Anthrax Glanders Listeriosis Salmonellosis Swine Erysipelas Leptospirosis Fowl Cholera Fowl Typhoid Pullorum Disease Clostridial Diseases (Black Disease) Clostridium perfringens infection (Enterotoxaemia) Ulcerative Lymphangitis As per veterinary medicine subject give me rivision of this disease for remembering
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veterinary medicine anthrax glanders listeriosis salmonellosis leptospirosis clostridial diseases revision notes
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Veterinary Disease Revision Guide
Quick-Reference Memory Aid for All 12 Diseases
1. ANTHRAX
Causative Agent: Bacillus anthracis - aerobic, Gram+, spore-forming, capsulated, NON-motile, non-hemolytic rod
Host Range: All warm-blooded animals; cattle, sheep, horses most susceptible. Pigs and dogs are resistant. Humans - zoonosis.
Pathogen Key Points (Memorize):
- Virulence factors: Polypeptide D-glutamic acid capsule (antiphagocytic) + Tripartite toxin = Protective Antigen (PA) + Lethal Factor (LF) + Edema Factor (EF)
- PA binds cell receptors; LF causes cell death (lethal toxin); EF causes edema (edema toxin)
- Spores survive in soil for decades (Sterne's strand used for vaccine)
Forms of Disease:
| Form | Route | Species |
|---|---|---|
| Per-acute / Acute | Ingestion of spores | Cattle, sheep |
| Sub-acute / Chronic | Ingestion | Horses, pigs |
| Cutaneous (Malignant pustule) | Skin contact | Humans |
| Pulmonary (Woolsorter's) | Inhalation | Humans |
| GI anthrax | Ingestion | Humans |
Clinical Signs:
- Cattle/sheep: sudden death, unclotted tarry blood from natural orifices, bloat, no rigor mortis
- Horses/pigs: colic, swelling of neck/throat region, death in 2-4 days
PM Findings: Splenomegaly (spleen is enlarged, dark, pulpy - "blackberry jam"), failure of blood to clot, hemorrhagic lymph nodes. Do NOT open carcass - exposes spores to air.
Diagnosis:
- Blood smear: stain with polychrome methylene blue - capsule stains pink/red (M'Fadyean's reaction)
- Culture on blood agar: "Medusa head" or "ground glass" colonies, non-hemolytic
- Ascoli's thermoprecipitin test (for hides, soil, old material)
- PCR, ELISA
Treatment: Penicillin G (drug of choice), Oxytetracycline, Ciprofloxacin
Prevention: Sterne's live spore vaccine (avirulent, non-encapsulated); burn/bury carcasses with lime; disinfect with 10% formalin
2. GLANDERS
Causative Agent: Burkholderia mallei (formerly Pseudomonas mallei) - Gram-, non-motile, non-spore-forming, aerobic rod
Host: Primarily equines (horses, mules, donkeys). Notifiable disease. Humans - occupational zoonosis (fatal if untreated).
Forms:
| Form | Location | Sign |
|---|---|---|
| Nasal glanders | Nasal mucosa | Ulcers, mucopurulent discharge, "Farcy buds" on nasal septum |
| Pulmonary glanders | Lungs | Nodules, pneumonia, chronic cough |
| Cutaneous glanders (Farcy) | Skin/lymphatics | Farcy pipes (lymphangitis), farcy buds (nodules) that ulcerate |
Key Mnemonic: "FAN" = Farcy, Acute, Nasal (the three forms)
Clinical Signs:
- Acute: fever, nasal discharge, lymphadenitis, death in weeks
- Chronic: wasting, intermittent fever, recurring nasal ulcers and skin nodules
Diagnosis:
- Mallein test (intradermal/ophthalmic) - main diagnostic; positive = swelling/discharge
- Complement fixation test (CFT)
- Culture: blood/glycerol agar
- Strauss reaction: guinea pig/male hamster inoculation → orchitis (positive)
Treatment: No approved treatment for animals - slaughter policy in most countries. Humans: cotrimoxazole + doxycycline.
Control: Test and slaughter; strict quarantine; notifiable.
