Page 349 - Feline Cardiology

362 Section K: Heartworm Disease

Table 23.2. Summary of reach-back effect of macrolytic lactones on Dirofilaria immitis
(modified from McCall 2005)
Drug (%) Age of Heartworms (Months) # Treatments Efficacy

Ivermectin 2 1 100
(6 mcg/kg, per os, 3 13 97.7
monthly) 4 14 95.1–97.8
5 31 98.7
5.5 12 52.2
7 29 94.9
8 16 56.3
Milbemycin 2 1 95.1
(500 mcg/kg, per 2 2 100
os, monthly) 3 13 96.7
4 14 49.3
4 12 41.4
4.5 12 12.7
5.5 12 1.1
6.5 12 15.9
8 16 0
Selamectin 2 1 100
(6 mg/kg, topically, 3 12 98.5
monthly) Adult 18 39.0
Moxidectin 2 1 100
(0.5 mcg/kg, per os) 4 1 85.9
Heartworm Disease (0.17 mg/kg SC q 6/12/18 2 97.2
Moxidectin
4/10
6 mo)
6
25
1
25
3
is an effective once-a-month preventive agent for heart- Atkins CE, DeFrancesco TC, Coats JR, Sidley JA, Keene BW.
worm disease in cats and it also controls roundworm Heartworm infection in cats: 50 cases (1985–1997). J Am Vet Med
infestations. It has the least reach-back effect of the mac- Assoc 2000;217:355–358.
rocytic lactones. Selamectin (6–12 mg/kg) and moxidec- Atkins CE, DeFrancesco TC, Miller MW, Meurs KM, Keene B.
Prevalence of heartworm infection in cats with signs of cardiore-
tin (1 mg/kg) are topical, once-a-month products, which spiratory abnormalities. J Am Vet Med Assoc 1998;212:517–520.
lie somewhere between ivermectin and milbemycin in Atkins CE, Vaden S, Arther RG, Ciszewski DK, Davis WL, Ensley SM,
reach-back effect. These products are effective at con- Chopade H. Renal effects of Dirofilaria immitis in experimentally
trolling common fleas, ear mites, and roundworms in infected cats. Proceedings, 13th triennial state of the heartworm
addition to heartworms. symposium, Memphis, TN, 2010, 21.
Atwell R, Evans E, Platt S, Litster AL. Feline dirofilariosis: Epidemiology
and diagnostics over 20 years in S.E. Queensland and Sydney,
REFERENCES Australia. Proceedings of the heartworm symposium ’01 San
Antonio, 2001, Batavia, IL, American Heartworm Society.
Boldface font indicates key references. Atwell RB, Litster AL. Surgical extraction of transplanted adult
Atkins C. Pearls of veterinary medicine: The diagnosis of feline heart- Dirofilaria immitis in cats. Vet Res Commun 2002;26:301–308.
worm infection. J Am Anim Hosp Assoc 1999;35:185–187. Berdoulay P, Levy JK, Snyder PS, Pegelow MJ, Hooks JL, Tavares LM,
Atkins C. Reassessing the definition of heartworm infection in cats. J Gibson NM, Salute ME. Comparison of serological tests for detec-
Am Vet Med Assoc 2007;231:1338. tion of natural heartworm infection in cats. J Am Anim Hosp
Atkins CE, Arther RG, Ciszewski DK, Davis WL, Ensley SM, Guity RS, Assoc 2004;40:376–384.
Chopade H, Hoss H, Settje TL. Echocardiographic quantification Borgarelli M, Venco L, Piga PM, Bonino F, Ryan WG. Surgical removal
of Dirofilaria immitis in experimentally infected cats. Vet Parasitol of heartworms from the right atrium of a cat. J Am Vet Med Assoc
2008;158:164–170. 1997;211:68–69.