Common Viral and Parasitic Diseases in Birds

What bacterial disease will not cause severe lymphocytosis?

Macrorhabdus ornithogaster

What causes Psittacine beak and feather disease?

Psittacine circovirus

What is susceptible to Psittacine circovirus?

All parrots but especially cockatoos

What is the pathophysiology of Psittacine circovirus?

Epitheliotropic excreted via feathers and feces

Affects immune organs

How is Psittacine circovirus transmitted?

Ingestion of inhalation of feces and feathers; during crop feeding

What are the forms of Psittacine circovirus?

Chronic and acute

What are the immune organs that Psittacine circovirus attacks?

Bursa of Fabricius (involudes in adults normally)

GIT lymphoid tissue

Liver, thymus

What does the acute form of Psittacine circovirus cause?

necrosis of bursa and severe leukopenia

hepatic necrosis

No feather abnormalities

What is the prognosis for Psittacine circovirus?

Death in 2-5 days

What is the classic form of Psittacine circovirus?

Chronic

What happens during chronic Psittacine circovirus?

Dystrophic feathers

Feather loss/discolored

Beak abnormalities

Immunosuppression and eventually death

How do you diagnose Psittacine circovirus?

PCR of feathers or histopathology (cytoplasmic inclusion bodies)

How do you treat Psittacine circovirus?

Supportive care and treat secondary infections

What is the prognosis of Psittacine circovirus?

Poor most die within 1 year of onset of C/S due to immunosuppression

How do you prevent Psittacine circovirus?

Disinfection with hydrogen peroxidase

Quarantine and testing

What are your ddx for Psittacine circovirus?

Anything that can disrupt blood supply to feathers like trauma, sepsis, malnutrition, polyomavirus, west nile, fenbendazole

What are the side effects of fenbendazole?

Mess up feathers

Bone marrow suppression

Hepatotoxic

What species get avian polyomavirus?

Budgies, nestlings and juveniles more susceptible

Other parrots too

What form of avian polyomavirus infects budgies?

Chronic

What form of avian polyomavirus infects parrots?

Acute

How is avian polyomavirus transmitted?

Horizontal

Shedding from droppings and feather dander

What is the tropism for avian polyomavirus?

Endotheliotropic

Why is avian polyomavirus more serious that psittacine circovirus?

Polyomavirus is endotheliotropic, not epitheliotropic

What are the C/S of avian polyomavirus in young budgies?

Neuro signs and coelomic distension

100% fatal

What are the C/S of avian polyomavirus in old budgies?

Fail to develop contour feathers

What are the C/S of avian polyomavirus in other birds (not budgies)?

SC hemorrhage

Necrosis of spleen and liver

Sudden death with or without feather abnormalities

Also, anorexia, crop stasis, CNS, coelomic distension

How do you diagnose Avian Polyomavirus?

Difficult antemortem, need multiple samples

PCR of blood/cloacal swabs is most common

Why is antemortem diagnosis of Avian Polyomavirus difficult?

There is a short viremia period so false negatives are common with PCR

How do you diagnose Avian Polyomavirus postmortem?

Necropsy, histopath, IHC, EM

What are your ddx for avian polyomavirus?

Feathers similar to circovirus

Systemic diseases like chlamydia, liver dz, clotting disorder, sepsis, pachecos, adenovirus, reovirus

How do you treat avian polyomavirus?

No tx, can prevent with vaccination in breeding facilities

Quarantine and testing

What is avian bornovirus linked to?

Proventricular dilation disease

What does avian bornavirus cause?

Fatal neurologic disease that affects enteric neurons and brain mostly

What birds are most often affected by avian bornovirus?

Psittacines 

What are the GI signs for classic avian bornavirus?

Weight loss, crop stasis, regurgitation, proventricular and intestinal dilation, undigested seeds in feces

What are the neurologic signs of avian bornavirus?

Tremors, ataxia, paresis, seizures, blindness, feather destructive behavior

Why is avian bornavirus confusing?

Can see both GI and neuro forms

Can see sudden death

Can be carriers without clinical signs

How do you diagnose avian bornavirus?

Imaging to look for dilation of proventriculus (cannot confirm or rule out)

Serology with PCR is good but multiple tests are needed to prove negativity

Crop biopsy

Histopath

What disease other than bornavirus can cause dilation of proventriculus?

Macrorhabdus and metal

What do you want for a crop biopsy of bornavirus?

Biopsy close to the vessels because they run along the nerves

Negatives are still common

What is on histopath for bornavirus?

Lymphoplasmacytic ganglioneuritis

How do you treat bornavirus?

