Bird 3 Flashcards
What are the 3 types of salmonellosis
- Paratyphoid
- Pullorum disease
- Fowl typhoid
Paratyphoid types of salmonella caused by, significance and transmission
Caused by - S. typhimurium, S. enteritidis - A NOTIFIABLE DISEASE Significance - Various species affected - Public health risk - uncooked eggs and egg products and improperly/inadequately cooked poultry meat - high risk Transmission - Horizontal ○ Faces -> egg -> chicken ○ Feed, litter ○ Wild birds ○ Other animals
Paratyphoid types of salmonella signs/lesions, diagnosis and treatment
Signs/lesions
- Reduced hatchability, dead embryos, sick and dead chickens
- Most die without clinical signs
- Congested liver/spleen, pin point foci of necrosis on the liver, retained yolk sac which is caseous
- In chronic - localised in joints - arthritis, ophthalmitis, encephalitis
Diagnosis
- Isolation of salmonella from lesions - whole genome sequencing - THEN NOTIFY
Treatment
- Antibiotics medication but it encourages carrier state (doesn’t eliminate) and encourages drug resistance
Paratyphoid types of salmonella control/prevention 7 strategies
- Regular monitoring of breeder/layer flocks by taking faecal litter swabs and culture and detection programs
- Management to minimise faecal contamination of eggs - reduce floor eggs with adequate nests, clean nests
○ Possible fumigation of eggs with formaldehyde as soon after collection as is possible - Hatchery management to minimise disease spread -> hygiene, fumigation of eggs
- Competitive exclusion via use of “pro-biotics” to establish normal flora
- Feed hygiene in human cooking
- Exclusion of wild birds, rodents and other potential carriers of salmonella from commercial flocks
- Vaccination - live attenuated strains of S. typhimurium distributed into drinking water
Pullorum type of salmonella cause, significance and transmission and signs
Cause - S. pullorum -> mainly affects gallinaceous birds
- Eradicated from commercial poultry industry but still in backyard poultry
- NOTIFIABLE DISEASE IN VICTORIA
Transmission
- Vertical - transovarian
- Horizontal - contaminated food, litter, fomites
Signs
- Embryo mortality and reduced hatchability of infected eggs
- If hatch chickens die within first few weeks of life -> spread disease horizontally - persist in environment
Pullorum type of salmonella lesions, diagnosis and control
Lesions
- Young birds
- acute form involves large congested spleen and liver
- Subclinical/chronic form - focal necrosis/abscessation of liver, heart and other viscera
○ Adult - Oophoritis, arthritis common
Diagnosis
- Isolation of organism from infected tissues
- Rapid whole blood agglutination test to detect antibodies in carrier hens -> then cull
Control
- Eradication with the removal of carrier hens
Fowl typhoid cause what age affect and significance
Cause - S. gallinarum that is serologically related to S. pullorum
- Mainly older birds not young
- SAME AS PULLORUM DISEASE
- Also NOTIFIABLE
Yersiniosis (pseudotuberculosis) cause, birds common in, predisposing factors and transmission
Cause - Yersinia pseudotuberculosis
- Cage, aviary birds, canaries, finches, budgies and other parrots
- Predisposing factors -> stress, overcrowding, climatic stress, breeding season - lowers resistance
Transmission
- Previously infected birds -> chronically/latently infected carrier birds
- Rodents
- Wild birds
Yersiniosis (pseudotuberculosis signs/lesions, diagnosis, treatment and prevention
Signs/lesions
- Acute death -> acutely sick birds or chronic wasting disease
- Acute - large swollen liver and spleen, haemorrhages on serosal surfaces
- Subclinical/chronic -> abscesses of spleen and liver
Diagnosis
- Visualisation of small gram negative rods with impression smear of affect tissue
- Or by culture or histopathology
Treatment
- Antibiotics -> sulphonamides, amoxicillin
Prevention and control
- Rodents
- Concrete floor
- Carriers
- Feed contamination
Staphylococcus cause, when occurs, 2 forms with clinica signs and diagnosis
- S. aureus (Coagulase positive -> ONLY ONE THAT CAUSES DISEASE)
- Opportunistic organism -> immunosuppressed,
Two forms
1. Septicaemic
2. Localised form
○ Arthritis, synovitis, osteomyelitis
§ Concrete hard floors -> breaks in skin -> “bumble foot”
§ Femoral head necrosis
Diagnosis - take a sample and do gram stain and catalyse test (positive ensure that is a disease causing organism)
Spirochaetosis (tick fever) cause, distrubution, transmission and signs/lesions
Cause - borrelia anserina -> main vector is argas persicus (fowl tick)
- Only found in warmer parts of the country (north) due to distribution of vector
