosed?

1. Serology → Microscopic Agglutination Test - MAT = Gold standard test. (single test is not enough to confirm dx)

   1. NB! Intermittent shedding -may be negative → Paired sampling (to wait for higher values)

   2. Not clinically useful because takes long

2. Haematology → (non- regenerative anaemia, lymphocytosis, neutrophilia, thrombocytopenia)

3. Blood chemistry → (elevated liver/ kidney enzymes; LD, GGT, urea, creatinine, SDMA)

4. Urinalysis → (glucose, protein, blood, pus, bilirubin),

5. USG → Show changes form of kidney. Cloud shaped/ not smooth edges.

6. PCR, cultivation, Dark field microscopy (spiral-shaped bacteria).

What are some differential diagnoses for Leptospirosis?

Babesiosis, intoxication, Lyme borreliosis, glomerulonephritis, bacterial pyelonephritis, acute pancreatitis, bacterial sepsis

How is Leptospirosis prevented?

1. Core vaccination. Killed vaccine

   1. 1: 12 weeks; 2: 16 weeks) then every 6-12 months

   2. L4 vaccine has 4 serovars, L2 has 2 serovars (No cross-protection)

2. Rodent control, avoid contact with reservoir hosts and contaminated areas

3. Inactivation by temperature, UV, disinfection, freezing.

Why is a killed vaccine used for leptospirosis?

Live vaccines cause shedding in urine

What is the treatment for Leptospirosis?

1. Causal: antibiotics (penicillin G, doxycycline, chloramphenicol, streptomycin, erythromycin)

2. Supportive: fluids (NB! Kidney damage- slow administration) glucose to support liver function.

3. Symptomatic (kidney → diet low in protein)

What is the prognosis for leptospirosis?

Depends on early intervention

What is important to tell an owner when their dog has leptospirosis?

Wear gloves and wash hands after touching the dog (Zoonotic)

What is bacterial cystitis?

Infection and inflammation of the urinary bladder

What are some causes of bacterial cystitis?

• Bacteria: E. coli, Staphylococcus, Enterococcus, Streptococcus, Proteus, Klebsiella, Pseudomonas, Pasteurella, Mycoplasma

• Non-infectious: chronic glucocorticoid administration, hyperadrenocorticism, chronic kidney disease, diabetes mellitus, stress

What is the pathogenesis of bacterial cystitis?

This infection typically ascends from the urethra to the bladder, resulting in colonisation of bladder epithelium. Predisposing factors include abnormalities of urine flow, decreased immunity, inadequate urine concentration, glucosuria, & systemic diseases.

What are some clinical signs of bacterial cystitis?

Pollakiuria, haematuria, dysuria, inappropriate urination, pain on abdominal palpation

How is bacterial cystitis diagnosed?

1. Urinalysis (cystocentesis or free catch): increased protein, haemoglobin, pH, WBCs, RBCs. Decreased urine specific gravity

2. Microscopy of sediments (struvite is often seen in bacterial infection)

3. USG

4. Bacterial culture

What is the treatment for bacterial cystitis?

Antibiotics (trimethoprim sulphate, penicillin, amoxicillin)

What is pyelonephritis?

Bacterial infection of the renal pelvis

What are some causes of pyelonephritis?

E. coli, Staphylococcus, Enterococcus, Streptococcus, Proteus, Klebsiella, Pseudomonas, Mycoplasma), rhinoliths, ureteroliths

What is the pathogenesis of pyelonephritis?

1. Ascending bacterial infection

2. Haematogenous infection

3. Rhinoliths/ureteroliths → prevent normal flow of urine out of kidneys

What are some clinical signs of pyelonephritis?

Kidney or flank pain, fever, malaise, vomiting, dysuria, haematuria, PU/PD

How is pyelonephritis diagnosed?

• Urinalysis: proteinuria pyuria, bacteriuria, &/ or haematuria. WBC cast may be present in fresh urine sediment.

• Biochemistry: normal or azotemia (renal/postrenal) &/or hyperglobulinemia. The animal may have kidney failure.

• USG: hyperechoic renal cortex, enlarged, dilated renal pelvis

What is the treatment for pyelonephritis?

Broad-spectrum antibiotics, IV antibiotics (fluoroquinolone + beta-lactam is most effective), fluids

What is prostatitis?

Inflammation of the prostate

What are some causes of prostatitis?

E. coli, Staphylococcus, Streptococcus, Mycoplasma spp.

What is the pathogenesis of bacterial prostatitis?

Infection may be haematogenous (acute prostatitis) or ascend from the urethra (chronic prostatitis)

What are some clinical signs of prostatitis?

Tenesmus, stranguria, pollakiuria, urine flow blockage, urethral discharge, fever, lethargy, painful gait, pain on abdominal palpation

How is prostatitis diagnosed?

Rectal palpation, ultrasound, radiography, cytology, culture

What is the treatment for prostatitis?

Antibiotics (chloramphenicol, clindamycin, erythromycin, enrofloxacin), castration

What is Lyme disease (borreliosis) caused by?

Borrelia burgdorferi sensu stricto, Borrelia afzelli, Borrelia garinii

How is borreliosis transmitted?

Ticks

What are some clinical signs of Lyme disease?

Renal disease (uremia, hyperphosphatemia, protein-losing nephropathy)

How is Lyme disease diagnosed?

Serology (Ab: ELISA, IFA)

What is the treatment for Lyme disease?

Antibiotics (penicillin, tetracyclines) for 30 days (IV or PO)

What are some parasites that can affect the urinary tract?

1. Capillaria plica – urinary bladder & urethra (dog)

2. Capillaria feliscati – urinary bladder (cat)

3. Dioctophyme renale – kidney (fish eating mammals)

Why can anaemia be found in leptospirosis?

Decreased erythropoietin produced by the kidneys

What indicators can you use to check the kidneys?

1. Urea

2. Creatinine

3. SDMA

What is a parasite which causes colour changes in the urine?

Babesia