Somebunny has parasites...
A fecal sample from a 4 month-old intact male English lop rabbit was submitted for gastrointestinal parasite evaluation. According to the owner, the rabbit has not been doing well lately.
A centrifugal fecal flotation with Sheather’s sugar solution (specific gravity, 1.26) was performed, and a number of these eggs were observed (Images 1–3) sizes ranged from 97.5 x 40 µM to 105 x 47.5 µM
Image 1: 100x magnification
Image 2: 200x magnification
Image 3: 400x magnification
Passalurus ambiguus are Oxyurids, commonly called pinworms and are distributed worldwide. The adults live in the cecum of rabbits. The eggs are passed in the feces of infected rabbits, and the eggs become infective within a short period of time. Infections with this nematode are usually subclinical.
The eggs can be detected by flotation techniques, and measure 95-105 x 45 µM.
The chicken or the egg?
Three chickens were submitted for necropsy to the Oklahoma Animal Diseases Diagnostic Laboratory. A history of poor feather condition, decreased egg production, and increased mortality was reported. The ceca of the birds were submitted for fecal examination and parasite identification. During gross examination several adult parasites were observed in one of the chicken’s cecum (Figures 1–3).
The fecal content was pooled for a centrifugal fecal floatation using sugar solution and the following eggs were observed (Figures 4 and 5).
Heterakis spp. are common parasites in poultry and wild bird hosts. Adults are found in cecum. Eggs are passed in the feces of poultry and become infective in the environment.
How were the chickens infected? Ingesting eggs from contaminated environment or through ingestion of earthworms that act as transport host.
Is it pathogenic? Heterakis gallinarum is usually nonpathogenic, however they act as vectors of the protozoan Histomonas melagridis (blackheaded disease) which can be a life threatening infection, particularly in turkeys.
How do you treat it? Piperazine is an anthelmintic approved by the FDA for use in chickens to treat ascarids. Fenbendazole has also been shown to reduce the number of Heterakis gallinarum in infected birds by less than 90%. (1, 2)
A fecal sample from a 2 year-old male rat rescued from a hoarding situation, was submitted for gastrointestinal parasites evaluation. The rat did not show any symptoms at submittal but the feces was soft in consistency.
For fecal analysis, a centrifugal fecal flotation with Sheather’s sugar solution (specific gravity, 1.26) was performed, and a low number of eggs were observed.
Trichosomoides crassicauda or bladder threadworm, is a parasite of the urinary bladder of rats. The female is 10–19 mm long; the male measures 1.5–3.5 mm. A curious fact about this parasite is that the male lives inside the uterus of its mate (hyperparasite).
The medium‐sized egg is lemon‐shaped with transparent polar plugs and measures about 60–70 by 30–36 μm. The shell is thick and brown, and contains either a morula or an L1 larva.
How did the rat become infected? Usually from mother rats to their offspring before weaning.
Is it pathogenic? The presence of the worms can cause nodules in the bladder wall.
How do you treat it? In laboratory animals successful treatment has been achieved with Ivermectin subcutaneously at 0.2 mg/kg or orally at 3mg/kg.
Which came first the parasite or the egg?
A fecal sample from a 6-month-old, spayed female, Siamese cat was submitted for a gastrointestinal parasite evaluation. The cat did not show any symptoms at submittal. For fecal analysis, a centrifugal fecal flotation with Sheather’s sugar solution (specific gravity, 1.26) was performed, and a low number of these eggs were observed
Image 1: 100X magnification
Image 2: 400X magnification
Demodex spp. eggs.
The fecal sample also showed Demodex spp. adults (Image 3)
Image 3: 200X magnification
Demodex spp. are small wormlike mites with short legs, they live in the hair follicles and sebaceous glands of mammals. Several species of Demodex often parasitize the same animal host, but each species tends to be restricted to a particular location. In cats, dermatitis associated with Demodex cati is rarely noticed and is usually localized on the head and in the ear canals. Demodex gatoi, is a much shorter and is more superficially dwelling than D. cati. Cases of feline demodicosis are believed to be associated with underlying immunosuppressive diseases.
Dropping like flies...
Several backyard poultry farms near the Des Moines river in central Iowa reported numerous deaths among their chickens. One farm lost 17 out of 21 backyard chickens. The referring veterinarian collected and submitted these flies for identification while further diagnostic investigations were being carried out.
These are Simulium flies, which have a characteristic humped appearance. These are small, stout bodied Nematoceran with short antennae having greater than 9 segments (Figure 1). They also have short prominent mouth parts with maxillary palps and distinctive wing venation with large veins crowded towards anterior edge (Figure 2). These flies have been associated with sudden death in backyard poultry flocks and can cause exsanguination and anaphylactic shock in livestock.
Figure 1: Short segmented antennae.
Figure 2: Wing venation.
An unexpected finding...
An apparently healthy shelter kitten was presented for routine ovariohysterectomy. While performing pre-surgical baseline labs the referring veterinarian found this egg on urinalysis. All other lab work was normal and the physical exam was unremarkable.
This is an egg of Pearsonmea, the bladder worm of cats and dogs. Eggs have the typical capillarid appearance being barrel or lemon shaped with two bipolar plugs and a rough shell. Focusing on the shell wall reveals a characteristic thick globular pattern of ridges, as depicted in the image below.
Special thanks to Dr. Jeba Jeba Jesudoss Chelladurai BVSc, MS, DACVM (Parasit) at Iowa State University for providing this case.
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