Transmission - tick bite or ingestion of infected tick
- Nocturnal feeding
Signs and lesions
- Acute form - anaemia, large congested spleen and liver -> sudden death
- Pericardial clouding
Spirochaetosis (tick fever) diagnosis, treatment and prevention
Diagnosis - for changes in the blood
Treatment - penicillin medication at early part of the disease
Prevention - tick prevention and possible vaccine
Colibacillosis cause, when occurs, predisposing factors and transmission
Cause - E. coli
- Opportunistic pathogen
Predisposing factors - avianpathogenic E.coli - doesn’t need these
- Respiratory pathogens -> CRD
- Environmental factors
- Immunosuppressive conditions
Transmission - faecal oral or with avian pathogenic E.coli could be respiratory
Colibacillosis 2 forms, other conditions it leads to, diagnosis and control
2 forms
1. Acute (colisepticaemia) -> avian pathogenic E.coli
○ Fibrin deposits around the liver and heart
2. Subacute/chronic (localised)
Other conditions
- Can cause arthritis, synovitis, osteomyelitis, spondylitis
Diagnosis
- Need to isolate bacteria and do antibiotic sensitivity as the strain is important for treatment
Control
- Hygiene - as faecal-oral route
- Predisposing factors
- Vaccination - doesn’t have the relevant strains
Avian influenza (fowl plague) what is signifiance and affected species
- EXOTIC TO AUSTRALIA
- OIE list A
- HIGH RISK TO HUMANS -> mainly in Asia where there is close contact between poultry and humans
○ Difficult for H5N1 to be transmitted to people only via contact with secretions of sick/dead birds
○ If infected -> symptoms similar to normal flu however mortality high
§ There are medications that are effective against avian influenza in humans - no vaccine
Affected species - Chicken & turkeys
- Ducks & geese -> don’t show the disease
- Wild & migratory birds (H5N1)
- Cage birds
- Humans -> what makes it dangerous that can be transmitted to humans - H5N1
Avian influenza what are the types and the high risk strain, how does it arise and transmission
Type of virus - TYPE A (birds), B and C ○ Sub-type from TYPE A § Neuraminidase (N): 9 § Haemagglutinin (H): 16 □ HIGH RISK STRAINS -> H5 and H7 - Genomic changes ○ Antigenic drift + antigenic shift results in change in tropism -> different tissues/species - How did it arise? -> we don't know Transmission - Shed in faeces - Horizontal transmission ○ Contact ○ Untreated surface water
Hihgly pathogenic avian influenza characteristics signs and lesions
- Characteristics ○ Usually one type of bird ○ High mortality ○ High morbidity ○ Rapid spread - Signs and lesions ○ Sudden death -> high mortality and morbidity ○ Haemorrhages, cyanosis of the comb
Highly pathogenic avian influenza diagnosis, control and prevention
- Diagnosis - we not involved, department of primary industries
- Control - kill all the animals in the area, strict quarantine measures
- Prevention
○ Vaccination - not used in Australia but is used in America
○ Biosecurity
§ Australia DOES NOT import live chickens or raw chicken products, only cooked chicken and sterilised eggs
□ Only egg products that DO NOT pose a risk of introducing avian influenza are permitted into Australia
® All imported/domestic egg products must be pasteurised
○ Proper cooking of meat/egg -> heat over 70 degrees for 30mins will kill virus
§ 80 degrees over one minute will also kill
What is the main pigment that indicates liver issues
Biliverdin
- Birds have very little biliverdin reductase
- Green pigment
- Accumulation in tissues
What are the main clinical signs of liver disease
- Mainly inapparent/silent
- appear in severe cases
○ Greenish colouration of urates (biliverdinuria): often the most obvious indication of liver failure
§ Due to failure of excretion of biliverdin in bile therefore excreted via kidney
○ Can also get greenish discolouration of the muscle - Usually terminal - convulsions and nerves signs
- Generally non-specific
○ “sick bird look”, weight loss and anorexia
○ distention of abdomen
○ Dyspnoea due to pressure of enlarged liver (extended past the sternum) on the lungs - Jaundice not usually evident
What diagnosic tests to assess liver function in live and dead birds
LIVE 1. serum chemistry 2. radiology 3. biopsy? - not recommended as risk of internal haemorrhage NECROSCOPY 1. gross lesions 2. microbiology 3. histopathology 4. impression smear (gram/giemsa stain)
Serum chemistry when assessing the liver, what are problems, important enzymes and summary
§ Problems
□ Interspecies variation
□ Unavailability of standards - not every species
□ Low specificity/sensitivity – especially enzymes
