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  • Author or Editor: Dwight D. Bowman x
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Objective—To determine the apparent prevalence of shedding of Cryptosporidium spp in healthy alpaca crias and their dams on 14 farms in New York and 1 farm in Pennsylvania.

Design—Cross-sectional study.

Animals—110 alpaca crias and their 110 dams.

Procedures—Fecal samples were obtained from 220 alpacas at 14 alpaca farms in New York and 1 farm in Pennsylvania. For each animal, age, sex, and health condition were recorded. A fecal score (1 = normally formed; 2 = soft or loose; 3 = diarrhetic) was recorded for each cria. Cryptosporidium oocysts were identified in fecal samples by a direct immunofluorescence assay.

Results—Apparent prevalence of fecal shedding of Cryptosporidium oocysts was 8% (95% confidence interval, 4% to 15%) in dams and was 7% (95% confidence interval, 3% to 13%) in crias. There was no significant difference in age between dams with positive fecal test results for Cryptosporidium oocysts (median age, 4 years; range, 3 to 8 years) and dams with negative results (median age, 4 years; range, 2.5 to 19 years). No significant difference was found in age between crias with positive fecal test results (median age, 20 days; range, 7 to 53 days) and those with negative results (median, 36 days; range, 2 to 111 days). No significant difference in fecal scores was found between crias with positive versus negative fecal test results.

Conclusions and Clinical Relevance—A higher than previously reported apparent prevalence of fecal shedding of Cryptosporidium oocysts in healthy alpacas was found. A zoonotic risk should be considered, especially for Cryptosporidium parvum.

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in Journal of the American Veterinary Medical Association


Objective—To evaluate the effect of nutritional plane on health and performance of dairy calves after infection with Cryptosporidium parvum.

Design—Randomized, controlled trial.

Animals—20 Holstein bull calves.

Procedures—Calves were assigned to a higher plane of nutrition (HPN; 0.30 Mcal intake energy/kg of metabolic body weight using a 28% protein-20% fat milk replacer) or conventional nutrition (CN; 0.13 Mcal intake energy/kg of metabolic body weight using a 20% protein-20% fat milk replacer). Calves were inoculated with C parvum oocysts at 3 days old. Fecal and health scores, oocyst counts, weight gain, dry matter intake, and hematologic variables were measured for 21 days. Data were analyzed with nonparametric and regression methods.

Results—Body weight (day 1), serum total protein concentration (day 3), and PCV (day 3) were not different between groups. Oocyst shedding was not different between groups. The PCV was higher in the CN group (40%), compared with the HPN group (32%) at the end of the study. Fecal scores (FS) improved faster in the HPN group (median, −0.1 FS/feeding), compared with the CN group (median, −0.06 FS/feeding). The HPN calves had better average daily gain (ADG) than did CN calves (median, 433 g/d vs −48 g/d, respectively). Feed efficiency (ADG:dry matter intake ratio) was better for HPN calves than CN calves (median, 131.9 g/kg vs −31.4 g/kg).

Conclusions and Clinical Relevance—After a pathogen challenge, calves maintained hydration, had faster resolution of diarrhea, grew faster, and converted feed with greater efficiency when fed a higher plane of nutrition.

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in Journal of the American Veterinary Medical Association



A 12-year-old neutered male domestic shorthair cat with chronic anterior uveitis and secondary glaucoma of the right eye was examined for persistent blepharospasm 2 weeks after corneal debridement and grid keratotomy for nonhealing superficial ulcerative keratitis.


Examination of the right eye revealed a central superficial corneal ulcer associated with corneal epithelial and subepithelial infiltrates and mild aqueous flare. Structures consistent with amoeboid cysts and trophozoites were detected in the cornea by in vivo confocal microscopy. Suppurative keratitis was identified cytologically. An Acanthamoeba spp was isolated through culture and identified by a PCR assay of corneal specimens.