3. LISTERIOSIS
Causative Agent: Listeria monocytogenes - Gram+, short rod, tumbling motility (end-over-end), beta-hemolytic, catalase+, motile at 4°C (psychrotrophic)
Host: Sheep, cattle, goats, pigs, poultry, humans. Soil organism; found in silage (spoiled).
Key Feature: Grows at refrigeration temperature (4°C) - important for food safety
Forms in Animals:
| Form | Species | Signs |
|---|---|---|
| Encephalitic (Circling Disease) | Sheep, cattle | Head tilt, circling, facial palsy, drooling, unilateral cranial nerve signs |
| Septicaemic | Neonates, monogastrics | High fever, death |
| Abortion | Cattle, sheep, goats | Late-term abortion, retained placenta |
| Ocular | Cattle | Keratoconjunctivitis |
Mnemonic for Listeria: "4 A's" = Abortion, Ataxia (circling), Anterior uveitis/ocular, Asymptomatic carriage
Pathogenesis: Enters via GI tract → intracellular pathogen → uses actin "rocket tails" (ActA protein) for cell-to-cell spread → reaches CNS via cranial nerves V, VII (hence circling + facial palsy)
PM: Microabscesses in brainstem, liver; necrotic foci in placenta
Diagnosis: Culture on PALCAM/Oxford agar; cold enrichment (4°C for weeks); CAMP test positive; Tumbling motility in hanging drop; PCR
Treatment: Ampicillin + Gentamicin (synergistic); Penicillin; Trimethoprim-Sulfa
Zoonosis: Pregnant women, elderly, immunocompromised most at risk (from dairy/deli meats)
4. SALMONELLOSIS
Causative Agent: Salmonella spp. (Enterobacteriaceae) - Gram-, rod, motile (peritrichous flagella), non-spore-forming, facultative anaerobe, H2S producer
Key Serovars in Vet:
| Serovar | Host | Disease |
|---|---|---|
| S. typhimurium | Calves, pigs, humans | Gastroenteritis |
| S. dublin | Cattle | Septicemia, abortion, pneumonia |
| S. choleraesuis | Pigs | Septicemia, enteric |
| S. enteritidis | Poultry, humans | Egg-borne infection |
| S. typhi/paratyphi | Humans only | Typhoid (not in animals) |
Clinical Signs:
- Acute: Fever, profuse watery/bloody diarrhea, dehydration, death in calves
- Septicemic form: Sudden death, jaundice, pneumonia (S. dublin in cattle)
- Chronic: Ill-thrift, diarrhea, debilitation
PM: Enteritis, necrosis of Peyer's patches, enlarged mesenteric LN, liver and spleen congestion, fibrinous peritonitis, "button ulcers" in chronic cases (mainly in pigs with S. choleraesuis)
Diagnosis: Culture on SS agar (Salmonella-Shigella), XLD agar, MacConkey agar (non-lactose fermenter); H2S production on TSI; Widal test (human); PCR; serology
Treatment: Fluoroquinolones, TMS, Ampicillin; Supportive therapy critical (fluids/electrolytes)
Zoonosis: Major public health concern - food safety; eggs, poultry, raw meat
5. SWINE ERYSIPELAS
Causative Agent: Erysipelothrix rhusiopathiae (formerly E. insidiosa) - Gram+, slender rod, non-spore-forming, non-acid-fast, microaerophilic, H2S+
Host: Primarily pigs; also turkeys (erysipelas), sheep (polyarthritis), fish (Erysipeloid in humans)
Mnemonic: "Erysi - Erysipelas - Erythema" (characteristic diamond skin lesion)
Forms:
| Form | Signs |
|---|---|
| Per-acute/Acute Septicemia | High fever (42°C), sudden death, skin congestion |
| Sub-acute (Urticaria/"Diamond Skin") | Characteristic raised, red/purple rhomboid/diamond-shaped urticarial plaques on skin |
| Chronic | Arthritis (vegetative endocarditis), joint swelling, lameness, vegetative endocarditis |
Key Diagnostic Clue: Diamond skin lesions (pathognomonic for field diagnosis)
PM:
- Acute: petechial hemorrhages on kidney ("turkey egg kidney"), splenic enlargement
