Necrotising fasciitis associated withEscherichia coliin a dog

Retrospective case series: Necrotising fasciitis in 23 dogs

BACKGROUND

Necrotising fasciitis (NF) is a rare, rapidly progressive subcutaneous bacterial infection. Few studies have characterised NF in dogs.

HYPOTHESIS/OBJECTIVES

To retrospectively describe clinical and laboratory findings, with treatments and outcomes, in dogs with NF.

ANIMALS

Twenty-three client-owned dogs treated at a veterinary teaching hospital between 1998 and 2021.

MATERIALS AND METHODS

Medical records and laboratory data from 23 dogs diagnosed with NF were reviewed.

RESULTS

Male dogs were significantly over-represented (p = 0.003). The most common presenting complaint was sudden lameness. Infection occurred in one or two limbs in 19 of 23 dogs, with right hindlimbs most often affected (13 of 23). Pitting oedema was evident in 14 of 23 dogs. Antibiotic and nonsteroidal anti-inflammatory drugs were administered before presentation in nine and 13 of 23 dogs, respectively. Common clinicopathological abnormalities included hypoalbuminemia, hyponatremia, elevated liver enzymes, elevated creatine kinase, increased bands and lymphopenia. Streptococcus canis was isolated from 18 of 23 dogs. Histopathological features included acute necrosis and severe neutrophilic inflammation. Fifteen dogs were euthanised or died, while surgical intervention led to survival in eight of 23 dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Dogs presenting for acute swelling of a limb with oedema should have the diagnosis of NF considered and early surgical intervention might increase survival.

Bicipital Tendinopathy and Carpal Valgus Following a Distant Direct Thoracoabdominal Skin Flap in a German Shepherd with Necrotizing Fasciitis

A 4 mo old German shepherd dog was presented following an acute onset lameness and swelling of the thoracic limb. Clinical signs, surgical findings, and culture results were consistent with a diagnosis of necrotizing fasciitis. Initial management consisted of extensive surgical debridement, wound lavage, and bandaging. Surgical closure was achieved with an axillary fold flap and distant direct single-pedicle thoracoabdominal flap. Three mo later, following deterioration of the lameness that was associated with carpal valgus, carpal subluxation, and tendinopathy of the distal radial insertion of the biceps brachii tendon, a closing wedge pancarpal arthrodesis and tenotomy of the biceps brachii tendon was performed. We hypothesize that extensive soft tissue trauma and subsequent fibrosis and tendon contracture following soft tissue reconstruction contributed to the complications seen. To the authors' knowledge, this is the first report of carpal valgus deformity and biceps brachii tendinopathy following a distant direct skin flap and axillary skin fold flap.

A review of topical therapy for skin infections with bacteria and yeast

BACKGROUND

Cutaneous infections with bacteria and yeasts are common in small animal practice. Treatment with systemic antibiotics or antifungal agents may not be ideal, because of the increasing development of multiresistant organisms, the cost and the possible adverse effects. Topical antimicrobials may be used as adjunctive therapy to systemic treatment or as sole therapy instead of systemic treatment.

OBJECTIVE

This literature review evaluated studies on topical antimicrobial treatment of skin infections.

METHODS

In vitro and in vivo studies evaluating topical antimicrobial agents were identified using a number of electronic and manual searches of textbooks and articles. Studies were evaluated, and the evidence for or against the use of the topical agents was extracted.

RESULTS

There is good evidence for the efficacy of chlorhexidine and, to a lesser degree, benzoyl peroxide in canine bacterial skin infections. There is limited evidence for the efficacy of silver sulfadiazine and medical honey against bacterial skin infections in the dog, and for the efficacy of hydrogen peroxide and stannous fluoride in the horse. Good evidence supports the use of a combination of chlorhexidine and miconazole in dogs with cutaneous Malassezia infections. There is insufficient evidence to recommend any other topical therapy for use in cutaneous infections.

CONCLUSIONS AND CLINICAL IMPORTANCE

Although many antimicrobial topicals are marketed in veterinary dermatology, the efficacy has been reported for only a minority of agents. Randomized controlled trials evaluating various topical treatments are therefore urgently needed.

Successful treatment of necrotizing fasciitis in the hind limb of a great dane

A 5-month-old, intact female Great Dane was presented for an acute onset of rapidly progressive lameness, severe pain, and diffuse swelling of the right hind limb. Ultrasound evaluation revealed echogenic fluid pockets extending along fascial planes of the right hind limb, from the proximal femur to the hock. Necrotic soft tissues were debrided, and closed-suction drains were placed. No foreign material was identified at surgery. Fluid culture identified a beta-hemolytic Streptococcus sp., and affected fascial histopathology was consistent with necrotizing fasciitis. Postoperatively, the puppy was managed with intravenous broad-spectrum antibiotics, local infusions of amikacin, and daily physical rehabilitation. Oral pentoxifylline was administered to treat bronchopneumonia and streptococcal toxic shock syndrome that developed secondary to necrotizing fasciitis. To our knowledge, this is the first report of a successfully managed case of beta-hemolytic, streptococcal, necrotizing fasciitis successfully managed after a single surgical debridement in combination with systemic broad-spectrum antibiotics, local amikacin infusion, active closed-suction drainage, daily cytology, massage, and passive range-of-motion exercises to maintain limb function.

Necrotising fasciitis in a bull due to infection with Arcanobacterium haemolyticum

CASE HISTORY

A 2-year-old Hereford bull was lame for one week before becoming recumbent.

CLINICAL AND PATHOLOGICAL FINDINGS

The scrotum and ventral perineal region were cold and blackened caudally. The semimembranosus and semitendinosus muscles were firm on palpation. The bull was subject to euthanasia, and necropsy revealed that the skin and S/C tissues of the caudal half of the scrotum were grey and necrotic. The caudal and distal aspects of the semimembranosus and semitendinosus muscles were grey and necrotic to a depth of approximately 15 cm, and these changes appeared to track along fascial planes. The tissue had an offensive smell, and large amounts of flocculent, watery, brown fluid and some gas were present. Histology of affected muscle and S/C tissues revealed coagulative necrosis, with oedema and large numbers of bacteria that were predominantly Gram-positive rods. Adjacent blood vessels contained thrombi while the epidermis overlying the affected areas appeared diffusely necrotic, suggesting infarction. Culture of the fluid yielded a pure growth of Arcanobacterium spp., which was identified as Arcanobacterium haemolyticum, using an API Coryne biochemical test strip.

DIAGNOSIS

Necrotising fasciitis and myositis due to Arcanobacterium haemolyticum.

CLINICAL RELEVANCE

Arcanobacterium haemolyticum has not previously been reported as a cause of necrotising fasciitis in any species. Necrotising fasciitis is probably an under-reported condition in cattle due to its clinical similarity to clostridial disease.