Symptomatic and antiamoebic (polyhexamethylene biguanide 0.02% ophthalmic solution) treatments were instituted. Over the following 6 weeks, the cat lost vision in the affected eye and lesions progressed to nonulcerative stromal keratitis associated with a dense paracentral corneal stroma ring infiltrate and anterior lens luxation. The globe was enucleated, and lymphoplasmacytic sclerokeratitis, anterior uveitis, and retinal detachment were noted. Acanthamoeba organisms were detected within the corneal stroma and anterior sclera with histologic and immunohistochemical stains. The amoebae were classified to the Acanthamoeba T4 genotype by DNA sequencing. The cat had no medical problems attributed to Acanthamoeba infection over 36 months after enucleation, until the cat was lost to follow-up.


Naturally acquired Acanthamoeba sclerokeratitis is described in a cat for the first time. Acanthamoeba infection should be considered for cats with superficial corneal disease refractory to appropriate treatments and especially occurring after ocular trauma, including keratotomy.

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in Journal of the American Veterinary Medical Association


Case Description—A 4-year-old Hanoverian gelding was evaluated because of a mobile worm-like structure in the right eye.

Clinical Findings—Ophthalmologic examination of the right eye revealed a white, thin, coiled, mobile parasite, which was presumed to be a nematode, located in the ventral portion of the anterior chamber of the eye; there also were vitreal strands located temporally and inferiorly near the margin of the pupil. Results of ophthalmologic examination of the left eye were unremarkable.

Treatment and Outcome—The horse was treated with a neomycin-polymyxin B-dexamethasone ophthalmic solution applied topically (1 drop, q 8 h) to the right eye and penicillin V potassium (22,000 U/kg [10,000 U/lb], IV, q 6 h). The horse was anesthetized. A stab incision was made in the cornea, and a viscoelastic agent was infused around the parasite. The parasite was extracted via the incision by use of an iris hook and tying forceps. The horse had an uncomplicated recovery from the procedure and retained vision in the right eye. Gross and microscopic examination was used to identify the parasite as an adult metastrongyloid nematode consistent with a fully developed male Parelaphostrongylus tenuis.

Clinical Relevance—To the authors' knowledge, this is the first report of intraocular parelaphostrongylosis in a horse. This report provided evidence that vision could be retained after treatment for intraocular P tenuis infection in a horse.

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in Journal of the American Veterinary Medical Association


Objective—To describe the clinical, endoscopic, and serologic features of an outbreak of besnoitiosis in 2 donkey operations in northeastern Pennsylvania and to report the outcome of attempted treatment of 1 naturally infected individual.

Design—Observational study.

Animals—29 donkeys (Equus asinus) in northeastern Pennsylvania.

Procedures—Donkeys were examined for lesions suggestive of besnoitiosis in an outbreak investigation. Information was collected regarding the history and signalment of animals on each premises. Rhinolaryngoscopy was performed to identify nasopharyngeal and laryngeal lesions. Serum samples were collected for immunofluorescent antibody testing and immunoblotting for Besnoitia spp. Skin biopsy samples were obtained from 8 animals with lesions suggestive of besnoitiosis for histologic examination. Quantitative real-time PCR assay for Besnoitia spp was performed on tissue samples from 5 animals.

Results—Besnoitiosis was confirmed in 6 of the 8 suspected cases. The most common lesion site was the nares, followed by the skin and sclera. Donkeys with clinical signs of disease had higher serum antibody titers and tested positive for a greater number of immunoblot bands than did donkeys without clinical signs of disease. All animals evaluated by PCR assay tested positive. Putative risk factors for disease included age and sex. Ponazuril was not effective at treating besnoitiosis in a naturally infected donkey.

Conclusions and Clinical Relevance—Knowledge of clinical and serologic features of besnoitiosis in donkeys will assist clinicians in the diagnosis and prevention of this disease in donkey populations. Besnoitiosis may be an emerging disease of donkeys in the United States.

Full access
in Journal of the American Veterinary Medical Association