- Chronic: strawberry/cauliflower vegetative endocarditis on mitral/aortic valves, fibrinous arthritis
Diagnosis: Culture on blood/serum agar; gelatin stab = "bottle brush" / "test tube brush" pattern; H2S+; mouse inoculation
Treatment: Penicillin G (highly effective - drug of choice); Erysipelas antiserum (passive immunization); Ampicillin
Prevention: Penicillin + antiserum for exposed pigs; Bacterin vaccine; Erysipelas toxoid
6. LEPTOSPIROSIS
Causative Agent: Leptospira interrogans (pathogenic); L. biflexa (saprophytic) - Gram-, spiral/helical, hooked ends, aerobic, motile
Key Serovars (Host-adapted):
| Serovar | Maintenance Host |
|---|---|
| icterohaemorrhagiae | Rats |
| canicola | Dogs |
| pomona | Pigs, cattle |
| hardjo | Cattle |
| grippotyphosa | Rodents, wildlife |
Transmission: Through contaminated water/mud; urine of carrier animals; enters via mucous membranes, skin abrasions
Clinical Signs:
| Species | Signs |
|---|---|
| Cattle | Milk drop syndrome, abortion, jaundice, hemoglobinuria (red water) |
| Dogs | Acute: fever, vomiting, jaundice, renal failure; Weil's disease picture |
| Pigs | Abortion, weak piglets, agalactia |
| Horses | Periodic ophthalmia ("Moon blindness"), abortion |
Pathogenesis: Leptospiremia → localize in kidney tubules → leptospiruria (excretion for months/years) → hepatic necrosis + tubular nephritis
Diagnosis:
- MAT (Microscopic Agglutination Test) - gold standard serology
- Dark-field microscopy of urine/blood
- Culture on Fletcher's/EMJH medium (slow growth, 6-8 weeks)
- Immunofluorescence; PCR
- Silver staining (Warthin-Starry) for tissue sections
Treatment: Penicillin (acute); Doxycycline/Streptomycin (carrier state/to clear renal shedding)
Zoonosis: Important; "Weil's disease" in humans (jaundice + renal failure + hemorrhage)
7. FOWL CHOLERA (Avian Pasteurellosis)
Causative Agent: Pasteurella multocida - Gram-, non-motile, non-spore-forming, bipolar staining (safety-pin appearance), capsulated coccobacillus
Host: Poultry (chickens, turkeys, ducks, geese); occasionally rabbits, cattle, pigs
Key Feature: Bipolar staining with Giemsa/Wright's stain - "safety pin" or "closed safety pin" appearance
Forms:
| Form | Signs |
|---|---|
| Per-acute | Sudden death with no premonitory signs; dead birds found in pen |
| Acute | Fever, anorexia, mucoid nasal/oral discharge, diarrhea (greenish-yellow), cyanosis of comb/wattle, respiratory distress |
| Chronic | Sinusitis, wry neck (torticollis), swollen wattles/joints, caseous exudate in sinuses |
PM:
- Acute: hemorrhagic enteritis, petechiae on serosal surfaces, pneumonia, enlarged/congested liver with focal necrosis ("pinpoint white foci")
- Chronic: caseous pneumonia, arthritis, fibrinous peritonitis
Diagnosis: Culture on blood agar; bipolar staining on blood smears; mouse inoculation; serology (tube agglutination); PCR
Treatment: Sulfonamides (sulfaquinoxaline), Tetracyclines, Fluoroquinolones, Penicillin
Prevention: Bacterin/killed vaccine; Fowl cholera bacterin; CRD-19 live vaccine; biosecurity; rodent control
8. FOWL TYPHOID
Causative Agent: Salmonella gallinarum - Gram-, non-motile (unique - unlike other Salmonella), non-flagellated
Host: Chickens and turkeys primarily; also pheasants
Key Distinction from Pullorum: S. gallinarum primarily affects adult birds; S. pullorum affects chicks
Clinical Signs:
- Fever, lethargy, anorexia, watery/greenish diarrhea
- Pale/anemic comb and wattles
- Adult birds more affected; high mortality in acute form