□ IM injections - increased plasma activity of several enzymes
§ Important chemistry enzymes
1. Aspartate amino transferase (AST, GOT)
® Found also in heart and skeletal muscles the - “leakage” enzyme (do CPK to exclude skeletal issues)
2. Lactate dehydrogenase (LDH)
® Found also in muscles, kidney, bone and RBCs*
® Shorter half-life than AST
3. Glutamate dehydrogenase (GLDH)
® Present also in kidney and brain
4. ALT (GPT) AP and GGT with questionable value
5. Bile acids - quite sensitive - the best
® Increased level correlate well with impaired liver “function”
® Kits have recently become available
§ In summary
□ AST ↑
□ Bile acids ↑
□ LDH ↑
What are the 3 main diseases of the liver
1) fatty ,iver
2) aflatoxicosis
3) hepatitis
1. bacterial
2. fungal
3. viral
4. parasitic
Fatty liver when physiological and when pathological
○ Normal -> physiological
§ Young newly hatched chicks that are reliant on metabolism of yolk - first 2 weeks of life
§ Laying hens active egg production have naturally fatty liver - yolk contains large lipid content and liver is the main producer of this
§ Nutritional -> large amount of calories without proper exercise
□ Is wanted in some restaurants -> force feed high calorie diets
○ Pathological -> due to fatty liver/haemorrhage syndrome and fatty liver/kidney disease
Fatty liver/Haemorrhage Syndrome signs, lesions, causes and control
○ Signs
§ Spontaneous mortalities often in obese hens with lower egg production
○ Lesions
§ Obese carcass, globules of fat in peritoneum, large pale friable liver, intrahepatic haemorrhages
○ Aetiology
§ High-energy diet
§ Little exercise
§ Warm condition
§ Low production
○ Control
Provide balance energy level diet - ensure not overweight
Aflatoxicosis cause, interspecies variation and signs
○ Aspergillus spp
○ Interspecies variation
§ Ducks and turkeys have high sensitivity showing acute hepatic necrosis and high mortality
§ Domestic fowl have lower sensitivity showing chronic hepatitis and low mortality
○ Generally due to moisture and heating/cooling of feed in silo
○ Signs
§ Reduced growth rate, poor productivity and ascites
Bacterial hepatitis cause and lesions
□ Cause -> Salmonella, E. coli, Pasteurella ® Often cause septicaemic conditions □ Lesions ® Pale liver, congested ® Multifocal necrosis ® Fibrosis ® Patchy discolouration
Viral hepatitis list the 7 types
- inclusion body hepatitis
- pscittacine adenoviral hepatitis
- pacheco’s disease
- herpesviruses of pigeons
- duck viral hepatitis
- big liver and spleen disease
- hepatitis-splenomegaly syndrome
Inclusion body hepatitis what caused by, what common in and onset
□ Common in young chickens usually 2-6 weeks old
□ Cause - one of the 12 fowl adenoviruses
® 3 groups that cause this in different species with 12 serotypes
□ Acute onset of mortality occurring over a period of 3 to 4 days (spiking mortality)
® After spiking mortality then goes away generally
Different strains cause different mortality rates
Inclusion body hepatitis lesions, diagnosis and treatment
□ Lesions
® Swollen liver with multiple pale haemorrahgic foci
□ Diagnosis
® Histopathological demonstration of liver with presence of inclusion bodies
® PCR is now available - using high resolution melt (HRM)
□ Treatment
® No treatment although supportive therapy may assist in recovery
® Live vaccine in Australia given to parents -> provide maternal antibodies
} Given the bird the virus but going to die soon anyway
} Don’t have a vaccine for all the strain
® Killed virus in other countries
Pacheco’s disease what caused by, is it in australia, signs and lesions
□ Caused by herpes virus in psittacine birds
□ Exotic disease to Australia
□ Signs
® High mortality, diarrhoea, biliverdinuria, tremors/convulsions
□ Lesions
Hepatic swelling, haemorrhage and necrosis
Histomoniasis (black head) what caused by, where present and transmission
□ Caused by Histomonas meleagridis
® Lives in caecal tubes and migrates to viscera such as the liver
® Fragile organism which doesn’t survive in environment
□ Transmission
® Carrier bird often domestic fowl
® Between birds via caecal worm Heterakis gallinarum by eating the eggs of this worm
Histomoniasis treatment and control
□ Treatment ® Dimetridazole -> cannot use in birds used for human consumption ® Removal of birds from source of infection □ Control ® Control Heterakis (the carrier worm) ® Control earthworms ® Regular medication Concrete/wire floor
List some general clinical signs of nervous system disease
- Ataxia
- Paresis
- Paralysis
- Seizures
- Tremors
- Circling
- Head tilt
- Nystagmus
- Abnormal mentation
