Lecture 24 and 25: Bacterial diseases

Most common locations for bacterial infections

Skin, Urinary, respiratory, GI tract

Diagnostics for bacterial infections

CBC/Chem/UA, cytology, culture and sensitivity

Acute hemorrhagic diarrhea syndrome. Diagnosed by ELISA, PCR, or fecal culture

C. perfringens

Treatment for C. perfringens

Metro, ampicillin, NO tetracycline

Toxin A and Toxin B. Diagnosed with fecal culture, antigen test, ELISA. Treated with metronidazole

C. difficile

Watery diarrhea. Diagnosed with fecal exam and culture. Treated Erythromycin and fluoroquinilones.

Campylobacter

Diagnosed by PCR, serology, culture. Treated with fluorquinolones, chloraphenicol, TMS, amoxicillin

Salmonella

Granulomatous colitis (boxer colitis)

E. coli

How do you diagnose bartonella?

Serum antibodies, PCR, in clinically ill animals w/ no other explanation for illness

Treatment of bartonella

• Doxycycline, azitrhomycin, fluroqunilones for 4-6 weeks

• Flea and tick control

• Check serum antibodies after treatment 🤷🏼‍♀️

What is main reservoir host for B. henselae and B. clarridgiae

Cats

How is C. felis transmitted?

Survives in flea feces → cat claws → scratch, open wounds

CS of bartonella in cats

• Fever and cardiac issues (most common) , lethargy, lymphadenopathy, uveitis, gingivitis, endocarditis, myocarditis, hyperglobulinemia, vasculitis, neuro

Diagnosis of bartonella in cats

• Blood culture, PCR assay, serology

• Test casts with clinical signs

Treatment of bartonella in cats

• Doxycycline

• Fluroquinolones

Zoonotic control of bartonella

• Flea control year round

• Claws should be trimmed regularly

• Bites and scratches should be avoided

• Wash any cat related wounds promptly

• Keep cats indoors

  • Avoid need sticks contaminated with blood from potentially infected animals

How is brucellosis transmitted?

Mucus membrane → Macrophages → LN → bacteria → repro organs

CS of brucella

• Abortion and infertility

• Lethargy, exercise intolerance, WL, back pain, lympadenopathy, poor hair coat

• Epididymitis, scrotal pain and swelling, sperm abnormalities, testicular atrophy

• Abortion, vulvar discharge, puppy death or bacteremia

How do we diagnose brucellosis?

• No single reliable test

• Serology

• Blood culture or PCR (definitive diagnosis)

Treatment of brucella

• Enrofloxacin

• Euthanasia

• prevention, quarantine/isolate, screen

Characteristics of clostridium

• Ubiquitous in the environment

• Neurotoxins produced by bacteria

• Dogs/cats are more resistant

Transmission of tetanus

High resilient spores introduced via wound/penetrating injury (affects inhibitory interneurons GABA)

How is botulism transmitted?

Ingestion of preformed toxin in bad food

CS of tetanus

Localized or generalized muscle rigidity of facet and eyes, limbs, stiff gait/sawhorse stance

CS of botulism

Flaccid paralysis w/ autonomic nervous system. 12 hours after ingestion

Diagnosis of tetanus

History and CS, serology for antibodies to tetanospasmin

Diagnosis of botulism

History and CS

Treatment of tetanus

• Remove source of infection (metronidazole combo w/ clindmycin/doxy)

• Control symptoms with supportive care (phenobarbital, phenothiazines, benzodiazepines)

Treatment of botulism

• Antitoxin (Type C botulism)

• Prognosis actually fair if can support for 2-3 weeks though muscle weakness can be prolonged

Inhabits mucosal surface of respiratory, digestive and urogenital tract (M. felis, M. cynos)

Non-hemotropic

Candidates mycoplasma haeomomitum, M. haemocelis, M. haemocanis

Hemotrophic

Do cats with bartonella get IMHA?

No

Diagnosis of non-hemotropic mycoplasma

Cytology, culture, PCR (can be normal flora)

Diagnosis of hemotropic mycoplasma

Culture or PCR

Treatment of non-hemotropic

Doxycycline, clindamycin, azitrhomycin, fluorrqinolone

Treatment of hemotropic mycoplasma

Doxycycline, marbofloxacin, pradoflaxcin

Most common Lepto classifications

• L. autumnalis

• L. bratislava

• L. canicola

• L. grioppotyphosa

• L. hardjo

• L. icterohaeomorrhagiae

• L. pomona

How is lepto transmitted?

• Cats subbclincial but will shed the organism

• Pass in urine → enter through abraded skin or through mucous membranes (ingestion, contaminated soil or water)

• Hepatic, renal, or pulmonary disease secondary to inflammation toxin production

CS of lepto

Fever, uveitis, vomiting, diarrhea, renomegaly, hepatomegaly, PU/PD, icterus

Diagnosis of lepto

• Globulin abnormalities

• Hypocalcemia and renal issues

• Microscopic agglutination test (MAT)- antibody titer

• Darkfield microscopy, PCR

Treatment of lepto

• Fluids for renal treatment

• Ampicillin/amoxicillin for acute phase

• Doxycycline for carrier phase

• Enrofloxacin

A- L. canicola

B- L. Icterohaemorrhagiae

C- L. grippotyphosa

D- L. pomona

E- L. hardjo

F- L. bratislava

H- L. autumnalis

LC of Yersinia

• Rodent flea → rodent/squirrles/prarie dogs

• C. felis is the vector

  • Cats and dogs are suspceptible

How do you transmit Yersinia?