PM:
- Enlarged, bile-stained (greenish-bronze) liver with focal necrotic foci
- Splenomegaly
- Swollen, bronze-colored liver = classic PM finding
- Necrotic foci in liver and spleen; caseous cecal cores
- Ovarian lesions: shriveled, discolored ova ("scrambled egg" appearance)
Diagnosis:
- Culture on brilliant green agar, MacConkey agar (non-lactose fermenter)
- Whole Blood Agglutination Test (WBAT) - field test using stained S. gallinarum antigen
- Tube agglutination test; PCR
Treatment: Furazolidone; Chloramphenicol; Sulfonamides (treatment rarely attempted - test-and-cull preferred)
Control: Test and slaughter; hatchery hygiene; NPIP (National Poultry Improvement Plan) schemes
9. PULLORUM DISEASE (Bacillary White Diarrhea)
Causative Agent: Salmonella pullorum - Gram-, NON-motile, no flagella
Host: Chickens mainly; turkeys; primarily young chicks (0-3 weeks)
Key Feature: Vertical transmission (transovarial) - hen passes infection to egg; chicks hatch infected
Clinical Signs in Chicks:
- White, chalky, pasty diarrhea (BWD = Bacillary White Diarrhea)
- Pasting of vent (feces stuck around cloaca)
- Huddling, chirping, weakness, drooped wings
- Mortality up to 100% in severe outbreaks
Clinical Signs in Adult Carriers:
- Mostly subclinical; reduced egg production, fertility, hatchability
- Peritonitis in hens
PM:
- White nodules in liver, spleen, lung, heart muscle, cecum - classic
- Cecal cores (caseous plug in cecum)
- Unabsorbed yolk sac in chicks
- Arthritis (swollen joints) in older survivors
Diagnosis:
- Whole Blood Plate Agglutination Test (WBPAT/WBAT) - main field test, rapid
- Culture: non-lactose fermenter on MacConkey; non-motile
- PCR
Treatment: Furazolidone; Gentamicin; Enrofloxacin (to reduce mortality, but not eliminate carrier state)
Control: WBAT testing of breeder flocks; test-and-cull; hatchery sanitation; NO VACCINE (prevents detection of carriers)
Mnemonic: "Pullorum = Paste = Perinatal/Perinatal" (pasted vents, perinatal/neonatal chicks, perinatal/vertical transmission)
10. BLACK DISEASE (Infectious Necrotic Hepatitis)
Causative Agent: Clostridium novyi Type B (main); also C. haemolyticum (C. novyi Type D) causes bacillary hemoglobinuria
Host: Sheep primarily; cattle occasionally; also associated with liver fluke migration (Fasciola hepatica)
Pathogenesis: KEY CONCEPT
Liver fluke larvae migrate through liver → create anaerobic necrotic areas → dormant C. novyi spores in liver activated → germinate → produce alpha toxin (necrotizing lecithinase) + other toxins → massive hepatic necrosis → toxemia → sudden death
Mnemonic: "Flukes wake the Clostridia"
Clinical Signs:
- Usually sudden death with no premonitory signs
- Animal found dead (often well-nourished)
- Short course: depression, abdominal pain if observed
PM:
- Subcutaneous venous congestion → skin turns black (hence "Black Disease") - due to congestion of subcutaneous vessels
- Large, gray-yellow necrotic foci in liver
- Peritoneal and pleural effusions (blood-tinged fluid)
- Rapid decomposition/bloating
Diagnosis:
- Fluorescent antibody technique (FAT) on liver impressions
- Anaerobic culture of liver; serology; toxin neutralization in mice
- Association with fluke infestation
Treatment: Penicillin (early cases); hyperimmune serum
Prevention: Clostridial vaccines (multivalent - "7-in-1", "8-in-1"); Fluke control (critical - remove the trigger); Drain boggy pastures
11. CLOSTRIDIUM PERFRINGENS INFECTION (Enterotoxaemia / Pulpy Kidney Disease)