What are the 4 main diseases of the brain and 3 of the spinal cord
Brain - Cranial trauma - Nutritional deficiencies - Toxicities - Encephalitides ○ Viral, bacterial, mycotic, parasitic Spinal cord and peripheral nerves - Cord compression syndromes - Nutritional deficiencies - Toxins
Cranial trauma what caused by, associated with and clinical signs
- Caused by panic/hysteria resulting in birds colliding with windows, glass wall
- Can be associated with infarction (acute stroke)
○ Atherosclerosis, yok embolism - Clinical signs
○ Blood in mouth, ear and eye
○ Signs of depression - head tilt, circling, paresis
○ Sudden death
Cranial trauma lesions and treatment
- Lesions ○ Areas of haemorrhaging within the cerebrum -> subcutaneous and tissue ○ Malasia -> softening of the brain - Treatment ○ Supportive treatment ○ Corticosteroids thought to help
What are the 2 main nutritional deficiencies
1) vitamin E deficiency induced encephalomalacia
2) thiamine deficiency (vitamin B1)
Vitamin E deficiency induced encephalomalacia how common, clinical signs, lesions and treatment
○ Not that common anymore due to cheap Vit E supplements
○ “crazy chick disease” and often affects young growing chickens
§ Not before 2 weeks as Vitamin E from yolk sac
○ Clinical signs
§ As neurological signs
○ Lesions
§ Swollen cerebellum, petechial and larger haemorrhages in cerebrum
○ Treatment
§ Required vit E supplementation
Thiamine deficiency (vitamin B1) when generally occurs, clinical signs and treatment
○ Often in pet birds or wild in rehabilitation centres if feed inappropriate diet
○ EG - magpies fed “butchers mince”
○ Clinical signs
§ Walking backwards, head tilt to the ceiling (opisthotonus) “star grazing”, can fall backwards
○ Treatment
§ Highly responsive to thiamine medication -> infection or supplementation in water/diet
What are the 5 main reasons for neurological signs in younger chicks
- Thiamine deficiency
- Aspergillosis - common
- Salmonellosis
- Entrococcosis
- Avian Encephalomyelitis
Encephalitides what are the causes and causes within
1) viral
1. infectious avian encephalomyelitis
2. newcastle disease
3. polymavirus
4. arbovirus infections
2) bacterial
1. salmonella
2. enterococcus
3. pasterurella
3) mycotic
1. aspergillosis
2. dactylariosis
4) parasitic
Infectious avian encephalomyelitis cause, transmission
○ Cause – Picornaviridae - Hepatovirus
○ Transmission
§ Infected chicks -> horizontal infection of “litter mates”
§ Non-immune hens infected during lay -> egg -> transmission -> vertically
Arbovirus infections what are the types
○ Eastern equine encephalitis
○ Western equine encephalitis
○ Highlands J virus
○ Israel Turkey meningoencephalitis
○ Murray Valley Encephalitis - in Australia
○ Kunjin virus - in Australia - septic virus, related to west Nile virus
○ West Nile virus infection
West nile virus infection causes, clinical signs and transmission
§ Flavivirus infecting wild, zoo birds, horses and humans
§ Clinical signs
□ Reluctant to walk, show incoordination “dropping off the sky”, ataxia, torticollis,
§ Transmission
□ Mosquitos transmit from birds to other birds, as well as birds to horses and humans
® Horses and humans are dead-end hosts
® ZOONOTIC -> humans can get encephalitides
What are the 2 main toxicities and types within
- Insecticides
- Medications
○ Coccidiostats
§ Wrong dose
§ Wrong species
§ Wrong combination
○ Dimetridazole - low margin of safety
○ Nitrofurazone
Cord compression syndromes what are the 4 types
1) developmental abnormalities - congenital scoliosis, lordosis, kyphosis
2) spondylolisthesis (kinky back)
3) trauma
4) tumours
Spondylolisthesis (kinky back) caused by, clinical signs and diagnosis
○ Caused by subluxation of 4th thoracic vertebrae (only free vertebrae of the birds) -> compression of the spinal cord
○ Clinical signs
§ Unable to walk, generally sit on their breast and flap their wings to try to move
○ Diagnosis
§ Post mortem - cut along the vertebral column to determine where the compression occurs
Trauma that leads to cord compression syndrome what types, clinical signs and diagnosis
○ Fractures of the vertebrae -> occur often at thoraco-lumbar junction
○ Severe osteoporosis
○ Severe haemorrhaging within or outside the spina cord
○ Osteomyelitis -> Pasteurella, strep, staphylococcus
○ Clinical signs - Similar to kinky back
○ Diagnosis - Same as kinky back
What are the 2 main tumours that lead to cord compression syndrome and clinical signs
- Markes disease - as described previously
- Renal carcinomas - budgies, are common aged 3-5 years
§ Generally doesn’t affect renal issues straight away -> lameness or paralysis
