Dermatitis In Pigs Research Articles

Swinepox dermatitis in backyard pigs in Northeastern Brazil

Abstract: This article describes five outbreaks of swinepox in backyard pigs in Northeastern Brazil. It affected backyard pigs from herds of poor hygienic-sanitary conditions with severe fly and lice infestations. The morbidity ranged from 33.3 to 100% among affected herds, with mortality reaching up to 60%. The affected pigs developed multifocal to coalescent gray to white papules and blisters in the skin, with eventual eruptions, evolving to erosions and crusts. In addition to skin lesions, affected piglets presented apathy, anorexia and fever. The disease was auto-limiting, resolving within 15 to 25 days. Histological examination revealed proliferative and ulcerative vesiculopustular dermatitis with ballooning degeneration of epithelial cells, perivascular inflammatory infiltrates of lymphocytes, plasma cells, neutrophils, eosinophils and some macrophages in the dermis. Intracytoplasmic eosinophilic inclusions were consistently observed in keratinocytes. Total DNA extracted from fresh tissue fragments obtained from one outbreak and formalin-fixed, paraffin-embedded (FFPE) tissue from the other four outbreaks was submitted to polymerase chain reaction (PCR) for Swinepox virus (SWPV) and Vaccinia virus (VACV). Genetic SWPV material was identified by PCR in fresh material from one outbreak. Nucleotide sequencing and phylogenetic analysis of the PCR amplicons (viral polymerase gene) demonstrated 100% homology with sequences from SWPV. All tissues were PCR negative for VACV. Swine poxvirus is present in backyard pigs in Northeastern Brazil, indicating the need of including SWPV in the differential diagnosis of dermatitis in pigs.

Control of Sarcoptes scabiei var. suis with ivermectin: influence on scratching behaviour of fattening pigs and occurrence of dermatitis at slaughter

The behaviour of fattening pigs, the occurrence of erythematous papular dermatitis in pigs at slaughter and the effects of treatment for mange with ivermectin at the start of the fattening period were evaluated at ten farms. At each farm, trial pigs were randomly allotted to a control or a treated group. At the start of the trial, the control group was injected intramuscularly with 5 mg kg −1 levamisole, and the treated group was injected subcutaneously with 300 μg kg −1 ivermectin. Skin scrapings, taken from each pig before medication at the start of the trial, and at slaughter, were examined for presence of sarcoptic mites. Pig behaviour was monitored at 2 week intervals from Week 5 to Week 13 of the trial. Carcasses of trial pigs were inspected for dermatitis at slaughter. Low to moderate Sarcoptes scabiei var. suis infestations were demonstrated at the start of the trial on five farms (S + farms). At slaughter, the mean percentage of Sarcoptes-positive pigs per pen on S + farms was 34.8% (range 11–60%) for the control group as compared with 0.5% (range 0–2.7%) for the ivermectin-treated group ( P < 0.01). No S. scabiei was recovered from any pig at any time from the five other farms (mange-free (S−) farms). The low initial levels of mange in the controls at S + farms resulted in a consistently high scratching index. Ivermectin treatment resulted in a significantly ( P < 0.01) lower prevalence of scratching, comparable with the prevalence observed at S− farms. High prevalences of generalized dermatitis at slaughter were observed in control pigs from all S+ farms. Ivermectin treatment resulted in much lower prevalences, reflected in a significantly ( P < 0.01) lower grand mean dermatitis index per pen for this group as compared with the controls. The majority of pigs from both treatment groups at all S− farms were free of papular lesions. These results indicate that low levels of sarcoptic mange at the start of fattening, left untreated, will result in a high prevalence of scratching during the fattening period and high prevalences of Sarcoptes and dermatitis at slaughter. Treatment with ivermectin at the start of fattening results in behaviour and dermatitis prevalences similar to those observed in mange-free herds.

An outbreak of ulcerative dermatitis in pigs.

An outbreak of ulcerative dermatitis in pigs.

A Peculiar Nutritional Dermatitis in Pigs

IN the course of our advisory duties, we have frequently encountered a number of cases of a peculiar dermatitis in pigs. The condition develops in pigs of about 10–12 weeks of age and is characterized initially by the development of red blotches under the skin of the hocks, spreading up the hind legs into the groin and over the belly and eventually over the back and ears. The dermatitis is accompanied by an acute irritation ; the pigs become very uncomfortable and rub continually against the sides of the sties. This rubbing usually breaks the skin, resulting in the formation of extensive scabs. Appetite is adversely affected and the pigs make little or no live-weight gain. Natural recovery is very slow, and as a result of the condition, the pigs may take several weeks longer to reach the bacon factory.