CT volumetric analysis permits comparison of tongue size and tongue fat in different canine brachycephalic and mesaticephalic breeds.

While macroglossia is a newly accepted component of brachycephalic obstructive airway syndrome (BOAS) in dogs, macroglossia with increased tongue fat is a well-known cause for obstructive sleep apnea (OSA) in people, and targeted reduction procedures such as midline glossectomy are used to treat people with OSA. While midline glossectomy has been described in dogs, tissue contributions to macroglossia have not been characterized. The purpose of this retrospective, descriptive, case-control study was to describe and compare volumetric dimensions of the tongue and tongue fat in brachycephalic (BC) and mesaticephalic (MC) dogs using CT images. Data collected included head and neck CT images from 17 BC and 18 control MC dogs. Multiplanar reformatted and 3D reconstructed images were created using image segmentation and specialized visualization software to calculate volumetric dimensions of the total tongue, tongue fat, and tongue muscle. Rostral and caudal topographical distributions of fat were compared. Total tongue and tongue muscle volume (P < 0.0001) and tongue fat volume (P = 0.01) normalized to body weight (BW) were greater in BC dogs. More fat was localized in the caudal tongue in both groups (P < 0.04). In regression analysis, BC conformation and increased weight were significant predictors of increased tongue fat volume. As in people, increased tongue fat may contribute to macroglossia and sleep-disordered breathing in BC dogs. Use of CT volumetry to identify tongue fat deposits may permit targeted surgical reduction of tongue volume in BC dogs and contribute substantially to treatment of BOAS.

Macroglossia in a pig diagnosed as Becker muscular dystrophy due to dystrophin pseudoexon insertion derived from intron 26.

We report a case of Becker muscular dystrophy in a 6-month-old, mixed-breed, castrated male pig detected with macroglossia at a meat inspection center. The pig presented a severely enlarged tongue extending outside its mouth. The tongue was firm and pale with discolored muscles. Histologically, there was severe fibrosis, fatty replacement, and myofiber necrosis, degeneration, and regeneration. Immunofluorescence showed focal and severely weak labeling for dystrophin at the sarcolemma of myocytes in the tongue. Analysis of dystrophin mRNA showed a 62 base pair insertion between exons 26 and 27. The insertion was derived from intron 26. Based on these findings, we diagnosed the case as Becker muscular dystrophy-the first known muscular dystrophy case induced by pseudoexon insertion in animals.

Clinical aspects, food management, and clinical evolution of a cat with hypertrophic muscular dystrophy / Aspectos clínicos, manejo alimentar e evolução clínica de um gato com distrofia muscular hipertrófica

Hypertrophic feline muscular dystrophy (HFMD), rarely reported in the literature, is a disease caused by a hereditary recessive dystrophin deficiency linked to the X chromosome, mainly affecting young male cats. Here, we presented the clinical aspects, food management, and clinical evolution of a seven-year-old mixed-breed cat diagnosed with HFMD, having a primary history of progressive tongue protrusion.

A distrofia muscular hipertrófica felina é uma doença causada por uma deficiência da distrofina com caráter hereditário recessivo ligado ao cromossomo X, com poucos registros de ocorrência na literatura, que acomete principalmente gatos machos jovens. Neste trabalho, são relatados os aspectos clínicos, manejo alimentar e evolução clínica de um gato, sem raça definida, de sete anos com histórico principal de protrusão progressiva da língua e diagnosticado com distrofia muscular hipertrófica felina.

Thermographic imaging in a dog with macroglossia from an encircling, strangulating lingual linear foreign body.

A dog presented 16 hours after an acute onset of severe generalized lingual swelling from an unknown cause. The dog had recently chewed a deer carcass. Initial physical examination and diagnostic testing did not reveal an underlying cause, and supportive care was provided. After 16 hours of hospitalization strangulating organic foreign material was found at the base of the tongue and removed. Macroglossia and secondary superficial lingual necrosis were successfully managed with supportive care while the patient was hospitalized. Thermographic imaging was used and indicated lingual hypothermia and subsequent normothermia, before and after removal of the linear foreign body respectively. Histopathologic analysis revealed the foreign body consisted of degenerate and autolyzed collagenous connective tissue, likely representing tissues such as tendon, fascia or a large thick-walled blood vessel which was suspected to have been consumed from the deer carcass. Thermographic imaging was employed and demonstrated to be consistent with hypoperfusion (hypothermia) of the affected tissue. Thermographic imaging adds value as an additional diagnostic tool for conditions with compromised blood flow.