§ Clinical signs
□ Perching with one leg and curling of the other foot
What nutritional deficiency leads to peripheral nerve damage and clinical signs
- Riboflavine (vitamin B2) deficiency (curls toe paralysis)
○ Paralysis of the toes
○ Occurs in young birds
What toxin leads to peripheral nerve issues cause and clinical signs
Botulism
- Cause - clostridium botulinum type C
○ Normal inhabitant of gastro-intestinal tract and environment
○ Usually exogenous origin
- Clinical signs
○ From legs to wings -> up towards the head and neck -> ascending paralysis - opposite to horse
§ “limberneck” -> end stage where the neck is flaccid
Botulism pathogenesis
○ During drought conditions with access to waterfowl = rotting vegetation
§ Invertebrates accumulate significant amounts of toxin -> birds then eat and die
§ Maggots and other insects may grow in decaying carcasses, concentrate toxin, eaten by other birds which result in many more birds being affected
○ In poultry farms - failure to remove bird carcasses from shed environment can result in cannibalism of them by other birds
○ Endogenous origin -> GIT stasis or other changed internal environment allowing overgrow of clostridium botulinum within the gut
Botulism diagnosis
○ Evidence of ingested maggots other invertebrates or carcass material
○ No gross or microscopic lesions present
○ Demonstration of toxin in intestinal contents, blood or other tissues which have been dead -> NOT DIAGNOSTICALLY USEFUL for living
Botulism treatment and control
- Treatment
○ Flushing GIT with clean water and other GIT stimulation
○ Antibiotics assist suppression of endogenous toxin production
○ Specific antitoxin may be administered
○ Supportive treatment - Control
○ Ensure prompt and thorough removal of carcasses of dead birds from the area
Removal of unaffected birds from the affected swap/lake may be possible in some situations
What are the main anatomical features of the avian skeleton
- light in weight
- pneumatic bones that communicate with respiratory system - humerus
- medullary bone in egg-laying birds as a labile reservoir for the supply of eggshell calcium
- a prominent sternum (keel bone), ulnar larger than radius
- fusion of anterior thoracic vertebrae (T1 – T3) to form notarium, a free T4, and fusion of the remaining thoracic, lumbar, sacral and first two coccygeal vertebrae to form synsacrum
What are the 7 main diseases of bone
1) twisted-leg syndrone, Valgus (outward), varus (inward)
2) dyschondroplasia (tibia dyschondroplasia)
3) osteodystrophy (rickets, soft bone syndrome)
4) chondrodystrophy
5) osteoporosis
6) fracture
7) osteomyelitis
Twisted-leg syndrome what does it commonly affect, cause and lesions
- Commonly affects broiler chickens and other rapidly growing birds - ostrich
- Cause -> due or exacerbated by marginal deficiencies of key nutrients
- Lesions -> distally rotated of tibiotarsus and condyle larger
○ Angular or rotational causes
○ Gastrocnemius tendon can become displaced leading to more pronounced rotation and lameness - Deviated toe
- Medial or lateral deviation of the toes -> Commonly affected broilers
- Genetic and environmental factors
Dyschondroplasia define what results in and predisposing factors
- Presents with a mass of avascular cartilage as cone-shape extending from epiphysis into diaphysis of affected bones
○ Results in bone weakness, pathological fracture and possible twisted leg
○ Most common in distal end of tibiotarsus - Inherited predisposition exacerbated by other factors:
○ promoting rapid growth
○ Calcium/phosphorus ratio in feed
○ Previous rickets
○ Acid/base imbalance
○ Mycotoxicosis
Osteodystrophy define and cause
- Failure in mineralisation of the bone results in weak, pliable bones
- Cause -> deficiency of calcium, phosphorus, vitamin D and/or calcium/phosphorus imbalance
○ Chicks - 1% calcium, Layer birds - need at least 4% calcium
Layer birds store calcium within their medullary bone - femur
Osteodystrophy clinical signs, lesions and diagnosis
- Clinical signs -> soft pliable maxilla (beck), S-shaped curvature of kneel bonw, bowed legs, thickening of ends of long bones especially tibiotarsus and tarsometatarsus, parathyroid enlarged
- Lesions -> thickened growth plate (may not be obvious)
- Radiology -> of the bone
Chondrodystrophy define and causes
- Abnormal growth of cartilage on one side of physis and/in physis of one of a pair of bones results in angulation of bone/limb
- Causes
○ Mycoplasma infections
§ M. meleagridis (affects turkeys only - not chickens)
§ M. iowae - exotic -> turkeys and possible chickens
§ M. gallisepticum?
