Experience level as a predictor of entry into the hypotympanum during feline total ear canal ablation and lateral bulla osteotomy.

OBJECTIVES: The study hypotheses were as follows: (1) owing to the unique anatomy of the feline middle ear, the hypotympanum would be entered in less than 100% of cats during total ear canal ablation and lateral bulla osteotomies (TECA-LBOs); and (2) incomplete penetration of the septum and subsequent failure to enter the hypotympanum is more likely to occur in surgeries performed by a novice surgeon when compared with an experienced surgeon and may be under-recognized. METHODS: Head CT was performed in 12 feline cadavers to confirm absence of gross ear disease. A novice surgeon and an experienced surgeon were randomly assigned to perform TECA-LBO on the left or right ear. Surgeons were blinded to each other's surgical technique. CT of cadavers was performed after the procedure. Successful penetration of the septum, entry into the hypotympanic cavity and amount of bone removed in bulla osteotomy, quantified via CT, were compared between the novice surgeon and experienced surgeon. RESULTS: The novice surgeon entered the hypotympanum in 3/12 (25%) procedures, compared with 9/12 (75%) procedures performed by the experienced surgeon. The experienced surgeon performed a larger osteotomy than the novice surgeon (3301 mm vs 1376 mm, P <0.0023). Regardless of surgeon experience, more bone was removed in surgeries in which the hypotympanum was entered. CONCLUSIONS AND RELEVANCE: Our results underscore the need for familiarity with feline middle ear anatomy when performing TECA-LBOs. Postoperative CT is recommended for novice surgeons to confirm entry into the hypotympanum.

Subcutaneous herniation of fetuses after blunt force trauma in a cat.

CASE SUMMARY: A stray female domestic shorthair cat was presented to the emergency service after being hit by a car. The patient was recumbent and vocalizing, with a small wound over the right lateral thorax, and two palpably firm swellings in the right cervical and thoracic soft tissues. The patient was sedated and humanely euthanized to prevent further pain and suffering. Post-mortem whole-body radiographs and subsequent necropsy revealed abdominal wall rupture with herniation of two near-term fetuses within the subcutaneous tissues along the right ventrolateral thoracic wall and neck. Within the abdomen, the right uterine horn was ruptured and a third extra-luminal fetus was identified. The left uterine horn remained intact, containing a fourth fetus. RELEVANCE AND NOVEL INFORMATION: Rupture of the abdominal wall or diaphragm are well-known potential complications of blunt force trauma, such as motor vehicle accidents. While traumatic uterine rupture and diaphragmatic herniation of the gravid uterus have both been reported in the veterinary literature, abdominal wall rupture with subcutaneous fetal herniation is highly uncommon.

Factors associated with early tibial tuberosity fracture after tibial plateau leveling osteotomy.

OBJECTIVE: To determine factors contributing to tibial tuberosity fracture (TTF) after tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Retrospective case-control study. ANIMALS: Dogs (n = 2490) with cranial cruciate ligament rupture that underwent 3000 TPLO surgeries. METHODS: Radiographs of 3000 stifles from dogs that underwent TPLO were reviewed for evidence of TTF. Two ratios were generated: (1) the height of the tuberosity over the width of the tibia at the most distal extent of the osteotomy (TW) and (2) the width of the narrowest point of the tuberosity over TW. RESULTS: Twenty-three (0.77%) cases of fracture were identified. Factors that correlated with increased odds of fracture were placement of antirotational pins distal to the insertion of the patellar ligament (PL), tuberosities with the narrowest point below the insertion of PL, placement of multiple pins distal to the PL, and bilateral simultaneous TPLO. Tuberosities that fractured were significantly taller and narrower than those that did not fracture. Rotation past the "safe point" and presence of a gap at the osteotomy were not correlated with fracture. CONCLUSION: Placement of multiple pins, pin placement distal to the insertion of the PL, location of the narrowest point of the tibial tuberosity distal to the insertion of the PL, and simultaneous bilateral TPLO were all associated with TTF in this study CLINICAL SIGNIFICANCE: Preoperative planning and postoperative assessment of TPLO should take into consideration the predisposing factors identified in this study to prevent TTF.

White-nosed coatis (Nasua narica) are a potential reservoir of Trypanosoma cruzi and other potentially zoonotic pathogens in Monteverde, Costa Rica.

We studied white-nosed coatis (Nasua narica) in Monteverde, Costa Rica to evaluate their potential as a reservoir for the vector-borne zoonotic parasite Trypanosoma cruzi and other selected microorganisms. We live-trapped 20 coatis in July and August 2011 and tested them for T. cruzi by blood smear, molecular analysis of blood, culture of blood and anal gland secretions, and serology. Seven coatis (35%) were polymerase-chain-reaction-positive for T. cruzi and one coati was also culture positive. We did not detect T. cruzi in anal gland secretions. All coatis were positive for Mycoplasma and Babesia, but were negative for Baylisascaris, Anaplasma, Candidatus Neoehrlichia lotoris, Ehrlichia, Bartonella, and several apicomplexan parasites. The possible pathogenicity of T. cruzi, Babesia, and Mycoplasma in coatis and their transmission potential to humans and domestic animals warrants further investigation.