NSAIDs to reduce inflammation

Supportive care with easily digestive diet

What does avian poxvirus infect?

All avian species

How is avian poxvirus transmitted?

Mechanical vectors from mosquitos is most common

Also from wounds, inhalation, and ingestion

What are the forms of avian poxvirus?

Cutaneous or dry form (classic form)

Mucosal or wet form

Septicemic form (uncommon)

What does the cutaneous or dry form of avian poxvirus look like?

Rapid growth of neoplastic like masses on featherless areas

What does the mucosa or wet form of avian poxvirus look like?

Diphtheritic lesions of oral cavity and trachea

Secondary infections

Blepharitis, conjunctivitis, and chemosis

What can cause conjunctivitis?

Avian poxvirus, Chlamydia pstitacia, and Mycoplasma

What is the septicemic form of avian poxvirus?

Polyserositis, lung congestion, tracheal congestion are all present

Lethargy, dyspnea, and anorexia are C/S

Death is very common

How do you diagnose avian poxvirus?

Cytology or histopathology seeing bollinger bodies (large cytoplasmic inclusion bodies)

How do you treat avian poxvirus?

Supportive care and tx secondary infections

How do you prevent avian poxvirus?

Mosquito screens and vaccination

What causes pachecos disease?

Psticcaine herpesvirus 1

What birds does psittacine herpesvirus -1 (Pachecos) infect?

New World birds like amazon parrots, conures, and macaws

Can infect some old world birds like cockatoos, gray parrots, and ring neck parakeet

How is Pachecos transmitted?

Horizontal from droppings or oral secretions

Will incubate for a long time

What are the C/S of pachecos disease?

Non-specific

Sudden death with liver necrosis (biliverdinuria)

Mucosal papillomas if a chronic disease

Can lead to chronic wasting

What is unique about mucosal papillomas from pachecos?

Can wax and wane or be progressive

What is a common sequelae to pachecos?

Biel and pancreatic duct carcinoma

How do you diagnose pachecos disease?

If a mucosa papilloma is present, highly suggestive

Usually made on necropsy

US can see a bile duct carcinoma

Need histopathology

Where does pachecos reside until disease pops up?

In the nerves (it is a herpesvirus duh)

How do you treat pachecos?

Acyclovir can help but will not cure

Do not remove mucosal papillomas unless they are causing discomfort

Prevention is best

What are the Knemidokoptes species?

K. pilae (scaly face)

K. jamaicensis (leg mite)

What commonly gets Knemidokoptes?

Budgies and chickens

What is the life cycle of Knemidokoptes?

3 week cycle on the host

What are the C/S of Knemidokoptes?

Porous proliferative encrustation with honeycomb appearance on mouth, cere, beak, periorbital area, pelvic limbs, and vent

How do you diagnose Knemidokoptes?

Scraping (false negatives are possible)

How do you treat Knemidokoptes?

Selamectin, ivermectin

Treat all contact birds and assess husbandry

What are the tracheal mytes?

Sternostoma tracheocolum

Sternostoma tracheacolum

What species get Sternostoma tracheacolum?

Finches and canaries

What is the life cycle of Sternostoma tracheacolum?

Entirely on respiratory tract with reinfection common

What are the C/S of Sternostoma tracheacolum?

Voice change, wheezing, clicking, dyspnea

How do you diagnose Sternostoma tracheacolum?

Difficult antemortem can try transillumination or tracheal wash

How do you treat Sternostoma tracheacolum?

Ivermectin, selamectin and supportive care

What does Trichomonas gallinae infect?

Raptors, pigeons, passerines, and budgies

How is Trichomonas gallinae transmitted?

Direct oral by raptors eating infecting pigeons

What are the C/S of Trichomonas gallinae?

Regurgitation, anorexia, difficulty swallowing, weight loss

Fibrinonecrotic plaques in mouth, esophagus, and crop

How do you diagnose Trichomonas gallinae?

Wet mount of a swab, crop aspirate, or lesion

How do you treat Trichomonas gallinae?

Imidazoles like metro, ronidazole, or carnidazole

What species get Giardia/

Cockatiels, budgies, lovebirds

How is Giardia transmitted?

Fecal-oral

What are the C/S of Giaridia?

Diarrhea, feather destructive behavior (from pain in GI and pluck feathers in the area), dry skin, or no signs

How do you diagnose Giardia?

Wet mount of fresh feces

Can try antigen test

How do you treat Giardia?

Metronidazole

Where can you collect blood?

Right is better than left jugular

Ulnar vein

Medial metatarsal vein