Anconeus muscle injury in a juvenile greyhound.

OBJECTIVE: To report anconeus muscle injury in a greyhound. ANIMAL: One 11-month-old female greyhound. STUDY DESIGN: Case report METHODS: The dog presented with a 6-week history of mild left foreleg lameness. Moderate pain was noted by palpation over the proximolateral ulna and distolateral humerus and by maximal elbow flexion. A laminar periosteal reaction on the caudodistal humerus was present on radiographs. At ultrasonic examination, disorganization of anconeus muscle fibers, and focal mixed echogenicity were noted. Precontrast and postcontrast computed tomography (CT) revealed a thin rim of periosteal new bone on the caudodistal humerus as well as heterogeneous contrast enhancement of soft tissue immediately caudal to the distal humerus. An unrelated greyhound cadaver dissection confirmed only the anconeus muscle attached to the site of noted periosteal reaction. A partial tear of the anconeus muscle was diagnosed. Treatment consisted of 4 weeks of oral meloxicam. Confinement space and exercise were incrementally increased over 14 weeks. RESULTS: Muscle healing was confirmed by ultrasonography and CT. The dog was able to have a successful racing career spanning 2 years with no lameness attributable to the previous anconeus muscle injury and retired for unrelated reasons. CONCLUSION: Radiography and ultrasonography helped diagnose anconeal muscle injury, and conservative management led to full return to function. CLINICAL SIGNIFICANCE: Clinicians should include anconeus muscle injury as a differential diagnosis in dogs with lameness and pain over the proximolateral ulna or distolateral humerus or on elbow flexion.

In vitro comparison of secure Aberdeen and square knots with plasma- and fat-coated polydioxanone.

OBJECTIVE: To determine (1) the minimum number of throws to form secure Aberdeen (AB) and square knots to start (SS) and end (SE) continuous patterns, in fat- and plasma-coated polydioxanone; and (2) compare relative knot security (RKS) and knot volumes of these secure SS, SE, and AB knots. STUDY DESIGN: In vitro experimental materials testing. SAMPLE POPULATION: Polydioxanone suture material (3 metric). METHODS: Each knot was tested 20 times, and throws incrementally added until secure SS, SE, and AB knots were found. RKS and knot volumes were calculated for SS, SE, and AB knots. RESULTS: Secure SE knots needed 5 throws in plasma or fat. Secure SS knots needed 4 throws in plasma, but 5 in fat. The minimum AB configuration that was secure in plasma or fat was 3+1, however, the 4+1 AB knot was also secure in fat. Mean (SD) RKS of secure knots were: SE 59.69% (5.91), SS 67.92% (12.50), AB 81.08% (8.99). AB knots had significantly higher mean RKS than any SS or SE knot in plasma or fat (P<.001). Mean knot volume of 3+1 AB knot was significantly smaller than any secure SS or SE knots by 22.6-69.4% (P<.0001). Mean knot volume of 4+1 AB knots was significantly smaller than all fat secure SS and SE knots by 19.9-57.5% (P=.0001). CONCLUSION: The knot security of the SS knot was decreased by fat coating polydioxanone suture, requiring an additional throw to keep it secure. Secure AB knots had a higher breaking strength and smaller knot volume than secure SS and SE knots. CLINICAL RELEVANCE: The AB may be preferable to square knots in continuous closures. As many body fluids contain lipid, surgeons should tie knot configurations considered secure in fat. We advise tying a 4+1 AB and placing a minimum of 5 throws to tie SS and SE knots using 3 metric polydioxanone.

Biceps brachii and brachialis tendon of insertion injuries in eleven racing greyhounds.

OBJECTIVE: To report injuries of the biceps brachii (BTI) or brachialis (BrTI) tendons of insertion in 11 racing Greyhounds. STUDY DESIGN: Case series. ANIMALS: Greyhounds (n=11). METHODS: Medical records (1990-2006) of racing Greyhound dogs with BTI injuries were reviewed. Preinjury, injury, and posttreatment information was obtained via trainer telephone questionnaire and individual greyhound race data. Outcomes between surgical and conservative management were compared. RESULTS: Dogs had elbow hyperextension, positive biceps test, and forelimb circumduction and 82% were male, whereas Queensland's male to female ratio of racing Greyhounds was almost equal. Eight dogs had right BTI injuries. Nine dogs had surgically confirmed tendon injuries: 5 combined BTI and BrTI, 2 mid-body BTI, 1 musculotendinous BTI, and 1 ulnar tuberosity avulsion fracture. Seven dogs were treated surgically (3 loop pulley sutures, single radial screw and washer, suture screws or fracture fixation in lag fashion), 2 dogs were euthanatized at surgery, 2 were rehomed and hence managed conservatively. All surgically treated dogs returned to near preinjury performance; 6 returned to racing and at least 4 won races in the same or higher grade. One conservatively managed dog returned to "pet" function. No dog reinjured its BTI or BrTI. CONCLUSION: BTI and BrTI avulsions are rare acute traumatic performance injuries of racing Greyhounds. CLINICAL RELEVANCE: Preinjury racing performance can be achieved with early surgical repair of BTI and BrTI and optimal postoperative management.

Genetic cause for congenital methemoglobinemia in an Australian Pomeranian dog.

Little is known about genetic causes of congenital methemoglobinemia in dogs. Here, we report a CYB5 R3 mutation in a Pomeranian dog with congenital methemoglobinemia. A 6-year-old neutered female Pomeranian dog was investigated for cyanosis noticed during anesthesia for an orthopedic procedure. The history included lifelong mild exercise intolerance and bluish tongue. Methemoglobinemia was diagnosed using co-oximetry. The CYB5 R3 gene was analyzed by comparing the patient's genomic DNA with the reference canine sequence. Mutation functional significance was investigated using snpEff and multispecies protein homology analyses. A homozygous missense single nucleotide CYB5 R3 mutation (ATC ➔ CTC at codon 194) caused a p.Ile194Leu substitution. The pIle194 residue is highly conserved in other mammals, supporting the likely pathogenicity of the substitution. The mutation described here is identical to that associated with familial methemoglobinemia in a family of Japanese Pomeranian dogs. This observation, together with the homozygous mutation found in our case, indicates that the mutant allele may be widespread within the Pomeranian breed internationally.