○ Nutritional deficiencies
§ Manganese
§ Choline, niacin, folic acid
Osteoporosis what assocaited with and pathogenesis
- Associated with thin bones may lead to pathological fractures -> caught in wire, bird handling
○ Can involve both cortical and medullary bones
§ Cortical bone provides strength while medullary bone is laid down - acts as a source of calcium -> if medullary bone is exhausted due to high production and dietary supply lead to loss of cortical bone to provide the calcium -> lead to clinical signs
osteoporosis cause and clinical signs
- Cause -> vitamin D deficiencies or Calcium:phorphorus ratio, lack of exercise
- Clinical signs
○ Fractures and callus formations
○ Lameness
○ Paralysis
○ Poor egg shell -> hold egg against light, if see lots of pores -> not good quality
○ Deviated sternum
Bone Fractures what are the 2 main causes and causes within
○ Traumatic
§ Treat with splinting for simple fractures
○ Pathological
§ Osteoporosis
§ External pressure -> rings on birds legs
§ Dyschondroplasia
§ Tumours -> osteopetrosis, osteoma, osteosarcoma, chondroma - not common
§ Osteomyelitis
Osteomyelitis define, causes , origin and lesions
- Inflammation of bone
- Causes
○ Staphylococcus, E.coli, Salmonella, Mycobacterium avium and other bacterial infections - Generally haematogenous origin -> localisation frequently at the growth plate
○ Lesions may spread along growth plate into joints -> arthritis or synovitis (enlargement of joint with increased viscosity of fluid)
§ Exudate from the joint -> smear, stain culture and coagulase test for bacteria identification
□ Different exudate colour and consistency does not identify the bacteria - Lesions in femur are frequently found in head/neck of femur (femoral head degeneration/necrosis)
What are the 2 diseases of joints and 5 diseases of muscles and tendons
Joint 1) gout 2) arthritis/synovitis Muscles 1) tenosynovitis 2) ruptured tendon syndrome 3) nutritional myopathy 4) deep pectoral myopathy 5) extertional/capture myopathy
Gout define, causes and diagnosis
- Accumulation of uric acid crystals in the joint/synovial sheaths resulting in swelling and lameness
- Causes
○ Chronic renal failure -> exacerbated by high protein diet
○ Idiopathic -> genetic predisposition suspected - Diagnosis
○ Post-mortem -> can see uric acid crystals in the joints
○ Arthrocentesis -> pus like accumulation of uric acid crystals visible on microscopic examination
Arthritis/synovitis signs, causes and diagnosis
- Lameness, reluctance to walk, enlargement of the joints
- Causes
○ Viral -> caused by reovirus especially in broiler chickens
○ Bacterial -> all bacteria involved in osteomyelitis, can spread from osteomyelitis or haematogenously - Diagnosis
○ Staining of the smears
○ Conventional culture
○ PCR - for viral causes
Ruptured tendon syndrome what occurs, common in, clinical signs, causes and treatment
- Spontaneous, uni or bi-lateral rupture of gastrocnemius tendon immediately above the hock joint
- More commonly in broiler chickens
- Clinical signs
○ Extremely painful -> perches on the edge of the table to relieve the hock joint
○ Acute lesions -> haemorrhage under skin
○ Chronic lesions -> green discolouration in sub cutis - Causes
○ Tenosynovitis, tendon structure, nutritional factors, spontaneous, management? - Treatment
○ Management -> increasing feeding space, decreased density -> seems to work
What causes nutritional myopathy and exertional/capture myopathy
Nutritional Myopathy
- Condition can be caused by deficiency of Vitamin E and/or selenium
Exertional/capture myopathy
- Common condition particularly in wild birds following trapping, chasing or transportation
Unwilling or unable to fly or walk may appear depressed
Anatomy of the respiratory system upper and lower and trachea as well as airspaces were present
Upper respiratory tract -> nostrils, nasal cavity, nasal sinuses, pneumatic bones of skull and conjunctiva
Lower respiratory tract -> consists of larynx, trachea, bronchi, lungs, airsacs and pneumatic bones
Trachea -> has complete rings - CANNOT USE INFLATABLE CUFFS
- Before bifurcation in the lungs -> flattened are -> syrinx (can be quite prominent depending on species)
Some birds - pelicans -> subcutaneous airspaces - normal to feel crackling of skin over these areas
What are the 5 main diseases of the respiratory system and where take sample for diagnostics
- Harder to take nasal swab from nares ○ Cartilage sits within the nasal cavity - Need to take from the choana (palatine cleft) Diseases 1. Rhinitis/conjunctivitis 2. Sinusitis 3. Tracheitis 4. Pneumonia 5. Airsacculitis'
Conjunctivitis and rhinitis signs and causes
- Signs ○ Serous discharge from nares results in mating of feathers around eyes and nostrils ○ Congested mucous membranes - red eye ○ Severe case -> closure of the eyes due to puss accumulation - Causes ○ Traumatic - fighting ○ Toxic ○ Infectious • Infectious bronchitis • Infectious laryngotracheitis • Chlamydiosis • Aspergillosis • Mycoplasmosis
