A 3-month old calf was submitted for necropsy to the Oklahoma Animal Disease Diagnostic Laboratory. The calf was found lying down 2 days before dying. During necropsy examination, the body presented moderate emaciation and anemia. The cecal and colonic contents were pasty with numerous parasites 1 to 1.5 cm long. (Image 1)
Image 1: Parasites found in cecal and colonic contents
Oesophagostomins are parasites of the large intestine of ruminants, swine and primates. The adults are 1 to 2 cm long and the eggs are 70 to 90 x 34 to 45 um. They are also called nodular worms because their larva can become encapsulated by a reactive inflammation in hypersensitive hosts. Acute inflammation may lead to diarrhea that can be fatal.
This calf also had high numbers of Moniezia sp. eggs, and Nematodirus helvetianus, with the last one being pathogenic in young animals that have no acquired immunity. (Image 2)
Image 2: Fecal centrifugation from small intestinal content
Hope for a New Year's Resolution
A parakeet pet was presented to the College of Veterinary Medicine Clinic, Southwestern University in Philippines, with localized thickened, crusty lesions on the legs and feet, and scales lifting off on the area. No signs of pruritus were noticed. (Images 1-3)
Microscopic examination of loose leg scales revealed the following. (Image 4)
Erlah Shermaine Roble, DVM, Assistant Professor at the College of Veterinary Medicine. Southwestern University PHINMA. Philippines
Images 1-3: Gross lesions upon presentation
Image 4: Microscopic finding of leg scales
Knemidocoptes sp. These mites burrow in the epidermis of the legs on birds, causing scales to lift and become loosened and the legs to become thickened and deformed. K. pilae is the species that commonly infest parakeets while K. mutans and K. jamaiciensis infest gallinaceous birds and canaries respectively. This case was resolved after oral administration of Ivermectin in drinking water.
A 2-year-old female Mongolian gerbil was submitted for necropsy to determine the cause of death as the owner has had multiple losses in the household. During necropsy, six specimens collected from the proximal area of the small intestine were incidentally found. All of the specimens recovered were identified as females containing spindle shaped eggs that measured 115 µm to 140 µm by 30 µm to 60 µm. (Images 1-3).
Case provided by: Tiana Sanders DVM, PhD Student, Texas A&M
Image 1: Eggs, 10x
Image 2: Caudal end, 10x
Image 3: Anterior end, 10x
Dentostomella translucida. Known as the “Gerbil Pinworm” is a threadworm found in the small intestine of gerbils. Females typically measure 1 cm to 3 cm in length and males are 0.6 cm to 1 cm. The identifying features of D. translucida include a mouth with no lips, five unequal teeth per esophageal sector, and a thick, translucent, transversely striated cuticle.
Typically, gerbils infected with D. translucida are asymptomatic and diagnosis may be difficult, as these parasites do not deposit their eggs around the perianal region.
Worms on the Brain
An adult female woodchuck presented to a wildlife clinic in New York state after being found on the side of the road. The woodchuck had multifocal crusts and pustules over most of the body, with skin sloughing, with mites and fleas noted on external examination. The animal displayed neurologic signs, with, minimal response to handling, and paddling reported. A dewormer and antibiotics were administered, but despite treatment, the woodchuck continued to decline, with no interest in food by the third day. Euthanasia was elected, and the animal was submitted for necropsy following a negative rabies test. Histologic examination of the brain revealed the following:
Timothy Wu, MS, DVM, Dipl. ACVP
Image 1 and 2: Histologic findings in the brain
Ascarid larva migrans (likely Baylisascaris sp.)
Histologic evaluation reveals numerous up to 60 um diameter nematodes, determined to be the larval stage, given the absence of genital tracts within the examined sections. The presence of lateral alae (arrow), coelomyarian-polymyarian musculature, and a uninucleate intestine are consistent with ascarid larvae. While other ascarids, such as Toxocara canis cannot be ruled out, the most likely diagnosis in this case is considered to be Baylisascaris sp. There are many species of Baylisascaris affecting wildlife, including Baylisascaris columnaris in skunks, Baylisascaris transfuga in bears, and Baylisascaris laevis in woodchucks. The most commonly discussed species is Baylisascaris procyonis, which affects raccoons, and can cause visceral larva migrans in a wide range of hosts, including humans. Ascarid migration of the central nervous system, as in this case, can cause severe clinical signs. Although quick diagnosis and treatment with corticosteroids and albendazole can prove effective, this is not always plausible, as diagnosis can prove difficult.
A 7-year-old male Siberian husky was taken to a clinic for a wellness check. The dog lives in a suburban area in a house with close access to a wooden area. According to the owner, he was acting playful and eating normal. The gross fecal exam was normal and the centrifugation with sugar solution revealed the following:
Image 1 and 2: Findings of centrifugation fecal with sugar
Sarcocystis sp. oocysts.
Dogs and other carnivores are definitive hosts of Sarcocystis sp. while ruminants, horses, swine and rabbits can act as intermediate hosts. Fully sporulated oocysts are eliminated thorough the dog’s feces and the schizogony and sarcocysts formation occurs in the intermediate hosts. Definitive hosts usually do not display clinical signs but the schizogony in the endothelium of the herbivore may result in serious disease. A known pathogenic species for equids is Sarcocystis neurona with opossums acting as definitive hosts.
Now serving eggs a la parasite
A backyard flock owner in Minnesota found the following specimen when she cracked one of their eggs.
Lindsey King DVM class 2024 at OSU
Kellee Sundstrom, MS, Veterinary Pathobiology, OSU
Prosthogonimus macrorchis, are poultry flukes found within the oviduct. Birds are infected with P. macrorchis after consuming an infected dragonfly. Because of the use of aquatic invertebrates as intermediate hosts, this parasite is commonly found in fowl surrounding water features, especially the Great Lake area. Potential clinical signs are weight loss, malformed eggs, or decreased egg production. Adult flukes are small, approximately 8mm long, often found within the oviduct on necropsy. A recent case report also described P. macrorchis in the egg of a backyard chicken. At this time, there is no labeled dewormer for P. macrorchis in poultry.
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