Always chick for parasitesA chicken less than 1 year-old, was submitted for necropsy to the Oklahoma Diagnostic Laboratory; the chicken belonged to a flock of mixed breeds with contact with ducks. During necropsy the following parasites were recovered.  Image 1: Specimen collected at necropsy. Dermanyssus sp.
These mites are infrequently found on the birds due to their feeding habits. They usually hide in nests and feed during the night. They are blood feeders and their life cycle can be completed in a week, adults can survive for months without having a blood meal. They can be differentiated from Ornithonyssus mites by observing the anal plate, the anus is located in the anterior half, while in Dermanyssus the anus is in the posterior half (Image 2). The chelicerae are long with minute chelae (Image 3). 
Image 2.
Image 3. This is bullA cattle producer from northeast Oklahoma found several of his cows open during the last pregnancy check. The previous year he purchased a new bull with a breeding soundness exam performed before purchasing. Due to the high number of open cows, he submitted a preputial wash and requested a new fertility test. The following is a video of the culture after 48 hours of initiation. Video: Culture pouch after 48 hours of initiation. Tritrichomonas foetus trophozoites. This parasite is sexually transmitted, causing early abortions, endometritis, and occasionally pyometra. Bulls are asymptomatic and remain infected indefinitely. Diagnosis is confirmed by culture or qPCR and control measures should be focused on biosecurity protocols, culling, and artificial insemination.
Image: Stained T. foetus (arrow). Unwanted "Neigh"borTwo specimens, as the one seen in Image 1, were submitted to the parasitology diagnostic laboratory. The specimens were collected from a 5-year-old mare with history of pruritus and scaly coat on the back.  Image 1: Specimen removed from a horse. Werneckiella equi (Damalinia equi), is the horse biting louse that belongs to the suborder Ischnocera. Lice from this group are characterized by having salient three-jointed antennae in species that infest mammals, comparing to the five-jointed antennae that infest birds, they feed on epithelial cells and skin debris. Groups of horses with poor body condition and confined in small spaces are more likely to be affected. Dog down on his luckA fecal sample from a 2-year-old male dog with history of soft stools and vomiting was submitted to the parasitology diagnostic laboratory. The dog did not have history of deworming treatments. The following structures were observed after fecal centrifugation with sugar solution  Image 1: Specimen at 10x objective.  Image 2: Specimen at 40x objective. Adelina sp., is an apicomplexan parasite of arthropods and oligochaetes that could be confused with Ancylostoma sp. eggs if not measured or if examined by inexperienced personnel. In this case it is a spurious parasite of the dog which is passing the oocysts, after ingesting arthropods or earthworms infected with the coccidian parasite. Unhealthy RelationshipThe following images belong to an 8-month-old Quarter Horse colt from Kansas with a history of lethargy, inappetence, and abdominal pain that worsened over approximately 2 weeks. The colt died and a necropsy was performed. On gross examination, the large colon exhibited changes consistent with infarction. The cranial mesenteric artery contained a thrombus and on histopathology, the following was identified.  Image 1: 2X objective  Image 2: 10X objective Strongylus vulgaris, is a member of the Strongylinae. The 4th and 5th larval stages migrate through the arterial system and cause verminous arteritis with marked intimal thickening and thrombus formation that can block arteries, causing infarction of intestinal walls commonly associated with anorexia, pyrexia, colic and death. Foals and yearlings are most commonly affected. Case provided by Dr. Giselle Cino. Wholly cowThe following blood sample belongs to a cow from a beef herd in northeast Oklahoma with history of weight loss, icterus and hemoglobinuria. Eight of 140 animals died with no previous symptoms.  Image 1: Blood smear from a cow. Anaplasma marginale is a tick transmitted pathogen which causes hemolytic anemia in cattle. In the US is mainly transmitted by the Dermacentor spp. ticks, however it can also be transmitted mechanically via biting flies, mosquitoes and contaminated fomites. Cattle infected with A. marginale show symptoms such as fever, abortion, icterus, weight loss and in some instances mortality. The morulae of A. marginale are found in erythrocytes of acutely infected cattle. |