ANSC 625 - Important Bacterial Diseases

Bacillus anthracis (rod bacteria, spore-forming)

What pathogen causes anthrax?

worldwide, enzootic in Texas and Minnisota but not seen east of Mississippi river

Where is anthrax mostly found?

wild and domestic cloven-hoofed herbivores

What animals get anthrax?

ingestion of spores from soil or contaminated feed/animal tissue, cutaneous wound contamination, inhalation

How is anthrax transmitted?

vegetative bacteria are released by carcass bloating, scavengers, or necropsy and sporulated when in contact with air

What happens to the anthrax bacteria after the animal dies?

septicemia with high fatality and hemorrhagic, swollen lymph nodes, necrosis

How does anthrax present in ruminants?

rapid death, staggering-> collapse, dyspnea, seizures

What are the signs of very acute anthrax?

fever, depression, respiratory and cardiac distress, staggering, seizures, death, bloody discharge from nose, mouth and anus, abortion, edematous swelling of ventral neck thorax and shoulders

What are the signs of acute anthrax?

chronic ill, septicemia with sudden death and oropharyngitis in pigs

How does anthrax present in humans, horses and pigs?

rigor mortis is absent or incomplete, blood fails to clot

In animals that have died from anthrax, what is characteristic?

optimal sample is cotton swab dipped in blood and dried to sporulate bacteria to then culture and PCR (warn lab)

How is anthrax diagnosed?

lymphatic tissue submitted for bacterial culture and PCR

How is anthrax diagnosed in animals that don't develop septic disease?

long-acting antibiotic, vaccination after treatment, cull

How is anthrax treated?

annual vaccination in endemic areas, rigid enforcement of quarantine, rapid detection and reporting of cases, isolation of sick animals and removal of well animals from contamination, treatment of asymptomatic animals, promt disposal of bodies, cleaning and disinfection of environment and equipment, insect repellents, decontaminate soils

How is anthrax controlled?

zoonotic, reportable

Anthrax is both ___ and ___

presents as primarily cutaneous disease following contact with carcasses, consuming raw/undercooked meat (GI), inhaling in labs, animal processing facilities, or bioterrorism, injected with contaminated needle

How do people get anthrax?

Anaplasma phagocytophilum (develops in cytoplasmic vacuoles of neutrophils)

What pathogen causes equine granulocytic anaplasmosis?

horses, burros, dogs, llamas, rodents

There are naturally recurring infections of equine granulocytic anaplasmosis in what animals?

vector borne through ixodes tick primarily

How is equine granulocytic anaplasmosis transmitted?

yes through tick bites only

Is equine granulocytic anaplasmosis zoonotic?

destruction of RBCs, WBCs, and platelets

What does equine granulocytic anaplasmosis cause?

fever, depression, mild limb edema, ataxia, anorexia, petechiation, jaundice

What are the signs of equine granulocytic anaplasmosis?

no

Is there a carrier state for equine granulocytic anaplasmosis?

demonstration of characteristic intracelullar inclusion bodies in blood smear, PCR/serology on blood

How is equine granulocytic anaplasmosis diagnosed?

antibiotics

How is equine granulocytic anaplasmosis treated?

tick control

How is equine granulocytic anaplasmosis controlled?

no

Is there a vaccine for equine granulocytic anaplasmosis?

equine granulocytic anaplasmosis

This horse has been anorexia and has petechiation on membranes. What disease does it likely have?

Streptococcus equi

What pathogen causes strangles?

only equids, high morbidity low mortality

What animals develop strangles?

fever, nasal discharge/pus, depression, enlargement of lymph nodes on head, abscesses in lymph nodes, pneumonia

What are the signs of equine strangles?

enlargement of retropharyngeal lymph nodes can cause respiratory distress

Why is it called strangles?

direct and indirect contact with exudate (pus)

How is Streptococcus equi transmitted?

bacterial culture of abscesses or nasal discharge

How is strangles diagnosed?

local therapy of abscesses, anti-inflammatory meds, +/-antibiotics

How is strangles treated?

good biosecurity between horses, vaccination based on risk

How is strangles prevented?

strangles

This horse also has nasal discharge. What disease does it likely have?