Lesson 88 - Herd Management with Viral Disease

What viruses affect the reproductive system in cattle?

1. infectious bovine rhinotracheitis

2. bluetongue virus

What viruses affect the respiratory system in cattle?

1. infectious bovine rhinotracheitis

2. bluetongue virus

3. bovine viral diarrhea

4. bovine corona virus

5. bovine respiratory syncytial virus

6. bovine parainfluenza-3 virus

7. influenza A virus

What viruses affect the gastrointestinal system in cattle?

1. rotavirus A

2. bovine corona virus

3. bovine viral diarrhea

What are the systemic viruses in cattle?

bovine leukemia virus

What viruses affect the neurological system in small ruminants?

border disease virus

What viruses affect the reproductive system in small ruminants?

1. border disease virus

2. bluetongue virus

3. peste des petits virus

What viruses affect the respiratory system in small ruminants?

1. bluetongue virus

2. peste des petits virus

3. jaagsiekte sheep retrovirus/ovine pulmonary adenocarcinoma

4. caprine arthritis-encephalitis virus

5. maedi-visna virus/ovine progressive pneumonia virus

What viruses affect the gastrointestinal system in small ruminants?

peste des petits virus

What viruses affect the locomotor system in small ruminants?

1. caprine arthritis-encephalitis virus

2. maedi-visna virus/ovine progressive pneumonia virus

What viruses affect the reproductive system in swine?

1. porcine parvovirus

2. porcine reproductive and respiratory syndrome virus

3. porcine circovirus-2

What viruses affect the respiratory system in swine?

1. porcine circovirus-2

2. porcine reproductive and respiratory syndrome virus

3. influenza A virus

4. pseudorabies virus

What viruses affect the gastrointestinal system in swine?

1. rotavirus A

2. transmissible gastroenteritis virus

3. porcine epidemic diarrhea virus

What viruses affect the neurological system in swine?

pseudorabies virus

What viruses are systemic in swine?

1. african swine fever virus

2. classical swine fever virus

What is the most common and costly disease affecting the north american beef cattle industry?

bovine respiratory disease complex/shipping fever pneumonia

What causes BRDC/shipping fever pneumonia?

stress from transition to feedlot, weaning, transportation, commingling, dehorning and castration

What happens once a cow is stressed in the pathogenesis of BRDC?

immunosuppression leads to viral and bacterial infections causing broncho-pneumonia

What viruses could be part of the BRDC?

1. bovine herpesvirus

2. bovine viral diarrhea virus

3. bovine respiratory syncytial virus

4. bovine parainfluenza virus 3

5. bovine adenovirus and coronavirus

What bacteria could be involved with BRDC?

1. Mannheimia haemolytica

2. Pasteurella multocida

3. Histophilus somni

4. Mycoplasma bovis

5. Bibersteinia trehalosi

What tests do we use to diagnose BRDC?

1. culture and susceptibility test for bacteria

2. PCR for virus and mycoplasma

What samples do we take for BRDC tests?

deep nasopharyngeal swab or transtracheal wash/bronchoalveolar lavage

What do we treat BRDC with?

long-acting, label approved antimicrobials like macrolides/phenicols and NSAIDs

What mainly causes the mortality with BRDC?

secondary bacterial pneumonia

How do we prevent BRDC?

1. weaning 2-3 weeks pre-shipment

2. vaccinate 2-3 weeks pre-shipment

3. bunk break

4. minimize stress

5. metaphylaxis

What is metaphylaxis?

administering antimicrobials in high-risk groups

What is a con to metaphylaxis?

it can be a big driver in antimicrobial resistance

What is Bovine coronavirus called in neonates?

calf coronavirus diarrhea

What is bovine coronavirus called in adults?

winter dysentery

What are the signs of calf coronavirus diarrhea?

watery, yellow-tan, feces, dehydration

What are the signs of winter dysentery?

acute watery, dark/hemorrhagic diarrhea and milk drop

What animals are typically affected by calf rotaviral diarrhea?

neonatal calves typically 1-3 weeks old

What are the signs of calf rotaviral diarrhea?

watery, yellow-green feces, dehydration and weakness

What are usually the outcomes of bovine coronavirus and rotavirus?

high morbidity but low mortality

How is bovine coronavirus and rotavirus transmitted?

fecal-oral, pen-level outbreaks with environmental contamination

What are the tests for bovine coronavirus and rotavirus?

1. fecal RT-qPCR

2. antigen ELISA

What is the treatment for bovine coronavirus and rotavirus?

fluids and electrolytes and use anti-microbials only for bacterial co-infection risk

How do we control bovine coronavirus and rotavirus?

1. colostrum management

2. strict hygiene and age segregation

3. pre-calving dam vaccination

What does bovine leukemia virus cause?

enzootic bovine leukosis

What is the clinical presentation of enzootic bovine leukosis?

usually subclinical but can have lymphocytosis and internal tumors/lymphosarcoma

What is the organ system that bovine leukemia virus affects?

hemolymphatic system

What are the consequences to enzootic bovine leukosis?