Flea bite, ingestion of infected rodent, inhalation of organism

CS of Yersinia

Fever, anorexia, depression, cervical swelling, dyspnea/respiratory, cough

Diagnosis of Yersinia pestis

• NSF CBC, chemistry, rads

• Culture, cytology, PCR, fluorescent antidbody of affected tissue

• Bipolar rods

Treatment of Yersinia

• Supportive care

• Drain abscesses

• Unclear which antibiotics

• Streptomycin, gentamicin, chloraphenicol, tetracycline

A 3-year-old Labrador Retriever presents with symmetrical, ascending weakness starting in the pelvic limbs. On neurological examination, hyporeflexia and hypotonia are noted. The owner reports that the dog ate some raw chicken a few days ago. Which of the following is the most likely diagnosis? (a) Canine Leptospirosis (b) Canine Tetanus (c) Canine Botulism (d) Canine Plague

(c) Canine Botulism

Which of the following statements about the etiology of canine botulism is correct? (a) It is caused by a gram-negative, aerobic bacterium. (b) The bacterium produces toxin in anaerobic, acidic environments. (c) The most common toxin subtype in canine cases is type B. (d) Toxin is actively secreted by the bacterial cells.

(b) The bacterium produces toxin in anaerobic, acidic environments.

A dog presents with dysuria, pollakiuria, and hematuria. Urinalysis reveals proteinuria, hematuria, and pyuria. Routine aerobic urine culture is negative. Which of the following pathogens should be suspected? (a) Clostridium botulinum (b) Yersinia pestis (c) Leptospira spp. (d) Mycoplasma spp.

(d) Mycoplasma spp.

Which of the following diagnostic findings is most indicative of canine mycoplasmal cystitis? (a) Observation of motile bacteria on urine sediment. (b) Persistent pyuria with negative routine aerobic urine culture. (c) Detection of Mycoplasma spp. in urine collected by voiding. (d) Elevated blood urea nitrogen and creatinine.

(b) Persistent pyuria with negative routine aerobic urine culture.

A dog from New Mexico presents with fever, lethargy, and a swollen, painful lymph node in the submandibular region. The owner mentions the dog frequently chases prairie dogs. Which of the following is the most likely causative agent? (a) Clostridium tetani (b) Leptospira spp. (c) Yersinia pestis (d) Mycoplasma canis

(c) Yersinia pestis

What is the primary mode of transmission for Yersinia pestis in endemic areas? (a) Direct contact with infected animals. (b) Ingestion of contaminated food or water. (c) Flea bites from infected rodents. (d) Aerosol transmission from infected dogs.

(c) Flea bites from infected rodents.

A dog with a wound on its paw exhibits muscle rigidity, a stiff gait, and a characteristic "risus sardonicus" facial expression. Which of the following neurotoxins is responsible for these clinical signs? (a) Botulinum toxin (b) Tetanospasmin (c) Tetanolysin (d) Mycoplasma cytotoxin

(b) Tetanospasmin

Tetanospasmin exerts its effects by inhibiting the release of which neurotransmitters? (a) Acetylcholine and norepinephrine (b) Dopamine and serotonin (c) Glycine and γ-aminobutyric acid (GABA) (d) Glutamate and aspartate

(c) Glycine and γ-aminobutyric acid (GABA)

Which of the following antibiotics is generally considered the drug of choice for treating canine plague? (a) Amoxicillin (b) Doxycycline (for less severe cases) (c) Enrofloxacin (d) Gentamicin

(d) Gentamicin

A dog presents with fever, vomiting, diarrhea, and icterus. Urinalysis reveals proteinuria and hematuria. The dog's owner lives in a rural area and the dog often drinks from puddles. Which of the following diagnostic tests would be most useful in initially screening for leptospirosis? (a) Aerobic urine culture (b) Point-of-care test for Leptospira antibodies (e.g., SNAP® Lepto) (c) Electromyography (d) Fecal cytology

(b) Point-of-care test for Leptospira antibodies (e.g., SNAP® Lepto)

Which of the following statements regarding the Microscopic Agglutination Test (MAT) for leptospirosis is correct? (a) A single negative MAT test rules out leptospirosis. (b) It can definitively identify the infecting serovar. (c) Obtaining paired titers at a 7-14 day interval is recommended to identify seroconversion. (d) Post-vaccinal titers are typically very low and never exceed 1:800.

(c) Obtaining paired titers at a 7-14 day interval is recommended to identify seroconversion.

A dog diagnosed with leptospirosis is being treated with penicillin. However, the veterinarian is concerned about the potential for the dog to become a carrier. Which of the following antibiotics is effective against the carrier state of leptospirosis by eliminating the organism from the kidneys? (a) Penicillin (b) Ampicillin (c) Doxycycline (d) Amoxicillin-clavulanate

(c) Doxycycline

A cat presents with unilateral conjunctivitis characterized by conjunctival hyperemia, edema, and a thick, white exudate. Corneal involvement is not noted. Cytology of the exudate reveals pleomorphic bacteria. Which of the following is a likely causative agent? (a) Chlamydia felis (b) Feline Herpesvirus-1 (c) Nonhemotropic Mycoplasma spp. (d) Bordetella bronchiseptica

(c) Nonhemotropic Mycoplasma spp.

Which class of antibiotics should generally be avoided in dogs with botulism due to their potential to block neuromuscular function? (a) Penicillins (b) Cephalosporins (c) Fluoroquinolones (d) Aminoglycosides

(d) Aminoglycosides