Introduction

Penguins are marine birds that live distributed along different climatic areas of the South hemisphere, including temperate, tropical and cold areas. These animals are classified in six genus and seventeen species (Willians, 1995). The Spheniscus magellanicus) popularly known as Magellan Penguin is taxonomically classified in the genus Spheniscus. The penguins of this species are approximately 70 cm in length and 3 to 4 kg in weight. They are easily identified by their black feathers on the dorsal area and wings, and white feathers on the ventral area. They usually eat krill, crustaceans, and fish; and it is important to notice that fish are responsible for penguins migration from the South coast of Brazil to the coastal region of the State of Alagoas, from May to October (Ruoppolo et al.,2004). Because of natural issues, such as natural selection and meteorological phenomena, or anthropic issues, such as pollution and oil leakage, many of these animals are found on beaches presenting symptoms associated with oil intoxication, malnutrition, musculoskeletal disturbances, dehydration, and immunosuppression (Sick, 1997). When they are found alive, these animals are sent to competent organs for rehabilitation, according to the legal determinations of IBAMA; nonetheless, in many cases it is hard for them to survive. Veterinary pathology studies are of major importance to evaluate the causa mortis of these animals, clarifying important questions related to these animals' anatomy, physiology, diseases, and death (Coelho, 2004). This study presents information about necropsy findings on the species Spheniscus magellanicus, identifying possible etiologies for the anatomical pathological alterations.

Materials and Methods

Twenty Spheniscus magellanicus were studied, after their capture in the coastal area of Baixada Santista [Praia Grande (10 animals), Santos (5 animals) and Itanhaém (5 animals)]. Five of these animals were dead by the time of capture and the other fifteen died at CETAS-RMA some days after being captured. Sixteen animals were refrigerated and four of them were submitted to necropsy right after their death. The necropsies were performed at the Animal Pathology Laboratory of the Monte Serrat-Unimonte Veterinary Hospital, from June to August, 2008. The instrumental used included blunt/blunt scissors, blunt/sharp scissors, #4 scalpel, anatomical tweezers, necropsy knives, knife sharpener, disposable gloves, and masks. Before the dissection, the animals were measured and weighted, and their skin was moisturized for a better incision. We used the necropsy techniques according to Rego & Matushima (2000), starting by an external examination to verify possible alterations on the beak, eyes, ears, feathers, skin and body condition, followed by an internal examination. The tissues fragments were conditioned in a 10% formalin solution for further histopathological examination and exceptional parasites found were conditioned in Raullet's solution for further identification by the stereoscope. All necropsies were photographically recorded.

Results

From the 20 animals, 18 were in a bad nutritional condition, presenting prominent sternum and atrophic chest muscles and two animals were in a regular nutritional condition, presenting slightly prominent sternum, according to the classification proposed by Coelho (2004). Two animals exhibited oil spots on the dorsal and ventral regions of their body. All penguins presented ectoparasites on their feathers, from which four animals were parasitized by Lepas sp, a species of oceanic cirripedes, all over their body and lower limbs. Five animals had alopecic lesions compatible with dermatitis on the wings. All penguins presented apparently normal eyes, beaks and ears at macroscopic examination. Considering the internal examination, we noticed the presence of oral ulcers in two animals, probably caused by foreign bodies (fish bone). In the esophagus of four animals we found caseous abscesses, possibly caused by foreign bodies. One of these abscesses had a diameter of 8 cm, determining an impairment for the animal's nourishment and consequent death. In 16 animals we noticed the presence of nematode parasites in the caudal portion of the esophagus. These parasites were observed in different quantities in all animals' ventricles. As long as these nematodes have some characteristics that resemble the parasite Anisakis sp.

Discussion and Conclusions

It was proposed a 1 to 5 scale to quantify their presence, as follows: score 1 represents a small quantity, score 2 represents a moderate quantity, score 3 represents a great quantity without obstruction, score 4 represents a great quantity with possible obstruction, and score 5 represents great quantity with total obstruction. Four animals presented score 1 (20%), six animals presented score 2 (30%), two animals presented score 4 (10%) and eight animals presented score 5 (40%). In the score 5 animals we noticed an important presence of a mucohemorrhagic fluid inside the stomach and ulcers on the mucosa. We also observed the same nematode parasites in the guts of 16 penguins (80%), and mucohemorrhagic fluid inside the guts of 10 penguins (50%). Three (15%) of the animals that were found dead presented an important amount of a translucid fluid (suggestive of water) inside their lungs. One of these animals had a history of being catch by a fisher net and drowning. None of the animals presented necroscopic alterations on the larynges, trachea, syringe and aerial sacs. Also, none of the animals presented lesions compatible with aspergillosis, which is a disease commonly found in ill birds, according to Jones et. al (2004). Six penguins (30%) presented cardiac ventricular hypertrophy. Based on macroscopic findings, we suggest that the causa mortis for these twenty penguins was: nematode parasitemia (mucohemorrhagic parasitic gastroenteritis) for 94% of the animals, esophagitis related to abscess for 2% of the animals, drowning for 2% of the animals, and non-determined cause for 2% of the animals. This study remarks the importance of the necropsy examination in order to determine the causa mortis. However, we assume that it is equally important to perform a histopathologic and microbiologic examination to better determine a final diagnosis.

References

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