1. moderate trade restrictions

2. reduced milk production

3. higher culling rates

What animals are mainly affected by Maedi-visna virus/OPP?

adult sheep >2-4 yrs with slow progressive course

What are the symptoms of Maedi-visna virus/OPP?

1. progressive weight loss

2. exercise intolerance/dyspnea

3. afebrile unless secondary infection

4. indurative hard-bag mastitis

5. occasionally neuro signs

How is maedi-visna virus/OPP transmitted?

colostrum/milk and respiratory secretions with a long incubation period

What are the diagnostic tests for maedi-visna virus/OPP?

1. flock screening with ELISA or AGID

2. confirm with PCR or histopathology

What is the treatment for MVV/OPP?

no treatment or vaccine; life-long infection

What are the herd control measures for MVV/OPP?

1. test and cull

2. buy from OPP-negative flocks

3. closed flock

4. avoid feeding colostrum/milk from positives

What animals typically get OPA/JSRV?

sheep 2-4 yrs old

What are the signs of OPA/JSRV?

1. progressive dyspnea

2. weight loss

3. copious clear/frothy nasal fluid

4. afebrile unless secondary infection

What is pathognomonic for OPA/JSRV?

positive wheelbarrow test which is copious amounts of clear/frothy nasal fluid when head is lowered

What are the diagnostic tests for OPA/JSRV?

1. wheelbarrow test

2. thoracic ultrasound supportive

3. RT-PCR on BAL/nasal fluid or histopathology to confirm

What is the treatment for OPA/JSRV?

no treatment or vaccine so cull affected animals

What are the clinical signs of CAEV?

1. chronic arthritis

2. mastitis

3. encephalitis especially in kids

How is porcine circovirus 2 transmitted?

1. oronasal via direct contact and fomites

2. shed in feces, respiratory secretions and urine

3. vertical transmission can occur

What animals are affected by PMWS?

young, nursery and growing pigs 2-4 months of age

What is PMWS?

postweaning multisystemic wasting syndrome or PCV-2 systemic disease

What is PCV2-SI?

porcine circovirus 2 subclinical infection that causes growth retardation

What animals are affected by porcine respiratory disease complex?

finishers

What circovirus causes reproductive failure?

PCV2-RD

What are the signs of porcine dermatitis and nephropathy syndrome (PDNS)?

1. 2-4 month old pigs

2. high fever

3. petechiae skin

4. hemorrhage in kidneys

5. necrotizing vasculitis

6. type III hypersensitivity reaction

What are the porcine circovirus associated diseases?

1. postweaning multisystemic wasting syndrome (PMWS/PCV2-SD)

2. porcine respiratory disease complex (PRDC)

3. PCV2-RD

4. porcine dermatitis and nephropathy syndrome (PDNS)

What is the diagnostic triad for porcine circovirus associated diseases?

1. clinical signs

2. lesions

3. viral detection in lesions

What diagnostic tests are used for PMWS and PCV2-RD?

IHC and/or qPCR

What do we use to monitor and conduct surveillance but not diagnose PCVAD?

ELISA

How do we control porcine circovirus associated disease?

1. good herd management

2. vaccines reduce viral load and shedding

What are the non-diarrhea coronavirus diseases?

1. vomiting and wasting disease/hemagglutinating encephalomyelitis

2. respiratory disease (PRCV)

What is the goal of external biosecurity?

keep disease out of the herd

What is the goal of internal biosecurity?

prevent disease within herd/flock from spreading to others

What type of biosecurity measure is strict visitor policies?

external biosecurity

What type of biosecurity measure is preventing farm access to wild animals and rodents?

external biosecurity

What type of biosecurity measure is quarantining new animals?

external biosecurity

What type of biosecurity measures is infection control measures like PPE and handwashing?

external biosecurity

What type of biosecurity measure is regular vet visits?

internal biosecurity

What type of biosecurity measure is cleaning between groups of animals?

internal biosecurity

What type of biosecurity is dedicated footwear/overalls for different farm sites?

internal biosecurity

What type of biosecurity is dedicated plan for sanitation/disinfection of each building?

internal biosecurity

What is quarantine?

keep newly acquired animals away from healthy animals

What is isolation?

separating animals with a confirmed disease from those currently well

What is part of our brucellosis federal program?

1. milk testing

2. serology on market animals

What is part of our bovine tuberculosis federal program?

1. interstate testing and slaughter facilities

2. dairy cattle testing

3. captive cervid programs

What might we implement with the emerging avian influenza issue?

vaccination of cattle or birds

What is outbreak synonymous with?

epidemic/epizootic

What is the first step to an investigation of an outbreak?

confirm that an outbreak exists and what the disease is

What organizations do we report to?

1. state animal health officials

2. USDA-APHIS vet services

What are notifiable diseases?

emergency incidents, emerging disease incidents, regulated disease incidents

What are monitored diseases?

those that are endemic in the united states and are required to be reported every 6 months to WOAH

What are the phases of an outbreak?

1. descriptive phase

2. analytical phase

3. intervention and control

What are the criteria for a case?

1. clinical signs

2. immunologic response

3. lab detection of agent