MORE IMPORTANT MYCOTOXICOSES IN PIGS - CO MPREHENSIVE CLINICOPATHOLOGICAL COMMUNICATION

A summary has been given on the clinic and pathomorphology of more imp ortant mycotoxicoses of swine based on the Hungarian observations. F-2 ((zearalenone) fusariotoxicosis (oestrogenic syndrome = oestrogenism) was frequently observed in growing and adult swine, as well. as in ne wborn piglets (Fig; I), Swelling of vulva and mammary glands was accom panied by edematic infiltration and by vaginal and rectal prolapsus in more severe cases and by crusted inflammation and necrosis of a part of teats in suckling piglets. Of the internal organs, edema and pletho ra was observed in the uterus, proliferation and metaplasia in the cer vical and vaginal mucosa (Fig. 2), as well as increase of follicular m aturation and cyst formation in the ovaria. Degeneration of germinal e pithelial cells (Figs 3 and 4) and disturbance of spermiogenesis were observed in the testis. According to the observations made on large-sc ale pig farms, fertilization rate of sows and gilts worsened during th e period of disease and increased the number of returners. Decreased t he litter size and increased the number of stillborn piglets. However the number of abortion did not increase. Splay leg and epidemic tremor were more frequently observed in newborn piglets. Fusariotoxicosis ca used by T-2 and other trichothecene toxins was associated with feed re fusal, occasionally vomiting, decreased body-mass gain, poor general r esistance and mass incidence of infertility in breeding stock. Uterus of gilts and sows became smaller (Fig. 5), cyclic ovulation ceased in the ovaria and a multiplex small cystic ovarian degeneration developed (Fig. 6). Involution of glands was observed in the endometrium (Figs 7 and 8). The so-called perinatal form of T-2 toxicosis was also obser ved and experimentally reproduced. In the course of this, the toxin ta ken up by the sows was excreted by the milk caused mass incidence of d isease and death in suckling piglets and alterations characteristic fo r the effect of T-2 toxin in certain organs (Figs 9, 10 and 11). Durin g the experimental induction of deoxynivalenol (DON) toxicosis on larg e-scale pig farms, decreased body-mass gain of fatteners, feed refusal and higher losses were observed, as compared to the control groups. I n case of stachybotryotoxicosis crusted-necrotic inflammation was obse rved on the skin of snout and lips due to rooting in the straw bedding contaminated with the toxin, as well as on the skin of teats of sows and suckling piglets (Figs 12, 13 and 14). The pathological examinatio n revealed haemorrhage all over the surface Fig. 15) of different orga ns. Macroscopic alterations indicating a nephropathy caused by ochrato xin could be demonstrated in 0.02% (approx. 400 pigs) of 2 million sla ughtered pigs in Hungary during a slaughterhouse screening test carrie d out in the seventies. Ochratoxin A (above a level of 10 mu g/kg) cou ld be demonstrated in 43.6 % of them. Ochratoxicosis followed by clini cal symptoms and deaths was observed in a Hungarian back-yard farm in 1992. The clinical symptoms were, as follows: anorexia, faintness, unc oordinated movement due to the weakness of the posterior body half, in creased water comsumption and urination, and later on, a significant b ody-mass gain. In a few cases diarrhoea, as well as haemorrhages in th e skin all over the body surface were also observed. The pathological examination of two died and 10 emergency slaughtered pigs revealed the enlargement of kidneys; the cortical substance was marbled, or diffus e, pale, grayish-brown discoloration in more developed stage (Fig. Id) . Numerous small, cysts of pinhead size filled with Liquid, capillarec tasia, as well as petechias were found in the hardly rupturable cortic al substance. Other organs were intact. In a few cases, pulmonar pleth ora and edema, as well as focal catarrhal bronchopneumonia were observ ed. Histopathological and electron microscopic examinations revealed z onal or diffuse renal fibrosis accompanied with the atrophy of parench yma. Fibrinoid matter cumulated in the cavity of Bowman-capsules and g lomeruli of intact renal bodies, as well as cyst-like dilatation of ce rtain renal bodies and tubular sections (Fig. 17), atrophy, local infl ammatory cellular infiltration and crystallization (Fig. 18) in the tu bular epithelium. Aflaxicosis has not been yet diagnosed in Hungary in connection with the consumption mixed feeds produced from Hungarian r aw materials because higher temperature and humidity is optimal for th e toxin production of Aspergillus flavus strains. More important clini c symptoms and pathomorphological characteristics of aflatoxicosis in swine has been detailed. Ergot poisoning (ergotism) is relatively rare ly observed in swine. Acute ergot poisoning is accompanied with vomiti ng, diarrhoea, spasms, agalactia, small litter size and abortion (imma ture, mummified fetuses). Chronic form of poisoning is characterized b y dry, gangrenous necrosis of peripheral parts of body (i.e. ears, tai l, teats, etc. Fig. 19) followed by feeding anomalies due to the spasm and obstruction of capillaries. In chronic cases, feed uptake, bodyma ss gain and fertility of animals decreases, as well as small, weak and stillborn piglets are farrowed. Finally the authors have also treated the practical aspects of the diagnosis of mycotoxicoses in swine. Acc ording to their experiences, the above treated pathological pictures w ith typical clinical features and pathomorphological changes can be ob served when the feed is contaminated by higher concentrations of a sin gle mycotoxin. In that cases, recognition of typical clinical symptoms and changes make easier the diagnosis. The diagnosis' is also support ed by the knowledge obtained during the experimental reproduction of t oxicosis using higher doses of purified toxins. However, majority of m ycotoxicosis cases observed in the practice are not characterized by t ypical clinical symptoms and pathomorphological alterations. This in c onnected to the mixed mycotoxin contamination of feeds where the conce ntration of the individual mycotoxins are also very low, their volume belongs to the so-called microdose level. It is not rare that only ret arded growing power and dicreased general resistance, lower feed conve rsion and reproductive indices call the attention for the mycotoxin co ntamination of feed. In this case, besides the qualitative and quantit ative detection of mycotoxins in the feeds, it should also be consider ed more carefully the possible role of other (management, ge