Sinuitis define, cause and the 2 main forms
- Inflammation of Infraorbital sinus ○ Not covered by bone -> make incision underneath the eye to get within - Cause ○ Mycoplasmosis - MOST COMMON ○ Fowl coryza - Avibacterium ○ Fowl Cholera - Pasteurella (previous lecture) ○ Various other bacteria Acute vs chronic form
Acute form of sinuitis signs, diagnosis and treatment
○ Signs
§ Sero-mucoid exudate, swollen face due to distention of sinus (often symmetrical)
§ Sinuses still compressible - runny pus
○ Diagnosis
§ Clinical signs, species affected and bacteriology (swab of exudate from choanae)
□ Some organisms need fastidious growth requirements - mycoplasma
○ Treatment
§ Parenteral and/or oral drinking water antibiotics
Chronic form of sinuitis signs, diagnosis and treatment
○ Signs
§ Caseous exudate in sinus +/- conjunctival sac, swollen sinuses presented as swollen face
§ Sinuses not compressible (DIFFERENTIATE BETWEEN ACUTE AND CHRONIC) -> solid pus
○ Diagnosis
§ Clinical signs, bacteriology (swab of exudate from choanae)
○ Treatment
§ Intervene immediately by removing the pus -> doesn’t respond to antibiotics
□ Surgical debridement in pet birds -> higher valuable birds
§ In large poultry systems -> remove the severely infected and treat others with antibiotics
Avian mycoplasmosis what are the 3 main form, species affected and economic significance
- Pathogenic Mycoplasmas ○ M. gallisepticum - most important ○ M. synoviae - arthritis ○ M. meleagridis - specific for turkeys - Species affected ○ Chicken, turkey, finch, parrot, ostrich, etc - Economic significance ○ With E. coli and Dust, ammonia and viruses -> leads to chronic respiratory disease
Avian mycoplasmosis transmission and signs/lesions
- Transmission
○ Vertical and horizontal transmission usually some venereal
§ Vertical transmission important with breeding stock - NEED TO ENSURE DON’T HAVE
○ Carrier birds - Signs/lesions
○ Conjunctivitis, rhinitis, synovitis
○ Reduced growth rate, egg production and hatchability, glass top eggs (deformities of top of egg)
Initially sero-mucoid later caseous - secondary bacterial
Avian mycoplasmosis diagnosis
- NEED TO ENSURE THEY ARE PATHOLOGENIC MYCOPLASMA
a. Need fastidious media to grow them -> specialist laboratory
b. Serological tests such as rapid serum agglutination (RSA) test and ELISA are available
§ Beware of vaccination status
c. PCR available as well
Avian mycoplasmosis treatment and control
- Treatment
○ Antibiotic treatment generally eliminates clinical signs not the infection -> will start shedding again later
§ Tylosin, tiamulin, tetracycline, lincomycin, enrofloxacin - NOT PENICILLIN
□ Beware of registration and withdrawing periods
○ Prevention and control important - Control
a. Eradication and quarantine
b. Vaccination (MOST POPULAR) and antibiotics on cases
§ Vaccine is an eyedrop
§ Not a lot of cases in Australia anymore due to VACCINE (made here in werribee)
Fowl Coryza (infectious C) cause, birds it infection, contributing factors and transmission
- Cause - Avibacterium paragallinarum
- Infects domestic fowls
○ Usually adult birds
○ Mainly layers in multi-age farms - Contributing factors
○ Multi-age farms - Rapid spread - via water or air - whole shed within 2 days
- Transmission
○ Carrier birds
○ Horizontally and rapid
§ Airborne
§ Water
Fowl coryza diagnosis and prevention and control
- Diagnosis ○ Incision into the sinus -> take swab from there § Place swab in media that is supplemented with NAD □ Gram negative bacilli - Prevention & Control ○ Eradication § Depopulate, disinfect, and leave vacant for 2-3 wk ○ Single age flocks ○ Reduce stresses ○ Vaccination § Killed vaccine § prior to the point of lay
Fowl coryza treatment
- Treatment ○Antibiotics § Sulfonamides ± trimethoprim § Tetracyclines § Erythromycin § Enrofloxacin (not available in Australia) ○ Withdrawing period ○ Current Australian regulations § Code of practice Label restrains - NO WAY CAN USE
Antibiotics use in poultry systems what need to consider, off-label use and registered antibiotics
- Only by a registered veterinarian
- Professional intervention
- Veterinary supervision and care
- Off-label use
○ Not when there is a label restraint
○ Must be backed up by scientific data
○ Should be registered at least for another food producing animal in Australia
Currently registered antibiotics for laying hens in Australia
• CTC, Nil WP
• OTC, 7d WP
• Amoxycillin 7d WP
• Trimethoprim, 14d WP
• Sulfonamides, 14d WP
• Lincospectin, Nil WP - don’t use unless really need to
What are some general clinical signs for diseases of the trachea
- None in mild cases
- Respiratory rales (gurgling)
- Coughing
- Breathing with open mouth
- Gasping (gaping!)
