Wildlife Case Report: Pekin Duck
by Thomas N. Tully, Jr., DVM, MS, DABVP (Avian Practice), DECZM (Avian); Louisiana State University – School of Veterinary Medicine Department of Veterinary Clinical Sciences Baton Rouge, LA USA
1.5-year-old, 3.48 kg, female Pekin duck (Anus platyrhynchos domestica)
The duck was presented with a 4-day history of rear limb paresis. Initially the condition was observed when the duck was unable to walk after its cage door was opened and using only its wings to move. The duck was found as a duckling and was raised for release in a nearby pond.
A plastic children’s wading pool with the wire cage provided an aquatic environment for the bird to swim.
Cat food (dry kibble) was the primary diet for the 2 ducks at this facility, although there were no cats owned by the rehabilitator.
No other disease problems had been observed by the owner prior to the ambulatory problem. The rehabilitator treated the bird with a Chinese herbal supplement (unknown manufacturer and contents) 2 day prior to presentation without any effect. There was no known past or current history of this bird being traumatized, injured, or attacked by a predator. Also the rehabilitator was not aware of any application of pesticide, herbicide, or contact with material containing heavy metal in or around the bird’s environment.
Physical exam findings
On the external physical examination the patient was quiet, alert, and responsive. Abnormalities noted included, bilateral “angel wing”, pale mucous membranes, bilateral rear limb paresis, a grade II pododermatitis lesion on the right foot, and attempts to move using only its wings. No other external problems were observed during the physical examination process.
What are the possible causes of the duck's problem?
Differential disease diagnoses determined following the initial physical examination included organophosphate and heavy metal (lead) toxicity, nutritional deficiency, and spinal trauma.
What would you do next?
Diagnostic tests were requested for a complete blood count, plasma chemistry panel, acytylcholinesterase and blood lead levels, and full body radiographic imaging. The blood was collected for the diagnostic tests and while waiting for the results the bird was treated with atropine (0.1 mg/kg), calcium EDTA (40 mg/kg), meloxicam (1mg/kg) and tube fed 60 ml of Emeraid Omnivore for nutritional support. The bumblefoot lesion was also cleaned and treated with a topical antimicrobial cream (silver sulfadiazine). Following treatment, the duck was placed in a large cage with stainless steel containers of fresh water and waterfowl diet.
The results of the diagnostic test were normal or negative except for what we considered a severe non-regenerative anemia of 12% (reference range 35-50%). At that time the patient was administered iron dextran (10 mg/kg). The patient remained in the hospital to stabilize its condition, provide supportive care including nutritional support, obtain full body radiographic images, and determine a definitive diagnosis.
The following day the bird was a more active, thus was prepared for diagnostic imaging. Due to the patient’s condition she was not anesthetized for imaging. Foreign mineral and metallic material was observed in the gastrointestinal track that was determined not to be obstructive. Other radiographic findings included chronic fracture of the right major metacarpus and right minor metacarpus, medullary sclerosis secondary to reproductive activity, and gas distension of the cloaca. The blood lead levels were normal and the duck was not showing any clinical signs associated with zinc toxicosis therefore the metallic material observed in the gastrointestinal track was determined to be nontoxic. There was no evidence of skeletal abnormalities that would indicate spinal trauma.
With the diagnostic test results the atropine, and CaEDTA treatments were discontinued and nutritional support with Emeraid Omnivore was continued twice a day. Hydrotherapy (swimming) was prescribed once a day to encourage use of the legs and for psychological benefit. The bird was also eating the waterfowl pellets provided in its hospital cage and maintaining a normal hydration status. Three days following its initial presentation the bird continued to improve and began to walk. During the ducks’ entire hospital stay it was supplemented with Emeraid Omnivore to boost its nutritional intake. On the fourth day of hospitalization the bird was walking and discharged to the rehabilitator with a tentative diagnosis of nutritional deficiency based on the inadequate diet, cat food, being fed and test results obtained during hospitalization. Four days after the patient was discharged another complete blood count was submitted and the duck’s packed cell volume had increased to 34%. The bird continued to recover on proper feed and care. Following a full recovery, the duck was subsequently released to a nearby pond.
A special thank you and recognition is deserving for Dr. Stephanie LaGrone and Dr. Max Rinaldi for their help and effort in caring for the duck while hospitalized.