Page 631 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

596 SECTION | VIII Rodenticides

VetBooks.ir Pleural, pericardial, mediastinal, and subarachnoid hemor- paradoxical venous thrombosis was reported in a person
with chlorophacinone exposure (Papin et al., 2007).
rhages (Kruse and Carlson, 1992), gastric and pulmonary
Death, reduced breeding performance, stillborn, and non-
hemorrhage (Olmos and Lo ´pez, 2007), hematemesis
(Dolin et al., 2006), and hemoperitoneum (Morgan et al., viable lambs, as well as reduced sperm motility of rams is
1996; Kim et al., 2010) have been reported in reported in sheep dosed with pindone (Robinson et al.,
brodifacoum toxicosis cases. 2005).
Gastrointestinal hemorrhage after endoscopic cold
mucosal biopsy (Zhao et al., 2010) and intestinal obstruc-
tion (Nie et al., 2010) have been reported. A number of Coagulopathy
other cases of brodifacoum (Braithwaite, 1982; Bruno Evidence of a coagulopathy is the second element of the
et al., 2000; Casner, 1998; Corke, 1997; Stanziale et al., diagnosis. Coagulation tests are normally run on live ani-
1997), bromadiolone (Chow et al., 1992), chlorophaci- mals, and a necropsy on dead animals, to support the
none (Dusein et al., 1984; Murdoch, 1983) and other anti- presence of a coagulopathy. The basic mechanisms of
coagulant rodenticide exposure are present in the human clotting have been reviewed (Seegers, 1969).
literature (Ross et al., 1992). Hematology: As discussed above, the anticoagulant
Misdiagnosis of rodenticide poisoning as ectopic preg- rodenticides reduce activity of factors II, VII, IX, and X
nancy (Wu et al., 2012), and successful treatment of preg- in circulation. For example, activities of 5% for factor II,
nant women with anticoagulant rodenticide toxicosis, 8% for factor VII, 4% for factor IX, and 6% for factor X
have been reported (Yan et al., 2013, Franco et al., 2013), have been reported in a brodifacoum case (Kim et al.,
although in one case, the neonate that showed evidence 2010; Wu et al., 2009) The one-stage prothrombin time
of fetal coagulopathy died at 4 days of age (Mehlhaff (OSPT) for evaluating factor VII is normally the most
et al., 2013). sensitive tool for early diagnosis because factor VII has
Bilateral ureteral and renal pelvis thrombus leading to the shortest half-life of the vitamin K 1 -dependent clotting
acute obstructive nephropathy (Reese et al., 2012), renal factors, e.g., about 6.2 h in dogs. Activated partial throm-
pelvic thrombus, (Pais, 2012), bruising, hematuria, and boplastin time (APTT) tests for all coagulation factors,
abdominal pain secondary to a perinephric hematoma except factor VII, are usually used in conjunction with
have been reported (Kapadia and Bona, 2008). OSPT. Activated coagulation time (ACT) is used in
Clinical signs in animals: Clinical signs in animals the same way as the APTT. ACT is easiest to use in a
are largely from canine cases (Woody et al., 1992). veterinary clinic setting since it only requires diato-
Sometimes, the only clinical signs in anticoagulant- maceous earth tubes and a heater block or water bath
poisoned animals are dyspnea, lethargy, or anorexia, but, (Byrne, 1970).
more often, depression, weakness, pallor, and ventral Laboratory test results of abnormally prolonged
hematomas are present (DuVall et al., 1989). In addition, OSPT, APTT, and ACT in the presence of normal throm-
pulmonary edema, pleural effusion, pericardial effusion bin time (TT), fibrinogen, circulating fibrin degradation
(Schulman et al., 1986), intratracheal hemorrhage products (FDPs), and platelet counts is consistent with
(McGuire et al., 1999), thymic hemorrhage (Elsinghorst, anticoagulant rodenticide poisoning. Occasionally, how-
2003), laryngeal obstruction (Peterson and Streeter, ever, animals with severe anemia may have elevated
1996), pericardial effusion and cardiac tamponade (Petrus FDPs and reduced platelet counts. An INR is frequently
and Henik, 1999), renal subcapsular hemorrhage (Radi measured in human coagulopathy cases (Boettcher et al.,
and Thompson, 2004), and hematometra (Padgett et al., 2011; Schmeits et al., 2009); rarely, thrombosis is
1998) have been reported. reported (De Paula et al., 2009; Papin et al., 2007).
Additional cases of diphacinone (Troy, 1988; The diagnostic protocol based on these coagulation
Schulman et al., 1986) and brodifacoum toxicosis (Baker factor evaluation tests (OSPT, APTT, ACT) cannot differ-
et al., 2002; Booth, 1989; Grayson, 1982; McSporran and entiate between short- and long-acting anticoagulant
Phillips, 1983) in dogs have been reported. Horses have rodenticide poisoning. The ability to recognize long-
been exposed experimentally (Boermans et al., 1991) and acting anticoagulants is critical, since therapeutic success
in the field (Ayala et al., 2007) to these rodenticides. may be based, at least in part, on the duration of vitamin
Brodifacoum may have been observed in neonatal puppies K 1 treatment. The ability to identify the specific anticoag-
(Munday and Thompson, 2003), and has been success- ulant rodenticide involved using analytical chemistry is
fully treated in a pregnant bitch (Hornfeldt and Phearman, discussed below.
1996). Coagulation testing is not always indicated after minor
In clinical settings, prolonged bleeding from injection exposure. Of 110 children ingesting anticoagulant rodenti-
sites is usually noticed. A few clinical signs are reported cides, eight had prolonged PTs. Seventeen percent (6 of
that are not directly attributable to the coagulopathy. A 34) were prolonged 48 h after exposure, while only 1.9%