- Breathing with extended neck
- Change of voice
- Tail bobbing - when perching shouldn’t move their tail up and down
List the 7 main diseases of the trachea
- Infectious bronchitis (IB)
- Infectious laryngotracheitis (ILT)
- Newcastle disease (ND)
- Pigeon herpesvirus infection
- Cryptosporidiosis
- Parasites
- Pox
Infectious bronchitis cause and variation within
- Cause - A gamma-coronavirus
- Variation in Viral antigens
○ Pathogenicity
○ Tissue tropism
§ Respiratory - small chicks and young birds most affected
§ Renal
§ Reproductive
□ Laying hen
□ Young chicks
Infectious bronchitis signs
○ Mild serous conjunctivitis/rhinitis/tracheitis - URT infection: mild cough/sneeze
§ Haemorrhages within the trachea (generally from secondary infection)
○ Serious disease - common in Australia, mild URT disease followed by mortality with polyuria
§ Pale and swollen kidneys
○ Effects on reproductive tract - reduce egg production, abnormal shape eggs, poor quality albumen, poor quality egg shells (wrinkly and rubbery eggs), can affect the oviduct and therefore young chicks may take longer to come into lay
Infectious bronchitis transmission, diagnosis, treatment and prevention
- Transmission
○ Carriers
○ Rapid causing 100% morbidity
○ Horizontal
§ Fomites , Air born - Diagnosis
○ RT-PCR (RNA virus) - quick and sensitive
○ Serology - ELISA - Treatment
○ No real treatment but helps to warm the environment
○ Electrolytes and use antibiotics to prevent secondary infection from mycoplasma - Prevention
○ Biosecurity - doesn’t work so well
○ Vaccination - MOST IMPORTANT WAY TO PREVENT DISEASE
§ What virus to use as vaccine -> need to identify via particular test
§ No cross protection so important
Infectious laryngotracheitis (ILT) what birds does it affect, caused by and transmission
- Only in gallinaceous birds - chickens, pheasants
- Caused by an alpha-Herpesvirus
- Transmission
○ Carrier birds - FOR LIFE
○ Shed in exudates
○ Aerosols, fomites, beetles, etc
○ Long Incubation period (6-12 d) - can vaccinate in the face of outbreak
Infectious laryngotracheitis diagnosis, signs
- Diagnosis
○ Histopathology - merging epithelial cells with intra-nucleus inclusion bodies, heterophils
○ PCR
○ Notifiable disease - Signs
○ Severe form – acute haemorrhagic to necrotizing tracheitis – severe dyspnoea, gasping, open mouth breathing, cough up blood / blood-stained exudate, significant mortality.
○ Mild form – conjunctivitis, rhinitis, tracheitis, reduced production, predisposition to C.R.D.
Infectious laryngotracheitis prevention and prevalence in australia
- Prevention ○ Isolation ○ Single-age flock ○ Vaccination § Only in endemic areas § 3 vaccines -> live ones - Prevalence in Australia ○ Increasingly large number of outbreaks in recent times ○ VIC and NSW are particularly affected ○ A wide range of operations are affected
Newcastle disease cause, structures and significance
- Cause - avulavirus (Paramyxoviridae)
- Affects variety of bird species
- High mortality and morbidity
- Socioeconomic losses
- OIE list A
○ An exotic disease to Australia - trade implications
What are the 3 forms of newcastle disease, mortality and signs
a. Velogenic
§ High mortality
§ Nervous system -> partial or complete paralysis and twisting or the neck
§ Respiratory system - tracheitis, swelling of the face
§ Enteric - caecal lesions, diarrhoea
b. Mesogenic
§ Variable mortality
§ Respiratory
§ Nervous
§ Reduced egg production, quality (shell, pigment, albumen)
§ No enteric signs
c. Lentogenic
§ Mild-subclinical respiratory signs
§ Predisposition for CRD (chronic respiratory disease, like mycoplasma)
Newcastle disease in other species and transmission
- NDV in other species ○ Turkeys, duck and geese, psittacine, ratites, pigeons, human § Pigeon paramyxovirus -> own NCD -> present in Victoria - Transmission ○ Direct § Live carrier birds § Poultry products and by-products ○ Indirect § Fomites § Air
Newcastle disease diagnosis and control/prevention
- Diagnosis ○ Differential diagnosis from ILT and AI ○ Take samples and send to primary industry ○ Virus isolation § Virulence determination ○ PCR (and sequencing) ○ Serology - monitoring NOT DIAGNOSIS § HI - Control/prevention - National policy ○ Eradication - no treatment ○ Quarantine and movement control -> via restricted area around the property, control area where blanket vaccination occurs ○ Import restriction ○ Vaccination
air sac/trachea mites what birds common in, clinical signs, diagnosis, treatment and control
- Common in canaries, finches, budgies
- Clinical signs - slight cough, wheezing, dyspnoea in severe infections - open mouth breathing, fluffed up, stopping singing (one of the first signs - as trachea was severely damaged)
- Diagnosis - clinical signs and response to treatment
- Treatment - medication with ivermectin - single drop applied to back of neck or within water
- Control - involve in elimination of carriers birds or by periodic strategic treatment to keep infection at low level
What are the 4 main diseases of the airsacs
- Mycoplasmosis
- IC
- Colibacillosis
- Respiratory mycosis
Respiratory mycoses cause, age and clinical sign s
- Aspergillus fumigatus -> can get from mould in grain
- Particularly in the first few days of life -> probably came from the hatchery
- Clinical signs
○ Increase mortality (loss of hatchability) - especially in younger birds and in hatcheries
○ Respiratory difficulty - lesions in trachea and lungs and sometimes eye
§ Ophthalmitis if lesions in the eye
○ Lethargic, off food, loss weight, regurgitate food
○ Abnormal pasture, twisted neck, paresis, paralysis -> if brain affected
respiratory mycoses predisposing factors, diagnosis, treatmetn and control
- Predisposing factors ○ Stress ○ Immunosuppression ○ Other diseases ○ Antibiotics - Diagnosis ○ Radiology ○ PM - nodular lesions § Biopsy - histopathology - Treatment ○ Late stages - just cull - Control ○ Hygiene ○ Cull and isolate the affected birds ○ Ensure mouldy feed aren't around
