JPC SYSTEMIC PATHOLOGY

RESPIRATORY SYSTEM

September 2017

P-P13 (NP)

 

Signalment (JPC #1455856):  California sea lion (Zalophus californianus)

HISTORY:  Found stranded on the Santa Barbara coast

HISTOPATHOLOGIC DESCRIPTION:  Lung:  Approximately 80% of the bronchi, bronchiole and alveolar lumina are filled with numerous macrophages, fewer lymphocytes, plasma cells, neutrophils, multinucleated giant cells, and numerous cross-sections of nematode adults and larvae admixed with variable amounts of mucus and fibrin.  The adult nematodes are 80-200 um in diameter and have a 5-10 um thick smooth outer cuticle, a thin hypodermis from which small lateral cords arise, a pseudocoelom lined by coelomyarian-polymyarian musculature, a large intestinal tract lined by few multinucleated cells, and male and female reproductive organs, with uteri often containing intraluminal larvae.  The larvae are 10-20 um in width, deeply-basophilic, and occasionally coiled.  Diffusely, alveolar septa are congested and expanded by increased clear space (edema), eosinophilic fibrillar material (fibrin), and moderate numbers of lymphocytes and plasma cells.  Multifocally, bronchiolar epithelium is hyperplastic, piling up to 5 cell layers thick, with mild goblet cells hyperplasia, and there is multifocal attenuation and loss.  In other areas, bronchiolar epithelial cells are necrotic with hypereosinophilic cytoplasm, pyknosis, and karyorrhexis.  Diffusely, interlobular septa, perivascular connective tissue, and pleura are moderately expanded by fibrin and edema.

Liver:  There is diffuse moderate congestion of sinusoids and multifocally hepatocytes contain a single clear cytoplasmic vacuole (lipid).

MORPHOLOGIC DIAGNOSIS:  Lung:  Pneumonia, granulomatous, diffuse, moderate, with edema and numerous intra-alveolar and intrabronchiolar nematode larvae and adults, California sea lion (Zalophus californianus), pinniped.

Liver:  Hepatic lipidosis, mild, with mild sinusoidal congestion.

ETIOLOGIC DIAGNOSIS:  Pulmonary parafilaroidiasis

CAUSE:  Parafilaroides decorus

GENERAL DISCUSSION:

PATHOGENESIS:

LIFECYCLE:

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS: 

TYPICAL LIGHT MICROSCOPIC FINDINGS:

ADDITIONAL DIAGNOSTIC TESTS: 

DIFFERENTIAL DIAGNOSIS:

Lungworms of phocid pinnipeds:

vasculitis

COMPARATIVE PATHOLOGY:

Species

Agent

 Site of adult

Dog

Eucoleus aerophila, Spirocerca lupi

Trachea, bronchi

 

Angiostrongylus vasorum

Pulmonary arteries

 

Oslerus osleri

Trachea, bronchi

 

Dirofilaria immitis

Pulmonary artery

 

Filaroides hirthi, Andersonstrongylus milksi

Bronchi, bronchioles, alveoli

 

Linguatula serrata (pentastome)

Nasal passages

Cat

Eucoleus aerophila, Filaroides rostratus

Trachea, bronchi

 

Aelurostrongylus abstrussus

Bronchioles, alveolar ducts

 

Paragonamus kellicoti (fluke)

 

Cattle

Dictyocaulus viviparous

Bronchi, bronchioles

Sheep, Goat

Dictyocaulus filaria

Bronchi, bronchioles

 

Protostrongylus rufescens

Bronchioles

 

Muellerius capillaris; Cystocaulus ocreatus

Alveoli

 

Oestrus ovis (bot)

Nasal cavity

Horse, Donkey

Dictyocaulus arnfieldi

Bronchi, bronchioles

Pig

Metastrongylus apri; M. salmi,

Bronchi, bronchioles

Avian

Syngamus trachea

Trachea

 

Cytodytes nudus (mite)

Air sacs

Rabbit (wild)

Protostrongylus boughtoni

Bronchi, bronchioles

Pinnipeds

Otostrongylus circumlitus

Trachea, bronchi,

 

Parafilaroides spp

Bronchioles, alveoli

New World Monkey

Filaroides cebus

Bronchioles, alveoli

 

Pneumonyssus simicola (mite)

Bronchi, bronchioles

Rats

Angiostrongylus vasorum, Parastrongylus cantonensis

Pulmonary arteries & capillaries

 

References:

  1. Garner MM, et al. Evidence of Brucella infection in Parafilaroides lungworms in a Pacific harbor seal (Phoca vitulina richardsi). J Vet Diagn Invest. 1997;9:298-303.
  2. Howard EB, Britt JO, Matsumoto G. Parasitic diseases. In: Howard EB, ed. Pathobiology of Marine Mammal Diseases. Vol 1. Boca Raton, FL: CRC Press, Inc.;1983:128-131.
  3. Jacobus K, Marigo J, Gastal SB, et al. Identification of Respiratory and Gastrointestinal Parasites of Three Species of Pinnipeds (Arctocephalus australis, Arctocephalus gazelle, and Otaria flavescens) in Southern Brazil. J Zoo and Wildl Med. 2016; 47(1):132-140.
  4. Maudlin EA, Peters-Kennedy J. Integumentary system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 1. 6th ed. Philadelphia, PA: Elsevier Saunders; 2016: 688.
  5. Measures LN. Lungworms of marine mammals. In: Samuel WM, Pybus MJ, Kocan AA, eds. Parasitic Diseases of Wild Mammals. 2nd ed. Ames, IA: Iowa State University Press; 2001:238-288.
  6. Simpson JG, Cornell LH. Diseases associated with stranding and captivity. In: Howard, EB, ed.  Pathobiology of Marine Mammal Diseases. Vol 2.  Boca Raton, FL: CRC Press, Inc.;1983:30-35.
  7. Van Bonn WG. Pinnipdia, Metazoan Diseases. In: Fowler ME, Miller RE, eds. Zoo and Wild Animal Medicine. Vol. 8. Philadelphia, PA: WB Saunders, Co.; 2015:447.
  8. Vercruysse J, Salomez A, Ulloa M, Osterhaus A, Kuiken T. Efficiency of ivermectin and moxidectin against Otostrongylus circumlitus and Parafilaroides gymnurus in harbor seals (Phoca vitulina). Vet Rec. 2003; 152, 130-134.

 

 


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