Causative Agent: Clostridium perfringens Types A, B, C, D (and E)
Key Types - "Memorize This Table":
| Type | Main Toxin | Disease | Species |
|---|---|---|---|
| Type A | Alpha | Gas gangrene, mild enteritis | All species; yellow lamb disease |
| Type B | Alpha + Beta + Epsilon | Lamb dysentery (hemorrhagic enteritis newborns) | Lambs, calves, foals |
| Type C | Alpha + Beta | Struck (adult sheep); hemorrhagic enteritis; Enterotoxemia of calves | Sheep, calves, piglets |
| Type D | Alpha + Epsilon | Pulpy Kidney Disease / Overeating Disease | Sheep (mainly), goats, cattle |
| Type E | Alpha + Iota | Enterotoxemia | Calves, rabbits |
Type D (Pulpy Kidney) - Most Exam-Important:
- Trigger: Sudden change to rich feed (overeating grain/lush pasture) → rapid fermentation → proliferation of C. perfringens Type D in gut → epsilon toxin production
- Signs: Sudden death in best-conditioned lambs; convulsions, opisthotonus, glycosuria; "found dead"
- PM: Soft/liquefied kidney (autolysis - "pulpy"); pericardial effusion; glucose in urine/aqueous humor (hyperglycemia due to epsilon toxin); "strawberry jam" gut contents
- Glycosuria = suggestive diagnostic PM finding (test urine in renal pelvis)
Lamb Dysentery (Type B):
- Neonatal lambs (<1 week)
- Hemorrhagic diarrhea, abdominal pain, death
Diagnosis: FAT on gut contents; toxin detection/mouse neutralization; culture; PCR
Treatment: Type B/C: hyperimmune serum + penicillin; supportive
Prevention: Dam vaccination (2-6 weeks pre-lambing) → passive immunity via colostrum; direct vaccination of lambs; avoid sudden dietary changes; Multivalent Clostridial vaccines
12. ULCERATIVE LYMPHANGITIS
Causative Agent: Corynebacterium pseudotuberculosis (ovis) - Gram+, pleomorphic rod, club-shaped, non-motile, non-spore-forming, catalase+, urease+
Also caused by: Corynebacterium ulcerans; occasionally Rhodococcus equi (foals)
Host: Horses primarily (also cattle, sheep - causes CLA = Caseous Lymphadenitis in sheep)
Pathogenesis: Wound/skin entry (often fetlock/lower leg area) → lymphatic spread → nodule formation → abscess → ulceration → thick greenish-yellow pus
Clinical Signs:
- Nodules and abscesses along lymphatics of lower limb (particularly fetlock and pastern area)
- Nodules rupture → ulcers discharging thick, greenish-yellow pus
- Lymphangitis of limb with cord-like thickening of lymphatics
- Lameness, swelling
- Chronic/relapsing course
Key Distinction from other lymphangitis:
| Disease | Agent | Key Feature |
|---|---|---|
| Ulcerative Lymphangitis | C. pseudotuberculosis | Horses; lower limb; green pus |
| Epizootic Lymphangitis | Histoplasma farciminosum | Horses; fungal; face/neck/limbs |
| Glanders (Farcy) | B. mallei | Horses; notifiable; farcy pipes |
| Sporotrichosis | Sporothrix schenckii | Horses, cats; fungal; "rosary" nodules |
PM (in CLA in sheep): Caseous, "onion ring" laminated abscess in lymph nodes; pale green pus
Diagnosis: Culture on blood agar (small, waxy, creamy colonies); biochemical ID; SynergELISA for flock screening; CAMP inhibition test (inhibits S. aureus CAMP factor)
Treatment: Penicillin; tetracyclines; drainage of abscesses; long course required
Prevention: Wound hygiene; CLA vaccine in sheep (Glanvac, Caseous D-T); avoid abrasive environments
QUICK COMPARISON TABLE - ZOONOTIC POTENTIAL
| Disease | Zoonosis | Human Risk |
|---|---|---|
| Anthrax | YES | Cutaneous, pulmonary, GI; Bioterrorism agent |
| Glanders | YES | Highly fatal; occupational |
| Listeriosis | YES | Meningitis, abortion in pregnant |
