VN June 2023

Vetnews | Junie 2023 37 o Chronic lesions; liver and kidney cirrhosis, pancreatic necrosis (budgerigar and pigeon), non-purulent meningitis. o Differential diagnosis: • Viral infections (Herpesvirus, Adenovirus, Polyomavirus, Paramyxovirus). • Bacterial infections (mycobacteria, Enterobacteriaceae, Pseudomonas). Treatment • Tetracyclines o Inhibit Chlamydia protein synthesis and are active only when intracellular reticulate bodies are actively replicating. o Disadvantages  Low intracellular concentration  Immunosuppression  Chelates with calcium, dietary calcium should be reduced to 0.7%or less.  Inhibition of autochthonous flora o The durationof therapy is empirically set at 45 days, the average lifespan of amacrophage. The tetracyclines commonly used include: • Oxytetracycline o Poorly absorbed from the intestinal tract, and, therefore, should not be used. • Chlortetracycline o Renally excreted and shouldbeused cautiously inbirds with renal disease. • Doxycycline calcium o Excreted extra-renally (faeces, bile). o Adequate plasma levels are often achievable in medicated drinking water and seeds. o May cause hepatic necrosis with elevation of AST. Resolves with cessation of therapy. • Enrofloxacin o clinical improvement and cessation of faecal shedding for five weeks post-treatment o not fully documented, and may not be effective clinically as doxycycline • Azithromycin o Amacrolide antibiotic able to penetratemacrophages o Anecdotal reports of effectiveness, but no clinical trials have been done as yet to confirm this o dosed orally once weekly for 3-6 weeks o The recommended dose is 40mg/kg SID 30 days Disinfection Free elementary bodies are unstable and can be inactivated in the environment within days. They are sensitive to: • Heat • Quaternary ammoniumproducts, • 70% ethanol, • 3%hydrogen peroxide Clinical signs in people Fever, chills, pneumonia, headache, weakness, fatigue, myalgia, chest pain, anorexia, nausea, vomiting, and diaphoresis. Psittacine Beak and Feather Disease TheOrganism PBFD virus, a Circovirus, is a non-enveloped single-strand DNA virus measuring 14-17 nm Clinical Signs • Two forms o Acute  Seen in juveniles aroundweaning age  Lethargic, fluffed, anorexic  Haematology may show a pancytopaenia and non-regenerative anaemia  Affected birds may die of severe hepatic necrosis before feather abnormalities develop.  Feather lesions have been noted in fledgling birds at 28-32 days old. o Chronic  Progressive replacement of normal feathers with dystrophic feathers (retained sheaths and blood supply, clubbed appearance, stress lines, constrictions, and abnormal shapes). The degree and location of the feather loss may depend on the state of the moult when the bird was initially infected. Typically, lesions develop in order of powder down, contour, primaries, secondaries, tail, and crest.  Poicephalus species and lories may only lose tail feathers and primary flight feathers. These feathers may then regrow.  Neophema spp may develop untidy plumage and lose feathers easily when handled.  Many coloured parrots develop feather colour changes – blue feathers become white, and green feathers become yellow.  Beak lesions are seen in cockatoos only - palatine necrosis, ulceration, elongation, and easily fractured beaks.  Immunosuppression is common in all species. Incidence • All psittacines are susceptible, but New World (South American) parrots (macaws, conures, Amazons) and cockatiels are rarely affected. Technical I Article >>> 38