| Salmonellosis | YES | Gastroenteritis, food poisoning |
| Swine Erysipelas | YES (Erysipeloid) | Skin infection in butchers/fishermen |
| Leptospirosis | YES | Weil's disease; jaundice + renal failure |
| Fowl Cholera | Mild | Rare respiratory/wound infections |
| Fowl Typhoid | NO | Not a human pathogen |
| Pullorum Disease | NO | Not a human pathogen |
| Black Disease | NO | Not a human pathogen |
| Enterotoxaemia | NO | Not a human pathogen |
| Ulcerative Lymphangitis | Mild | Rare cutaneous (butchers) |
MASTER DIAGNOSTIC TESTS - QUICK RECALL
| Disease | Pathognomonic/Key Diagnostic Test |
|---|---|
| Anthrax | M'Fadyean's capsule stain; Ascoli's test; "Medusa head" colonies |
| Glanders | Mallein test; Strauss reaction (orchitis in guinea pig/male hamster) |
| Listeriosis | Tumbling motility; PALCAM agar; cold enrichment |
| Salmonellosis | SS agar; XLD agar; H2S on TSI; non-lactose fermenter |
| Swine Erysipelas | Diamond skin lesion; "test tube brush" gelatin stab |
| Leptospirosis | MAT (gold standard); dark-field microscopy; EMJH/Fletcher's medium |
| Fowl Cholera | Bipolar staining (safety pin); blood agar culture |
| Fowl Typhoid | WBAT; non-motile Salmonella; bronze liver at PM |
| Pullorum Disease | WBPAT; white nodules in organs; non-motile; vertical transmission |
| Black Disease | FAT on liver; necrotic foci; fluke association |
| Enterotoxaemia | Glycosuria (PM); pulpy kidney; epsilon toxin detection |
| Ulcerative Lymphangitis | Green pus; lower limb nodules; C. pseudotuberculosis culture |
TREATMENT QUICK REFERENCE
| Disease | Drug of Choice |
|---|---|
| Anthrax | Penicillin G |
| Glanders | Slaughter (animals); Cotrimoxazole + Doxycycline (humans) |
| Listeriosis | Ampicillin + Gentamicin |
| Salmonellosis | Fluoroquinolones; supportive fluids |
| Swine Erysipelas | Penicillin G + Antiserum |
| Leptospirosis | Penicillin (acute); Doxycycline/Streptomycin (carrier) |
| Fowl Cholera | Sulfonamides; Tetracyclines |
| Fowl Typhoid | Test and cull (preferred); Furazolidone |
| Pullorum Disease | Furazolidone; test and cull |
| Black Disease | Penicillin; Clostridial vaccine; fluke control |
| Enterotoxaemia | Hyperimmune serum; Multivalent vaccine; prevent overeating |
| Ulcerative Lymphangitis | Penicillin; drainage; wound hygiene |
MEMORY HOOKS - EXAM RAPID RECALL
- Anthrax = Spores + No rigor mortis + Unclotted blood + Splenomegaly + M'Fadyean stain
- Glanders = Mallein test + Farcy pipes + Notifiable + Male hamster orchitis
- Listeriosis = Circling disease + Silage + Psychrotrophic + Intracellular
- Salmonellosis = S. dublin (cattle abort) + S. choleraesuis (pigs) + Non-lactose fermenter
- Swine Erysipelas = Diamond skin + Strawberry heart + Turkey egg kidney
- Leptospirosis = MAT + Hooked ends + Hardjo (cattle) + Moon blindness (horses)
- Fowl Cholera = Safety pin + Sudden death + Pasteurella multocida
- Fowl Typhoid = Adult birds + Bronze liver + Non-motile Salmonella + WBAT
- Pullorum = Chicks + Pasted vent + White nodules + Vertical + WBPAT
- Black Disease = Flukes activate Clostridia + Black skin + Necrotic liver foci
- Enterotoxaemia = Epsilon toxin + Pulpy kidney + Overeating + Best lamb dies
- Ulcerative Lymphangitis = Horse + Lower limb + Green pus + C. pseudotuberculosis
This covers all 12 diseases with causative agent, host, clinical signs, PM findings, key diagnostics, treatment, and prevention. Good luck with your revision!
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